Circuits for vocal learning

Question 1

Acoustic structure of bird song

Answer 1

see notes

· Syntax - specific timing and ordering of song elements
· Note
· Element
· Syllable 
- Phrase 

see notes

Question 2

Acoustic structure of bird song research

Answer 2

Hsu et al. (2018)

Question 3

Hsu et al. (2018)

Answer 3

Investigating the identity, distribution, and evolution of bird species is important for both biodiversity assessment and environmental conservation. The discrete wavelet transform (DWT) has been widely exploited to extract time-frequency features for acoustic signal analysis. Traditional approaches usually compute statistical measures (e.g., maximum, mean, standard deviation) of the DWT coefficients in each subband independently to yield the feature descriptor, without considering the intersubband correlation. A new acoustic descriptor, called the local wavelet acoustic pattern (LWAP), is proposed to characterize the correlation of the DWT coefficients in different subbands for birdsong recognition. First, we divide a variable-length birdsong segment into a number of fixed-duration texture windows. For each texture window, several LWAP descriptors are extracted. The vector of locally aggregated descriptors (VLAD) is then used to aggregate the set of LWAP descriptors into a single VLAD vector. Finally, principal component analysis (PCA) plus linear discriminant analysis (LDA) are employed to reduce the feature dimensionality for classification purposes. Experiments on two birdsong datasets show that the proposed LWAP descriptor outperforms other local descriptors, including linear predictive coding cepstral coefficients, Mel-frequency cepstral coefficients, perceptual linear prediction cepstral coefficients, chroma features, and prosody features. Furthermore, the proposed LWAP descriptor, followed by VLAD encoding, PCA plus LDA feature extraction, and a simple distance-based classifier, yields promising results that are competitive with those obtained by the state-of-the-art convolutional neural networks.

Question 4

Song dialects in different populations of white-crowned sparrows (Marler & Tamura, 1962)

Answer 4

see notes

Question 5

Song dialects in different populations of white-crowned sparrows (Marler & Tamura, 1962) research

Answer 5

Baptista and Kind (1980)

Question 6

Marler and Tamura (1962)

Answer 6

The phenomenon of “dialect” variation in bird song, appearing as a consistent differ- ence in the predominant song type between one population and another of the same species, has a special interest for biologists, serving as a focus for attention in discus- sion of such diverse topics as speciation (for example, Huxley, 1942; Mayr, 1942), learning (Thorpe, 1954, 1958) and the mechanisms of social communication (Marler, 1959). The White-crowned Sparrow (Zonotrichia leucophrys) affords one of the best known cases of such “dialect” variation among North American birds, and it has been commented upon by many who have observed this species (Blanchard, 1941; Peterson, 1941). Before the ontogenetic basis of such local song variation can be assessed and before its evolutionary significance can be satisfactorily determined, careful descrip- tions of the nature and extent of the variation are required. This paper seeks to provide some of this necessary information by describing song variation in the individual and in a population, both at one time and from year to year, and also by comparing songs in three populations, two adjacent and one distant

Question 7

Baptista and Kind (1980)

Answer 7

We sampled the songs of 18 populations of montane Whitecrowned Sparrows (Zonotrichia leucophrys oriantha)in order to define their dialect groups, if any, and to explore vocal affinities with other western subspecies ofZ. leucophrys. We found a clear-cut regional differentiation of song primarily on the basis of syllabic morphology and secondarily on the sequence of elements in the song. The birds of the Sierra Nevada and the San Bernardino Mountains of California constitute a fairly homogeneous dialect group related to another distinct group in the Warner Mountains, California, which are separated from the Sierra Nevada to the north by habitat unsuited to breeding oriantha. Those in two nearby but isolated desert ranges share a unique song type resembling that ofZ. l. gambelii. Oriantha in the Wallowa Mountains, Oregon, to the northeast of the Steens Mountains, are allied with the dialect region of the northern Rocky Mountains. Syllabic morphology and the sequence of song elements also suggest certain vocal affinities of oriantha with other western subspecies ofZ. leucophrys. For instance, the songs of oriantha in the Sierra Nevada, Warner Mountains, and San Bernardino Mountains have elements in common with those ofnuttalliin central California and pugetensis north of the Columbia River. The songs of oriantha at Hart Mountain and in the Steens Mountains are very similar to those of gambelii in Alaska and the western Canadian Rockies. The songs oforianthain the San Bernardino Mountains (a population founded after 1907)are identical with those of the central Sierra Nevada, and thus trace the origin of the founding group. We postulate that these and other data are consistent with Rand’s interpretation of the subspecific differentiation of these sparrows in Pleistocene refugia

Question 8

Isolated young white-crowned sparrows distinguish and learn their own-species song from tape tutors (Gould and Marler, 1987)

Answer 8

see notes

Young males recognise and learn species-specific songs played along with several songs from other species

Question 9

Isolated young white-crowned sparrows distinguish and learn their own-species song from tape tutors (Gould and Marler, 1987) research

Answer 9

Peters and Nowicki (2017)

Question 10

Peters and Nowicki (2017)

Answer 10

Mostsongbirdslearn their songs through imitation. However, what a male sings as an adult is not necessarily a complete inventory of what he memorized at some earlier point in time: songbirds commonly memorize more material than they eventually sing as adults. Work withswampsparrows,Melospiza georgiana, first confirmed that males rehearse many of the song models to which they are exposed during the sensory phase of song acquisition but subsequently include only a subset of those rehearsed songs in their adult repertoire. This process of overproduction and selective attrition has since been demonstrated in other species as well. More recently, the persistent memory of tutor songs rehearsed but not included in the adult repertoire has been demonstrated at the neural level. Furthermore, memories of song models heard during the sensory phase of acquisition but never detected during rehearsal in the sensorimotor phase also may persist into adulthood. Here we review behavioural and neural studies of overproduction and attrition in song learning. We discuss factors that may trigger the persistence of some models and the rejection of others in an individual’s repertoire and possible functional consequences of this phenomenon. Data from human speech research indicates that humans also may unconsciously retain memories of features of languages heard early in life but never spoken.

Question 11

Seasonality and overlap between sensory phase and sensorimotor phase in different bird species (Brainard & Doupe, 2002)

Answer 11

see notes

Zebra finches sing the same song all life long, whilst canaries can change it from year-year

Question 12

Seasonality and overlap between sensory phase and sensorimotor phase in different bird species (Brainard & Doupe, 2002) research

Answer 12

Bird fanciers have known for centuries that songbirds learn their songs. This learning has striking parallels to speech acquisition: like humans, birds must hear the sounds of adults during a sensitive period, and must hear their own voice while learning to vocalize. With the discovery and investigation of discrete brain structures required for singing, songbirds are now providing insights into neural mechanisms of learning. Aided by a wealth of behavioural observations and species diversity, studies in songbirds are addressing such basic issues in neuroscience as perceptual and sensorimotor learning, developmental regulation of plasticity, and the control and function of adult neurogenesis

Question 13

Zebra finch song development (Bolhuis & Gahr, 2006)

Answer 13

· Until age of 60-80 days - plastic song
- After 100 days - full song

see notes

Question 14

Zebra finch song development (Bolhuis & Gahr, 2006) research

Answer 14

· Song learning in songbirds has strong similarities with speech acquisition in human infants. Songbirds need to learn their songs from an adult conspecific. This occurs in two phases: a memorization phase, early in life, during which the young bird forms a neural representation (a ‘template’) of the song of a tutor; and a sensorimotor phase, during which the bird’s own vocal output is matched to the stored template.
· A network of interconnected brain nuclei, known as the ‘song system’, is involved in the perception, learning and production of song. Within the song system, the caudal pathway is important for song production. The rostral pathway is involved in song perception and in vocal sensorimotor learning. Initial claims that there are correlations between functional (for example, seasonal or sex) song differences and differences in song system morphology have not been supported by recent findings.
· Two regions outside the song system show neuronal activation (measured as increased expression of immediate early genes) when zebra finches are exposed to song. In one of these regions, the caudomedial nidopallium (NCM), neuronal activation on exposure to the tutor song is significantly correlated with the strength of song learning. An electrophysiological study showed that a familiarity index, based on neuronal habituation rates in the NCM, was significantly greater in tutored males than in untutored males, and significantly positively correlated with the strength of song learning.
· Zebra finch females do not sing, but nevertheless can learn the characteristics of their father’s song and form a preference for it over novel songs. When female zebra finches that were reared with their fathers were re-exposed to their fathers’ song, they showed significantly greater neuronal activation in the caudomedial mesopallium (CMM), but not in the NCM or hippocampus, compared with when they were exposed to novel song.
· Neuronal activation in the NCM and CMM is not an artefact of isolation rearing, and is not related to attentional mechanisms.
· The NCM and the CMM might be parallel stores that contain the neural substrate for tutor (or father’s) song memory, or the ‘template’. The NCM might be more directly functionally linked to the premotor nuclei in the song system. The CMM overlaps with the intermediate and medial mesopallium (IMM) that contains the neural substrate for imprinting memory in domestic chicks. The NCM and CMM may be homologous with subdivisions of the mammalian auditory association cortex, which in humans are associated with auditory learning in relation to speech acquisition.
- Further multidisciplinary research is needed to determine whether the NCM and CMM contain the neural substrates of song memory, or whether this information is stored elsewhere in the brain. The neuroanatomical connectivity and functional relationship between these two brain regions and the song system needs to be investigated, in order for us to better understand the overall process of bird song learning. Such analyses may, ultimately, have heuristic value for the study of speech aquisition in humans.

Question 15

Birds raised in isolation do not develop full songs (Brainard & Doupe. 2002)

Answer 15

see notes

Question 16

Birds raised in isolation do not develop full songs (Brainard & Doupe. 2002) research

Answer 16

Feher et al. (2009)

Question 17

Brainard and Doupe (2002)

Answer 17

Bird fanciers have known for centuries that songbirds learn their songs. This learning has striking parallels to speech acquisition: like humans, birds must hear the sounds of adults during a sensitive period, and must hear their own voice while learning to vocalize. With the discovery and investigation of discrete brain structures required for singing, songbirds are now providing insights into neural mechanisms of learning. Aided by a wealth of behavioural observations and species diversity, studies in songbirds are addressing such basic issues in neuroscience as perceptual and sensorimotor learning, developmental regulation of plasticity, and the control and function of adult neurogenesis

Question 18

Feher et al. (2009)

Answer 18

Culture is typically viewed as consisting of traits inherited epigenetically, through social learning. However, cultural diversity has species-typical constraints1, presumably of genetic origin. A celebrated, if contentious, example is whether a universal grammar constrains syntactic diversity in human languages2. Oscine songbirds exhibit song learning and provide biologically tractable models of culture: members of a species show individual variation in song3and geographically separated groups have local song dialects4,5. Different species exhibit distinct song cultures6,7, suggestive of genetic constraints8,9. Without such constraints, innovations and copying errors should cause unbounded variation over multiple generations or geographical distance, contrary to observations9. Here we report an experiment designed to determine whether wild-type song culture might emerge over multiple generations in an isolated colony founded by isolates, and, if so, how this might happen and what type of social environment is required10. Zebra finch isolates, unexposed to singing males during development, produce song with characteristics that differ from the wild-type song found in laboratory11or natural colonies. In tutoring lineages starting from isolate founders, we quantified alterations in song across tutoring generations in two social environments: tutor–pupil pairs in sound-isolated chambers and an isolated semi-natural colony. In both settings, juveniles imitated the isolate tutors but changed certain characteristics of the songs. These alterations accumulated over learning generations. Consequently, songs evolved towards the wild-type in three to four generations. Thus, species-typical song culture can appearde novo. Our study has parallels with language change and evolution12,13,14. In analogy to models in quantitative genetics15,16, we model song culture as a multigenerational phenotype partly encoded genetically in an isolate founding population, influenced by environmental variables and taking multiple generations to emerge

Question 19

Auditory feedback and song templates (Konishi, 1965; Nordeen & Nordeen, 1992)

Answer 19

· Birds deafened (removal of cochlea) prior to onset of subsong stage - no normal song
· Birds match produced song to memorised song template
- Auditory feedback also imp for maintenance of full songs

see notes

Question 20

Auditory feedback and song templates (Konishi, 1965; Nordeen & Nordeen, 1992) research

Answer 20

Nordeen and Nordeen (1992)

Question 21

Nordeen and Nordeen (1992)

Answer 21

Although songbirds rely on auditory input for normal song development, many species eventually attain adult song patterns that are thought to be maintained without reference to auditory feedback. In such species, it is believed that a central motor program for song is established when the stereotyped adult song pattern is achieved. However, we report here that in the Australian zebra finch, stereotyped song patterns gradually change in adult males following bilateral cochlear removal. By 16 weeks after surgery, deaf birds accurately reproduced only 36% of the song syllables produced prior to surgery. Moreover, on average, the phonology of over 50% of the syllables produced by deaf birds was either only slightly similar or unlike the phonology of any syllable produced prior to surgery. In contrast, control birds accurately retained over 90% of their syllables over a comparable time period and less than 5% of their syllables was unmatched or only slightly similar in phonology to previously recorded syllables. In many of the deafened birds, changes in song patterns were not evident until 6–8 weeks after surgery. These data indicate that continued auditory input is necessary to maintain the patterns of neural organization supporting learned song in zebra finches and raise questions concerning the neural sites and cellular mechanisms that mediate this feedback control.

Question 22

Developmental plasticity during the sensitive period (Nelson et al., 1995)

Answer 22

· Sensitive period has constrained onset and end time
· But env factors can modulate period:
- Local adaptations in length and onset of breeding season (e.g. coastal v montane populations of white-crowned sparrows)

see notes

• Length and freq of social exposure to singing males (e.g. zebra finches raised by females could learn songs after exposure to males long after end of normally occurring sensitive period; Eales, 1987)

see notes

Question 23

Developmental plasticity during the sensitive period (Nelson et al., 1995) research

Answer 23

Eales (1987)

Bölting and von Engelhardt (2017)

Question 24

Eales (1987)

Answer 24

Captive male zebra finches,Taeniopygia guttata, that were raised by females, in complete isolation from adult males, retained the ability to learn song from an adult male when this tutor was later made available to them. Despite their lack of experience of adult males, youngsters recognized the more suitable quality of adult male song, learning it even when they were sexually mature if a tutor became available. They did not use female call notes as song elements unlike those that remained isolated from adult males. The results therefore suggest that, first, young birds do not need to experience adult male song during the dependent period for song learning to occur later and, second, until sufficient suitable material has been heard the sensitive phase remains open-ended, and the young male remains capable of song learning.

Question 25

Bölting and von Engelhardt (2017)

Answer 25

▪ Background: Individual differences in behaviour are widespread in the animal kingdom and often influenced by the size or composition of the social group during early development. In many vertebrates the effects of social interactions early in life on adult behaviour are mediated by changes in maturation and physiology. Specifically, increases in androgens and glucocorticoids in response to social stimulation seem to play a prominent role in shaping behaviour during development. In addition to the prenatal and early postnatal phase, adolescence has more recently been identified as an important period during which adult behaviour and physiology are shaped by the social environment, which so far has been studied mostly in mammals. We raised zebra finches (Taeniopygia guttata) under three environmental conditions differing in social complexity during adolescence-juvenile pairs, juvenile groups, and mixed-age groups - and studied males’ behavioural, endocrine, and morphological maturation, and later their adult behaviour.
▪ Results: As expected, group-housed males exhibited higher frequencies of social interactions. Group housing also enhanced song during adolescence, plumage development, and the frequency and intensity of adult courtship and aggression. Some traits, however, were affected more in juvenile groups and others in mixed-age groups. Furthermore, a testosterone peak during late adolescence was suppressed in groups with adults. In contrast, corticosterone concentrations did not differ between rearing environments. Unexpectedly, adult courtship in a test situation was lowest in pair-reared males and aggression depended upon the treatment of the opponent with highest rates shown by group-reared males towards pair-reared males. This contrasts with previous findings, possibly due to differences in photoperiod and the acoustic environment.
- Conclusion: Our results support the idea that effects of the adolescent social environment on adult behaviour in vertebrates are mediated by changes in social interactions affecting behavioural and morphological maturation. We found no evidence that long-lasting differences in behaviour reflect testosterone or corticosterone levels during adolescence, although differences between juvenile and mixed-age groups suggest that testosterone and song behaviour during late adolescence may be associated.

Question 26

Social experience influences song development and can override innate predispositions

Answer 26

White-crowned sparrows were exposed to both strawberry finches tutors and own-species song playbacks (Baptista and Petrinovich, 1984)

see notes

Question 27

Social experience influences song development and can override innate predispositions research

Answer 27

Baptista and Petrinovich (1984)

Ljubicic et al. (2016)

Question 28

Baptista and Petrinovich (1984)

Answer 28

Naive 50-day-old white-crowned sparrows (Zonotrichia leucophrys nuttalli) were placed in cages with two compartments in which they could see and interact with a single social tutor. Birds were tutored with the song of their own subspecies, the song of a different subspecies, or that of an alien species, the strawberry finch (Amandava amandava). Each of the 12 birds learned the song of his social tutor. The alien song was learned even though there was abundant conspecific song present in the acoustic environment. These findings indicate that social tutoring can be effective beyond the 10–50-day sensitive phase found with tape tutoring, and that the song of an alien species can be learned from a social tutor. We conclude that neither the sensory template theory nor the current descriptions of the sensitive phase are adequate, without modification, to provide an understanding of song development in the white-crowned sparrow. Because young in the wild learn their songs from social tutors, data from studies of social tutoring provide a better basis to understand factors involved in song learning than data based on studies of tape tutoring

Question 29

Ljubicic et al. (2016)

Answer 29

Social animals must learn during development how to integrate successfully into their group. In vocal learners such as songbirds and humans, the development of vocal communication is initially guided by social interactions with the parents. Later on, vocal development is further shaped through interactions with peers and by attending to the consequences of others interacting. It is difficult to assess, however, how social forces combine to shape the outcomes of vocal development. We first review technical advances that make it possible to track social influences on vocal development in songbirds. We then outline methods for simulating the social environment of vocal learning. Such virtual environments would present birds with interactive scenarios in order to directly assess social influences over developmental time scales.

Question 30

How do the birds sing?

Answer 30

see notes

Question 31

How do the birds sing? research

Answer 31

Konishi (1985)

Question 32

Konishi (1985)

Answer 32

The study of birdsong has made significant contributions to the development of modern ethology. Concepts such as species-specificity in animal signals, innate predisposition in learning, and sensory templates for motor development were put forth first in birdsong research (Marler 1957, 1 964, Konishi 1965b, Hinde 1982). Also, it was the study of song development that elevated the much debated issue of instinct versus learning from the realm of semantic discourse and confusion to an experimentally tractable subject (Marler 1983). The recent discovery of neural substrates for song has introduced a new dimension to the study of birdsong, making integration of behavioral and neurobiological studies feasible (Nottebohm et aI1976). Neurobiological concepts and methods are now directly applicable to this field. This integrated approach can address not only some of the outstanding issues that arose in behavioral studies and that are refractory to further behavioral analysis, but it also makes birdsong an attractive subject for the study of such basic issues as neural coding, learning, memory, developmental plasticity, and sensorimotor coordination. In this review I shall examine critically the major current issues and ideas in this field, placing special emphasis on the topics related to the development, learning, and neural control of song. Because extensive listings and reviews of recent literature on birdsongs are available (Kroodsma & Miller 1982a,b), the references cited are limited to those essential for the discussion of facts and theories on selected topics.

Question 33

Bird song is neurally controlled

Answer 33

see notes

· Brain areas involved in song production and learning in a typical songbird:
o Song production pathway (posterior vocal pathway)
o HVC (higher vocal centre)
o RA (robust nucleus of the arcopallium)
- nXIIts (hypoglossal nucleus that connects to the muscles of the syrinx)

Question 34

Bird song is neurally controlled research

Answer 34

Nottebohm (2005)

Question 35

Nottebohm (2005)

Answer 35

There is a tradition in biology of using specific animal models to study generalizable basic properties of a system. For example, the giant axon of squid was used for the pioneering work on nerve transmission; the fruit fly (Drosophila) has played a key role in researchers discovering the role of homeobox genes in embryogenesis; the sea slug (Aplysia) is used to study the molecular biology of learning; and the round worm (Caenorhabditis elegans) is used to study programmed cell death. Basic insights gained from these four systems apply widely to other multicellular animals. Here, I will review basic discoveries made by studying birdsong that have helped answer more general questions in vertebrate neuroscience

Question 36

Bird song learning pathway

Answer 36

see notes

· Song learning pathway (anterior forebrain): area X, LMAN (lMAN, lateral portion of the magnocellular nucleus of the anterior neostriatum), DLM (medial portion of the dorsolateral thalamus)
- Lesions of these nuclei affect song learning but not production of chrystallised songs

see notes

Question 37

Bird song learning pathway research

Answer 37

Jarvis et al. (2005)

Nottebohm (1984)

Question 38

Jarvis et al. (2005)

Answer 38

We believe that names have a powerful influence on the experiments we do and the way in which we think. For this reason, and in the light of new evidence about the function and evolution of the vertebrate brain, an international consortium of neuroscientists has reconsidered the traditional, 100-year-old terminology that is used to describe the avian cerebrum. Our current understanding of the avian brain — in particular the neocortex-like cognitive functions of the avian pallium — requires a new terminology that better reflects these functions and the homologies between avian and mammalian brains.

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Question 39

Nottebohm (1984)

Answer 39

The last fifteen years have yielded an ever increasing amount of information about brain pathways for song control in songbirds. I review here aspects of this work which suggest that the size of brain networks for song control may limit how much can be learned. In addition, sustained learning in adulthood may relate to plasma levels of gonadal hormones and to the replacement of dendrites, synapses and neurons. Mechanisms involved in this pathway “rejuvenation” may be similar to mechanisms for brain self-repair

Question 40

Not all birds are vocal learners (Jarvis et al., 2000)

Answer 40

Hummingbirds have developed a wealth of intriguing features, such as backwards flight, ultraviolet vision, extremely high metabolic rates, nocturnal hibernation, high brain-to-body size ratio and a remarkable species-specific diversity of vocalizations(1-4). Like humans, they have also developed the rare trait of vocal learning, this being the ability to acquire vocalizations through imitation rather than instinct(5,6). Here we show, using behaviourally driven gene expression in freely ranging tropical animals, that the forebrain of hummingbirds contains seven discrete structures that are active during singing, providing the first anatomical and functional demonstration of vocal nuclei in hummingbirds. These structures are strikingly similar to seven forebrain regions that are involved in vocal learning and production in songbirds and parrots(7-13)-the only other avian orders known to be vocal learners(5). This similarity is surprising, as songbirds, parrots and hummingbirds are thought to have evolved vocal learning and associated brain structures independently(5,14), and it indicates that strong constraints may influence the evolution of forebrain vocal nuclei.

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Question 41

Genetic basis of song learning: Zenk and Fos expression (Jarvis & Nottebohm, 1997; Kimbo & Doupe, 1997; Mello & Ribeiro, 1998; Moorman et al., 2001)

Answer 41

· During sensory and sensorimotor phase IEGs (immediate early genes) activated
· Immunocytochemistry (detecting proteins with injected antibody with fluorescent dye to visualise it)
· Listening to song - expression of mRNA of gene Zenk in auditory brain areas (HVC, NCM)
- Producing song - Zenk and Fos expression in the song nuclei of anterior and posterior pathways

see notes

Question 42

Genetic basis of song learning: Zenk and Fos expression (Jarvis & Nottebohm, 1997; Kimbo & Doupe, 1997; Mello & Ribeiro, 1998; Moorman et al., 2001) research

Answer 42

Peters et al. (2014)

Question 43

Peters et al. (2014)

Answer 43

The evolution of enhanced cognitive ability has sometimes been attributed to sexual selection. An association between the mating success of males and their cognitive ability could arise either through male–male competition or through female choice. Specifically in the latter case, sexual selection would act more readily if males advertized their cognitive ability through display. Most traits involved in sexual display, however, seem unlikely to have any inherent relationship with cognition beyond that which arises through the effect of cognitive abilities on acquisition of resources and, in turn, the effect of resources on development of the display trait. In contrast, for displays whose development and expression require learning, a direct link with cognition is possible because of a shared dependence on brain function. The parallel effects of developmental stress on song-learning and cognition provide a compelling explanation for an association between attributes of the song and cognitive ability. We outline the hypothesis that sexually selected qualities of song serve as an indicator of cognitive abilities. We first present evidence that song-learning is itself a challenging cognitive task. We then give evidence that sexual selection favors well-learned song. Next, we review evidence that song and cognitive ability both are affected by developmental stresses. We consider recent experimental data testing the relationship between song and cognitive ability. Finally, we suggest that the accuracy with which songs are learned may be an optimal indicator of other cognitive abilities

Question 44

Undirected and directed song involve different brain areas (Jarvis et al., 1998)

Answer 44

· Zebra finch song changes slightly when singing towards female
· Context-dependent Zenk expression in Area X: when bird sings solo/presence of male
- Although not required for production of crystallised song, anterior pathway can be active

see notes

Question 45

Undirected and directed song involve different brain areas (Jarvis et al., 1998) research

Answer 45

Male zebra finches display two song behaviors: directed and undirected singing. The two differ little in the vocalizations produced but greatly in how song is delivered. “Directed” song is usually accompanied by a courtship dance and is addressed almost exclusively to females. “Undirected” song is not accompanied by the dance and is produced when the male is in the presence of other males, alone, or outside a nest occupied by its mate. Here, we show that the anterior forebrain vocal pathway contains medial and lateral “cortical-basal ganglia” subdivisions that have differential ZENK gene activation depending on whether the bird sings female-directed or undirected song. Differences also occur in the vocal output nucleus, RA. Thus, although these two vocal behaviors are very similar, their brain activation patterns are dramatically different.q

Question 46

RA plays a critical role in bird song production

Answer 46

• RA differs in size in male and female zebra finches (Nottebohm & Arnold, 1976)
• RA lesions/cutting RA-nXIIts projection affects bird song production
• RA larger in white-crowned sparrow males than in non-singing females (Baker et al., 1984) and Carolina wren (Nealen & Perkel, 2000)
• RA grows and shrinks in white-crowned sparrow males seasonally (Brenowitz et al., 1998)

see notes

Question 47

RA plays a critical role in bird song production research

Answer 47

Nottebohm and Arnold (1976)

Baker et al. 91984)

Nealen and Perkel (2000)

Brenowitz et al. (1998)

Question 48

Nottebohm and Arnold (1976)

Answer 48

In canaries and zebra finches, three vocal control areas in the brain are strikingly larger in males than in females. A fourth, area X of the lobus parolfactorius, is well developed in males of both species, less well developed in femal canaries, and absent or not recognizable in femal zebra finches. These size differences correlate well with differences in singing behavior. Males of both species learn song by reference to auditory information, and females do not normally sing. Exogenous testosterone induces singing in female canaries but not in female zebra finches. This is believed to be the first report of such gross sexual dimorphism in a vertebrate brain

Question 49

Baker et al. (1984)

Answer 49

The volumes of brain regions involved in vocal control were measured in adult female white-crowned sparrows (Zonotrichia leucophrys nuttali) captured in the summer, and in captive males held on long-day or short-day photoperiods. There is a large sex difference in the volume of two nuclei, the caudal nucleus of the hyperstriatum ventrale (HVc) and the robust nucleus of the archistriatum (RA), which correlates with a large sex difference in singing behavior. There were no differences in the size of HVc and RA in adult males held on summer or winter photoperiods, even though the ‘summer’ males had high androgen levels and were singing, whereas the ‘winter’ males had regressed testes and were not singing. The data bear on hypotheses concerning the relationship between size of brain nuclei and song learning.

Question 50

Nealen and Perkel (2000)

Answer 50

Sexual and interspecific differences in the size of passerine bird song repertoires are related to differences in the size of song‐control regions (SCR) within the brain. Most species of Thryothorus wrens (family Certhiidae) are known to duet, and, in both sexes, song repertoire sizes are related to the size of the SCR. However, one member of this genus, the Carolina wren T. ludovicianus, is very sexually dimorphic in its singing behavior: Males develop large song repertoires, whereas females do not sing. In this study, Nissl staining was used to investigate whether the marked gender difference in the behavior of this species is related to sexual dimorphism of the SCR. Carolina wren males, as predicted, possess the largest premotor song nuclei within the genus; these nuclei could not be identified within Nissl‐stained female tissue. The cellular bases for gender differences in SCR morphology also were examined: Males and females differed strongly in the size and density of neurons making up the regions in which SCRs exist in the male forebrain. Interspecific comparison provided no evidence for a decoupling of behavioral and neural evolution within this clade. Male Carolina wrens possess the largest song repertoires and SCRs within the genus, whereas females of this species represent the opposite behavioral and neural extremes of this songbird group. These results are consistent with the hypothesis that the size of the passerine song repertoire is limited by the amount of neural tissue devoted to singing

Question 51

Brenowitz et al. (1998)

Answer 51

Seasonal plasticity in the morphology of telencephalic nuclei that control song behavior has been reported for diverse species of songbirds. The only published report of a lack of seasonal changes in the song nuclei of a seasonally breeding bird is that of Baker et al. in the Nuttall’s subspecies of white‐crowned sparrow (Zonotrichia leucophrys nuttalli) . In this study, they brought wild birds into the laboratory and exposed them to either “summer” or “winter” photoperiods. Previous studies have shown that exposing wild‐caught white‐crowned sparrows to long‐day photoperiods in the laboratory may not induce circulating concentrations of testosterone (T) as high as those seen in wild breeding birds. Changes in circulating T are primarily responsible for the seasonal morphological changes in the song nuclei. To determine whether there is seasonal plasticity of the song system in this subspecies, we measured circulating T, morphological attributes of the song nuclei, and song behavior in wild Nuttall’s white‐crowned sparrows during the spring and fall. Testis size and circulating T concentrations were greater in spring than fall birds. The absolute volumes of the song nuclei HVc, RA, and Area X, and their volumes relative to those of either the total telencephalon or three thalamic nonsong nuclei, were significantly greater in the spring than fall sparrows. Song behavior also changed seasonally; fall birds sang shorter songs than did spring birds. These results show that there is seasonal plasticity of the song system in wild Nuttall’s white‐crowned sparrows. Seasonal plasticity can now be regarded as a common feature of the seasonally breeding songbirds studied thus far

Question 52

Sexual dimorphism in HVC volumes (Brenowitz et al., 1985; Brenowitz, 1997; MacDougall-Shackleton & Ball, 1999; Ball & MacDougall-Shackleton, 2001)

Answer 52

· Diff in HVC volume systematically relate to diffs in singing between sexes
- In zebra finches only males sing

see notes

Question 53

Sexual dimorphism in HVC volumes (Brenowitz et al., 1985; Brenowitz, 1997; MacDougall-Shackleton & Ball, 1999; Ball & MacDougall-Shackleton, 2001) research

Answer 53

Brenowitz et al. (1985)

Arnold et al. (1986)

Question 54

Brenowitz et al. (1985)

Answer 54

Duetting involves production of song by female and male birds in close temporal coordination. We studied the neural network controlling song in 3 tropical duetting species. The volumes of song control regions (SCRs) in the brain, neuronal density in nucleus robustus of the archistriatum (RA) which is one of these SCRs, total number of neurons in RA, and somal size of neurons in RA were measured and compared to values published for zebra finches and canaries in which only males sing. The extent of sexual dimorphism in SCR volumes, RA neuronal density, and total neuronal number in RA varied in a graded fashion across species and was correlated with extent of sexual dimorphism in song repertoire size in any one species. Somal size of RA neurons was identical in males and females of each duetting species, regardless of relative repertoire size. Of all SCRs, the caudal nucleus of the ventral hyperstriatum appeared to have the greatest relative size in the song system of duetting birds compared to non-duetting species.

Question 55

Arnold et al. (1986)

Answer 55

Sex differences in the neural song system in oscine song birds develop in response to estradiol secreted during early periods of development. Estradiol produces sex differences in cell number and in the proportion of cells which are steroid targets. The pattern of development of these sex differences varies in different brain regions, suggesting that the mechanisms of estradiol regulation of neural development may also vary. The magnitude of sexual dimorphism in the neural song system varies across species, and is generally correlated with the magnitude of sexual dimorphism in vocal ability. Large species differences in neural structure can potentially be explained by small differences in the ontogenetic pattern of estradiol secretion, as is suggested by studies of neural development.

Question 56

Neural reconstruction and neurogenesis in the adult bird brain (Kirn & DeVoogd, 1989; Nordeen & Nordeen, 1990)

Answer 56

· Seasonal variations in HVC and RA volume

- HVC and RA volumes correlate with size of song repertoire and size of song system

Question 57

Nordeen and Nordeen (1990)

Answer 57

In many species of birds the propensity to learn songs from conspecifics is greatest during one or more distinct periods in life. These ‘sensitive’ learning periods, together with our detailed knowledge of the neural circuitry controlling avian song, have facilitated the discovery of radical neuroanatomical changes that accompany vocal development. One of the most remarkable of these changes is the production and incorporation of new, song-related neurons. The neurogenesis of specific cell types during song development helps create and recreate motor pathways for song production and provides synaptic plasticity that may both encourage and temporally constrain learning

see notes

Question 58

Kirn and DeVoodg (1989)

Answer 58

Several song-related regions in the adult zebra finch brain have substantially more neurons in males than in females. Such differences appear to arise from sex differences in circulating steroids during early posthatch life. In the present study, developmental mechanisms involved in the production of sex differences are explored by examinations of the normal time course of posthatch neurogenesis and cell death in vocal control circuits. As a first step toward determining whether rates of neuron production may be different in males and females, tritiated thymidine, a marker of cell division, was administered to zebra finches at various times during the first month after hatching. Birds were sacrificed at 60 d. The number of cells formed after hatching and present at 60 d was then evaluated in 3 vocal control regions–HVc (hyperstriatum ventralis pars caudalis) and its 2 principal targets, RA (robust nucleus of the archistriatum) and Area X. Cell death was quantified by counts of normal and pyknotic, degenerating cells made in these nuclei in additional, untreated birds of both sexes at 5 d intervals from 5 to 45 d of age. The combined results of these experiments suggest that differential cell death is a major factor in the development of sex differences in the song control system and provide the first direct evidence for sex differences in cell death in the developing telencephalon. Although developmental time tables differ among the 3 brain areas examined, at specific ages significantly higher numbers of pyknotic cells were observed in HVc, RA, and presumptive Area X in females compared to males. Peak levels of cell death in RA occur 4–6 weeks after hatching. This is about 3 weeks after the onset of sex differences in steroid levels that, in turn, lead to differential organization of song system nuclei. This pattern of results suggests that designation for death and actual cell loss are temporally dissociated in this system. Neuron proliferation for HVc and Area X, but not RA, continues throughout the first 30 d after hatching, and a significant sex difference was found in the number of cells present in HVc at 60 d that were formed after hatching. Comparisons of the timing of cell death and cell incorporation suggest that this difference may be best accounted for by differential survival of neurons formed after hatching rather than differential rates of neuron production. Neither differential neurogenesis nor differential neuron death can fully account for the apparent extreme sexual dimorphism in the number of neurons in Area X

Question 59

Changes in the female zebra finch brain after early DHT hormone treatment (Gurney, 1981; Schlinger & Arnold, 1991; Frankl-Vilches & Gahr, 2018)

Answer 59

· Castrated zebra finch males sing normally
- Induced singing behaviour in females organised by oestrogens but activated by androgens

see notes

Question 60

Changes in the female zebra finch brain after early DHT hormone treatment (Gurney, 1981; Schlinger & Arnold, 1991; Frankl-Vilches & Gahr, 2018) research

Answer 60

Liu et al. (2015)

Question 61

Liu et al. (2015)

Answer 61

Speech and vocal impairments characterize many neurological disorders. However, the neurogenetic mechanisms of these disorders are not well understood, and current animal models do not have the necessary circuitry to recapitulate vocal learning deficits. We developed germline transgenic songbirds, zebra finches (Taneiopygia guttata) expressing human mutant huntingtin (mHTT), a protein responsible for the progressive deterioration of motor and cognitive function in Huntington’s disease (HD). Although generally healthy, the mutant songbirds had severe vocal disorders, including poor vocal imitation, stuttering, and progressive syntax and syllable degradation. Their song abnormalities were associated with HD-related neuropathology and dysfunction of the cortical–basal ganglia (CBG) song circuit. These transgenics are, to the best of our knowledge, the first experimentally created, functional mutant songbirds. Their progressive and quantifiable vocal disorder, combined with circuit dysfunction in the CBG song system, offers a model for genetic manipulation and the development of therapeutic strategies for CBG-related vocal and motor disorders

Question 62

Which animals are vocal learners? (Lattenkamp & Vernes, 2018)

Answer 62

see notes

· Songbirds, parrots, hummingbirds
- Bats, whales, dolphins, seals, elephants, prob mice and goats

Question 63

Which animals are vocal learners? (Lattenkamp & Vernes, 2018) research

Answer 63

Siemers et al. (2009)

Lattenkamp et al. (2020)

Question 64

Siemers et al. (2009)

Answer 64

Shrews are very vocal animals. We tested behaviourally whether the high-pitched laryngeal ‘twittering’ calls of as-yet unclear function serve for communication or echo-based orientation. We used a representative species from each of the two largest phylogenetic groups of shrews. In both species, experimental manipulation of substrate density, but not of the likelihood of conspecific presence, affected the shrews’ call rate when exploring an unknown environment. This adaptation of call rate to the degree of habitat clutter parallels bat echolocation and suggests that shrews may use the echoes and reverberations of their calls for identifying routes through their habitat or for probing habitat type. To assess the acoustic feasibility of shrew echo orientation, we ensonified shrew habitats in the field with an ‘artificial shrew’ (small speaker mounted close to a sensitive microphone). The data showed that shrew-like calls can indeed yield echo scenes useful for habitat assessment at close range, but beyond the range of the shrews’ vibrissae.

Question 65

Lattenkamp et al. (2020)

Answer 65

Vocal production learning (VPL), or the ability to modify vocalizations through the imitation of sounds, is a rare trait in the animal kingdom. While humans are exceptional vocal learners, few other mammalian species share this trait. Owing to their singular ecology and lifestyle, bats are highly specialized for the precise emission and reception of acoustic signals. This specialization makes them ideal candidates for the study of vocal learning, and several bat species have previously shown evidence supportive of vocal learning. Here we use a sophisticated automated set-up and a contingency training paradigm to explore the vocal learning capacity of pale spear-nosed bats. We show that these bats are capable of directional change of the fundamental frequency of their calls according to an auditory target. With this study, we further highlight the importance of bats for the study of vocal learning and provide evidence for the VPL capacity of the pale spear-nosed bat.

Question 66

Point mutation in FOXP2 gene (transcription factor) causes human speech and language deficits (Webb & Zhang, 2004; Furlong, 2018)

Answer 66

· Human language deficits: aphasia, stuttering, articulation disorders, verbal dyspraxia, most prominent in children, cluster in families
- FOXP2 gene (human chromosome 7) - verbal dyspraxia (Kang & Drayna, 2011)

· Diff to humans where gene sequence undergone change presumably in relation to evolution of language, bird FOXP2 extremely conserved
· Sequences from vocal-learning mammals (whales, dolphins) don’t share human-unique substitutions in FOXP2 gene
- FOXP2 one gene in gene network underpinning vocal learning

see notes

Question 67

Point mutation in FOXP2 gene (transcription factor) causes human speech and language deficits (Webb & Zhang, 2004; Furlong, 2018) research

Answer 67

Kang and Drayna (2011)

Heston and White (2015)

Chabout et al. (2016)

Chen et al. (2013)

Mendoza et al. (2014)

Lawton et al. (2014)

Question 68

Kang and Drayna (2011)

Answer 68

Vocal communication mediated by speech and language is a uniquely human trait, and has served an important evolutionary role in the development of our species. Deficits in speech and language functions can be of numerous types, including aphasia, stuttering, articulation disorders, verbal dyspraxia, and specific language impairment; language deficits are also related to dyslexia. Most communication disorders are prominent in children, where they are common. A number of these disorders have been shown to cluster in families, suggesting that genetic factors are involved, but their etiology at the molecular level is not well understood. In the past decade, genetic methods have proven to be powerful for understanding these etiologies. Linkage studies and molecular genetic analyses in a large family containing multiple individuals affected with verbal dyspraxia led to the discovery of mutations in the FOXP2 gene. This gene encodes a forkhead domain transcription factor, a finding that has led researchers to a new avenue of investigation into the substrates and mechanisms that underlie human speech development. In studies of stuttering, linkage and candidate gene approaches in consanguineous families identified mutations in the lysosomal enzyme-targeting pathway genes GNPTAB, GNPTG, and NAGPA, revealing a role for inherited defects in cell metabolism in this disorder. In specific language impairment, linkage studies have identified several loci, and candidate gene association studies are making progress in identifying causal variants at these loci. Although only a small fraction of all cases of speech and language disorders can be explained by genetic findings to date, the significant progress made thus far suggests that genetic approaches will continue to provide important avenues for research on this group of disorders.

Question 69

Webb and Zhang (2004)

Answer 69

FoxP2 is the first identified gene that is specifically involved in speech and language development in humans. Population genetic studies of FoxP2 revealed a selective sweep in recent human history associated with two amino acid substitutions in exon 7. Avian song learning and human language acquisition share many behavioral and neurological similarities. To determine whether FoxP2 plays a similar role in song-learning birds, we sequenced exon 7 of FoxP2 in multiple song-learning and nonlearning birds. We show extreme conservation of FoxP2 sequences in birds, including unusually low rates of synonymous substitutions. However, no amino acid substitutions are shared between the song-learning birds and humans. Furthermore, sequences from vocal-learning whales, dolphins, and bats do not share the human-unique substitutions. While FoxP2 appears to be under strong functional constraints in mammals and birds, we find no evidence for its role during the evolution of vocal learning in nonhuman animals as in humans

Question 70

Heston and White (2015)

Answer 70

Mutations in the FOXP2 transcription factor cause an inherited speech and language disorder, but how FoxP2 contributes to learning of these vocal communication signals remains unclear. FoxP2 is enriched in corticostriatal circuits of both human and songbird brains. Experimental knockdown of this enrichment in song control neurons of the zebra finch basal ganglia impairs tutor song imitation, indicating that adequate FoxP2 levels are necessary for normal vocal learning. In unmanipulated birds, vocal practice acutely downregulates FoxP2, leading to increased vocal variability and dynamic regulation of FoxP2 target genes. To determine whether this behavioral regulation is important for song learning, here, we used viral-driven overexpression of FoxP2 to counteract its downregulation. This manipulation disrupted the acute effects of song practice on vocal variability and caused inaccurate song imitation. Together, these findings indicate that dynamic behavior-linked regulation of FoxP2, rather than absolute levels, is critical for vocal learning.

Question 71

Chabout et al. (2016)

Answer 71

Development of proficient spoken language skills is disrupted by mutations of theFOXP2transcription factor. A heterozygous missense mutation in the KE family causes speech apraxia, involving difficulty producing words with complex learned sequences of syllables. Manipulations in songbirds have helped to elucidate the role of this gene in vocal learning, but findings in non-human mammals have been limited or inconclusive. Here, we performed a systematic study of ultrasonic vocalizations (USVs) of adult male mice carrying the KE family mutation. Using novel statistical tools, we found thatFoxp2heterozygous mice did not have detectable changes in USV syllable acoustic structure, but produced shorter sequences and did not shift to more complex syntax in social contexts where wildtype animals did. Heterozygous mice also displayed a shift in the position of their rudimentary laryngeal motor cortex (LMC) layer-5 neurons. Our findings indicate that although mouse USVs are mostly innate, the underlying contributions of FoxP2 to sequencing of vocalizations are conserved with humans.

Question 72

Chen et al. (2013)

Answer 72

Humans and songbirds are among the rare animal groups that exhibit socially learned vocalizations: speech and song, respectively. These vocal-learning capacities share a reliance on audition and cortico-basal ganglia circuitry, as well as neurogenetic mechanisms. Notably, the transcription factors Forkhead box proteins 1 and 2 (FoxP1, FoxP2) exhibit similar expression patterns in the cortex and basal ganglia of humans and the zebra finch species of songbird, among other brain regions. Mutations in either gene are associated with language disorders in humans. Experimental knock-down of FoxP2 in the basal ganglia song control region Area X during song development leads to imprecise copying of tutor songs. Moreover, FoxP2 levels decrease naturally within Area X when zebra finches sing. Here, we examined neural expression patterns ofFoxP1andFoxP2mRNA in adult Bengalese finches, a songbird species whose songs exhibit greater sequence complexity and increased reliance on audition for maintaining their quality. We found thatFoxP1andFoxP2expression in Bengalese finches is similar to that in zebra finches, including strong mRNA signals for both factors in multiple song control nuclei and enhancement ofFoxP1in these regions relative to surrounding brain tissue. As with zebra finches, when Bengalese finches sing,FoxP2is behaviorally downregulated within basal ganglia Area X over a similar time course, and expression negatively correlates with the amount of singing. This study confirms that in multiple songbird species,FoxP1expression highlights song control regions, and regulation ofFoxP2is associated with motor control of song

Question 73

Mendoza et al. (2014)

Answer 73

Intact function of the Forkhead Box P2 (FOXP2) gene is necessary for normal development of speech and language. This important role has recently been extended, first to other forms of vocal learning in animals and then also to other forms of motor learning. The homology in structure and in function among the FoxP gene members raises the possibility that the ancestral FoxP gene may have evolved as a crucial component of the neural circuitry mediating motor learning. Here we report that genetic manipulations of the singleDrosophilaorthologue,dFoxP, disrupt operant self-learning, a form of motor learning sharing several conceptually analogous features with language acquisition. Structural alterations of thedFoxPlocus uncovered the role ofdFoxPin operant self-learning and habit formation, as well as the dispensability ofdFoxPfor operant world-learning, in which no motor learning occurs. These manipulations also led to subtle alterations in the brain anatomy, including a reduced volume of the optic glomeruli. RNAi-mediated interference withdFoxPexpression levels copied the behavioral phenotype of the mutant flies, even in the absence of mRNA degradation. Our results provide evidence that motor learning and language acquisition share a common ancestral trait still present in extant invertebrates, manifest in operant self-learning. This ‘deep’ homology probably traces back to before the split between vertebrate and invertebrate animals

Question 74

Lawton et al. (2014)

Answer 74

FoxP2 is a highly conserved vertebrate transcription factor known for its importance in human speech and language production. Disruption of FoxP2 in several vertebrate models indicates a conserved functional role for this gene in both sound production and motor coordination. Although FoxP2 is known to be strongly expressed in brain regions important for motor coordination, little is known about FoxP2’s role in the nervous system. The recent discovery of the well-conservedDrosophila melanogasterhomolog,FoxP, provides an opportunity to study the role of this crucial gene in an invertebrate model. We hypothesized that, like FoxP2,DrosophilaFoxP is important for behaviors requiring fine motor coordination. We used targeted RNA interference to reduce expression of FoxP and assayed the effects on a variety of adult behaviors. Male flies with reduced FoxP expression exhibit decreased levels of courtship behavior, altered pulse-song structure, and sex-specific motor impairments in walking and flight. Acute disruption of synaptic activity in FoxP expressing neurons using a temperature-sensitiveshibireallele dramatically impaired motor coordination. Utilizing a GFP reporter to visualize FoxP in the fly brain reveals expression in relatively few neurons in distributed clusters within the larval and adult CNS, including distinct labeling of the adult protocerebral bridge – a section of the insect central complex known to be important for motor coordination and thought to be homologous to areas of the vertebrate basal ganglia. Our results establish the necessity of this gene in motor coordination in an invertebrate model and suggest a functional homology with vertebrate FoxP2

Question 75

Infant vocal development (Kuhl, 2000)

Answer 75

· 6-month-old infants
· Discrim of prototype sound and similar sounds
· Dishabituation paradigm
- Infants failed to discrim sounds close to phenotype

see notes

Question 76

Infant vocal development (Kuhl, 2000) research

Answer 76

Okanoya (2015)

Mampe et al. (2009)

Kuhl and Rivera-Gaxiola (2008)

Question 77

Okanoya (2015)

Answer 77

Bengalese finches (BFs) are a domesticated strain of wild white-rumped munias imported from China to Japan 250 years ago. Bengalese songs are composed of multiple chunks of song notes, and each chunk is a combination of 2–5 song notes. Furthermore, chunks are arranged in a finite-state probabilistic automaton. We studied how and why BFs sing such complex songs. We found the following: (1) ancestral strains sing simpler songs; (2) there is high learning specificity in whiterumped munias but not in BFs; (3) BFs have larger song control nuclei and higher glutamate receptor gene expression levels than white-rumped munias; (4) both BFs and white-rumped munia females prefer complex songs as measured by the nest string assay, and males with complex songs are physically fitter than males with simpler songs. These results indicated the sexual selection scenario of song complexity in Bengalese finches. We further examined factors related to domestication. We examined songs of white-rumped munias in subpopulations of Taiwan. Where there is a sympatric species with white-rumped munias, songs were simpler. This led to a hypothesis that in the wild, songs needed to be simple to secure species identification, but under domestication this constraint was unnecessary. Based on these results, we extended our research into the socio-emotional domain. All indexes suggested that white-rumped munias have higher levels of stress and social shyness, which should be adaptive in natural environments, but could limit opportunities for learning complex songs. Evolution of song complexity involves factors related to the strength of sexual selection and relaxation of species identification as well as socioemotional factors because of domestication. The results of the present study on BFs should be useful in discussing the possible biological origins of human speech relating to proximate and ultimate factors

Question 78

Mampe et al. (2009)

Answer 78

Human fetuses are able to memorize auditory stimuli from the external world by the last trimester of pregnancy, with a particular sensitivity to melody contour in both music and language1,2,3. Newborns prefer their mother’s voice over other voices4,5,6,7,8and perceive the emotional content of messages conveyed via intonation contours in maternal speech (“motherese”)[9]. Their perceptual preference for the surrounding language10,11,12and their ability to distinguish between prosodically different languages13,14,15and pitch changes[16]are based on prosodic information, primarily melody. Adult-like processing of pitch intervals allows newborns to appreciate musical melodies and emotional and linguistic prosody[17]. Although prenatal exposure to native-language prosody influences newborns’ perception, the surrounding language affects sound production apparently much later[18]. Here, we analyzed the crying patterns of 30 French and 30 German newborns with respect to their melody and intensity contours. The French group preferentially produced cries with a rising melody contour, whereas the German group preferentially produced falling contours. The data show an influence of the surrounding speech prosody on newborns’ cry melody, possibly via vocal learning based on biological predispositions.

Question 79

Kuhl and Rivera-Gaxiola (2008)

Answer 79

Infants learn language(s) with apparent ease, and the tools of modern neuroscience are providing valuable information about the mechanisms that underlie this capacity. Noninvasive, safe brain technologies have now been proven feasible for use with children starting at birth. The past decade has produced an explosion in neuroscience research examining young children’s processing of language at the phonetic, word, and sentence levels. At all levels of language, the neural signatures of learning can be documented at remarkably early points in development. Individual continuity in linguistic development from infants’ earliest responses to phonemes is reflected in infants’ language abilities in the second and third year of life, a finding with theoretical and clinical implications. Developmental neuroscience studies using language are beginning to answer questions about the origins of humans’ language faculty

Question 80

Vocal learning is enhanced by social interactions (Kuhl et al., 2003)

Answer 80

· 9 month old infants
· 12 lab sessions
· Control group listened to English speaker
- Exposure to recorded Mandarin, w/o interpersonal interaction, had no effect

see notes

Question 81

Vocal learning is enhanced by social interactions (Kuhl et al., 2003) research

Answer 81

Goldstein et al. (2003)

Marler and Tamura (1964)

Question 82

Goldstein et al. (2003)

Answer 82

Birdsong is considered a model of human speech development at behavioral and neural levels. Few direct tests of the proposed analogs exist, however. Here we test a mechanism of phonological development in human infants that is based on social shaping, a selective learning process first documented in songbirds. By manipulating mothers’ reactions to their 8-month-old infants’ vocalizations, we demonstrate that phonological features of babbling are sensitive to nonimitative social stimulation. Contingent, but not noncontingent, maternal behavior facilitates more complex and mature vocal behavior. Changes in vocalizations persist after the manipulation. The data show that human infants use social feedback, facilitating immediate transitions in vocal behavior. Social interaction creates rapid shifts to developmentally more advanced sounds. These transitions mirror the normal development of speech, supporting the predictions of the avian social shaping model. These data provide strong support for a parallel in function between vocal precursors of songbirds and infants. Because imitation is usually considered the mechanism for vocal learning in both taxa, the findings introduce social shaping as a general process underlying the development of speech and song.

Question 83

Marler and Tamura (1964)

Answer 83

Male white-crowned sparrows have song “dialects,” acquired in about the first 100 days of life by learning from older males. In the laboratory an alien white-crowned sparrow dialect can be taught. Once the song is established further acoustical experience does not change the pattern. White-crowned sparrows do not copy recorded songs of other sparrow species presented under similar conditions

Question 84

Development of human speech (Doupe & Kuhl, 1999)

Answer 84

see notes

Question 85

Development of human speech (Doupe & Kuhl, 1999) research

Answer 85

Stromswold (1998)

Lai et al. (2001)

Question 86

Doupe and Kuhl (1999)

Answer 86

Human speech and birdsong have numerous parallels. Both humans and songbirds learn their complex vocalizations early in life, exhibiting a strong dependence on hearing the adults they will imitate, as well as themselves as they practice, and a waning of this dependence as they mature. Innate predispositions for perceiving and learning the correct sounds exist in both groups, although more evidence of innate descriptions of species-specific signals exists in songbirds, where numerous species of vocal learners have been compared. Humans also share with songbirds an early phase of learning that is primarily perceptual, which then serves to guide later vocal production. Both humans and songbirds have evolved a complex hierarchy of specialized forebrain areas in which motor and auditory centers interact closely, and which control the lower vocal motor areas also found in nonlearners. In both these vocal learners, however, how auditory feedback of self is processed in these brain areas is surprisingly unclear. Finally, humans and songbirds have similar critical periods for vocal learning, with a much greater ability to learn early in life. In both groups, the capacity for late vocal learning may be decreased by the act of learning itself, as well as by biological factors such as the hormones of puberty. Although some features of birdsong and speech are clearly not analogous, such as the capacity of language for meaning, abstraction, and flexible associations, there are striking similarities in how sensory experience is internalized and used to shape vocal outputs, and how learning is enhanced during a critical period of development. Similar neural mechanisms may therefore be involved.

Question 87

Stromswold (1998)

Answer 87

If language is the result of specialized structures in the brain and if these language-specific structures are genetically encoded, one would expect to find evidence of the heritability of language. In this article I review the results of family aggregation, pedigree, sex ratio, commingling, and segregation studies of spoken language disorders. The results of these studies provide evidence that, although spoken language disorders are genetically and behaviorally heterogeneous, genetic factors may play a substantial role in many cases of developmental spoken lan- guage disorders

Question 88

Lai et al. (2001)

Answer 88

Individuals affected with developmental disorders of speech and language have substantial difficulty acquiring expressive and/or receptive language in the absence of any profound sensory or neurological impairment and despite adequate intelligence and opportunity1. Although studies of twins consistently indicate that a significant genetic component is involved1,2,3, most families segregating speech and language deficits show complex patterns of inheritance, and a gene that predisposes individuals to such disorders has not been identified. We have studied a unique three-generation pedigree, KE, in which a severe speech and language disorder is transmitted as an autosomal-dominant monogenic trait4. Our previous work mapped the locus responsible, SPCH1, to a 5.6-cM interval of region 7q31 on chromosome 7 (ref.5). We also identified an unrelated individual, CS, in whom speech and language impairment is associated with a chromosomal translocation involving the SPCH1 interval6. Here we show that the geneFOXP2, which encodes a putative transcription factor containing a polyglutamine tract and a forkhead DNA-binding domain, is directly disrupted by the translocation breakpoint in CS. In addition, we identify a point mutation in affected members of the KE family that alters an invariant amino-acid residue in the forkhead domain. Our findings suggest thatFOXP2is involved in the developmental process that culminates in speech and language

Question 89

Development of bird song (Doupe & Kuhl, 1999)

Answer 89

see notes

Question 90

Development of bird song (Doupe & Kuhl, 1999) research

Answer 90

Human speech and birdsong have numerous parallels. Both humans and song-birds learn their complex vocalizations early in life, exhibiting a strong dependence on hearing the adults they will imitate, as well as themselves as they practice, and a waning of this dependence as they mature. Innate predispositions for perceiving and learning the correct sounds exist in both groups, although more evidence of innate descriptions of species-specific signals exists in songbirds, where numerous species of vocal learners have been compared. Humans also share with songbirds an early phase of learning that is primarily perceptual, which then serves to guide later vocal production. Both humans and songbirds have evolved a complex hierarchy of specialized forebrain areas in which motor and auditory centers interact closely, and which control the lower vocal motor areas also found in nonlearners. In both these vocal learners, however, how auditory feedback of self is processed in these brain areas is surprisingly unclear. Finally, humans and songbirds have similar critical periods for vocal learning, with a much greater ability to learn early in life. In both groups, the capacity for late vocal learning may be decreased by the act of learning itself, as well as by biological factors such as the hormones of puberty. Although some features of birdsong and speech are clearly not analogous, such as the capacity of language for meaning, abstraction, and flexible associations, there are striking similarities in how sensory experience is internalized and used to shape vocal outputs, and how learning is enhanced during a critical period of development. Similar neural mechanisms may therefore be involved

Question 91

Functional resemblance of the connectivity between brain areas in humans and song nuclei in songbirds (Jarvis, 2007)

Answer 91

see notes

Question 92

Functional resemblance of the connectivity between brain areas in humans and song nuclei in songbirds (Jarvis, 2007) research

Answer 92

Bolhuis et al. (2010)

Marler (1970)

Tchernichovski and Marcus (2014)

Soha and Peters (2015)

Question 93

Bolhuis et al. (2010)

Answer 93

o Unlike non-human primates, songbirds learn to vocalize very much like human infants learn to speak. In both cases, young individuals form auditory memories of the vocalizations of adults during a sensitive period, and they acquire their own vocalizations through a transitional phase that is called ‘subsong’ in birds and ‘babbling’ in infants.
o In songbirds, a network of interconnected brain nuclei, known as the song system, is involved in the perception, learning and production of song. Parts of the song system are analogous — and possibly homologous — to human basal ganglia as well as regions in the frontal cortex that are involved in speech.
o In songbirds, regions outside the song system, in the caudal pallium, are involved in auditory memory; activation of one of these regions, the caudiomedial nidopallium (NCM), is related to the strength of tutor song memory. These pallial regions are analogous — and possibly homologous — to a region in the human temporal lobe known as the auditory association cortex that is involved in speech processing.
o In both humans and songbirds, the vocal ‘motor regions’ are also involved in auditory perception. For learning and maintenance of speech and birdsong, continual interaction between auditory and motor regions to match what is heard and what is produced is necessary.
o Some species of songbirds including Bengalese finches (Lonchura striata domestica) have types of note-to-note transition rules that could be expressed as ‘finite-state syntax’, which is a simpler form of human syntax.
o FOXP2 is the first gene specifically implicated in speech and language, and its sequences are more than 90% conserved between birds and mammals. FOXP2 is regulated developmentally and seasonally and by singing activity in songbirds, and experimentally downregulated FOXP2 levels impair song learning.
Further multidisciplinary research is needed to study the molecular, neural and cognitive mechanisms of birdsong, and its similarities with human speech. Such analyses may ultimately have heuristic value for the study of speech acquisition and production in humans and its underlying mechanisms

Question 94

Marler (1970)

Answer 94

Ever since Aesop animals have served as a kind of mirror for man, although the reflections are usually viewed with some sense of condescension on our part. It is obvious to anyone who thinks even half seriously about the matter that man and the animals are fundamentally different, or so we are told. Yet it may be that the chances of solving some of the questions that plague us about human behavior would be in creased if we remind ourselves that man still has much in common with his animal ancestry. Some of our confusion about the position to take vis-a-vis our animal ancestors surely stems from uncertainty concerning the appropriate questions to ask about the causes of our own behavior. If we can only achieve a more thorough understanding of the rules that govern the behavior of animals, we may then be in a better position to

Question 95

Tchernichovski and Marcus (2014)

Answer 95

Studies of vocal learning in songbirds typically focus on the acquisition of sensory templates for song imitation and on the consequent process of matching song production to templates. However, functional vocal development also requires the capacity to adaptively diverge from sensory templates, and to flexibly assemble vocal units. Examples of adaptive divergence include the corrective imitation of abnormal songs, and the decreased tendency to copy over-abundant syllables. Such frequency-dependent effects might mirror tradeoffs between the assimilation of group identity (culture) while establishing individual and flexibly expressive songs. Intriguingly, although the requirements for vocal plasticity vary across songbirds, and more so between birdsong and language, the capacity to flexibly assemble vocal sounds develops in a similar, stepwise manner across species. Therefore, universal features of vocal learning go well beyond the capacity to imitate

Question 96

Soha and Peters (2015)

Answer 96

Peter Marler made a number of significant contributions to the field of ethology, particularly in the area of animal communication. His research on birdsong learning gave rise to a thriving subfield. An important tenet of this growing subfield is that parallels between birdsong and human speech make songbirds valuable as models in comparative and translational research, particularly in the case of vocal learning and development. Decades ago, Marler pointed out several phenomena common to the processes of vocal development in songbirds and humans—including a dependence on early acoustic experience, sensitive periods, predispositions, auditory feedback, intrinsic reinforcement, and a progression through distinct developmental stages—and he advocated for the value of comparative study in this domain. We review Marler’s original comparisons between birdsong and speech ontogeny and summarize subsequent progress in research into these and other parallels. We also revisit Marler’s arguments in support of the comparative study of vocal development in the context of its widely recognized value today

Question 97

Brain activation to speech in infants (Kuhl, 2010)

Answer 97

see notes

Functional neuroimaging shows that motor activity becomes increasingly synchronised with auditory area by age 6-12 months

Question 98

Brain activation to speech in infants (Kuhl, 2010) research

Answer 98

The last decade has produced an explosion in neuroscience research examining young children’s early processing of language. Noninvasive, safe functional brain measurements have now been proven feasible for use with children starting at birth. The phonetic level of language is especially accessible to experimental studies that document the innate state and the effect of learning on the brain. The neural signatures of learning at the phonetic level can be documented at a remarkably early point in development. Continuity in linguistic development from infants’ earliest brain responses to phonetic stimuli is reflected in their language and prereading abilities in the second, third, and fifth year of life, a finding with theoretical and clinical impact. There is evidence that early mastery of the phonetic units of language requires learning in a social context. Neuroscience on early language learning is beginning to reveal the multiple brain systems that underlie the human language faculty

Question 99

summary

Answer 99

· Birds learn to sing by listening to songs - they practice singing whilst listening to themselves
· This involves specialised brain areas in which gene activity underpins perceptual and motor processes required in this type of learning
· Birds have predisposition to learn (sensitive period) and neural templates (Species-specific song) but not completely fixed and vary depending on env
- Human infants learn to speak in similar ways