Language evolution

Question 1

what are the challenges in studying language

Answer 1

complex cognition, no evidence in fossil record, hard to compare human speech to anything else

Question 2

what is thought to be the main precursor for language / main trait of language

Answer 2

Referentiality : words stand for things

Question 3

what is the traditional view of animal communication

Answer 3

communication expresses the signals inter state / affect, now it is known it can also be referential

Question 4

what is an animal signal

Answer 4

the signal refers to an object and is given in its presence

Question 5

what are the traits of functionally referential calls in animals

Answer 5

have specific acoustic structure, produced in specific context, elicit a specific response from the listeners

Question 6

what is the criteria for functional referentiality

Answer 6

there is a signaler who clearly signals the object and meaning of object (production specificity), and a receiver who understands the signal and behaves accordingly (perception specificity)

Question 7

describe the vervet monkey alarm call system

Answer 7

they have different calls to signal different kinds of predators, each call elicits specific behavioural response

Question 8

evidence of language learning in chimps

Answer 8

Keith and Cathy Hayes trained chimp to say papa, mama, cup. Chimps have intentional gestures signifying different things (play, food, request care). Chimps trained to learn signs, but not spontaneous use. Chimps used lexigram boards to communicate through visual symbols → learnt to use words in combination and had spontaneous use.

Question 9

what is the gestural hypothesis and its supporting evidence

Answer 9

language evolved from gestures. Non-human primates use gestures in intentional, referential and flexible ways. Gestures are under great vocabulary control

Question 10

what are the challenges with the gestural hypothesis

Answer 10

If language started with gestures, why switch? → maybe speech allowed for greater spatial reach and better communication at night, allowing for free hand use. How did the switch occur in the brain?

Question 11

what is the vocal origin of language

Answer 11

language arose from vocal calls → evidence = alarm system in monkeys and animals songs (complex learnt vocalisations)

Question 12

what are the neuroanatomical precursors to language

Answer 12

broca’s (language production), wernicke’s (language comprehension), arcuate fasciculus (connects the two)

Question 13

what kind of area change happened to brocas

Answer 13

greatly expanded in humans, development of mirror neurons (also in homologous area in chimps F5) Area may have evolved to control facial movement in non-human primates and then evolved to control speech in humans

Question 14

which pathway is more prominent in the arcuate fasciculus in humans

Answer 14

the dorsal pathway (sensory-to-motor) is more prominent and also have more fibres in comparison to chimps, left lateralized!

Question 15

what is vocal usage learning

Answer 15

ability to control production of pre-existing calls. Ability to learn the appropriate social/ecological contexts in which the call is produce

Question 16

what is vocal production learning (vocal learning)

Answer 16

the ability to modify acoustic and syntactic structure and/or sounds produced, including imitation and improvisation as a result of experience / interaction with the environment

Question 17

what is the difference between innate and learnt signals

Answer 17

Innate signals are things we know from birth, often associated with internal affect and emotional aspects (don’t require external auditory input). Learnt is speech and song we learn through experience with environment (required external auditory input and auditory feedback from oneself)

Question 18

what is the difference between a call and a song

Answer 18

calls are simpler acoustic structure often used to communicate coordination and responses to threat, songs are more complex acoustic structure used for mate attraction or defending territory

Question 19

how are zebra finches similar to humans in terms of vocal learning

Answer 19

both show evidence of a sensitive period and the need for exposure to environment to learn songs or language → baby birds without tutors will not ever learn their proper song, children experiencing neglect from young age never able to properly learn language

Question 20

what are the 2 hypothesis about why humans are capable of articulating sounds

Answer 20

it may be due to the position of the larynx (it is positioned much lower compared to other primates), or it could be due to better control resulting from differences in the brain

Question 21

what is the limbic vocal control pathway

Answer 21

controls voluntary innate emotional vocalisation. Pathway = anterior cingulate cortex → PAG → reticular formation

Question 22

what is the laryngeal motor cortical pathway

Answer 22

controls learned vocalisations. Pathway = motor cortex → brain stem phonatory nuclei

Question 23

what is similar about human and bird brains that is not the same in primate brains

Answer 23

the direct connections between the motor cortex and laryngeal nuclei in the brainstem. Birds have direct connection in forebrain and the nuclei which innervate the syrinx

Question 24

what is the Jungers-Kuypers hypothesis

Answer 24

Direct connections between motor cortex and laryngeal nuclei in the brain stem are only present in humans.

Question 25

what is the function of the dorso-lateral part of the striatum

Answer 25

: part of the sensorimotor loop, involved in the processing of motor input and output

Question 26

what is the function of the dorso-medial section of the striatum

Answer 26

it is the associative section, has circuit that go the association cortices projecting from caudal nucleus

Question 27

how many amino acid changes have occurred to the FOXp2 gene

Answer 27

3 since the human/mouse split and 2 are unique to humans

Question 28

what do mutations to the FOXp2 gene tells us about its function

Answer 28

mutation associated with heritable speech and language deficits (the Ke family had unintelligible speech, articulatory impairment). May be involved in the interaction between declarative and procedural learning systems. Affects striatum physiology

Question 29

what abnormalities were found in the KE family

Answer 29

changes in density of brain matter in broca’s, motor area, wernickes, angular gyrus, caudate nucleus, putamen and cerebellum

Question 30

what happened to songbirds when manipulating the foxp2 gene

Answer 30

limited song learning, reduced plasticity and spine density of the striatum, had fewer dendritic spines associated with plasticity)

Question 31

how does the basal ganglia work in song learning

Answer 31

Motor—basal ganglia (striatum/area X in birds)—circuit for song learning