Chapter 2: an Integrative Study to Behavior Flashcards
characterizing sounds made by animals:
a ___ shows the cahnges in pressure over time that compse a sound. If it changes in height, then the amplitude and thus ____ varies. if it changes in width, then the____ varies.
a WAVEFORMS shows the cahnges in pressure over time that compse a sound. If it changes in height, then the amplitude and thus INTENSITY varies. if it changes in width, then the FREQUENCY (PITCH) varies.
Researchers often use a _____ (sonogram), a visual representation of sound frequencies over time. In a spectrogram, intensity is shown using colour or grayscale. We can learn about whether the animal produces high or low ____ sounds, their ___, and how different sounds are structureed over time.
Researchers often use a spectrogram (sonogram), a visual representation of sound frequencies over time. In a spectrogram, intensity is shown using colour or grayscale. We can learn about whether the animal produces high or low frequency sounds, their intensity, and how different sounds are structureed over time.
3 proximate hypotheses for the development of song and song dialects in birds
1) Genetic differences hypothesis: differences in song are the result of genetic differences
2) Acoustic stimulus hypothesis: differences in song are the result of differences in the bird’s acoustic environment.
3) Social interaction hypothesis: differences in song are the result of social interactions between a young bird and its tutor.
the ____ ____ hypothesis Predicts that groups of birds singing different dialects will be genetically distinct from one another. Is this supposed by white crowned sparrows?
GENETIC DIFFERENCES HYPOTHESIS. this is not supported by white crowned sparrows. Population genetic studies found little genetic differentiation among six different dialect groups of white-crowned sparrows
the ____ ____ hypothesis predicts that young males learn the dialect of that region by listening to what adult males are singing. Explain the experiments used to test this
the ACOUSTIC DIFFERENCES HYPOTHESIS.
Tested by hand-raising sparrows in the laboratory
Birds not exposed to song started singing when 150 d old, but did not exhibit the full song of white-crowned sparrows: something was missing from the social environment
Exposing young sparrows to a song dialect when 10-50 d old resulted in young sparrows mimicking the exact version they heard on recordings at 150 d: provides powerful support for acoustic differences hypothesis.
IN THE FINCH HYPOTHESIS:
A spectrogram of a male zebra finches song is shown with those of his two male offspring. The first son’s hearing was intact and he was able to copy his father’s son.
The second son was experimentally deafened an he never sang a typical zebra finch song.
According to this hypothesis, young white-crowns have a special ____ ____10 to 50 days after hatching when their neural systems can acquire information from listening to white-crown song, but not to any other species’ song. Late in life, the bird matches his own plastic song with his memory of the tutor’s song and eventually imitates it perfectly – but does not sing elements of the song sparrow’s song that he heard during his development. What hypothesis does this support?
According to this hypothesis, young white-crowns have a special sensitive period 10 to 50 days after hatching when their neural systems can acquire information from listening to white-crown song, but not to any other species’ song. Late in life, the bird matches his own plastic song with his memory of the tutor’s song and eventually imitates it perfectly – but does not sing elements of the song sparrow’s song that he heard during his development.
this is part of the SOCIAL INTERACTION HYPOTHESIS.
explain the social interaction hypothesis and how young white crowns can be influenced by their social tutor THAT THE SEE, VS THAT JUST HEAR.
Young white-crowns were placed in cages where they could see and hear song sparrows or strawberry finches which acted as social tutors
Young white-crowns learned the song of their social tutor
A white-crowned sparrow that has been caged next to a strawberry finch will learn the song of its social tutor but will NOT learn the song of a nearby but UNSEEN white-crowned sparrow.
Social acoustical experience can OVERRIDE PURELY ACOUSTICAL stimulation during the development of white-crowned sparrow singing.
ON GENE THAT CONTRIBUTES TO CHANGES IN THE SONG CONTROL SYSTEM IS THE ____ GENE, WHICH CODES FOR THE PROTEIN ____ THAT IS EXPRESSED IN BRAIN REGIONS AFTER THE BIRD HEARS SONG OF ITS OWN SPEICES.
ON EGENE THAT CONTRIBUTES TO CHANGES IN THE SONG CONTROL SYSTEM IS THE ZENK GENE, WHICH CODES FOR THE PROTEIN ZENK THAT IS EXPRESSED IN BRAIN REGIONS AFTER THE BIRD HEARS SONG OF ITS OWN SPEICES.
For birds that only listen to songs, where is ZENK detected? what about birds that sing?
For birds that only listen to songs, ZENK is only detected in brain regions associated with auditory processing.
But in birds that sing, the ZENK protein is also found in regions of the brain that control song PRODUCTION.
Outline the neural pathway of the sound system of a typical songbird.
Neural pathways carry signals from the ____ to the ____ to the muscles of the song-producing syrinx. Other pathways connect the nuclei such as the ___ and area____ that are involved in song learning rather than song production.
Neural pathways carry signals from the HVC to the nXIIts to the muscles of the song-producing syrinx. Other pathways connect the nuclei such as the IMAN and area X that are involved in song learning rather than song production.
HVC: higher vocal center
RA: robust nucleus of the arcopallium
IMAN: the lateral portion of the magnocellular nucleus of the anterior nidopallium
NCM: the caudomedial neostriatum
X: area X
nXIIts: tracheosyringeal portion of the hypoglossal nucleus
the ____ is the KEY for song learning; if it is reduced or absent, there is no song learning
LMAN
if you disrupt the pathway from ____ to ___ to ____, you impair the ability to produce song.
if you disrupt the pathway from HVC to RA to nXIIts, you impair the ability to produce song.
the _____ sends a message to the syrinx that produces dongs
nxIIts
In species such as the white-crowned sparrow in which males sing and females do not, the ____ should be bigger in males brains than in female brains
In species such as the white-crowned sparrow in which males sing and females do not, the RA should be bigger in males brains than in female brains
The robust nucleus of the arcopallium (RA) in the male and female zebra finch
the ____ can respond to the social environment of starlings. Keith Sockmann found that In starlings, the ____ is the only song control nucleus that grows substantially in males that are exposed to high-quality (longer) songs of other males for a week
The RA can respond to the social environment of the bird. Keith Sockmann found that In starlings, the RA is the only song control nucleus that grows substantially in males that are exposed to high-quality (longer) songs of other males for a week
there are changes in the size of the ___ nucleus of the ____ (RA) of male starlings in relation to high quality (long) songs of other starlings
there are changes in the size of the robust nucleus of the arcopallium (RA) of male starlings in relation to high quality (long) songs of other starlings
The RA can respond to the social environment of the bird: when they hear high quality songs, the RA grows, helping the bird produce a better song
In swamp sparrows, One mechanism that could help a young male control his song type output would be a set of specialized neurons in the ___ that respond selectively to SONG TYPE (not social climate like RA responds to high quality songs from others).
Activity in these cells could contribute to his ability to monitor what he is singing so that he could adjust his repertoire strategically.
One mechanism that could help a young male control his song type output would be a set of specialized neurons in the HVC that respond selectively to song type. Activity in these cells could contribute to his ability to monitor what he is singing so that he could adjust his repertoire strategically.
Image: When the three songs are presented to the sparrow, one of the HVC relay neurons reacts substantially only to song type B. Other cells, not shown here, respond strongly only to song type A, while still others fire rapidly only when song type C is the stimulus. Indicates that there are specialized neurons in the HVC that fire to selective song types.
