Lecture 12 & 13: Patel Flashcards Preview

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Flashcards in Lecture 12 & 13: Patel Deck (32)
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1
Q

How are birdsong’s represented?

A

Firstly by composers due to a lack of technology Nowadays by a sonogram

2
Q

What are the three parts of a sonogram/ bird song?

A

Notes - individual parts Syllables - a group of notes Phrase- repeated syllables

3
Q

How can you test whether birds learn songs from other birds?

A

Hand rear the birds in isolation Control the auditory input using a speaker Only test with juvenile birds

4
Q

Do birds learn songs from other birds? Experiments with chaffinches.

A

Raised with normal songs (adult tutor bird played) - Reproduces this song Raised in acoustic isolation - Produces a song with similar duration and tempo but different notes, syllables and phases Raised with a tutor song of a different but similar species - Learns the other species song (similar template?)

5
Q

Is bird song learnt or innate?

A

There is a critical window where the juvenile must hear the tutor song to produce the correct song However the bird will still sing if raised in isolation

6
Q

What are the stages of song development?

A

Sensory period, Sensory-Motor period, Crystallised

7
Q

Describe the sensory period of song development:

A

Critical window Birds listen and learns tutor song

8
Q

Describe the sensory-motor period of song development.

A

There is a sub song (soft, variable with rambling syllables). The song is also plastic- requires rehersal. Eventually the syllables and phrases are repeated, refined and can be recognised. Eventually the tutor birds songs is reproduced.

9
Q

Describe the crystallised period of song development?

A

Song develops characteristic volume, duration, and order Song then cannot be changed.

10
Q

What do sonograms look like throughout the stages of song development?

A

Decreased reproduction

Formation of distinctive characteristics: notes –> syllables –> phrases

Decreased plasticity

11
Q

What are the different mechanisms of learning bird song

A

Seasonally closed, age limited, open-ended

12
Q

What is an open-ended learner?

A

Those birds which are not limited by age to when they can learn a song. Can learn year on year. E.g. lyre bird

13
Q

What is a seasonally closed learner.

A

Strict seasons for different stages of song development. Once crystallised cant be changed

14
Q

What are age-limited learners?

A

Song development periods can overlap, but age is important in defining the critical window (first year). Once the song is crystallised it cant be changed.

15
Q

How is a bird song produced?

A

Air produced from sacs rather than lungs Body wall muscle must be coordinated to expell air from air sacs. Air movement causes tympaniform membranes to vibrate causing the production of sound waves. Internal and external syringeal muscles alter tension of the tympaniform membrane –> altering of vibration freq.

16
Q

How does the brain control birdsong - Posterior vocal pathway?

A

HVc has cell bodies with axons –> RA –> nXIIts and respiratory control

17
Q

How does the brain control birdsong - Anterior vocal pathway?

A

Loop between DLM, LMAN and area X

18
Q

What happens if you lesion different parts of the brain? - HVC lesion

A

Disrupts song production Disrupts the calls already learnt -evidence suggests HVC is always active during bird song not just when singing

19
Q

What happens when the RA is lesioned?

A

Disrupts the production of birdsong - Active just before singing

20
Q

What do birds learn about their song?

A

Creative with the songs they hear- improvise, imitate and invent. - out of 200 plastic syllables 45 crystalise (overproduction and reduction) - Phrase number decreases from 3 to 1.

21
Q

How to birds learn about their song?

A

Action based learning - Position vocalisations are reinforced Vocalisations are compared to a memory template - Listen to the syllables produced and remember the correct ones.

22
Q

How can you test whether birds recognise songs from con-specifics?

A

Rear song sparrows and swamp sparrows in isolation Expose fledglings to a variety of tape noises (song and swamp)

23
Q

What were the results of testing whether birds recognise songs from con-specifics?

A

Preffered conspecifics song but also copied features from other species song 20% of the time. - Swamp sparrow song is simpler - Song sparrows learn swamp sparrows syllables if in correct syntax an tempo

24
Q

Do birds appear to have innate templates?

A

Yes - still sing when raised in isolation (fewer, longer, simpler notes) - isolate songs vary between species

25
Q

How can you experimentally test whether birds need to hear themselves sing?

A

Remove the cochlea after the sensory learning period but before the senesory motor period - deaf birds songs are fragmented and non specific —> insert diagram

26
Q

What are song selective neurons?

A

Neurons which are active when the bird hears itself or a con-specifics song.

27
Q

Where are song selective neurons located?

A

HVc and LMAN - LMAN responds to own songs (order of syllables)

28
Q

What happens if you lesion LMAN?

A

In juvenile –> inhibition of mature singing In adult –> no change this shows the anterior vocal pathway is involved in learning songs (i.e. forms innate template)

29
Q

How are hormones responsible for singing?

A

Related to testosterone levels and size of song nuclei —> increase size of nuclei due to neurogenesis and synapse formation occurs during sensory period. Only males sing?

30
Q

How do we know that hormones are responsible for singing?

A

Castrate a male –> no longer sing Replace testosterone in castred male –> sing Give testosterone to a female –> sing

31
Q

How are testosterone and song crystallisation linked.

A

Castrated male cannot crystalise an advanced plastic song. Provide testosterone –> crystalisation

32
Q

What links are there between HVc and song repertoire?

A

Positive correlation Size of HVc increases –> larger song repertoire.