L12 Birdsong P2 Flashcards
(17 cards)
What is reward prediction error?
difference between received and predicted reward
expectation Vs outcome
How does reward prediction error work?
Dopamine neurons activated by more reward than predicted (positive prediction error)
they are at baseline when received reward = predicted reward
how is reward prediction coded in birdsong?
- VTA neurons encode performance error during singing
- predicted = no response
- distorted = decrease in DA neuron firing
when is error response large?
error responses larger for syllables that were distorted most often
VTAerror neuron response to birdsong during non-singing
- if not singing, bird cannot adjust
- needs to sing and listen to itself
- VTAneurons do not respond if the bird is only listening to distorted or undistorted syllables
- performance related assessment
how do responses evaluate syllables?
independently rather than depending on recent history of syllable error rate
what is the neural pathway for prediction error in birdsong
- DA neurons talk to area X, but also receive instructions
- Auditory circuit –> DA neurons –> Area X
What does VTA contain?
DA and GABAergic interneurons (inhibitory/suppression)
roles of Aiv and Vp in song circuitry
- Aiv and Vp upstream
- if auditory circuit causes Vp to be activated, suppresses GABAergic activity causing disinhibition with DA neurons
- leads to activation/firing of DA neurons
- works both ways
- CONTROL OF VTA DA NEURONS VIA Aiv AND VP ALLOWS PLASTICITY OF SYLLABLE FREQUENCY
how do VTAerror neurons react to distorted/undistorted targets
- suppression of VTAerror neurons after distorted target is similar to DA response to worse than predicted reward outcome
- Activation of VTAerror neurons after undistorted target similar to DA response to better than predicted reward outcome
where is the song stored? what was mechanism for working out?
- IEG expression (ZENK)
- if bird sings own song, ZENK expression increases in song system
- if bird hears a recording of species-specific song –> ZENK expression seen in structures outside the song system
- two of these are the caudal parts of both the medial nidopallium (NCM) and the medial mesopallium (CMM)
NCM and CMM
caudal parts of the medial nidopallium and medial mesopallium
regions of the caudal forebrain activated when bird is exposed to conspecific song and could be part of the neural substrate for memory of the tutor song
Great tit
- songs important to mate attraction
- urban songs shorter, faster and unusual compared with forest
- min frequency is also higher in urban
- result of environment
what is connection with artificial light and birdsong
- higher artificial light accelerates time of song onset
- light pollution the cause?
Robin studies
- chorus initiation relative ton civil twilight correlated with artificial light present during true night
- choruses where there is no artificial light don’t begin during true night, instead they track onset of civil twilight
- proliferation of artificial nocturnal lighting may strongly affect singing behaviour in the American Robin at the population level
reproduction and light pollution?
- female passerines leave territory earlier in morning to perform extra-pair mating. supports hypothesis that females target earliest singing males - timing of dawn song is a quality indicator
- artificial lighting then would disrupt link between quality and dawn song - making yearling males more attractive
- SO LIGHT POLLUTION CAN LEAD TO MALADAPTIVE MATE CHOICE DECISION OF FEMALES AND THEREBY ALTERS SELECTION PRESSURES ON MATING BEHAVIOUR
effects of light pollution
- effect timing of reproductive behaviour, individual mating patterns, information contained in previously reliable quality-indicator traits
- may cause female Blue Tits to lay eggs earlier, lead to mismatch in timing of peak food demand by offspring
- lead to maladaptive timing of reproduction
- could also cause males to sing earlier and lead to increase extra-pair success
