Feature Analysis in Toads Flashcards

1
Q

Quick visual classification of predators and prey

A

Predator-like stimulus → toad turns away and jumps to safety
Prey-like stimulus → series of motor actions that are part of the FAP

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2
Q

Prey FAPs

A

Orient (o)
Approach (a)
Fixate (f)
Snap (s)
Does not have to start at orient, can also repeat steps

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3
Q

Ewert & colleagues lab experiment with different stimuli

A

Used dummy stimulus and measured turns per minute
3 conditions: fake worm (horizontal rectangle), fake “anti-worm” (vertical rectangle), and square (could represent shadow of predator)
Preference for worm-like stimulus → high releasing value (turns/min increased as stimulus became longer)
Turns/min decreased as stimulus became taller (“anti-worm”)
Turned towards square if small (prey), turned away from square if large (predator)

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4
Q

Property of invariance

A

Stimulus contrast and velocity were not important

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5
Q

Configural property

A

Shape of stimulus and direction of movement were most important

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6
Q

Neural mechanisms of prey detection

A

Contralateral projections from retina to the optic tectum (OT)
Parallel projections to OT and thalamic pretectum (TP)
Topographic map of visual space in OT (retinotopy)

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7
Q

Visual electrophysiology

A

Specific regions of the retina map onto the contralateral optic tectum and pre-tectum (systematic one-to-one map of visual space)

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8
Q

Feature detection in tectal T5 cells and thalamic-pretectal area (TH3) cells

A

T5(2) cells could be considered an integrator of T5(1) cells and TH3 cells → T5(1) cells excite T5(2) cells when a worm-like stimulus is presented, TH3 cells inhibit T5(2) cells when an anti-worm stimulus is presented

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