the neural basis of object and face recognition
DESCRIPTION
The neural basis of Object and face recognition. 0. 2. TE receptive field. V1 receptive field. V4 receptive field. Ventral pathway receptive field properties. Firing rate. Stimulus. Responses of IT neurons to various stimuli. Neural Coding. - PowerPoint PPT PresentationTRANSCRIPT
The neural basis ofObject and face recognition
Ventral pathway receptive field properties 0
2
TE receptive fieldV4 receptive field V1 receptive field
Responses of IT neurons to various stimuli
Fir
ing
rate
Stimulus
Neural Coding
The question of specificity:Is a face cell truly a “face specific”
#1
#10 #100
Face selectivity in single units human MTL(Jennifer Aniston cell)
Face selectivity in single units human MTL
Face neuron clusters in IT
Responses of IT (TE)
neurons
Tanaka’s stimulus reduction method
Tanaka et al, 1991
Tanaka Features
Columns in IT
Optical imaging in IT cortex
Columns in IT (seen with optical imaging)
Columns in IT
Microstimulation of face populations in IT
Cortical Microstimulation biases perceptual decisions
fMRIfMRI
The human visual pathways
Malach et al., PNAS 1995
Object-Selective Regions in the Human BrainLateral Occipital Complex: LOC
10-4
10-4
10-10
10-4
10-10
right hemisphere
lateral view
ventral view
left hemisphere
>
Grill-Spector et al. , Neuron 1998
Objects from motion
Objects from texture
Objects from luminance
Cue-independent representations
Left hemisphere
lateral
Are Faces Special?Are Faces Special?Having a dedicated Having a dedicated
representationrepresentation
Face-related activation
Whole vs. Parts
12V41664256 2h
Whole vs. Parts
Face blindness (Prosopagnosia)
Is face blindness associated witha disfunctional FFA
NO!
But it may depend on the integrity of the face network
(its connections with other areas)
Functional organization of the human ventral areas
Hasson et al., 2003
Distributed & overlapping representation of
faces & objects in ventral temporal cortex
Haxby et al., 2001
Mapping the similarity between visual categories
Kriegskorte et al., 2008
A division between animate and inanimate objects
Mapping is similar in humans and monkeys