1. Object recognition in the inferior temporal cortex
Retinotopy is not useful for object recognition, which is related to shape
Object recognition does not appear to occur in the earlier retinotopic visual areas
Recording in inferior temporal cortex (IT) shows object constancy and little retinotopy

3. Inferotemporal Cortex

4. Lesion studies in monkeys
Kluver-Bucy syndrome: temporal lobe lesions with complex social, sexual and eating behavior changes and visual impairments
With more restricted lesions, inferior temporal gyrus (inferotemporal cortex) was shown to be critical for visual impairments
Task was matching a choice to a target.

5. Object recognition not learning
IT lesions cause loss of previous discriminations
Qualitative abnormalities: generalize on features, ignore shape, e.g. respond to edge of circle and edge of triangle not shape of triangle
Used spatial location to solve some visual problems

6. What is the nature of the representation in IT?
Represents intrinsic shape and omits aspects that depend on specific viewing conditions (object centered recognition)
EVIDENCE:
Monkeys with IT lesions don’t generalize across hemifields as normal ones do (location is part of cue for them)
Vary distance of discs of absolute size and they can’t relearn the discrimination (retinal size cue problem; stuck on local size)

7. More evidence
IT lesioned monkeys impaired at views of the same stimulus in different orientations
(discrepant findings like doing P v.T discriminations may be explained by local features giving a difference cue)
Changes in illumination impair IT lesioned monkeys
IT monkeys are not confused by mirror images
(normal ones are!)

8. Single unit recording evidence
Large bilateral receptive fields
Not retinotopically organized
Cluster in groups with similar properties tuned to stimulus shape (e.g. hand like)
Cell responses modulated by task demands, if monkey must respond or discrimination is hard, the cell response is enhanced (not related to motivation)

13. Representing objects in IT
Prefer 3-D objects
Object can be defined by luminosity, texture, motion, speckle size
Some selective for normal, not scrambled, faces: overall structure important
Position, retinal image size, orientation minimally affect response (even faces rotated in depth can be ‘recognized’)