Recognising objects and faces

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Recognising objects and faces
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General problems

• Given that objects move on a surface, why do they
  not appear to change shape?
• How do we recognise objects that we can only
  partially see?
• How do we extract the definitive properties of
  each object from stimulation on the retina?
• How do we match the definitive object properties
  to a stored item in long-term memory (LTM)?

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How do we refer to these problems?

• shape constancy
• occlusion
• extracting the definitive properties
• finding a match in LTM

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Basic theoretical accounts of object
representation

• Templates and Alignment theories (e.g., Ullman,
  1989 Bülthoff Edelman, 1992)

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• Features (Selfridge, 1961).

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• Structural descriptions (e.g. Marr, 1982)

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Part-based theories (e.g., Marr Nishihara,
1978 Biederman, 1987)
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Representing faces

• Faces as wholes not parts (in contrast to houses)
• Effect of inversion on face processing (in
  contrast to houses)

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Effects of probe type (Tanaka and Farah, 1993
Donnelly and Davidoff, 1999)
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Scrambled stimuli
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Effects of inversion on face processing
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References Biederman, I. (1987).
Recognition-by-components A theory of human
image understanding. Psychological Review, 94,
115-147. Brown, J. M., Weisstien, N. and May, J.
G. (1992) Visual search for simple volumetric
shapes. Perception and Psychophysics, 51,
40-48. Bülthoff, H. H. and Edelman, S. (1992).
Psychophysical support for a two-dimensional view
interpolation theory of object recognition.
Proceedings of the National Academy of Sciences,
89, 60-64. Donnelly, N. and Davidoff, J. B.
(1999). The mental representations of faces and
houses Issues concerning wholes and parts.
Visual Cognition, 6, 319-343. Marr, D. (1982).
Vision. W. H. Freeman San Francisco Marr, D. and
Nishihara, N. K. (1978). Representation and
recognition of the spatial organization of
three-dimensional shapes. Proceedings of the
Royal Society of London Series B, 200,
269-294. Palmer, S. E. (1999).Vision Science
From Photons to Phenomenology. MIT Press
Cambridge, MA Tanaka, J. and Farah, M. (1993).
Parts and wholes in face recognition. Quarterly
Journal of Experimental Psychology, 46A,
225-245. Ullman, S. (1989). Aligning pictorial
descriptions An approach to object recognition.
Cognition, 32, 193-254.