What do theories of face perception tell us about object perception in general?
Face perception is the process by which the brain and mind understand and interpret the human face. The cognitive and neural processes in face recognition differ greatly from those observed for object recognition. Both objects and faces are generally considered to be “viewpoint-dependent” meaning that performance in recognition is better when viewed from a familiar viewpoint. However when considering Biederman’s (1987) recognition-by-components theory he found that objects can be recognised equally as easily from all viewpoints. This is due to his belief that objects are recognised from the individual basic shapes that make the whole object; these are called “geons”. Recognition of an object occurs when the stored representation of an object best fits the geon based information. However according to Bruce and Young (1986) face recognition starts with the visual encoding of the features of a face, meaning that one is able to identify a face viewed from any angle through its features as identified in their model for face recognition. Whilst cognitive and behavioural processes are involved for face and object recognition, and said processes vary greatly between the two, there are also important neural processes involved in face and object recognition. Particularly the role of the Fusiform face area for face recognition and the role of the inferotemporal cortex for object recognition. Other psychologists explain the different recognition processes between face and object recognition through the theory of expertise, whereby face recognition does not have face specific processing but is due to individuals having a greater expertise at individuating faces. Diamond and Carey’s (1986) study aims to support the expertise hypothesis by showing that experts process their objects of expertise in the same way as faces, therefore supporting their hypothesis that it is not due to face specific processing. One main difference that is generally supported in most studies is that faces are processed in a holistic fashion and objects are processed in a parts basis.
Face and Object Processing: Cognitive and Behavioural factors.
Evidence shows that faces are processed holistically (Tanaka et al, 2004). The holistic processing of faces has been shown through behavioural studies by identifying and observing the inversion effect, the part-whole effect and the composite effect. The part-whole effect demonstrates that memory for a face part is more accurate when that part is presented in the whole face than when presented alone. In Farah et al’s (1994) study, recognition performance for face parts was much better when the whole face was presented than only a single feature. The inversion effect states that performance in face recognition decreases for inverted (upside-down) stimulus compared to when viewed upright. Diamond and Carey (1986) tested the inversion effect on perceptual dog experts amongst many other recognition tests and the inversion effect was shown to be more sever for faces than object classes; this further supports theories of upright faces being processed holistically and inverted faces (and objects) being processed in parts and gives further evidence to the differing processes between object and face recognition. However when considering processes involved in object recognition, similarities can be drawn between the inversion effect and the viewpoint dependent element of the recognition-by-components theory.
Biederman’s (1987) “recognition-by-components” theory states that all objects are made up of basic shapes called “geons”. Simple shapes such as blocks, spheres, cylinders arcs etc. He states that recognition of an object occurs when a stored representation of an object best fits with the geon based information recognised. He also states that object recognition was found to be viewpoint invariant meaning that the object can...
Please join StudyMode to read the full document