ECVP 2003 Abstract

Cite as:
Wilson S, Goddard P A, Hamilton G, 2003, "A two-tiered hierarchy for perceptual change" Perception 32 ECVP Abstract Supplement

A two-tiered hierarchy for perceptual change

S Wilson, P A Goddard, G Hamilton

The Necker cube (NC) figure appears to switch between two 3-D perceptual alternatives, 'cube up' (CU) and 'cube down' (CD). However, experienced observers not only report CU and CD but also a myriad of 2-D percepts. Four experienced observers recorded perceptual changes that occurred during observation periods lasting 5 min. In one period they recorded when the CU percept began and finished, thereby giving the number and duration of CU percepts; this was repeated for CD and 2-D percepts. The sum of the durations for the percept of CU was about the same as that for CD; taken together CU and CD percepts accounted for between a third and a half of an observation period. The sum of the 2-D percepts accounted for between a half and two-thirds of an observation period. The distributions of CU and CD percept durations were similar and were modelled adequately by gamma distributions. These percepts tended to be brief (about 1 s) compared to the far more stable, and normally distributed, 2-D percepts. The difference between the characteristics of CU/CD and 2-D percepts is consistent with a system that operates at at least two different tiers of perceptual change. At one level, changes can occur between 2-D and 3-D interpretations. Further changes can occur within either the 3-D or 2-D interpretations, such that if a 3-D interpretation has been accepted then there can be further changes between CU and CD at this subordinate level. Most models of perceptual change only consider this subordinate level.

These web-based abstracts are provided for ease of seaching and access, but certain aspects (such as as mathematics) may not appear in their optimum form. For the final published version of this abstract, please see
ECVP 2003 Abstract Supplement (complete) size: 1712 Kb