PERFORMANCE IN A DELAYED COMPARISON DISCRIMINATION TASK AS A FUNCTION OF STIMULUS INTERPRETATION

In a sequential same-different comparison task given to students, physically similar visual stimuli with the same interpretation were more poorly discriminated than equally similar stimuli with different interpretations. Physical similarity of stimulus pairs was held constant by using parametrically controlled computer-generated visual forms and by using each pair of figures as both a same-interpretation pair and as a different-interpretation pair. The interpretation variable used the ambiguous-figure properties of the forms. The 2 forms in each pair could be seen as representing the same object given 1 way of interpreting them; a 2nd interpretation applied to only 1 member of the pair. The discrimination results held for interstimulus intervals of 300 ms and 13 s. Similarities between the present studies and categorical perception studies were noted.