Stimulus-response compatibilities during top-bottom discriminations.

Participants indicated whether a small dot was located near the top or bottom pole of a rotated object. Response times increased as a function of object orientation more for top trials than for bottom trials. The interaction between orientation and response was shown to be due to a relationship between response times and the dot's height on the screen. The orientation effect was influenced, positively and negatively, by a vertical arrangement of the response keys depending on whether the upper or lower key was used for the top response. Horizontal key placement produced an intermediate orientation effect, with asymmetries of about 180 degrees depending on which hand was used for top responses. This task appears to reflect spatial stimulus-response compatibilities more than object processing. (PsycINFO Database Record (c) 2008 APA, all rights reserved).