| Abstract: | The present study focuses on the relation between stimulus features and psychophysiological responsivity by using a modified version of the information detection paradigm. Compound pictorial and verbal stimuli were used as the relevant stimuli that Ss were instructed to memorize. Skin conductance responses were measured during the subsequent presentation of a sequence of test stimuli. We hypothesized that the electrodermal responsivity to the critical stimulus would reflect the degree it matches the relevant one. The results indicated that when the critical stimulus was identical to the relevant stimulus, responsivity was maximal. Neutral stimuli produced minimal responsivity, and critical stimuli that only partially matched the relevant one produced intermediate levels of responsivity (in spite of the subjects' awareness of the differences between the critical and the relevant stimuli). Comparison of the geometric and contrast models for similarity showed that the pattern of responsivity violated the minimality and symmetry assumptions of the geometric model. The relation between cognitive processes and psychophysiological responsivity is discussed, as are implications for the application of the guilty knowledge technique for detecting information. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
