Abstract
A case of increase in normalized pulse volume (NPV) to the critical item in the field Concealed Information Test (CIT), is reported. NPV is a new index of alpha-adrenergically mediated finger vascular tone, which normally decreases in response to a critical item in CIT as the result of phasic sympathetic activation, 6 to 10 sec after the onset of a CIT question. In the present case, however, NPV increased 5 sec after the onset of the critical item. Comparing this response to the other indices of the examinee and of other cases, it has been suggested that phasic sympathetic activation was followed by sympathetic inhibition. It was also suggested that parasympathetic activation or superiority of parasympathetic activity might have occurred because heart rate decreased to the critical item. Possible psychophysiological explanations of this phenomenon have been discussed.
