Parietal ERP Activity and Appetite

Recent research on brain activity suggests that visual attention increases in response to emotional images. This increase is reflected in signs of greater activity, in response to different emotional visual stimuli, in parietal and parietooccipital areas in several studies employing neuroimaging techniques and event-related potentials (ERPs). In the latter case, greater parietal and parietooccipital negativities have been observed. The objective of the present study was to examine the role of a person's level of motivation towards the emotional stimulus with respect to this ERP pattern. Two groups of stimuli were presented to 60 participants: neutral or N (photographs of taps) and appetitive or A (photographs of cakes). The level of hunger was measured via a questionnaire. Recordings were taken at PO3, PO4, P7, and P8. The largest differences, as a function of appetite, were produced between 575 and 625 ms. Multiple regression analyses were carried out to study the relationship between subjects' appetite and their ERP recordings in response to A and N stimuli. There was a significant negative association between appetite and 575–625 mean amplitude in response to stimulus A at PO3 and PO4.