Examining Face Perception with Self-Reports and Neural Measures: An SSVEP study

Abstract

This study investigated the relationship between self-reported face recognition abilities, and behavioral and neural responses during face perception. Neural activity related to the processing of attended and unattended faces was recorded with electroencephalography (EEG) measurements using steady-state visually evoked potentials (SSVEPs). It was then compared to the neural activity during object recognition. Participants with varying self-reported scores on the PI20 questionnaire (Twenty Item Prosopagnosia Index) took part in two SSVEP experimental tasks, one on visual face processing and the other on visual object processing. The SSVEP response was elicited by rapidly repeating visual stimuli displayed at a frequency of 6 cycles per second, or 6 Hz, which was the base frequency. Within each cycle, four stimulus presentations featured the same standard face or object, while on the fifth presentation, a different face or object appeared. This oddball stimulus, inserted among the base-level stimuli, was presented at a frequency of 1.2 Hz. It differed primarily from the standard stimulus in higher-level characteristics, making it ideal for assessing higher-level visual processes. The oddball power, i.e., the response at the oddball frequency, was used to measure discrimination between standard and oddball stimuli. In the first session participants were either instructed to focus on the faces being presented or the color of the fixation point. This was done to see the effect of attention on face perception as we could see the neural responses to both attended and unattended faces. The second session's emphasis was on objects and in both tasks, a memory test followed each trial. The results indicate that the oddball power for faces is negatively associated with PI20 scores, i.e., higher discrimination responses to faces tend to go with better self-reported face recognition ability. This effect was especially clear over the right occipito-temporal cortex. Thus, this study has revealed a link between neural variations in the right occipito-temporal cortex and self-reported face recognition. This knowledge could be useful in a variety of fields, such as designing training programs for people with problems recognizing faces and add to our understanding of the neural bases of face processing.Efnisorðin eru : Psychology (sálfræði), face perception (andlitsskynjun), steady-state visually evoked potentials (SSVEPs), face recognition (andlitskennsl), self-reported face recognition ability (sjálfsmetin hæfni í andlitskennslum).