Abstract
To investigate if emotional face processing requires central attention, a psychological refractory period paradigm was combined with the event-related potential (ERP) technique. Participants were asked to categorize tones as high (900 Hz or 2000 Hz) or low (200 Hz or 426 Hz) as quickly and accurately as possible and then to indicate if a face expressed fear or a neutral expression. Stimulus onset asynchrony (SOA) between the presentation of the tone and the face was manipulated (SOA: 300, 650 or 1000ms) to vary the amount of central attention available to perform the face expression task (less central attention available at short than long SOAs). The amplitude of frontally distributed ERP components associated to emotional face processing (computed as the difference between fear and neutral conditions: Eimer & Holmes, 2007) were measured at all SOAs. The first component (175-225 ms post-visual stimulus onset), which is thought to reflect rapid initial detection of the emotion, was not affected by SOA, F(2,50) = 2.24, p = .12. However, a significant effect of SOA was observed on a later sustained frontal positivity (300-400 ms post-visual stimulus onset), that is thought to reflect the conscious evaluation of emotional content, F(2,50) = 5.33, p = .01. For both components, no effect of SOA was observed in a subsequent control experiment in which both stimuli were presented but only a response to the expression of the face was required, F(2,32) = 2.80, p = .10 and F(2,32) = 1.26, p = .30. These results suggest that the rapid perceptual detection of the facial expression is independent of central attention. In contrast, the subsequent cognitive stage of conscious evaluation of emotional content does require central attention to proceed.
Meeting abstract presented at VSS 2018