Abstract
Humans can initiate ultrafast saccades towards faces as early as 100ms post-stimulus onset (Crouzet & Thorpe, 2010, J Vis), and even the mean saccadic reaction time can be as short as 120-130 ms, imposing very serious temporal constraints on the underlying mechanisms. To try and understand which brain structures are involved in triggering these very short latency responses, we explored the neural sources of these saccades by simultaneously recording ocular movements and electroencephalography under a variety of conditions. For example, subjects were required to make fast and accurate saccades to gray-scale face images that were pasted into complex and varied background scenes with random positions and sizes. We sought to determine the earliest activity which could predict the location of a visual face target. Single trial EEG classification results indicate that EEG potentials recorded over occipital locations reliably predicted the location of the face as early as 50ms post-stimulus onset. These results suggest the intriguing hypothesis that there may be face-selective neural representations in early visual areas.
Meeting abstract presented at VSS 2014