Abstract
It has been suggested that eye-movements both betray and influence the chosen stimulus in a judgement of facial attractiveness. We were interested in generalising this observation to see whether patterns of eye-movements would change according to the type of decision to be made when faced with a series of binary choices made with the same stimulus set. Two 4deg colour patches were presented 4deg either side of (temporary) fixation. The suprathreshold patches were defined along a vectors in CIE space between 'red' and 'green' centred on 'yellow'. The stimuli were either modulated in colour or luminance and the subject required to respond using a key-press. Eye-movements were recorded monocularly with an EyeLink2 at 250 samples/sec with a spatial resolution of 0.1deg. In separate blocks of the same stimulus set, subjects (n=18) were required to decide if the patches were the same or different (discrimination), which was redder, which was brighter, and which they preferred. Stimuli remained on the screen until the decision was made and eye-movements were recorded for the duration. Our main finding is that the pattern of eye-movements, in terms of position, number and duration of fixations, are uniquely related to the task at hand. Eye-movements were influenced both by the difficulty of the task and whether it was a judgement of colour or luminance difference. When the task was one of preference, the eye-movements did not reflect the pattern seen for facial attractiveness, but were distinct from that of discrimination, or from judgements of colour or luminance. We conclude that eye-movements do provide insight onto the underlying processes of stimulus analysis and decision, but in a way that reflects an ongoing interaction between stimulus- and task-based influences.
Meeting abstract presented at VSS 2016