Fig. 1.

Task and behavioural data. (a) Participants were shown a small circle in their left upper visual field, which consisted of noise or noise plus an embedded low contrast grating (shown here; the grating has higher contrast than in the actual experiment for illustration purposes). The stimulus was shown for 1 s, after which participants had 1 s to respond (indicated by the fixation dot turning red). Inter-stimulus intervals were 20–30 s. (b) Average reaction times (left) and D-primes (right) for all participants.