Spatially localised distortions of perceived duration.

A fundamental question about the perception of time is whether the neural mechanisms underlying duration judgements are universal and centralised in the brain or are modality specific and distributed.

Time perception has traditionally been thought to be entirely dissociated from spatial vision. However, we have shown that the apparent duration of a dynamic stimulus can be manipulated in a local region of visual space by adapting to oscillatory motion or flicker. This implicates a role for spatially localised temporal mechanisms in the generation of duration perception.

Following prolonged exposure to 20 Hz drifting motion or luminance flicker, 10Hz drifting motion or flicker seems shorter in the adapted region of visual space compared to an identical stimulus in a different region. Apparent onset and offset timings are not influenced, demonstrating a direct and spatially localised effect on duration perception rather than an indirect effect on the time course of neural processing.

The effects of adaptation on duration perception can also be dissociated from motion or flicker perception per se. Although 20Hz adaptation reduces both the apparent temporal frequency and duration of a 10Hz test stimulus, 5Hz adaptation increases apparent temporal frequency but has little effect on duration perception.

We have concluded that there is a peripheral, spatially localised and essentially visual component involved in sensing the duration of visual events.