Effect of Short-Term Motion Adaptation on Subjective Time
İnci Ayhan1, 2 & Doğa Gülhan2
1 Boğaziçi University, Department of Psychology
2 Boğaziçi University, Cognitive Science M. A. Program
The apparent duration can be manipulated in a local region of visual field by adaptation to motion or flicker (Johnston, 2006). These shifts in subjective duration following temporal frequency adaptation were linked to concurrent changes in the temporal impulse response of early visual neurons via a contrast gain mechanism (Johnston et al, 2010). Early source contrast gain effects are known to be manifested in the response of higher-level motion areas such as area MT+ (Kohn& Movshon, 2003). It has also been provided evidence for a short-term motion adaptation effect with a locus in the area MT+ independent of the feedforward connections from the early-level visual motion areas (Priebe & Lisberger, 2002). Here, we investigated whether short-term adaptation to motion changes the apparent duration of a successively presented dynamic stimulus. As hypothesised, we found that brief adaptation in the millisecond range causes compression in perceived duration of a dynamic pattern, but more importantly, only when the coherence level is above motion coherence thresholds, implying a locus where global motion is processed. We also observed a slight motion direction effect, which we link to changes in the phase of the temporal impulse response of transient system neurons. These results imply a common component but separate underlying mechanisms for motion and duration perception in higher-level motion areas, complementing our previous work with a similar dissociation in early areas processing temporal information.
DATE : Friday, 16 December
TIME : 12.40-13.30
ROOM : A 130