Where's the time? Temporal recalibration is absent without awareness.
56.317, Tuesday, 20-May, 2:45 pm - 6:45 pm, Jacaranda Hall
Regan Gallagher1, Kielan Yarrow2, Derek Arnold1; 1School of Psychology, University of Queensland, 2Department of Psychology, City University
The relative timing at which two sensory events seem synchronous is flexible. Prolonged exposure to temporally offset audio and visual signals (adaptation) results in a distortion of perceived timing; events presented in the same order and near the same offset as the adapted stimuli are more likely to be judged as synchronous. This is known as temporal recalibration (TR). The mechanisms underlying audio-visual timing judgments are not well established, and there is debate concerning the role of attention, with some suggesting that the determination of audio-visual timing takes place pre-attentively, and other evidence suggesting that the relative timing of the two signal streams must be attended. We therefore decided to investigate the role of awareness -- the assumption being that TR should be degraded for subliminal adaptation if conscious attention of timing is required for audio-visual temporal judgments. As a control condition, we measured the tilt aftereffect (TAE), which is known to be robust for subliminal adaptation. We used dichoptic presentations to mask awareness of the dynamics and orientation of visual adaptors and tests. Consistent with previous findings, we found that the TAE could be elicited by either supra- or sub-liminal adaptation. In contrast, we found that only supra-liminal adaptation resulted in a robust TR. These results suggest conscious awareness of the adapting visual dynamics is important for recalibrating temporal relationships, an effect we attribute to the need to consciously attend the adapted audio-visual temporal offset.