Evoked Potentials to Visual Apparent Motion after Auditory and Visual Time Interval Adaptation Utku Kaya1,2, Fazilet Zeynep Yıldırım3,4, Hulusi Kafaligonul1,3
[email protected] 1
[email protected]
[email protected]
National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey. 2 Informatics Institute, Middle East Technical University, Ankara, Turkey. 3 Interdisciplinary Neuroscience Program, Bilkent University, Ankara, Turkey. 4 Institute of Psychology, University of Bern, Bern, Switzerland
40th European Conference on Visual Perception ECVP 2017. 27-31 August 2017, Berlin, Germany
INTRODUCTION Accumulating evidence suggests that Recent studies have shown that authe timing of brief stationary sounds ditory time interval can alter apparaffects visual motion perception. ent motion perception not only through concurrent stimulation but also through brief adaptation.
The adaptation aftereffects for auditory time intervals were found to be similar to those for visual time intervals, suggesting the involvement of a central timing mechanism.
A fundamental question is whether they are mostly mediated by a central supramodal mechanism or by distributed (modality-specific and/or crossmodal) sensory processes.
In the current study, we aimed to address this question by looking for the cortical processes involved in time interval aftereffects on visual motion.
DESIGN & METHOD VISUAL
100
SHORTER LONGER
Adaptation Phase
Blank Interval (1-2 s.)
Observers were adapted to different time intervals by using either brief sounds or visual flashes
RESULTS
SHORTER - LONGER
Response
The evoked activity was examined to the subsequently presented visual apparent motion.
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Time
98
Shorter Longer 96
Baseline
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Visual
VISUAL
AUDITORY 400
500
600 ms
Fp
AF
AF
F
F
FC
FC
right
right
C
C
left
left
CP
CP
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600 ms
Both auditory and visual time interval adaptation led to significant changes in the ERPs elicited by the apparent motion. However, these changes were in the opposite direction. Also, for each modality, they mainly occurred in different time windows and clustered over distinct scalp sites.
Shorter < Longer
P
P
PO
PO
O
O III (190-220 ms)
IV (340-400 ms)
p
