title: Flicker adaptation of low-level cortical visual neurons contributes to temporal dilation.
abstract: Several seconds of adaptation to a flickered stimulus causes a subsequent brief static stimulus to appear longer in duration. Nonsensory factors, such as increased arousal and attention, have been thought to mediate this flicker-based temporal-dilation aftereffect. In this study, we provide evidence that adaptation of low-level cortical visual neurons contributes to this aftereffect. The aftereffect was significantly reduced by a 45° change in Gabor orientation between adaptation and test. Because orientation-tuning bandwidths are smaller in lower-level cortical visual areas and are approximately 45° in human V1, the result suggests that flicker adaptation of orientation-tuned V1 neurons contributes to the temporal-dilation aftereffect. The aftereffect was abolished when the adaptor and test stimuli were presented to different eyes. Because eye preferences are strong in V1 but diminish in higher-level visual areas, the eye specificity of the aftereffect corroborates the involvement of low-level cortical visual neurons. Our results suggest that flicker adaptation of low-level cortical visual neurons contributes to expanding visual duration. Furthermore, this temporal-dilation aftereffect dissociates from the previously reported temporal-compression aftereffect on the basis of the differences in their orientation and flicker-frequency selectivity, suggesting that the visual system possesses at least two distinct and potentially complementary mechanisms for adaptively coding perceived duration.
authors.affiliation: Northwestern University, Department of Psychology, 2029 Sheridan Road, Evanston, IL 60208, USA. lauraortegat@gmail.com
authors.forename: Laura
authors.initials: L
authors.lastname: Ortega
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Guzman-Martinez
authors.forename: Marcia
authors.initials: M
authors.lastname: Grabowecky
authors.forename: Satoru
authors.initials: S
authors.lastname: Suzuki
mesh_terms: D000222:Adaptation, Physiological; D001288:Attention; D004056:Differential Threshold; D005260:Female; D005829:Geniculate Bodies / Q000502:physiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D010469:Perceptual Distortion / Q000502:physiology*; D013997:Time Factors; D013998:Time Perception / Q000502:physiology*; D014481:United States; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology