title: Bottlenecks of motion processing during a visual glance: the leaky flask model.
abstract: Where do the bottlenecks for information and attention lie when our visual system processes incoming stimuli? The human visual system encodes the incoming stimulus and transfers its contents into three major memory systems with increasing time scales, viz., sensory (or iconic) memory, visual short-term memory (VSTM), and long-term memory (LTM). It is commonly believed that the major bottleneck of information processing resides in VSTM. In contrast to this view, we show major bottlenecks for motion processing prior to VSTM. In the first experiment, we examined bottlenecks at the stimulus encoding stage through a partial-report technique by delivering the cue immediately at the end of the stimulus presentation. In the second experiment, we varied the cue delay to investigate sensory memory and VSTM. Performance decayed exponentially as a function of cue delay and we used the time-constant of the exponential-decay to demarcate sensory memory from VSTM. We then decomposed performance in terms of quality and quantity measures to analyze bottlenecks along these dimensions. In terms of the quality of information, two thirds to three quarters of the motion-processing bottleneck occurs in stimulus encoding rather than memory stages. In terms of the quantity of information, the motion-processing bottleneck is distributed, with the stimulus-encoding stage accounting for one third of the bottleneck. The bottleneck for the stimulus-encoding stage is dominated by the selection compared to the filtering function of attention. We also found that the filtering function of attention is operating mainly at the sensory memory stage in a specific manner, i.e., influencing only quantity and sparing quality. These results provide a novel and more complete understanding of information processing and storage bottlenecks for motion processing.
authors.affiliation: Department of Electrical and Computer Engineering, University of Houston, Houston, Texas, United States of America ; Center for Neuro-Engineering and Cognitive Science, University of Houston, Houston, Texas, United States of America.
authors.forename: Haluk
authors.initials: H
authors.lastname: Öğmen
authors.affiliation: Department of Electrical and Computer Engineering, University of Houston, Houston, Texas, United States of America.
authors.forename: Onur
authors.initials: O
authors.lastname: Ekiz
authors.affiliation: Department of Electrical and Computer Engineering, University of Houston, Houston, Texas, United States of America.
authors.forename: Duong
authors.initials: D
authors.lastname: Huynh
authors.affiliation: Center for Neuro-Engineering and Cognitive Science, University of Houston, Houston, Texas, United States of America ; College of Optometry, University of Houston, Houston, Texas, United States of America.
authors.forename: Harold E
authors.initials: HE
authors.lastname: Bedell
authors.affiliation: School of Optometry and Vision Science, University of Bradford, Bradford, United Kingdom.
authors.forename: Srimant P
authors.initials: SP
authors.lastname: Tripathy
mesh_terms: D000328:Adult; D003198:Computer Simulation; D006801:Humans; D057567:Memory, Long-Term / Q000502:physiology*; D008570:Memory, Short-Term / Q000502:physiology*; D008954:Models, Biological; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult