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.

Metacontrast masking and attention do not interact

“…2 (the first column). In agreement with previous studies (Huyhn et al, 2015;Ogmen et al, 2013), we found a main effect of set size for six of seven observers. In fact, the observer for which set size was not present in the best model (SOA and set size interaction alone was sufficient to fit data), was SA who is one of the authors and extremely trained on orientation judgment tasks.…”

“…We obtained masking functions after transforming response errors to a probability-like measure such that performance values of 0.5 and 1 correspond to chance and perfect performance, respectively. We calculated transformed performance (Ogmen et al, 2013) as:…”

“…Another process known to control the transfer of information from sensory memory to VSTM is attention (e.g., Gegenfurtner & Sperling, 1993;Makovski & Jiang, 2007;Ogmen, Ekiz, Huynh, Bedell, & Tripathy, 2013;Palmer, 1990;Sreenivasan & Jha, 2007;Tombu et al, 2011). Since both attention and visual masking control (i.e., modulate) the transfer of information from sensory memory to VSTM, a natural question is whether these processes operate independently or they interact with each other.…”

The perceived present: What is it, and what is it there for?

“…Another possibility is transformation of information into other representational formats, such as linguistic format (e.g., for describing tastes, musical sounds, etc.). It is likely that much of the information in the perceived present is lost without entering further stores or processing, because of processing bottlenecks (Jacob et al, 2013;Öğmen, Ekiz, Huynh, Bedell, & Tripathy, 2013;Sperling, 1960) or interference from subsequent information input. Greene (2016) commented that the results of a study by Keysers, Xiao, Földiák, and Perrett (2001) suggested that "the information provided by a brief display can be compartmentalized and buffered against interference from information that follows as soon as 14 ms later" (p. 222).…”

Is conscious perception a series of discrete temporal frames?

“…That would certainly be an advantage. Information is likely to be lost before it exits from perceptual processing, partly because of the need for attentive Discrete temporal frames 74 maintenance (Rensink, 2000) and partly because of the increasingly limited capacity of postperceptual stores (Jacob et al, 2013;Öğmen et al, 2013;Sligte et al, 2010;Sperling, 1960).…”