Thursday, November 03, 2005

Visual system (Gv) information bottleneck research review

I just skimmed an interesting review article in Trends in Cognitive Sciences on the information processing bottleneck of the visual system (Gv?).

The abstract is posted below, plus some clarifying information from the introduction. The figure in this post represents the author neat attempt to summarize the research literature re: the areas of the brain associated with the three primary sources of the bottleneck (I like the way they graphically show the areas of the brain via the overlay of research study citations). If you double click on the image, your browser should present you with a larger more readable version.

Marois, R. & Ivanoff, J. (2005). Capacity limits of information processing in the brain Trends in Cognitive Sciences, 9(6), 296-305.

  • Despite the impressive complexity and processing power of the human brain, it is severely capacity limited. Behavioral research has highlighted three major bottlenecks of information processing that can cripple our ability to consciously perceive, hold in mind, and act upon the visual world, illustrated by the attentional blink (AB), visual short-term memory (VSTM), and psychological refractory period (PRP) phenomena, respectively. A review of the neurobiological literature suggests that the capacity limit of VSTM storage is primarily localized to the posterior parietal and occipital cortex, whereas the AB and PRP are associated with partly overlapping fronto-parietal networks. The convergence of these two networks in the lateral frontal cortex points to this brain region as a putative neural locus of a common processing bottleneck for perception and action.
Additional information from the introduction
  • A rich history of cognitive research has highlighted three major processing limitations during the flow of information from sensation to action, each exemplified by a specific experimental paradigm. The first limitation concerns the time it takes to consciously identify and consolidate a visual stimulus in visual short-term memory (VSTM), as revealed by the attentional blink paradigm.This process can take more than half a second before it is free to identify a second stimulus.
  • A second, severely limited capacity is the restricted number of stimuli that can be held in VSTM, as exemplified by the change detection paradigm.
  • A third bottleneck arises when one must choose an appropriate response to each stimulus. Selecting an appropriate response for one stimulus delays by several hundred milliseconds the ability to select a response for a second stimulus (the‘psychological refractory period’).

No comments: