Plasticity in human blindsight

Reconciling current approaches to blindsight

“…Training and learning processes are other factors to be taken into consideration. Both in animal models (Dineen & Keating, 1981;Humphrey, 1974) and in blindsight patients (Bridgeman & Staggs, 1982;Chokron et al, 2008;Henriksson, Raninen, Näsänen, Hyvärinen, & Vanni, 2007;Stoerig, 2006;Zihl, 1980;Zihl & Werth, 1984) training can increase the degree to which stimuli are available to behavioral control and potentially even to subjective awareness (Sahraie et al, 2006). Viewed from this perspective, a differentiation between blindsight of type 1 and type 2 can be viewed as a differentiation between dynamically changing and both situationally and experience-dependent differences in the network integration of Perceptual Algorithmic Modules within SAS.…”

“…In a forced choice procedure, performance can be improved by training in both monkeys subjected to bilateral ablation of the primary visual cortex (V1) (Dineen & Keating, 1981;Humphrey, 1974) and patients demonstrating blindsight (e.g. Bridgeman & Staggs, 1982;Chokron et al, 2008;Henriksson et al, 2007;Raninen et al, 2007;Stoerig, 2006;Zihl, 1980;Zihl & Werth, 1984). In blindsight patients, training may not only improve the behavioral performance but also the subjective awareness (e.g.…”

A Spatially Oriented Decision Does Not Induce Consciousness in a Motor Task

“…Experiments using stimuli with a potential confound between motion and position do not form the only basis for the two visual systems distinction; others use clinical data from blindsight, where some visually guided motor capability remains despite lack of perception (Bridgeman & Staggs, 1982;Weiskrantz, 1996), or from dissociations due to other lesions (Goodale, Pelisson, & Prablanc, 1986;Goodale et al, 1994). But inherent in the clinical studies is the danger that a system that is unified and coordinated in normal subjects becomes fragmented in the patients, giving the false impression of separation of function.…”

Interaction of cognitive and sensorimotor maps of visual space

“…Another way to interpret the relationship between cognitive and motor representations of visual space is to do Experiments done with stimuli with a potential confound between motion and position do not form the only basis for the two-visual-systems distinction; in others, clinical data have been used, as from blindsight, in which some visuaIIy guided motor capability remains despite lack of perception (Bridgeman & Staggs, 1982;Weiskrantz, Warrington, Sanders, & MarshaII, 1974), or from other lesions (Goodale et aI., 1994;Goodale, Pelisson, & Prablanc, 1986). We can conclude that the evidence for two distinct functional representations of visual space in humans is strong, but that the interaction between the systems is not as simple as it once seemed.…”