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Evidence for perceptual learning with repeated stimulation after partial and total cortical blindness.

Trevethan CT, Urquhart J, Ward R, Gentleman D, Sahraie A - Adv Cogn Psychol (2012)

Bottom Line: Lesions of occipital cortex result in loss of sight in the corresponding regions of visual fields.The traditional view that, apart from some spontaneous recovery in the acute phase, field defects remain permanently and irreversibly blind, has been challenged.Positive auditory feedback was provided during the training task for correct detection of a spatial grating pattern presented at specific retinotopic locations using a temporal two alternative forced-choice paradigm (Neuro-Eye Therapy).

View Article: PubMed Central - PubMed

ABSTRACT
Lesions of occipital cortex result in loss of sight in the corresponding regions of visual fields. The traditional view that, apart from some spontaneous recovery in the acute phase, field defects remain permanently and irreversibly blind, has been challenged. In patients with partial field loss, a range of residual visual abilities in the absence of conscious perception (blindsight) has been demonstrated (Weiskrantz, 1986). Recent findings (Sahraie et al., 2006, 2010) have also demonstrated increased visual sensitivity in the field defect following repeated stimulation. We aimed to extend these findings by systematically exploring whether repeated stimulation can also lead to increased visual sensitivity in two cases with total (bilateral) cortical blindness. In addition, for a case of partial blindness, we examined the extent of the recovery as a function of stimulated region of the visual field, over extended periods of visual training. Positive auditory feedback was provided during the training task for correct detection of a spatial grating pattern presented at specific retinotopic locations using a temporal two alternative forced-choice paradigm (Neuro-Eye Therapy). All three cases showed improved visual sensitivity with repeated stimulation. The findings indicate that perceptual learning can occur through systematic visual field stimulation even in cases of bilateral cortical blindness.

No MeSH data available.


Related in: MedlinePlus

A, B, and C represent the target contrasts and detection scores for targetspresented at the centre, left, and right of the display for the bilateralcase B2. In all plots, target contrasts are shown in dark lines and the greylines plot the detection score.
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Figure 3: A, B, and C represent the target contrasts and detection scores for targetspresented at the centre, left, and right of the display for the bilateralcase B2. In all plots, target contrasts are shown in dark lines and the greylines plot the detection score.

Mentions: Schematic representation of targets shown on the display screen to thebilateral cases. Letters A-F on this figure refer to the correspondingletters on the data plots in Figures2 and 3.


Evidence for perceptual learning with repeated stimulation after partial and total cortical blindness.

Trevethan CT, Urquhart J, Ward R, Gentleman D, Sahraie A - Adv Cogn Psychol (2012)

A, B, and C represent the target contrasts and detection scores for targetspresented at the centre, left, and right of the display for the bilateralcase B2. In all plots, target contrasts are shown in dark lines and the greylines plot the detection score.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3303112&req=5

Figure 3: A, B, and C represent the target contrasts and detection scores for targetspresented at the centre, left, and right of the display for the bilateralcase B2. In all plots, target contrasts are shown in dark lines and the greylines plot the detection score.
Mentions: Schematic representation of targets shown on the display screen to thebilateral cases. Letters A-F on this figure refer to the correspondingletters on the data plots in Figures2 and 3.

Bottom Line: Lesions of occipital cortex result in loss of sight in the corresponding regions of visual fields.The traditional view that, apart from some spontaneous recovery in the acute phase, field defects remain permanently and irreversibly blind, has been challenged.Positive auditory feedback was provided during the training task for correct detection of a spatial grating pattern presented at specific retinotopic locations using a temporal two alternative forced-choice paradigm (Neuro-Eye Therapy).

View Article: PubMed Central - PubMed

ABSTRACT
Lesions of occipital cortex result in loss of sight in the corresponding regions of visual fields. The traditional view that, apart from some spontaneous recovery in the acute phase, field defects remain permanently and irreversibly blind, has been challenged. In patients with partial field loss, a range of residual visual abilities in the absence of conscious perception (blindsight) has been demonstrated (Weiskrantz, 1986). Recent findings (Sahraie et al., 2006, 2010) have also demonstrated increased visual sensitivity in the field defect following repeated stimulation. We aimed to extend these findings by systematically exploring whether repeated stimulation can also lead to increased visual sensitivity in two cases with total (bilateral) cortical blindness. In addition, for a case of partial blindness, we examined the extent of the recovery as a function of stimulated region of the visual field, over extended periods of visual training. Positive auditory feedback was provided during the training task for correct detection of a spatial grating pattern presented at specific retinotopic locations using a temporal two alternative forced-choice paradigm (Neuro-Eye Therapy). All three cases showed improved visual sensitivity with repeated stimulation. The findings indicate that perceptual learning can occur through systematic visual field stimulation even in cases of bilateral cortical blindness.

No MeSH data available.


Related in: MedlinePlus