Regeneration of specific nerve cells in lesioned visual cortex of the human brain: An indirect evidence after constant stimulation with different spots of light

Rd, Potthoff

doi:10.1002/jnr.490400610

Cited by 13 publications

(3 citation statements)

References 15 publications

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“…Yet there was a small increase of 4.2% in stimulus detection when patients were later tested with high-resolution perimetry and a reduction of the blind field between 3.7% and 4.2% in conventional perimetry on a Tübinger Automatic Perimeter (TAP-2000). This finding is in agreement with earlier reports (e.g., Hyvärinen, Raninen & Näsänen, 2002;Julkunen et al, 2003;Julkunen et al, in press;Kasten et al, 1999;Kasten & Sabel, 1995;Kasten et al, 1998a;Mueller et al, 2003;Poggel, Kasten, Müller-Oehring, Sabel, & Brandt, 2001;Poggel et al, 2004;Potthoff, 1995;Schmielau, 1989;Schmielau, Wong, & Ling, 1998;Werth & Moehrenschlager, 1999;Werth & Seelos, 2005;Wuest, Kasten, & Sabel, 2004). Interestingly, very similar increases were observed in most of our other investigations, which varied between 2% and 8% (please note that the percentage relates to the size of the visual field, which was investigated with two independent perimetric methods including measurement of both intact and defective visual field areas).…”

Section: Discussionsupporting

confidence: 91%

Vision restoration therapy does not benefit from costimulation: A pilot study

Kasten

Bunzenthal

Müller‐Oehring

et al. 2007

Journal of Clinical and Experimental Neuropsychology

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Visual field deficits in patients have long been considered to be nontreatable, but in previous studies we have found an enlargement of the intact visual field following vision restoration therapy (VRT). In the present pilot study, we wished to determine whether a double-stimulation approach would facilitate visual field enlargements beyond those achieved by the single-stimulus paradigm used in standard VRT. This was motivated by the findings that following visual cortex injury in animals, the size of receptive fields could be enlarged by systematic costimulation, where two stimuli were used to excite visual cortex neurons (Eysel, Eyding, & Schweigart, 1998). Patients (n = 23) with stable homonymous field deficits after trauma, cerebral ischemia, or hemorrhage (lesion age > 6 months) carried out either (a) standard VRT with a single stimulation (n = 9), or vision therapy with (b) a parallel costimulation (n = 7) or (c) a moving costimulation paradigm (n = 7). Training was carried out twice daily for 30 min over a 3-month period. Before and after therapy, visual fields were tested with 30 degrees and 90 degrees Tübinger automatic perimetry (TAP) and with high-resolution perimetry (HRP). Eye movements were recorded with an eye tracking system. When data of all three types of visual field training were pooled, we found significant improvements of stimulus detection in HRP (4.2%) and fewer misses within the central 30 degrees perimetrically (-3.7% right eye, OD, or -4.4% left eye, OS). However, the type of training did not make any difference such that the three training groups profited equally. A more detailed analysis of trained versus untrained visual field areas in 16 patients revealed a superiority of the trained area of only 1.1% in HRP and between 3.5% (OS) and 4.4% (OD) in TAP. Spatial attention and alertness improved significantly in all three groups and correlated significantly with visual field enlargements. While vision training had no influence on the patient's testimonials concerning their visual abilities, the patients significantly improved in a practical paper-and-pencil number tracking task (Zahlen-Verbindungs Test; ZVT). Visual field enlargement does not benefit from a double-stimulation paradigm, but visual attention seems to play an important role in vision restoration. The improvements in trained as well as in untrained areas are explained by top-down attentional control mechanisms interacting with local visual cortex plasticity.

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Section: Discussionsupporting

confidence: 91%

Vision restoration therapy does not benefit from costimulation: A pilot study

Kasten

Bunzenthal

Müller‐Oehring

et al. 2007

Journal of Clinical and Experimental Neuropsychology

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“…Training of incremental thresholds (Zihl, 1980) does appear to produce improvements in other visual functions, e.g., the ability to discriminate colors, as well as visual acuity, while other researchers have reported that each visual function, such as light detection, recognition of shapes, and perception of colors, must be trained separately and that no transfer occurs (Potthoff, 1995;Schmielau, 1989).…”

Section: Discussionmentioning

confidence: 95%

Computer-Based Training of Stimulus Detection Improves Color and Simple Pattern Recognition in the Defective Field of Hemianopic Subjects

Kasten¹,

Poggel²,

Sabel

2000

Journal of Cognitive Neuroscience

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In a previously conducted randomized placebo-controlled trial, we were able to demonstrate significant visual field enlargement induced by restitution therapy in patients with cerebral lesions [Kasten, E., Wuest, S., Behrens-Bamann, W., & Sabel, B. A. (1998c). Computer-based training for the treatment of partial blindness. Nature Medicine, 4, 1083-1087.]. Visual field training was performed on a computer monitor for 1 hr per day over a period of 6 months. Since the procedure included only stimulation with white light, in the present study we investigated if this simple detection training had a transfer effect on color or form recognition in the trained area (i.e., in the absence of modality specific training). Answering this question would be crucial for planning optimal restitution therapy: In case there is no transfer of training effects to other visual modalities, a specific treatment of each visual function must be performed in order to achieve maximum benefit. Therefore, we analyzed the data from 32 patients with visual field defects who had participated in the original trial and whose form and color recognition had been investigated. The experimental group (n = 19, restitution training) experienced not only an increase of 12.8% correctly detected stimuli (PeriMa program, p <.05), but also an improvement of 5.6% in pattern recognition (PeriForm) and of 6.1% in color perception (PeriColor), respectively. In contrast, the placebo group (n = 13, fixation training) showed no significant changes from baseline to final outcome in any of the visual modalities (PeriMa: 0.3%; PeriForm: -0.3%; PeriColor: 0.4%). Conventional perimetry yielded an increase of 7.8% detected stimuli in the experimental group, but only of 1.2% in the placebo group (p <.05). For form recognition and color perception, the differences between the results of the experimental and the placebo groups narrowly missed significance. However, correlations of diagnostic results showed that mainly those patients who had achieved visual field enlargement also improved in color and form perception: r =.67 (p <.05) between PeriMa and PeriForm and r =.32 between PeriMa and PeriColor. We conclude that visual restitution training using a simple white light stimulus has at least some influence on improving other visual functions such as color and pattern recognition. This result supports the "bottleneck theory" of visual restitution, i.e., training effects can be explained as a process of perceptual learning and increased processing of information by residual structures surviving lesions of the primary visual pathways.

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“…Computer technology has increased the scope and duration of cognitive rehabilitation [83], and visual stimulation has been implicated in the restoration of function in brain injured patients. PotthoOE [84] demonstrated that regeneration of speci® c nerve cells in the visual cortex can be promoted with the aid of visual training. The use of VR would provide a means by which such regeneration could be promoted, although precise psychophysiological correlates have yet to be determined [85].…”

Section: Enriching the Therapeutic Environmentmentioning

confidence: 99%

The rehabilitation of brain injured children: the case for including physical exercise and virtual reality

Grealy

Heffernan²

2001

Pediatric Rehabilitation

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Whilst substantial advances in rehabilitation programmes for brain injured children have been made, there is still a fundamental need to improve understanding of the rehabilitation process and how this can be incorporated into practice. It is argued here that taking a neurological approach to improving cognition, mood and social functioning is likely to be of great bene® t to the patient. Theoretical reasons are outlined as to why activities such as interactive exercise can improve both the structure and function of the brain, and it is recommended that further research is carried out to establish the eOE ectiveness of these types of activities.

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Regeneration of specific nerve cells in lesioned visual cortex of the human brain: An indirect evidence after constant stimulation with different spots of light

Cited by 13 publications

References 15 publications

Vision restoration therapy does not benefit from costimulation: A pilot study

Vision restoration therapy does not benefit from costimulation: A pilot study

Computer-Based Training of Stimulus Detection Improves Color and Simple Pattern Recognition in the Defective Field of Hemianopic Subjects

The rehabilitation of brain injured children: the case for including physical exercise and virtual reality

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