Dissociations in Coherence Sensitivity Reveal Atypical Development of Cortical Visual Processing in Congenital Achromatopsia.
Invest Ophthalmol Vis Sci
; 57(4): 2251-9, 2016 Apr 01.
Article
in En
| MEDLINE
| ID: mdl-27124317
ABSTRACT
PURPOSE:
While basic visual functions have been described in subjects with congenital achromatopsia (ACHM), little is known about their mid- or high-level cortical visual processing. We compared midlevel cortical visual processing in ACHM subjects (n = 11) and controls (n = 20).METHODS:
Abilities to detect global form, global motion, and biological motion embedded in noise were tested across a range of light levels, including scotopic, in which both ACHM subjects and controls must rely on rods. Contrast sensitivity functions (CSFs) were also measured.RESULTS:
Achromatopsia subjects showed differential impairments across tests. In scotopic conditions, global form was most impaired, while biological motion was normal. In a subset of three ACHM subjects with normal scotopic CSFs, two of the three showed global form perception worse than controls; all showed global motion comparable to controls; and strikingly, two of the three showed biological motion perception superior to controls.CONCLUSIONS:
The cone signal appears to play a crucial role in the development of perception of global form, as in ACHM this is impaired even in scotopic conditions, in which controls also have to rely on rods, and even in ACHM subjects with no scotopic spatial vision loss. In contrast, the rod signal appears sufficient for the development of normal (or even superior) extrastriate biological motion perception. These results suggest that ACHM leads to atypical development of cortical vision, highlighting the need to better understand the potential for further reorganization of cortical visual processing following new therapies aimed at restoring cone function.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Visual Perception
/
Color Vision Defects
Type of study:
Diagnostic_studies
/
Observational_studies
Limits:
Adult
/
Female
/
Humans
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Male
/
Middle aged
Language:
En
Journal:
Invest Ophthalmol Vis Sci
Year:
2016
Document type:
Article
Affiliation country: