motion-acuity-test-for-visual-field-acuity-measurement-with-motion

Motion-Acuity Test for Visual Field Acuity Measurement with Motion-Defined Shapes

The standard visual acuity measurements rely on stationary stimuli, either letters (Snellen charts), vertical lines (vernier acuity) or grating charts, ...

erratum-motion-acuity-test-for-visual-field-acuity-measurement-with

Erratum: Motion-Acuity Test for Visual Field Acuity Measurement with Motion-Defined Shapes

This corrects the article ...

Polish Academy of Sciences

Induction of a central retinal lesion in both eyes of adult mammals is a model for macular degeneration and leads to retinotopic map reorganization in the primary visual cortex (V1). Here we characterized the spatiotemporal dynamics of molecular activity levels in the central and peripheral representation of five higher-order visual areas, V2/18, V3/19, V4/21a,V5/PMLS, area 7, and V1/17, in adult cats with central 10° retinal lesions (both sexes), by means of real-time PCR for the neuronal activity reporter gene  The lesions elicited a similar, permanent reduction in activity in the center of the lesion projection zone of area V1/17, V2/18, V3/19, and V4/21a, but not in the motion-driven V5/PMLS, which instead displayed an increase in molecular activity at 3 months postlesion, independent of visual field coordinates. Also area 7 only displayed decreased activity in its LPZ in the first weeks postlesion and increased activities in its periphery from 1 month onward. Therefore we examined the impact of central vision loss on motion perception using random dot kinematograms to test the capacity for form from motion detection based on direction and velocity cues. We revealed that the central retinal lesions either do not impair motion detection or even result in better performance, specifically when motion discrimination was based on velocity discrimination. In conclusion, we propose that central retinal damage leads to enhanced peripheral vision by sensitizing the visual system for motion processing relying on feedback from V5/PMLS and area 7. Central retinal lesions, a model for macular degeneration, result in functional reorganization of the primary visual cortex. Examining the level of cortical reactivation with the molecular activity marker  revealed reorganization in visual areas outside V1. Retinotopic lesion projection zones typically display an initial depression in  expression, followed by partial recovery with postlesion time. Only the motion-sensitive area V5/PMLS shows no decrease, and even a significant activity increase at 3 months post-retinal lesion. Behavioral tests of motion perception found no impairment and even better sensitivity to higher random dot stimulus velocities. We demonstrate that the loss of central vision induces functional mobilization of motion-sensitive visual cortex, resulting in enhanced perception of moving stimuli.

Plasticity Beyond V1: Reinforcement of Motion Perception upon Binocular Central Retinal Lesions in Adulthood.

Deprivation of patterned visual information, as in early onset congenital cataract patients, results in a severe impairment in global motion perception. Previously we reported a delayed maturation of the peripheral visual field representation in primary visual area 17, based on a 2-D DIGE screen for protein expression changes and in situ hybridization for the activity reporter gene ZIF268. To corroborate these findings we here explore the binocular pattern deprivation (BD)-regulated expression of brain-derived neurotrophic factor (BDNF), a well-described neurotrophin precipitously regulated by early visual experience. To assess the timing of maturation-related BDNF expression we compared the central and the peripheral visual field representations of area 17 of 1, 2, 4 and 6-month-old and adult cats reared under normal visual conditions. To scrutinize the outcome of BD, four different deprivation strategies were compared, including early onset BD from birth and lasting for 2, 4 or 6 months (2BD, 4BD, 6BD), and late onset BD for 2 months upon 2 months of normal vision (2N2BD), as animal models of congenital and delayed onset cataract. During normal cortical development the BDNF transcript levels, measured by quantitative RT-PCR, remained stable. Higher BDNF mRNA levels were found in central area 17 of 2BD and 6BD animals compared to age-matched controls. In central area 17, the high BDNF mRNA levels at the end of the BD period may activate a mechanism by which plastic processes, halted by deprivation, may begin. We here confirm that the peripheral visual field representation of area 17 matures slower than its central counterpart. Only in central area 17 normal visual input upon BD could upregulate BDNF mRNA which may lead to a fast activation of local plastic adaptations.

Kalina Burnat

Nencki Institute of Experimental Biology

Polish Academy of Sciences

Motion-Acuity Test for Visual Field Acuity Measurement with Motion-Defined Shapes

Erratum: Motion-Acuity Test for Visual Field Acuity Measurement with Motion-Defined Shapes