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Updated: May 16, 2026
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A Large Lateral Craniotomy Procedure for Mesoscale Wide-field Optical Imaging of Brain Activity
Published on: May 7, 2017
Visual cortical activity reflects faster accumulation of information from cortically blind fields
Tim Martin1, Anasuya Das, Krystel R Huxlin
1Department of Psychology, Kennesaw State University, Kennesaw, GA 30144, USA. tma2010@yahoo.com
Brain : a Journal of Neurology
|November 22, 2012
Summary
Cortically blind individuals show slower information processing in their blind visual fields. Enhancing information accumulation rate in specific brain areas may improve visual function recovery.
Area of Science:
- Neuroscience
- Cognitive Science
- Ophthalmology
Background:
- Cortical blindness results from damage to the visual cortex, leading to significant visual field loss.
- Understanding information processing in the blind visual field is crucial for developing effective rehabilitation strategies.
Purpose of the Study:
- To investigate brain responses and information processing components in individuals with cortical blindness during a visual task.
- To explore the relationship between brain activity in specific regions and the efficiency of perceptual decision-making in the blind visual field.
Main Methods:
- Functional magnetic resonance imaging (fMRI) was used to measure brain activity.
- The EZ-diffusion model of decision-making was applied to analyze information accumulation.
- Nine cortically blind observers performed a global direction discrimination task.
Main Results:
- Cortically blind subjects exhibited slower information accumulation in their blind fields compared to their good fields and controls.
- Activity in perilesional cortex, V3A, and hMT+ correlated with faster information accumulation in the blind field.
- Individual differences in perilesional cortex response were observed.
Conclusions:
- The rate of information accumulation is a key factor determining the severity of visual impairment in cortical blindness.
- Targeting perilesional cortex, V3A, and hMT+ may enhance visual function recovery.
- Rehabilitation strategies should focus on improving the speed of information accumulation.
Related Concept Videos
01:24Vision
Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed.
01:14Motor and Sensory Areas of the Cortex
The cerebral cortex, the brain's outermost layer, is pivotal in processing complex cognitive tasks, emotions, and various sensory inputs and executing voluntary motor activities. This intricate structure is divided into three primary functional areas: the motor areas, sensory areas, and association areas.
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex.
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex.
01:20Parallel Processing
The brain processes sensory information rapidly due to parallel processing, which involves sending data across multiple neural pathways at the same time. This method allows the brain to manage various sensory qualities, such as shapes, colors, movements, and locations, all concurrently. For instance, when observing a forest landscape, the brain simultaneously processes the movement of leaves, the shapes of trees, the depth between them, and the various shades of green. This enables a quick and...
01:12Visual Agnosia
Visual agnosia is a condition characterized by the inability to recognize visually presented objects despite having normal vision. For instance, a person with visual agnosia can describe the shape and color of an object but cannot identify or name it. This impairment does not affect their visual field, acuity, color vision, brightness discrimination, language, or memory. An example of this condition in a social setting is someone at a dinner party asking for "that silver thing with a round end"...
01:26Visual System
Light enters the eye through the cornea, a transparent, dome-shaped surface covering the surface of the eyeball that helps to direct and focus incoming light. This light is then channeled toward the pupil, an adjustable opening whose size is controlled by the iris. The iris, a pigmented muscle, regulates the amount of light entering the eye by contracting or dilating the pupil, thereby ensuring optimal light levels for clear vision.
Once through the pupil, the light passes through the lens, a...
Once through the pupil, the light passes through the lens, a...
01:21Association Areas of the Cortex
Association areas are regions of the cerebral cortex that do not have a specific sensory or motor function. Instead, they integrate and interpret information from various sources to enable higher cognitive processes such as memory, learning, and decision-making. Some key association areas include the following:
Prefrontal Association Area: This area is located in the frontal lobe and is involved in planning, decision-making, and moderating social behavior. It connects with primary motor areas,...
Prefrontal Association Area: This area is located in the frontal lobe and is involved in planning, decision-making, and moderating social behavior. It connects with primary motor areas,...