Blindsight, Essay Example

Blindsight is a condition where the individual is blind and cannot visually see anything; however, the individual can in fact report the location of objects or stimuli. Research for this condition is currently underway in order to explain the disorder from a physiological standpoint. In this paper, the visual outcome of blindsight is hypothesized to be a condition occurring from the disruption in the Ventral Visual Stream of the visual neurological pathway in the brain.

In the case of an individual with blindsight disorder, previous research has found that an individual can detect stimuli without visually seeing it. Therefore, the individual has registered the physical stimuli from the environment by use of the sensory organs, such as photoreceptors in the eyes. These receptors connect to the visual cortex in the brain through a sequence of neurons. It is along the neurological pathway in a blindspot patient that the perception of vision is altered and the individual cannot visually see the stimuli, but is aware of the stimuli. There are two different pathways that emerge from the striate cortex in the brain, one of which goes to the vision portions of the parietal lobe. The Blob (V1) region in the visual cortex is comprised of color-sensitive neurons and the Interblob (V1) separates the regions and is comprised of form and motion neurons. (Kolb and Whishaw, 2013)

The Blob (V1) and Interblob (V1) are separated into two different pathways leading to the cortex. It is therefore predicted that an individual with blindspot has a disruption in the color pathway, but not in the form and movement pathway at the Ventral stream portion of the pathway. The Dorsal Visual Stream originates in the occipital cortex and projects to the parietal cortex and consists of the form and motion visual perceptions; whereas, the Ventral Visual Stream originates in the occipital cortex and projects to the temporal lobe and consists of the dynamic form and color forms of perception. In order to test this hypothesis, neurons from the Ventral Visual Stream in the temporal lobe should be examined and compared to neurons from the Dorsal Visual Stream in the parietal lobe. (Kolb and Whishaw, 2013)

References

Kolb, B. and Whishaw, I.Q. (2013). An Introduction to Brain and Behavior Fourth Edition Chapter 9. How Do We Sense, Perceive, and See the World?