The brain constitutes the most essential organ of the central nervous system (CNS). It is vital in processing the various functions of sense organs like touch, smell, taste, hearing, and sight. Among these, vision may be considered as the most important function which is controlled by the cerebral cortex of the brain that is divided into dorsal and ventral streams. There is a need to know about the comparative anatomy of these two streams.
The dorsal stream starts in the primary visual cortex, V1, and ends in Posterior Parietal Cortex (PPC). Ventral stream also starts in V1 but proceeds through extrastriate cortex regions V2, V3, V4 to the Inferior Temporal Lope (ITL) that consists of PIT (posterior inferotemporal), CIT (central inferotemporal), and AIT (anterior inferotemporal). The dorsal stream is mainly involved in spatial consciousness, the location of objects in space, and the regulation of actions. The ventral stream is involved in the identification of objects and the representation of the structure.
The dorsal stream without being influenced by any factors provides a thorough map of the visual field, precise body image, awareness and understanding of spatial relationships, noticing and examining the movements, gaining knowledge of tasks that involve coordination of the body in space. The ventral stream is influenced by factors known as extra-retinal such as attention, working memory, and stimulus salience. The dorsal stream receives a high amount of magnocellular input whereas the ventral stream receives an equal amount of both magnocellular and parvocellular input. Hence, the dorsal stream is known as the ‘where pathway’ and the ventral stream is known as the ‘what pathway’.
Behavior control enables a person to respond to a particular situation under awareness such as survival, love, power, freedom, or any other basic human need. Conscious perception enables a person to become aware of changes taking place such as fatigue. Previously, it was described that the sensation of fatigue is derived from the differences in subconscious homeostatic control systems which are perceived by consciousness-producing structures in the brain (Clair Gibson Alan et al., 2003).
It may indicate that an internal subconscious state of mind may not be regulating the behavior control in contrast to that observed in conscious perception. c)The implications of having two sets of neurological wiring are that, persons can better adapt to situations in all aspects of life by tightly regulating their willingness, in other words, a ‘yes’ or ‘no’ condition. This would strengthen their decision-making attitude and behavior stability would be achieved that might enable them to work hard on failures and conquer anything. Conscious perception enables a person to better focus on problem-solving skills and perform a given job through the aid of visual memory.
Earlier workers described that individuals were found to have better visual working memory when they remembered the objects grouped bottom-up compared to ungrouped objects, according to gestalt grouping principles (Woodman, Vecera, & Luck, 2003)
According to Gestalt theory, when a person especially looks at a tree he would notice branches, leaves, flowers, etc, but when he looks at the tree as a whole unit, he may not be conscious of individual units. Here, it is reasonable to hypothesize that if the same person is in need of flowers and fruits of the tree the next day, he would use the information stored in his memory like the structure and an approximate number of branches, location of flowers and fruits and finally devises a simple plan to climb the tree and get the job done easily.
It may indicate that he is able to remember well the objects (flowers and fruits) arranged or grouped in a single place. This has implications for the development of planning skills. Finally, an earlier theory has described that spatial discontinuity in projected edges of objects helps in perceiving them as occluded and non-occluded objects of a single unit. (Kellman & Shipley, 1991). It suggests a discriminating attitude of the brain and implications for quick identification of objects that appear with altered dimensions. This strategy has also implications for initiating a drive towards correcting structural deformities.
References:
- Control Theory. (n.d). Web.
- Clair Gibson Alan, Baden Denise, A., Lambert Mike, I., Lambert E. Vicki, Harley Yolande, X. R., Hampson Dave, Russell Vivienne, Noakes Tim D (2003). The conscious perception of the sensation of fatigue. Sports medicine, 33,167-176. Web.
- Woodman, G.F., Vecera, S.P., Luck, S.J. (2003). Perceptual organization influences visual working memory. Psychon Bull Rev, 10, 80-7. Web.
- Kellman PJ, Shipley TF.(1991). A theory of visual interpolation in object perception. Cognit Psychol. 23,141-221. Web.
- Gestalt Theory of Visual Perception. (n.d). Web.