Functional specialization (brain)
[1][2] Gall and Spurzheim were the first to observe the crossing of pyramidal tracts, thus explaining why lesions in one hemisphere are manifested in the opposite side of the body.
Gall considered the most compelling argument in favor of phrenology the differences in skull shape found in sub-Saharan Africans and the anecdotal evidence (due to scientific travelers and colonists) of their intellectual inferiority and emotional volatility.
In Italy, Luigi Rolando carried out lesion experiments and performed electrical stimulation of the brain, including the Rolandic area.
Phineas Gage became one of the first lesion case studies in 1848 when an explosion drove a large iron rod completely through his head, destroying his left frontal lobe.
He recovered with no apparent sensory, motor, or gross cognitive deficits, but with behaviour so altered that friends described him as "no longer being Gage," suggesting that the damaged areas are involved in "higher functions" such as personality.
In the XX century, in the process of treating epilepsy, Wilder Penfield produced maps of the location of various functions (motor, sensory, memory, vision) in the brain.
An example of Fodor's concept of modules is seen in cognitive processes such as vision, which have many separate mechanisms for colour, shape and spatial perception.
[10] One of the fundamental beliefs of domain specificity and the theory of modularity suggests that it is a consequence of natural selection and is a feature of our cognitive architecture.
Researchers Hirschfeld and Gelman propose that because the human mind has evolved by natural selection, it implies that enhanced functionality would develop if it produced an increase in "fit" behaviour.
To account for this problem, the coordinate-based Talairach and Tournoux stereotaxic system is widely used to compare subjects' results to a standard brain using an algorithm.
Zielasek and Gaeble have set out a list of requirements in the field of neuropsychology in order to move towards neuropsychiatry: Research in the study of brain function can also be applied to cognitive behaviour therapy.
As therapy becomes increasingly refined, it is important to differentiate cognitive processes in order to discover their relevance towards different patient treatments.
[14] Examples of therapies that involve imagery, requiring right hemisphere activity in the brain, include systematic desensitization[15] and anxiety management training.
(Watson et al., 1993) This area of functional specialization was also supported by lesion study patients whose damage caused cerebral motion blindness,[26] a condition now referred to as cerebral akinetopsia[27] Studies have found the frontal lobes to be involved in the executive functions of the brain, which are higher level cognitive processes.
Lesion studies support these findings where left frontal lobe patients exhibited problems in controlling executive functions such as creating strategies.
[30] The dorsolateral, ventrolateral and anterior cingulate regions within the prefrontal cortex are proposed to work together in different cognitive tasks, which is related to interaction theories.
[28] For instance, Miller and Cummings found that the dorsolateral prefrontal cortex is specifically involved in the manipulation and monitoring of sensorimotor information within working memory.
In one experiment, Sperry flashed images in the right visual field (RVF), which would subsequently be transmitted to the left hemisphere (LH) of the brain.
When Sperry et al. flashed images in the left visual field (LVF), the information processed would be sent to the right hemisphere (RH) of the brain.
[32] In addition, Soojin Park and Marvin Chun posited that activation in the PPA is viewpoint specific, and so responds to changes in the angle of the scene.
A remarkable precedent of this orientation is the research of Justo Gonzalo on brain dynamics [35] where several phenomena that he observed could not be explained by the traditional theory of localizations.
A very similar gradients scheme was proposed by Elkhonon Goldberg in 1989 [37] Other researchers who provide evidence to support the theory of distributive processing include Anthony McIntosh and William Uttal, who question and debate localization and modality specialization within the brain.
McIntosh's research suggests that human cognition involves interactions between the brain regions responsible for processes sensory information, such as vision, audition, and other mediating areas like the prefrontal cortex.
McIntosh found activation (an increase blood flow), in an area of the occipital cortex, a region of the brain involved in visual processing,[39] when the auditory stimulus was presented alone.
One of his main arguments is that since the late 1990s, research in cognitive neuroscience has forgotten about conventional psychophysical studies based on behavioural observation.
In general, this may produce false or exaggerated findings and may increase potential tendency to ignore regions of diminished activity which may be crucial to the particular cognitive process being studied.
In fact, the proposed distributive scheme of the functional cortical gradientes by J. Gonzalo[36] already tries to join both concepts modular and distributive: regional heterogeneity should be a definitive acquisition (maximum specificity in the projection paths and primary areas), but the rigid separation between projection and association areas would be erased through the continuous functions of gradient.
