Multimodal ‘association’ area

The posterior multimodal association area is located at the junction of the parietal, temporal, and occipital lobes. It pools and integrates somatic, auditory, and visual stimuli for complex perceptual processing. As such, this area is involved primarily with visuospatial localization, language, and attention. Lesions here interfere with awareness of one s body position and of the space in which it moves as well as the ability to integrate and make sense of elements of a visual scene. In other words, these patients have normal visual acuity but cannot focus on an object of interest. 

The limbic multimodal association area is partially located in each of the temporal, parietal and frontal lobes. It is concerned with emotional expression and memory storage. Although these functions appear to be unrelated, it is important to note that the emotional impact of an event is a major determinant of whether the event is remembered. Once again, it is important to remember that, although each of these multimodal association areas has its own characteristic function, all are highly interconnected and work together toward an end result. 

The following findings are of particular interest activation of the area of the human brain known to be an important source of the chemically distinct brain activation pattern in animal REM activation of a vast area of the limbic forebrain which is known to mediate emotion and to motivate behaviour in humans activation of the limbic areas controlling emotion, especially fear and activation of multimodal association areas of the brain. 

The unimodal association areas in turn project to multimodal sensory association areas that integrate information about more than one sensory modality. The highest level of cognitive brain function takes place in these areas. These areas process, integrate, and interpret sensory information and then link these data to the planning of movement and goal-directed action. 

Following the development of the motor program, neurons originating in the multimodal motor association areas transmit impulses by way of association tracts to neurons of the primary motor cortex. The primary motor cortex is located in the precentral gyrus, which is the most posterior region of the frontal lobe adjacent to the multimodal motor association areas (see Figure 6.3) this area initiates voluntary contractions of specific skeletal muscles. Neurons whose cell bodies reside here transmit impulses by way of descending projection tracts to the spinal cord, where they innervate the alpha motor neurons (which innervate skeletal muscles). 

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