Perceptual Deficits and the Inability To Receive Sensory Information - Essay Example

Besides enabling inter-hemispheric interaction, the corpus callosum has also been demonstrated to be essential in the process of attention1. From the hemispheres, the lateral geniculate bodies relay sensory signals to the occipital lobes, which is the primary visual cortex. Here, an initial analysis of the image is done and the composed image of the retinal signal is sent to higher centers of processing for further interpretation (Glickstein p.118-127). Although, perception can also be achieved by olfaction, audition as well as visual, each of this sensory information follows different modalities.

Visual perception can be object of space, face (with the involvement of internal factors), or top-down perceptional operations in identifying objects in varying perspectives (Cabeza, 1997). Each of these tends to activate different sub sections of the brain functions. For instance, Cabeza (1997), explained that object occipito-parietal pathways, while top-down perceptual processing (i.e. when objects are in varying and unusual views) involves frontal, parietal and anterior cingulated regions.

Furthermore, object processing is said to be left lateralized, while face processing tend to be right lateralized or bilateral (Cabeza, 1997a).Cabeza (1997b), argue that perception and at times, identification also depend, to a large extent, on the retrieval of information relevant in the particular perception. Bruner (1970), believes that memory and perception cannot be separated. Along this line, Begley et al (1986) explained that the brain could store huge amount of information with different areas storing facts, such as names, images and events, necessary for perception and identification (p.48-54). In this regard, Cabeza (1997b) said the prefrontal lobe play a crucial role in retrieving stored information, while the right inferior parietal cortex is involved in recognition and recall.

The cerebellum, traditionally believed to play just motor cortex functions has been demonstrated to be involved in cognition (intelligence, processing speed, cognitive learning skills, visual spatial processing, recall etc) and perceptual functions (1997b).Such is the complexity of the human brain functioning involved with processing sensory information, perception and identification. Some of the most compelling evidences for the functional neuroanatomical divisions of the brain functions involved with perception and processing sensory signals have been provided by patients with specific cognitive impairments following localized brain injury (Aguirre and Mark, 1999).

Over the last century several dozens of patients have been reported to exhibit inability to carry out one cognitive function or the other. Such impairments have varied widely depending enormously on the part of the brain concerned and the function carried out by that part of the brain. This has engaged the minds of several researchers,