A Neuropsychological Study of Interhemispheric Integration of Involuntary Memory Processes

Abstract

Split Brain Syndrome as it is described in neuropsychology includes impairments of perceptual and motor activity, more specifically the impairments in coordination of motor responses in bimanual tasks as well as in perception, speech and space impairments (Gazzaniga, 2004; Moskovichjute et al., 1982; Homskaja, 2007).There's little evidence about the specification of memory processes impairments in the corpus callosum (cc) pathology (Simernickaja, 1989; Guise et al., 1999; Mayers & Sperry, 1985; Zaidel & Sperry, 1974). On the one hand, it can be explained by the instability of the symptoms (Clark & Geffen, 1989; Gazzaniga, 2000). Since there are distinct lateral differences in memory impairments we can assume, that there are different aspects of memory activity that are laterilized. And that memory is a complex holistic integrative activities, means that we need a mechanism of interaction of left-and right-brain perspective. We can logically assume, that cc pays its' role in integration of memory processes and if it occurs pathology, the hole memory system suffers because of the fact, that cc connects all cortical sections of left and right hemisphere. On the other hand, studies of the cc pathology are traditionally focused on the measurement of the voluntary level of the mental activity. In this case, several authors noted the similarity of symptoms of cc and right hemisphere pathology (Buklina, 2004; Kovyazina & Balashova, 2009). So, we can assume that specifically involuntary processes (that laterilized in right hemisphere) are the first to suffer in the patients with the loss of interhemispheric connectivity based on cc abnormalities. Symptoms in this case are more stable because of the lack of compensation. Thus, specifically the involuntary memory system is to be more vulnerable due to cc impairment.The involuntary memory is an organism's ability to store, retain, and recall information and experiences without conscious effort (Falikman & Kojfman, 2005). Involuntary memory (compared with voluntary) is automatic process and is characterized by high rate, rigidity, unconsciousness (Gippenrejter & Romanov, 2000; Falikman & Kojfman, 2005). It's mostly perceptual and motor skills. Neuroimaging studies demonstrate the involvement in voluntary and involuntary memory fundamentally different structures, which function almost independently (Buckner et al., 1996).The involuntary level of memory activity includes skills which are the consequence of automatic, repeated, standard unconsciousness actions as well as priming effects.Learning in psychology is traditionally described as acquiring changes of individual cognitive and behavioral patterns in accordance with previous experience. The learning ability of brain (the ability to develop new skills) is connected with neuroplasticity (the ability of the human brain to change as a result of one's experience). The most studied is the phenomenon of plasticity of primary sensory and motor cortex (Grunwald, 2008). CC which is responsible for integrative activity of brain hemispheres and interhemispheric transfer of information supplies normal functioning of motor sphere and perception brain systems and hence influences sensorimotor learning. Therefore, symptoms of the cc pathology occur primarily in the sensorimotor area (Korsakova & Moskovichjute, 2007).Another subsystem of involuntary memory along with the sensorimotor learning is perceptual subsystem, which traditionally includes priming effects. Priming effect is a change of velocity and accuracy of the reaction after the presentation of information, which is connected with content or context of the task, but not directly correlated to its purpose and requirements. Also priming effects can be observed in the increased probability of spontaneous retrieving this information in suitable conditions (Falikman & Kojfman, 2005). There are different types of priming (on several grounds):* Emotional and cognitive. …