Contribution of Callosal Connections to the Interhemispheric Integration of Visuomotor and Cognitive Processes

Abstract

In recent years, cognitive neuroscience has been concerned with the role of the corpus callosum and interhemispheric communication for lower-level processes and higher-order cognitive functions. There is empirical evidence that not only callosal disconnection but also subtle degradation of the corpus callosum can influence the transfer of information and integration between the hemispheres. The reviewed studies on patients with callosal degradation with and without disconnection indicate a dissociation of callosal functions: while anterior callosal regions were associated with interhemispheric inhibition in situations of semantic (Stroop) and visuospatial (hierarchical letters) competition, posterior callosal areas were associated with interhemispheric facilitation from redundant information at visuomotor and cognitive levels. Together, the reviewed research on selective cognitive functions provides evidence that the corpus callosum contributes to the integration of perception and action within a subcortico-cortical network promoting a unified experience of the way we perceive the visual world and prepare our actions.

Mirror illusion reduces motor cortical inhibition in the ipsilateral primary motor cortex during forceful unilateral muscle contractions

“…The fact that visual information is solely processed in the ipsilateral hemisphere corresponding to the mirror image implies that the mirror creates a visual illusion as if participants exercised the left hand. Although not measured in the present experiment, there is evidence that the anterior portion of the corpus callosum, involved in interhemispheric inhibition (IHI), contributes to the integration of perception and action within a subcortico-cortical network creating a unified experience of how we perceive the visual world and prepare our actions (Schulte and Muller-Oehring 2010). It is suggested that stimulus-driven activity in one hemisphere suppresses activity in the opposite hemisphere by increasing the amount of IHI (Avanzino et al 2014;Chiarello and Maxfield 1996).…”

Brain Commissural Anomalies

“…The causes of these differences may be; faster axonal conduction in the right hemisphere relative to the left (Barnett & Corballis, 2005) or the degree of hemispheric specialization (Nowicka et al, 1996;Rugg & Beaumont, 1978) more gray matter relative to white matter in the left hemisphere than in the right (Gur et al, 1980); other anatomical differences between both hemispheres. It appears that the ratio of gray and white matter may be underlying functional asymmetry (Schulte & Müller-Oehring, 2010). A correlation between callosal connectivity and prolonged interhemispheric transfer time have been reported in split-brain patients and in acallosal patients ( Iacoboni et al, 2000;Mooshagian et al, 2009;Paul et al, 2007;Reuter-Lorenz et al, 1995;Roser & Corballis, 2002).…”

“…In this issue the corpus callosum has an important role than other commissures. The corpus callosum involves in lower-level processes (Schulte & Müller-Oehring, 2010), transferring sensory information (Banich, 1998), interhemispheric visuomotor integration (Banich, 1998;Schulte & Müller-Oehring, 2010;Mordkoff & Yantis, 1993), hemispheric specialty (Doron & Gazzaniga, 2008) and contribution in development of higher-order cognitive functions (Gazzaniga, 2000;Doron & Gazzaniga, 2008). So, the corpus callosum is needed to maintain an integrated sense of self with regards to body awareness and planning of actions.…”

“…In split-brain patients, however, several investigators have noted that transfer of some types of visual information is usually spared (Eviatar & Zaidel, 1994;Uddin et al, 2008).The condition that cortical commissures are no longer available some information can be transferred between the hemispheres through subcortical pathways (Funnell et al, 2000) by the subcortical coordination of cortical networks (Uddin et al, 2008). In regard to involvement of the corpus callosum in lower-level visuomotor functions, split-brain research indicates that the corpus callosum acts in an inhibitory fashion within a subcortico-cortical network Roser & Corballis, 2003), while recent research on callosal degradation without disconnection have shown cooperative role for the corpus callosum (Schulte & Müller-Oehring, 2010) in conscious perception (Marzi et al, 1996;Müller-Oehring et al, 2009). In addition to mentioned functions, recently the enhanced redundancy gain (co-activation model) (Bucur et al, 2005;Schulte et al, 2006;Turatto et al, 2004) and mediate interhemispheric processing advantages Iacoboni et al, 2000;Roser & Corballis, 2003) a possible role for the corpus callosum are reported.…”

What can be learned from white matter alterations in antisocial girls.

“…The corpus callosum has abundant projections to and from the hemispherical cortices, and thus is crucial for interhemispheric communication. The genu and body are subsections of this white matter tract and interconnect parts of the frontal, temporal, and parietal lobes that play an important role in motoric processes, executive functioning, and emotion processing 39 . Alterations of the corpus callosum are also linked to several other neuropsychiatric disorders, such as attention deficit hyperactivity disorder 40,41 , autism 42,43 , Tourette syndrome 44 , or developmental dyslexia 45 .…”