Alexithymia, Interhemispheric Transfer, and Right Hemispheric Specialization: A Critical Review

Abstract

Background: One neural model of alexithymia relates the condition to poor interhemispheric transfer, while another model associates it with a disturbance in right hemisphere activity. Methods: The available empirical evidence directly relating alexithymia to a deficit in interhemispheric transfer and/or in right hemisphere activity is critically reviewed. Results: The interhemispheric transfer studies have related alexithymia to a deficit in transfer, but the nature and directionality of the transfer deficit have yet to be determined. Many of the hemispheric specialization studies do not relate alexithymia to a right hemisphere dysfunction. Shortcomings of these studies are reviewed. Conclusions: The hypothesis that alexithymia is related to a deficit in the right-to-left transfer of emotional information and to a right hemisphere impairment in emotion processing remains to be tested directly and definitively. Suggestions for future research are made.

Temporal Stability of Alexithymia Over a Five-Year Period in Outpatients with Major Depression

“…One potential explanation is that the three factors of alexithymia have different origins in depressed patients, as presented recently [23]. Also other biological explanations, like interhemispheric transfer or right hemispheric specialisation, for personality construct of alexithymia, have to be empirically studied [24]. …”

Emotional categorization: Individual emotional differences and laterality effects in healthy and persons with multiple sclerosis

“…Considerable evidence demonstrated that individual differences, for example, in temperament are associated with differences in brain and peripheral physiological functioning (see [13,7]). Findings from some studies suggest that alexithymia (less ability to identify and communicate feelings) could be investigated as a continuous personality trait associated with either the interhemispheric transfer of information [21] or the relative development and activation of the two hemispheres in non-clinical and clinical populations ( [22]; but see [23]) or as a syndrome related to some psychiatric disturbance such as Multiple Sclerosis. Therefore, individual differences in processing emotional stimuli provide a potentially rich source of information about the relationship between emotion and cognition, in normal people but also in individuals suffering from neurobiological impairment.…”

“…Recent works focused on alexithymia have proposed different hypotheses to explain it in structural and functional terms (see [23]). In structural terms, one neural hypothesis suggests that alexithymia is related to poor interhemispheric transfer, in normal as well as clinical populations [21,23,62].…”

“…In structural terms, one neural hypothesis suggests that alexithymia is related to poor interhemispheric transfer, in normal as well as clinical populations [21,23,62]. Another hypothesis associates it with a poor right hemisphere activity [22].…”

“…Few studies suggest the potential clinical value of callosal involvement and alexithymia and its interest as a model to study interhemispheric disconnection (e.g. [23,70]), specifically in MS patients.…”