Emotional words: what's so different from just words?
Aphasic patients, in particular global aphasics, may still swear and produce emotional utterances with ease. Based on these clinical observations we investigated emotional word "reading" in a series of different experiments over 25 years, not only in aphasic patients, but also in the left (LVF) and right (RVF) visual fields of healthy subjects, and in a depth-recorded epileptic patient. Across these experiments we found: i) behaviorally a strong emotional word effect in the left visual field (right hemisphere - RH) of normals, correlating well with the emotional word performance of aphasic patients, pointing to a specific role of the right hemisphere; ii) electro-physiologically a specific early (100-140 msec) brain response to emotional words during scalp recordings in healthy subjects subsequent to right visual field (left hemisphere - LH) stimulation, that source localization procedures project to posterior areas of the right hemisphere; iii) preliminary data of a very early (60 msec) activation of the left amygdala in a depth-recorded epileptic patient when the same emotional words were presented to the right visual field (left hemisphere); and iv) a consistent gender difference showing that the above findings might be relevant for men only. Both hemispheres therefore appear to be implicated in emotional word "reading" but in different ways. We propose that the left amygdala via extrastriate connections acts as a detector of emotional word content at a very early stage of processing; that this amygdala response subsequently modulates the cortical response to emotional words asymmetrically, rendering the left visual cortex less sensitive to emotional words than that of the right hemisphere; and that this modulation is gender dependent.
Landis
Theodor
T
Department of Neurology, Medical School and University Hospital Geneva, Geneva, Switzerland. theodor.landis@hcuge.ch
D000339:Affect / Q000502:physiology*; D001037:Aphasia / Q000503:physiopathology; D001921:Brain / Q000502:physiology; D004292:Dominance, Cerebral / Q000502:physiology*; D004644:Emotions / Q000502:physiology*; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D012737:Sex Factors; D013060:Speech / Q000502:physiology*