Hemispheric dissociation of anxiety and autonomic arousal during lateral visual field viewing: a case report

We report a clinical case illustrating rapid, reversible, and reproducible hemispheric differences in subjective experience and autonomic arousal during lateral visual field viewing. A man in his 40s with longstanding anxiety and depression showed repeatable shifts in affective state, self-appraisal, and appraisal of the clinician when alternately viewing through the right versus left lateral visual field while holding the same shame-evoking interpersonal scenario in mind. Pulse rate measured with a fingertip pulse oximeter was observed to co-occur with these shifts (anxious/shame state ≈105 bpm; calm/secure state ≈85-90 bpm; baseline ≈95 bpm). Across 72 consecutive patients entered into the author's practice, 89% showed a clinically useful between-field difference in momentary anxiety and 49% showed a marked difference of the type described in this case report. Together with prior findings from split-brain research, Wada studies, fMRI, repetitive transcranial magnetic stimulation (rTMS), and lateral visual field stimulation (LVFS) paradigms, this observation is consistent with the partial functional independence of two hemispheric experiential systems-one of which is more childlike and more affected by past trauma-and with history-dependent meaning as a driver of physiological response. We interpret the case within Dual-Brain Psychology (DBP) and relate the findings to the Emotion-Type Hypothesis (ETH), proposing a distinction between lateralized emotional functions (as characterized by ETH) and hemispheric experiential dominance (as characterized by DBP). On this account, a hemispheric experiential system may function as the dominant organizing self while recruiting emotional and cognitive capacities distributed across both hemispheres. This synthesis may help reconcile population-level associations between emotion type and hemispheric specialization with the within-individual variability in hemispheric emotional valence observed under lateral visual field viewing.