Deep Brain Stimulation (DBS)Original ArticleCase Report: Stimulation of the Right Amygdala Induces Transient Changes in Affective Bias

BackgroundSensitive outcome measures are needed to quantify the effects of neuromodulation in mood disorders.ObjectiveThis study examined the utility of a novel affective bias (AB) task in identifying transient mood changes induced by amygdala stimulation in a single rare participant.MethodsLocalized, pulsed electrical stimulation was delivered for 8 min during measures of AB and self-reported mood. Responses were compared with those gathered without stimulation on the same day in the same setting, using paired t-tests.ResultsStimulation of the basolateral nucleus of the right amygdala at 50 Hz, 15 V, and 200 μs pulse-width produced a significant positive shift in AB (t = −2.864, df = 53, P = .006), despite equivocal findings on self-reported mood (t = −.184, df = 12, P = .857).ConclusionAffective bias may be more sensitive to stimulation-induced fluctuations in mood than subjective report, suggesting utility as an outcome measure in neuromodulation studies.