title: Neurons in the human amygdala selective for perceived emotion.
abstract: The human amygdala plays a key role in recognizing facial emotions and neurons in the monkey and human amygdala respond to the emotional expression of faces. However, it remains unknown whether these responses are driven primarily by properties of the stimulus or by the perceptual judgments of the perceiver. We investigated these questions by recording from over 200 single neurons in the amygdalae of 7 neurosurgical patients with implanted depth electrodes. We presented degraded fear and happy faces and asked subjects to discriminate their emotion by button press. During trials where subjects responded correctly, we found neurons that distinguished fear vs. happy emotions as expressed by the displayed faces. During incorrect trials, these neurons indicated the patients' subjective judgment. Additional analysis revealed that, on average, all neuronal responses were modulated most by increases or decreases in response to happy faces, and driven predominantly by judgments about the eye region of the face stimuli. Following the same analyses, we showed that hippocampal neurons, unlike amygdala neurons, only encoded emotions but not subjective judgment. Our results suggest that the amygdala specifically encodes the subjective judgment of emotional faces, but that it plays less of a role in simply encoding aspects of the image array. The conscious percept of the emotion shown in a face may thus arise from interactions between the amygdala and its connections within a distributed cortical network, a scheme also consistent with the long response latencies observed in human amygdala recordings.
authors: Computation and Neural Systems, California Institute of Technology, Pasadena, CA 91125;
authors: Shuo
authors: S
authors: Wang
authors: Division of Humanities and Social Sciences, California Institute of Technology, Pasadena, CA 91125;
authors: Oana
authors: O
authors: Tudusciuc
authors: Departments of Neurosurgery and.
authors: Adam N
authors: AN
authors: Mamelak
authors: Epilepsy and Brain Mapping Program, Huntington Memorial Hospital, Pasadena, CA 91105; and.
authors: Ian B
authors: IB
authors: Ross
authors: Computation and Neural Systems, California Institute of Technology, Pasadena, CA 91125;Division of Humanities and Social Sciences, California Institute of Technology, Pasadena, CA 91125;Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125.
authors: Ralph
authors: R
authors: Adolphs
authors: Computation and Neural Systems, California Institute of Technology, Pasadena, CA 91125;Departments of Neurosurgery andDivision of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125Neurology, Cedars-Sinai Medical Center, Los Angeles, CA 90048; Ueli.Rutishauser@cshs.org.
authors: Ueli
authors: U
authors: Rutishauser
mesh_terms: D000679:Amygdala / Q000166:cytology / Q000502:physiology*; D000818:Animals; D004567:Electrodes, Implanted; D004644:Emotions / Q000502:physiology*; D005145:Face / Q000502:physiology; D000882:Haplorhini; D006801:Humans; D008297:Male; D009474:Neurons / Q000166:cytology / Q000502:physiology*
keywords: hippocampus; human single unit; intracranial; limbic system; medial temporal lobe