Emotional memory and perception in temporal lobectomy patients with amygdala damage.
BACKGROUND
The human amygdala is implicated in the formation of emotional memories and the perception of emotional stimuli--particularly fear--across various modalities.


OBJECTIVE
To discern the extent to which these functions are related.


METHODS
28 patients who had anterior temporal lobectomy (13 left and 15 right) for intractable epilepsy were recruited. Structural magnetic resonance imaging showed that three of them had atrophy of their remaining amygdala. All participants were given tests of affect perception from facial and vocal expressions and of emotional memory, using a standard narrative test and a novel test of word recognition. The results were standardised against matched healthy controls.


RESULTS
Performance on all emotion tasks in patients with unilateral lobectomy ranged from unimpaired to moderately impaired. Perception of emotions in faces and voices was (with exceptions) significantly positively correlated, indicating multimodal emotional processing. However, there was no correlation between the subjects' performance on tests of emotional memory and perception. Several subjects showed strong emotional memory enhancement but poor fear perception. Patients with bilateral amygdala damage had greater impairment, particularly on the narrative test of emotional memory, one showing superior fear recognition but absent memory enhancement.


CONCLUSIONS
Bilateral amygdala damage is particularly disruptive of emotional memory processes in comparison with unilateral temporal lobectomy. On a cognitive level, the pattern of results implies that perception of emotional expressions and emotional memory are supported by separate processing systems or streams.
Brierley
B
B
Section of Cognitive Neuropsychiatry, Institute of Psychiatry and GKT School of Medicine, De Crespigny Park, London SE5 8AF, UK.
Medford
N
N
Shaw
P
P
David
A S
AS
D000328:Adult; D000679:Amygdala / Q000473:pathology / Q000503:physiopathology*; D038481:Anterior Temporal Lobectomy / Q000009:adverse effects*; D001284:Atrophy; D001925:Brain Damage, Chronic / Q000503:physiopathology* / Q000523:psychology; D004644:Emotions / Q000502:physiology*; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology / Q000601:surgery*; D005149:Facial Expression; D005239:Fear / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007360:Intelligence / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D010364:Pattern Recognition, Visual / Q000502:physiology; D011183:Postoperative Complications / Q000503:physiopathology / Q000523:psychology; D011594:Psychometrics; D011932:Reading; D012660:Semantics; D013067:Speech Perception / Q000502:physiology