Mood and spatial memory: emotion and right hemisphere contribution to spatial cognition

Depressed persons show an impairment of spatial cognition that may reflect the influence of affective arousal on right hemisphere cognition. We examin ed normal university students to determine whether individual differences i n mood and arousal levels would be related to performance on a spatial memo ry task. Right-hemisphere specialization for this spatial memory task was c onfirmed by a left field advantage for the targets and this field asymmetry was enhanced as task difficulty was increased. Event-related brain potenti als (ERPs), assessed with a 64-channel sensor array, showed a processing ne gativity contralateral to the target in the P300 interval (300-500 ms after the target appeared). This effect increased as task difficulty was increas ed. A stronger posterior negativity for good (rather than bad) targets may suggest that attention was allocated toward the good locations. A suggestio n of right hemisphere sensitivity to mood in this normal sample was a tende ncy for the subjects high in Negative Arousal not to show the normal right hemisphere (left field) superiority for the spatial memory task. Interestin gly, a medial frontal lobe negativity was elicited in the ERPs by the bad t argets, perhaps paralleling the error-related negativity observed in other paradigms. This medial frontal negativity was also seen in response to the feedback stimulus for the bad targets. Motivation may be important to this frontal effect: It was enhanced for subjects describing themselves as high in either positive or negative affective arousal during the task. (C) 1999 Elsevier Science B.V. All rights reserved.