Anterior electroencephalographic asymmetry changes in elderly women in response to a pleasant and an unpleasant odor

Greater left than right frontal EEG activation has been associated with inc reased positive and/or decreased negative affect, whereas greater right tha n left frontal activation has been associated with the opposite pattern. Su bstantial research has documented the trait properties of asymmetry, as wel l as responses to pleasant and unpleasant stimuli. The present study examin ed changes in anterior alpha asymmetries in response to pleasant (vanilla), unpleasant (valerian), and neutral (water) odors. As predicted, Vanilla pr oduced relative left frontal activation compared to valerian and water. Fro ntal asymmetry did not differ in response to valerian compared to water. Th e results are consistent with the hypothesis that the left frontal region o f the brain is involved in positive/approach-related emotion, and extend pr evious results into the olfactory realm. (C) 2000 Elsevier Science B.V. All rights reserved.