Electroencephalogram alterations during perception of pleasant and unpleasant odors

The olfactory system enables humans and many animals recognize and categorize different odors and can determine many behavioral and social reactions. For human beings, odor stimuli are highly associated with many processes such as emotions, attraction, mood, etc. One approach to understanding the olfaction is to monitor and analyze human brain activity during perception of odors. In this paper, we analyze electroencephalogram (EEG) of five participants during perception of unpleasant and pleasant odor stimuli. We identify the regions of the brain cortex that are active during discrimination of unpleasant and pleasant odor stimuli. We also show that, classification of EEG signals during perception of odors can reveal the pleasantness of the odor with relatively high accuracy.