Concentration effects of green odor on event-related potential (P300) and pleasantness

The effects of eight compounds, constituting the so-called "natural green odor", including leaf alcohol, on the event-related potential (P300) were investigated. In experiments with a series of single compounds, each of these eight compounds could be characterized by an overall change consisting predominantly of an increase, a decrease or no change in the amplitude of P300, whereas in experiments with a series of two-component mixtures, noticeable synergism could not be demonstrated, contrary to our expectation. Experiments with leaf alcohol (3Z-hexenol) performed at two concentrations showed a significantly different degree of pleasantness and an increase or decrease in the amplitude of P300 depending on their concentration, suggesting that concentration is important in odorant-presentation studies.