Correlation between platelet monoamine oxidase activity and the strength of a visual illusion

On the basis of recent neurophysiological results related to research in the noradrenergic system we predicted a correlation between platelet MAO activity, serum DBH and the strength of the contrast illusion (Uznadze effect) provoked in the visual field. The mechanism of this illusion is that the neuronal representation of a previously inspected figure distorts the correct perception of a subsequently displayed test figure. Those layers that play important role in these processes are under massive noradrenergic influence. This gives sufficient reason to test our hypothesis. Thirty healthy subjects were submitted to blood sampling and psychological experiment. A significant negative correlation was found between MAO activity and the strength of the contrast illusion (r:-0.3634; p < 0.05). This result is relevant to the hypothesis that platelet MAO activity could be a good marker of the activity of the monoaminergic systems in the brain. At the same tune the correlation that was found suggests that the fixed set method could be a useful noninvasive tool for biological personality research on this field. (C) 2002 Elsevier Science Ltd. All rights reserved.