Anterior asymetrical alpha activity predicts Iowa gambling performance: distinctly but reversed.

Animal research indicates that the prefrontal cortex (PFC) plays a crucial role in decision making. In concordance, deficits in decision making have been observed in human patients with damage to the PFC. Contemporary accounts of decision making suggest that emotion guides the process of decision making by ways of providing for reward-punishment contingencies. A task capable of assessing the influence of reward and punishment on decision making is the Iowa gambling task. In this task decisions become motivated by inherent punishment and reward schedules. Insensitivity for punishment together with a strong reward dependency results in risk taking, which is in the gambling task the disadvantageous strategy. Interestingly, the processing of punishment and reward is argued to be lateralized over the right and left PFC, respectively. Here we investigated whether more relative left compared to right-sided frontal brain activity (left-sided dominance) quantified as reduced alpha (8-12 Hz) activity in the electroencephalogram (EEG) would lead to a more risky, disadvantageous pattern of decision making. Contrary to what was expected, relatively more right compared to left frontal brain activity was strongly associated with the disadvantageous strategy. The results are discussed in terms of recent theoretical accounts which argue that the functional interpretation of baseline frontal alpha activity depends on the mental operation involved and does not necessarily imply inactivity.