Abstract: The relationship between emotion and decision-making is of significant interest in the field of scientific psychology as well as in economics research. The emotions that individuals experience for post-decisional outcomes are not only influenced by properties of the outcomes (e.g. magnitude, valence), but also by the paths of individuals’ action (e.g., action vs. inaction) to reach it. Considerable behavioral researches have claimed that emotional reactions to outcomes following decisions to act are typically more intense than are those following decisions not to act. This well-known phenomenon has been labeled ‘action effect’ (Landman, 1987, Kahneman and Tversky, 1982). Though numerous convergent studies on decision-making have reported this phenomenon, few have reached agreement on its cognitive mechanism. By simultaneously recording event-related potentials (ERPs) data from participants with different locus of control (internal versus external locus of control, ILC vs ELC ) engaged in a simple gambling task, the present study aimed to further investigate the role of attribution of responsibility in inducing the “action effect”.
Fifteen ILC participants (7 males and 8 females, age18-25, M=20.69±2.28 years) and fourteen ELC participants (5 males and 9 females, age17-25, M=20.42±2.19years) took part in the experiment. The two groups were selected from 256 volunteers recruited from Southwest University in China with the Adult Nowicki-Strickland Internal-External Control Scale (ANSIECS). The participants in the experiment were all right-hand, had normal or corrected-to-normal vision and had no neurological or psychological disorders. Each participant signed a consent form prior to the experiments and was paid after the experiment, according their performance. The study was approved by the local academic committee.
In this experimental task, participants were first presented with two choice options and were told that the computer would choose one of two options for them. Both choices were randomly associated with identical monetary gains and losses in each trial. Participants were asked to decide whether to keep the computer choice (inaction condition) or to choose the other one (action condition). Subsequently, a feedback conveying the outcomes of the two options (either gaining or losing money) was provided. By manipulating the action types that depended on whether the participants followed the chosen options by the computer and the valence of the feedback in the gambling task, four conditions were included: inaction-gain; inaction-loss; action-gain; and action-loss.
The behavioral data showed that, whatever the feedback outcomes were winning or losing, the emotions and responsibility experienced by the ILC participants for the feedback outcomes were not significantly different between following their action and inaction; while the emotions and responsibility experienced by the ELC participants for the feedback outcomes following their action were more intense than that following their inaction. Moreover, the FRNs and P300s elicited by the feedback outcomes following action and inaction were no differences for the ILC participants, whereas the two ERP components elicited by the feedback outcomes following action were both larger than that following inaction for the ELC participants. In short, the action effect is not evident in ILC participants, but evident in EIC participants. Thus, it most likely that action effect is induced by different degree of sense of responsibility to identical outcomes following variant behavior.

Key words: action effect, internal locus of control, external locus of control, FRN, P300