Objective: During life-span an individual faces all kind of choices, but the evaluation of their “goodness” may vary according to many parameters. Impaired decision-making is related to cognitive control dysfunction in patients with attention-deficit hyperactivity disorder (ADHD). Children with ADHD have deficits in different dimensions of executive functions, more specifically deficit in working memory. These impairments are stable into young adult age. In order to investigate whether feedback information could have a spillover effect on decision-making in ADHD patients, we designed a study where participants had to perform a modified version of the Gneezy-Potters (1997) neuroeconomic game.
Method: 32 adults participants were endowed with 20 points at the beginning of each trial, and then asked to invest an amount of these points in a risky project among the following choices: 0, 4, 8, 12, 16, 20. The probability to win 3 times the amount invested was 1/3, whereas the probability to loose the entire investment was 2/3. The whole session was composed of 10 games x 4 blocks x 4 trials, overall 160 trials. Outcomes were presented immediately after half of the trials (condition “feedback”, FB), while the other half were presented at the end of each block (condition “no feedback”, NOFB). Conditions were alternated at each block. During the sessions, EEG was continuously recorded using 64 active Ag/AgCl electrodes and referenced to the link earlobes.
Results: ANOVA analysis between groups (F(1,10)=5.039, p<0.05) showed that control participants’ gains were higher in the FB condition (MFB=373 points) compared to NOFB (MNOFB=361 points), while ADHD’s gains were higher in the NOFB condition (MNOFB=370 vs. MFB=354 points). Reaction times were longer in the FB condition (MFB=1574 vs. MNOFB=935 ms) compared to the NOFB condition irrespective of the participants’ group (F(1,8)= 9.619, p=0.015). ERPs analysis of the difference between FB and NOFB electrophysiological activity showed larger differences in the control group over frontal regions (~700 -1000 ms after selecting the investment option) whereas ADHD’s differences were posterior. We found that feedback trials evoked larger amplitudes in ERP over central regions at latencies 300 -500 ms.
Conclusion: These results highlight the importance of feedback information in the Gneezy-Potters’ task and selected differences in the decision-making process by ADHD young adults compared with control participants.
Acknowledgments: This study was supported by the FNS (CR 1311-138032).