Previous reports documented abnormalities in cognitive functions and decision-making (DM) in patients with chronic pain, but these changes are not consistent across studies. Reasons for these discordant findings might include the presence of confounders, variability in chronic pain conditions, and the use of different cognitive tests. The present study was aimed to add evidence in this field, by exploring the cognitive profile of a specific type of chronic pain, i.e., chronic low back pain (cLBP). Twenty four cLBP patients and 24 healthy controls underwent a neuropsychological battery and we focused on emotional DM abilities by means of Iowa gambling task (IGT). During IGT, behavioral responses and the electroencephalogram (EEG) were recorded in 12 patients and 12 controls. Event-related potentials (ERPs) were averaged offline from EEG epochs locked to the feedback presentation (4000 ms duration, from 2000 ms before to 2000 ms after the feedback onset) separately for wins and losses and the feedback-related negativity (FRN) and P300 peak-to-peak amplitudes were calculated. Among cognitive measures, cLBP patients scored lower than controls in the modified card sorting test (MCST) and the score in this test was significantly influenced by pain duration and intensity. Behavioral IGT results documented worse performance and the absence of a learning process during the test in cLBP patients compared to controls, with no effect of pain characteristics. ERPs findings documented abnormal feedback processing in patients during IGT. cLBP patients showed poor performance in the MCST and the IGT. Abnormal feedback processing may be secondary to impingement of chronic pain in brain areas involved in DM or suggest the presence of a predisposing factor related to pain chronification. These abnormalities might contribute to the impairment in the work and family settings that often cLBP patients report.

Several pieces of evidence have highlighted the presence of an age-related decline in risky decision-making (DM), but the reason of this decline is still unclear. The aim of the present study was to investigate the neural correlates of feedback processing in risky DM. Twenty-one younger (age <50 years) and 15 older (age >50 years) adults were tested with the Iowa Gambling Task (IGT) during Event Related Potentials (ERP) recording. The analysis was focused on the feedback-related negativity (FRN) and P3, two ERP components that represent different stages of feedback processing. Behavioral results revealed that older adults, despite showing a significant learning trend, completed the IGT with a gain of a smaller amount of money compared to the younger ones. ERP results revealed that while the FRN response was comparable in the two groups, the P3 amplitude was significantly reduced after negative feedback in older adults, compared with the younger ones. Furthermore, the difference in the P3 amplitude evoked by positive and negative feedback was significantly correlated with age. Hence, the present findings suggest that older adults seem to be less willing to shift attention from positive to negative information, and that this relevant change in the later stages of feedback processing could be the cause of a poor performance in risky DM contexts.

Dopamine systems mediate key aspects of reward learning. Parkinson's disease (PD) represents a valuable model to study reward mechanisms because both the disease process and the anti-Parkinson medications influence dopamine neurotransmission. The aim of this pilot study was to investigate whether the level of levodopa differently modulates learning from positive and negative feedback and its electrophysiological correlate, the error related negativity (ERN), in PD. Ten PD patients and ten healthy participants performed a two-stage reinforcement learning task. In the Learning Phase, they had to learn the correct stimulus within a stimulus pair on the basis of a probabilistic positive or negative feedback. Three sets of stimulus pairs were used. In the Testing Phase, the participants were tested with novel combinations of the stimuli previously experienced to evaluate whether they learned more from positive or negative feedback. PD patients performed the task both ON- and OFF-levodopa in two separate sessions while they remained on stable therapy with dopamine agonists. The electroencephalogram (EEG) was recorded during the task. PD patients were less accurate in negative than positive learning both OFF- and ON-levodopa. In the OFF-levodopa state they were less accurate than controls in negative learning. PD patients had a smaller ERN amplitude OFF- than ON-levodopa only in negative learning. In the OFF-levodopa state they had a smaller ERN amplitude than controls in negative learning. We hypothesize that high tonic dopaminergic stimulation due to the dopamine agonist medication, combined to the low level of phasic dopamine due to the OFF-levodopa state, could prevent phasic "dopamine dips" indicated by the ERN needed for learning from negative feedback.

Although there have been suggestions that altered cognitive control and food reward sensitivity contribute to overeating in obese individuals, neurophysiological correlates of these mechanisms have been poorly investigated. The current study investigated event-related potentials (ERP) in 24 severely obese and 26 normal weight individuals in fasting condition, using a novel Simon task with food and object distractors. The study showed that conflict in the Simon task for the food distractor increased with hunger in both groups but was larger with respect to a neutral condition only in the obese individuals. ERP showed higher N1amplitudes in both groups for food distractor, reflecting early food processing. The P2 latency was delayed and the effect of distractors on N2 amplitude was smaller in the obese subjects, reflecting altered neural mechanisms associated with selective attention and cognitive control, all contributing hypothetically to delay response selection of these individuals faced with food distractor.