Is decreased prefrontal cortical sensitivity to monetary reward associated with impaired motivation and self-control in cocaine addiction?

Objective: This study attempted to examine the brain's sensitivity to monetary rewards of different magnitudes in cocaine abusers and to study its association with motivation and self-control.

Method: Sixteen cocaine abusers and 13 matched healthy comparison subjects performed a forced-choice task under three monetary value conditions while brain activation was measured with functional magnetic resonance imaging. Objective measures of state motivation were assessed by reaction time and accuracy, and subjective measures were assessed by self-reports of task engagement.

Subjective sensitivity to monetary gradients is associated with frontolimbic activation to reward in cocaine abusers.

Drug addiction is characterized by marked disruptions in the ability to process reward. Here we evaluated in cocaine addicted and healthy control participants the subjective sensitivity to reward gradients and its association with neural responses to sustained reward. A self-report questionnaire was used to assess the former.

The effect of graded monetary reward on cognitive event-related potentials and behavior in young healthy adults.

Temporal correlates of the brain circuit underlying reward processing in healthy adults remain unclear. The current study investigated the P3 and contingent negative variation (CNV) as putative reward-related temporal markers. The effect of sustained monetary reward on these event-related potentials and on behavior was assessed using a warned reaction-time paradigm in 16 young healthy subjects.

The effect of unilateral somatosensory stimulation on hemispheric asymmetries during slow wave sleep.

Study Objectives: To examine the effect of unilateral somatosensory stimulation on the laterality of delta band activity during slow wave sleep (SWS).

Design: Participants napped for two hours on two separate days. Two types of vibratory stimuli were randomly presented to one hand: a short and more intense vibration (rare stimulus) and a long and less intense vibration (frequent stimulus).