The dataset contains structural T1-weighted and functional magnetic resonance brain imaging data, from 37 men (aged 20-30), along with questionnaire-assessed measurements of trait-like eveningness, distinctness, sleep quality, personality type, anxiety levels, sensitivity to punishment and rewards, behavioral inhibition and activation system, attention deficits. In this study fMRI version of Monetary Incentive Delay task (MID) was used. The recruitment criteria excluded individuals with self-reported history of psychiatric or neurological conditions and current medication use. All the brain imaging sessions were performed between 1 PM and 5 PM in order to control the effect of time of day on acquired images. To control the seasonal effect, all scans were performed during 2 weeks in summer. This dataset is particularly valuable for researchers investigating circadian rhythmicity and may contribute to large-scale multicenter meta-analyses exploring structural brain correlates of eveningness and distinctness. Additionally, it can support studies focused on affective processing.