Impulsive decisions arise from preferring smaller but sooner rewards compared to larger but later rewards. How neural activity and attention to choice alternatives contribute to reward decisions during temporal discounting is not clear. Here we probed (i) attention to and (ii) neural representation of delay and reward information in humans (both sexes) engaged in choices. We studied behavioral and frequency specific dynamics supporting impulsive decisions on a fine-grained temporal scale using eye tracking and magnetoencephalographic (MEG) recordings. In one condition participants had to decide for themselves but pretended to decide for their best friend in a second prosocial condition, which required perspective taking. Hence, conditions varied in the value for themselves versus that pretending to choose for another person. Stronger impulsivity was reliably found across three independent groups for prosocial decisions. Eye tracking revealed a systematic shift of attention from the delay to the reward info...