In this thesis we focused on rewarding stimuli and tried to model reward processes in humans that could be related to irrational reward-seeking behaviors. We provided evidence showing that stimuli associated with reward (a) bias attention and (b) trigger peaks of wanting in order to obtain said associated reward. We conducted a meta-analysis and experimental studies showing that attention is biased toward rewarding stimuli and that this bias critically depends on the affective relevance of the stimulus for the observer's current concerns. Moreover, we conducted a systematic review and an experimental study suggesting that stimuli associated with a reward trigger peaks of wanting that are directly modulated by the reward's relevance for the observer's concerns, independently of the liking experienced felt once the reward is consumed. These findings support the idea that affective relevance might represent a key mechanism influencing both attentional and motivational processes of rewarding stimuli.