The role of dopamine in the psychological architecture of pleasure and reward indicates that it is an important element in determining reinforcement (Arias-Carrión & Pöppel, 2007, p . 484) . This role was postulated by the discovery of dopamine in reward pathways originating from the midbrain (2). From these findings it was demonstrated that dopamine has a profound impact on the existence of “reward-seeking behaviors” (Arias-Carrión & Pöppel, 2007, p. 481). A 2006 study by Mathias Pessiglione and his colleagues showed that subjects treated with L-DOPA, a precursor of dopamine, were more likely to remember decisions that led to rewards and to continue making those decisions (3). Although the central experiment in this study was conducted in the form of gambling, the effects that dopamine has on decision making and reinforcement may be derived from the observed effects that L-DOPA had on participants. This derivation can be made not only because L-DOPA is synthesized into dopamine once in the brain, but also because gambling is an enlightening behavior in terms of how it represents general reward-seeking behaviors and decisions. As Óscar Arias-Carrión and Ernst Pöppel state, “DA [dopamine] is the brain's tool for reinforcing behavior” (Arias-Carrión & Pöppel, 2007, p. 486). Furthermore, it has been demonstrated through experimentation that the reactivity of dopamine levels in the brain to rewarding experiences is characterized by a certain degree of neuronal plasticity (4). In this context, “plasticity” refers to the brain's ability to alter its responses to experiences based on how novel or unique the experience is. This quality can help the brain act like a sieve, filtering out experiences that aren't n...... middle of paper ......re rapid release of dopamine into the synapse (13). Although these mechanisms are different, they both essentially achieve the same end result of euphoria, wakefulness, and increased motor activity. These symptoms mirror those of a person with high levels of dopamine, as seen in psychotic patients. In fact, high doses of stimulants can even lead to psychotic states involving hallucinations. The contrasting effects of antipsychotics and stimulants not only on behavior but also on cognition and physiological processes help generate a greater understanding of how dopamine influences both the mind and body. Although the many nuances and subtleties of dopamine neurotransmission are not well understood, looking at how psychoactive drugs affect the normal functioning of dopamine may help create stronger links between this neurotransmitter and human behavior..