naturally satisfy the body's needs. When high reports of negative symptoms were recorded, there were significant irregularities in the left VS. Anhedonia, the inability to feel pleasure, is a commonly reported symptom in psychosis; experiences are present in most people with schizophrenia. Anhedonia arises as a result of the inability to feel motivation and drive towards both the desire to engage in as well as to complete tasks and goals. Previous research has indicated that a deficiency in the neural representation in regards to goals and the motivation to achieve them, has demonstrated that when a reward is not present, a strong reaction is noted in the ventral striatum; reinforcement learning is intact when contingencies about stimulus-reward are implicit, but not when they require explicit neural processing; reward prediction errors are what the actual reward is versus what the reward was predicted to be. In most cases positive prediction errors are considered an abnormal occurrence. A positive prediction error response occurs when there is an increased activation in a brain region, typically the striatum, in response to unexpected rewards. A negative prediction error response occurs when there is a decreased activation in a region when predicted rewards do not occur. Anterior Cingulate Cortex (ACC) response, taken as an indicator of effort allocation, does not increase with reward or reward probability increase, and is associated with negative symptoms; deficits in Dorsolateral Prefrontal Cortex (dlPFC) activity and failure to improve performance on cognitive tasks when offered monetary incentives are present; and dopamine mediated functions are abnormal. Neurobiology Psychosis has been traditionally linked to the overactivity of the neurotransmitter dopamine. In particular to its effect in the mesolimbic pathway. The two major sources of evidence given to support this theory are that dopamine receptor D2 blocking drugs (i.e., antipsychotics) tend to reduce the intensity of psychotic symptoms, and that drugs that accentuate dopamine release, or inhibit its reuptake (such as amphetamines and cocaine) can trigger psychosis in some people (see stimulant psychosis). NMDA receptor dysfunction has been proposed as a mechanism in psychosis. This theory is reinforced by the fact that dissociative NMDA receptor antagonists such as ketamine, PCP and dextromethorphan (at large overdoses) induce a psychotic state. The symptoms of dissociative intoxication are also considered to mirror the symptoms of schizophrenia, including negative symptoms. NMDA receptor antagonism, in addition to producing symptoms reminiscent of psychosis, mimics the neurophysiological aspects, such as reduction