User:Tolber2K/Psychosis

Negative Symptoms
Psychosis is associated with ventral striatal (VS) which is the part of the brain that is involved with the desire to 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. The impairment that may present itself as anhedonia derives from the inability to not only identify goals, but to also identify and engage in the behaviors necessary to achieve goals. Anhedonia arises as a result of the inability to feel motivation and drive towards both the desire to engage in as well as complete ion of tasks and goals. Studies support a deficiency in the neural representation of goals and goal directed behavior by demonstrating that when the reward is not anticipated, there is a strong correlation of high reaction in the ventral striatum; Previous studies indicate that a deficiency in the neural representation regarding goals and the motivation to achieve them, by demonstrating 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 o f 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.