Motivational processes are complex and multifaceted, with both directional and activational
aspects. Behavioral activation and exertion of effort are functions that enable organisms to …

Addiction is commonly identified with habitual nonmedical self-administration of drugs. It is
usually defined by characteristics of intoxication or by characteristics of withdrawal …

Apathy and anhedonia are common syndromes of motivation that are associated with a wide
range of brain disorders and have no established therapies. Research using animal models …

Food is a powerful natural reinforcer that guides feeding decisions. The vagus nerve
conveys internal sensory information from the gut to the brain about nutritional value; …

Apathy is a debilitating syndrome associated with many neurological disorders, including
several common neurodegenerative diseases such as Parkinson's disease and Alzheimer's …

In everyday life, we have to decide whether it is worth exerting effort to obtain rewards. Effort
can be experienced in different domains, with some tasks requiring significant cognitive …

Motivation has been defined as the process that allows organisms to regulate their internal
and external environment, and control the probability, proximity and availability of stimuli. As …

Cognitive control is subjectively costly, suggesting that engagement is modulated in
relationship to incentive state. Dopamine appears to play key roles. In particular, dopamine …

Addictive drugs are habit-forming. Addiction is a learned behavior; repeated exposure to
addictive drugs can stamp in learning. Dopamine-depleted or dopamine-deleted animals …

Parkinson's disease causes a characteristic combination of motor symptoms due to
progressive neurodegeneration of dopaminergic neurons in the substantia nigra pars …