In psychology, the mind is an abstract concept used to characterize thoughts, feelings, subjective states, and self-awareness that presumably arise from the brain. It is usually contrasted with body, matter, or physicality, and the issue of the nature of this contrast and specifically the relation between mind and brain is called the mind-body problem. The mind is often understood as a faculty that manifests itself in mental phenomena like sensation, perception, thinking, reasoning, memory, belief, desire, emotion, and motivation. The mind is the primary domain of psychology, and cognitive psychologists and neuropsychologists, in particular, are interested in how brain states affect mind states. Many mental health professionals acknowledge that there are layers of consciousness to the mind and are interested in accessing the deeper workings of the mind. The mind-body problem has been a subject of debate for centuries, and there are different views on the nature of the mind. Some philosophers argue that the brain alone cannot fully account for the actions of the mind, while others consider the mind to be non-physical. However, most psychologists and neuroscientists believe that the mind arises from the brain and is a product of its activity.