The human brain is the most sophisticated organ in the known universe. It is so complex that relatively little was understood about its functions until recent advances in brain physiology provided greater insight. Many of these insights are now being integrated into other fields, such as psychology and psychiatry.
Origins of Thought
Human thought developed as the brain gradually evolved over millions of years. The development of the limbic system, which is responsible for memory, basic drives and motivations, and emotional learning and response, developed before humans arrived, according to Jonathan Haidt, psychology professor at the University of Virginia and author of "The Happiness Hypothesis." Later, the frontal cortex, responsible for abstract thought, planning and decision-making, developed in primates. Early humanoids inherited this pre-existing structure and continued to evolve, resulting in the great expansion of the frontal cortex that makes distinctly human thought possible.
Conscious and Unconscious Minds
The conscious mind is the portion of your mind that you are aware of. The unconscious mind, sometimes referred to as the subconscious mind, is "that part of the mind wherein psychic activity takes place of which the person is unaware," according to Princeton University's WordNet database. The unconscious mind governs the limbic system, according to clinical hypnotherapist Filipe Rodrigues. It contains thoughts and desires that profoundly influence your behavior even though you are not aware of them. According Rodrigues, the senses take in about 2 million pieces of information every second, far too much for the conscious mind to process. For this reason, most of the human mind is unconscious.
Automatic Thought
An automatic thought is a thought that is involuntary, unintentional and effortless, according to New York University psychologists James S. Uleman and John A. Barge. Automatic thoughts arise from the unconscious mind and are transferred to the conscious mind. If these thoughts are largely negative, depression and anxiety disorders can result.
Concrete vs. Abstract Thought
Abstract thinking is "a level of thinking about things that is removed from the facts of the 'here and now,' and from specific examples of the things or concepts being thought about," according to Mark Ylvisaker, PhD and former professor of communication sciences at the College of Saint Rose. Abstract thinking is a uniquely human capability. Concrete thinkers can conceive of objects like a chair or a tree, but only abstract thinkers can conceive of ideas such as justice or freedom.
Thought Disorders
Thought disorders occur when a person's thoughts sink into incoherence and are generally recognized when a person's speech patterns become disorganized, according to the Mental Health Consumer/Survivor Network. Schizophrenia is the most common thought disorder, occurring in about 1 percent of Americans. People with schizophrenia might experience auditory or visual hallucinations, as well as delusions -- ideas that are untrue and that have no rational basis. They might have difficult speaking, expressing emotions and making plans and decisions.
