Mental representations are manipulated, combined, and evaluated in the absence of the original stimuli. Thought is that process of internal symbol use that supports reasoning, planning, and imagination.

It includes directed problem solving, spontaneous mind-wandering, and the inner speech of everyday reflection. Thought can be propositional, imagistic, or motoric. Working memory provides the temporary workspace in which much of conscious thought unfolds. Unconscious thought processes continue to influence judgment and creativity.

Disorders of thought appear in the formal thought disorder of schizophrenia, the racing thoughts of mania, and the repetitive themes of obsessive states. Techniques that externalize thought—writing, dialogue, diagramming—often improve clarity and control. Thought is both the medium of private experience and the tool by which humans construct science, art, and technology.

• Internal manipulation of mental representations
• Supports reasoning, planning, and imagination
• Occurs in directed and spontaneous forms
• Can be disordered in characteristic ways