Abscesses occur when an area of tissue becomes infected and the body's immune system tries to fight it. White blood cells move through the walls of the blood vessels into the area of the infection and collect within the damaged tissue. During this process, pus forms.
cognition cogÂ·niÂ·tion (kÅg-nÄ­sh'Én) n. The mental faculty of knowing, which includes perceiving, recognizing, conceiving, judging, reasoning, and imagining.
Freebase(0.00 / 0 votes)Rate this definition: Cognitive psychology. Cognitive psychology is the study of mental processes. The American Psychological Association defines cognitive psychology as The study of higher mental processes such as attention, language use, memory, perception, problem solving, and thinking..