This article needs attention from an expert on the subject. See the talk page for details. WikiProject Psychology or the Psychology Portal may be able to help recruit an expert. (September 2009) This article is missing citations or needs footnotes. Please help add inline citations to guard against copyright violations and factual inaccuracies. (February 2010) Habituation, a form of non-associative learning, is the psychological process in humans and other organisms in which there is a decrease in psychological and behavioral response to a stimulus after repeated exposure to that stimulus over a duration of time. Contents 1 Background 2 Neurobiology of Habituation 3 Psychological significance in humans 4 See also 5 References 6 External links // Background

Not to be confused with habit, habituation refers specifically to a type of non-associative learning in which repeated exposure to a stimulus leads to decreased responding.1 The learning underlying habituation is a fundamental or basic process of biological systems and does not require conscious motivation or awareness to occur. Habituation enables organisms to distinguish meaningful information from irrelevant background stimuli. Habituation can refer to a decrease in behavior, subjective experience, or synaptic transmission. The changes in synaptic transmission that occur during habituation have been well-characterized in the Aplysia gill and siphon withdrawal reflex.

Habituation has been shown in essentially every species of animal, as well as in the large protozoan Stentor coeruleus.2 It is also essential to note that the decrease in responding is specific to the habituated stimulus (For example, if one was habituated to the taste of lemon, their responding would increase significantly when presented with the taste of lime) (Domjan, 2010). Two factors that can influence habituation include the interstimulus interval (ISI), or the amount of time between each successive presentation of the stimulus, and the stimulus duration, or the length of time the stimulus is presented. Shorter ISIs and longer durations increase habituation; longer ISIs and shorter durations decrease habituation (Domjan, 2010). Neurobiology of Habituation

It is a neutral form of learning in which a neutral stimulus is repeated many times. The first time it is applied it is novel and evokes a reaction (the orienting reflex or "what is it?" response). However, it evokes less and less electrical response as it is repeated. Eventually the subject becomes habituated to the stimulus and ignores it. This is associated with decreased release of neurotransmitter from the presynaptic terminal because of decreased intracellular Ca++. The decrease in intracellular Ca++ is due to gradual inactivation of Ca++ channelscitation needed. Psychological significance in humans

Habituation need not be conscious—for example, a short time after a human dresses in clothing, the stimulus clothing creates disappears from our nervous systems and we become unaware of it. In this way, habituation is used to ignore any continual stimulus, presumably because changes in stimulus level are normally far more important than absolute levels of stimulation. This sort of habituation can occur through neural adaptation in sensory nerves themselves and through negative feedback from the brain to peripheral sensory organs. Habituation is frequently used in testing psychological phenomena. Both adults and infants gaze less at a particular visual stimulus the longer it is presented. The amount of time spent looking at a new stimulus after habituation to the initial stimulus indicates the effective similarity of the two stimuli. It is also used to discover the resolution of perceptual systems. For instance, by habituating someone to one stimulus, and then observing responses to similar ones, one can detect the smallest degree of difference that is detectable.

Dishabituation is when a second stimulus is presented in unison with a primary stimulus, and may briefly increase habituated response toward the primary stimulus until an organism distinguishes, or discriminates the differences between two different stimuli. Dishabituation has been demonstrated as being inherently different than psychological sensitization. See also Psychology portal Banner blindness Habit Hedonic adaptation Neural adaptation Konrad Lorenz, Behind the Mirror: A Search for a Natural History of Human Knowledge: on habituation Tachyphylaxis, the effect of continued exogenous entries (habituation of) into the metabolism of an organism within the scope/field of biological chemistry References ^ Bear, M.F., Conners, B.W., and Paradiso, M.A. (2007) Neuroscience, Exploring the Brain ^ Wood, D.C. (1988). Habituation in Stentor produced by mechanoreceptor channel modification. Journal of Neuroscience, 8, 2254-2258. External links Look up habituation in Wiktionary, the free dictionary. Dana Sugu & Amita Chaterjee ‘Flashback: Reshuffling Emotions’, International Journal on Humanistic Ideology, Vol. 3 No. 1, Spring-Summer 2010 [1] Usabilityfirst.com."Definition of Habituation". Retrieved August 29, 2008. BBC "Definition in context". Retrieved August 24, 2009. v · d · eLearning Simple non-associative learning Habituation · Sensitization Associative learning Operant conditioning · Classical conditioning · Imprinting · Observational learning v · d · ePsychophysiology Appetite  · Arousal  · Biofeedback  · Blushing  · Consciousness  · Cerebral dominance  · Habituation  · Lie detection  · Orientation  · Reaction time  · Reflex  · Satiation  · Self stimulation  · Sensation  · Sleep  · Psychological stress