A heuristic model of sensory adaptation

Abstract

Adaptation is a universal process in organisms as diverse as bacteria and humans, and across the various senses. This article proposes a simple, heuristic, mathematical model containing tonic and phasic processes. The model demonstrates properties not commonly associated with adaptation, such as increased sensitivity to changes, range shifting, and phase lead. Changes in only four parameters permit the model to predict empirical psychophysical data from different senses. The relatively prolonged time courses of responses to oral and topical capsaicin are used to illustrate and validate this mathematical modeling approach for different stimulus profiles. Other examples of phenomena elucidated by this modeling approach include the time courses of taste sensation, brightness perception, loudness perception, cross-adaptation to oral irritants, and cutaneous mechanoreception. It also predicts such apparently unrelated phenomena as perceived alcohol intoxication, habituation, and drug tolerance. Because the integration of phasic and tonic components is a conservative, highly efficacious solution to a ubiquitous biological challenge, sensory adaptation is seen as an evolutionary adaptation, and as a prominent feature of Mother Nature's small bag of tricks.

Centrally-mediated sensory information processing is impacted with increased alcohol consumption in college-aged individuals

“…(for reviews, see Kumar et al, 2004Kumar et al, , 2009). Imaging and neurobiological research has shown that chronic alcohol consumption can lead to white matter degradation, disrupt neurocircuitry, and impact neural plasticity which can alter neurotransmission, particularly by increasing tonic inhibition (Cardenas et al, 2005;Crews et al, 2005;Herting et al, 2010;McBurney and Balaban, 2009;Oscar-Berman and Marinkovic, 2007;Pfefferbaum et al, 2010;Santhakumar et al, 2007;Sullivan and Pfefferbaum, 2005). Particularly relevant to the collegeaged population, high doses of adolescent ethanol exposure has been shown to produce lasting changes in functional brain activity (for review, see Ehlers and Criado, 2010).…”

Tinnitus What and Where: An Ecological Framework

“…In this review, adaptation is defined broadly, as “adjustment” ( 1 , 21 ). An adaptation level or “normal level” exists for all sensory dimensions including perception of frequency and intensity of stimuli ( 1 ).…”

An Adaptation Level Theory of Tinnitus Audibility

“…Adaptation level effects and similar “differential contextual effects” (Marks and Arieh, 2006 ) have been demonstrated in perception of: touch, taste, olfaction (Marks and Arieh, 2006 ), pain (Rollman, 1979 ; Kyle et al, 2009 ), weight (Helson, 1948 ), temperature (Masuyama, 1994 ), loudness (Marks, 1994 ), vision (Helson, 1964 ), phobias (Lauterbach, 1979 ), and even market research (Della Bitta and Monroe, 1974 ). There are a number of overlapping terms to describe change in perception with repeated exposure including acclimatization, adaptation, stimulus failure, fatigue as well as habituation (Helson, 1964 ; Mazess, 1975 ; McBurney and Balaban, 2009 ). The use of the terms are often governed by the training of the author, for example, adaptation is often used in physiology to describe a change, possibly short-term, in the response of sensory systems following stimulation, habituation is a decrease in response after repeated stimulation, sensitization an increase in response with repeated stimulation.…”