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Stimulus Habituation

Date: June 3, 2024

How to cite: Barata, R. (2024) Stimulus Habituation. Human-Animal Science.


Habituation is the nonassociative learning process whereby an organism becomes less responsive to repeated stimulus presentations.


Habituation gives an individual the ability to ignore insignificant, repetitive events. Habituation exhibits the same properties in simple and complex individuals, such as forgetting, overlearning, and stimulus generalization. 

The function of habituation for the individual is, to some degree, an adaptation to its environment or present situation resulting from a phylogenetic history. From a survival point of view, it is more beneficial to respond to novel events rather than non-helpful or harmful regular ones. 

Changes in some aspects of the environment are responsible for an individual's responsiveness. Individuals unable to habituate to insignificant stimuli face difficulties attending to more essential stimuli. An organism may stop responding to a stimulus in one aspect of its behavior while continuing to respond to the stimulus in several other ways. 

Habituation vs. Reflex

Even though the main characteristic of habituation is the decrease of a particular response initially elicited by a stimulus, not all instances in which repetitions of a stimulus result in a reduction of response are habituation. Still, it may instead be an example of instinctive behavior. Instinctive behavior includes such activities as nest-building, migration, hibernation, and mating behavior. One of the simplest types of innate behaviors is the reflex. A reflex is an unlearned or innate response to a specific class of stimuli.

Hinde & Tinbergen (1958) classified the descriptive term species-specific behavior as complex, unlearned, and relatively unmodifiable behavior patterns a particular animal engages in under certain circumstances.

Lorenz and Tinbergen (1970) referred to species-specific action patterns as fixed action patterns to highlight that some behaviors occur similarly for all species. Barlow (1968, 1977) evaluated the concept of Fixed Action Pattern (FAP) as a fundamental unit of behavior and concluded that most FAP had some degree of variability and was not rigidly stereotyped, suggesting that the term "fixed" could better be replaced by "modal." The term "modal" explicitly recognized the variation in behavior within individuals. Species-typical modal action patterns have been identified in several characteristics of animal behavior, including sexual behavior, territorial defense, aggression, and prey capture.

Another behavior that often displays habituation is the orienting response or reflex (Pavlov, 1927, 1960). Both animals and humans exhibit an orienting response to a novel stimulus. An individual may stop their current activity and redirect to a new stimulus. The orienting response will disappear if the stimulus is presented repeatedly with no consequence.

Leaton's (1976) experiment on startle reflex reaction in rats by presenting a single tone in three phases had significant importance on long-term and short-term habituation effects on the frequency of the stimulus presentations. The results showed that a more intense startle reaction was observed the first time the tone was presented, becoming less intense during the next ten days in the first phase, where the single tone was presented only once a day. However, the long-term habituation did not result in the absence of the startle reflex because, on the 11th day, the rats still reacted even at low intensity. The second phase increased the frequency of the presentation of the single tone, and the startle response temporarily disappeared. However, the spontaneous recovery event was observed in phase three, with procedures similar to those used in phase one. 

While stimuli can result in habituation that affects innate reflexes and the degree of response, habituation hasn't been shown to remove reflexive instinctive behaviors permanently.

Principles of Habituation Revised

Thompson and Spencer (1966) listed nine main habituation principles observed in people and a wide variety of other species. The following properties are classified as short-term habituation (1-4); long-term habituation (5-6); modulation of habituation (7); dishabituation (8-9).

  1. "Given that a particular stimulus elicits a response, repeated applications of the stimulus result in decreased response (habituation). The decrease is usually a negative exponential function of the number of stimulus presentations."
  2. "If the stimulus is withheld, the response tends to recover over time (spontaneous recovery)."
  3. "If repeated series of habituation training and spontaneous recovery are given, habituation becomes successively more rapid (this phenomenon might be called potentiation of habituation)."
  4. "Other things being equal, the more rapid the frequency of stimulation, the more rapid and/or more pronounced is habituation."
  5. "The weaker the stimulus, the more rapid and/or more pronounced is habituation. Strong stimuli may yield no significant habituation."
  6. "The effects of habituation training may proceed beyond the zero or asymptotic response level."
  7. "Habituation of response to a given stimulus exhibits stimulus generalization to other stimuli."
  8. "Presentation of another (usually strong) stimulus results in recovery of the habituated response (dishabituation)."
  9. "Upon repeated application of the dishabituation stimulus, the amount of dishabituation produced habituates (this phenomenon might be called habituation of dishabituation)."

Rankin et al. (2008) suggested a review of those principles and added a tenth principle:

  1. "Repeated application of a stimulus results in a progressive decrease in some parameter of a response to an asymptotic level. This change may include decreases in frequency and/or magnitude of the response. In many cases, the decrement is exponential, but it may also be linear; in addition, a response may show facilitation prior to decrementing because of (or presumably derived from) a simultaneous process of sensitization."
  2. "If the stimulus is withheld after response decrement, the response recovers at least partially over the observation time ("spontaneous recovery")."
  3. "If repeated series of habituation training and spontaneous recovery are given, habituation becomes successively more rapid (this phenomenon might be called potentiation of habituation)."
  4. "Other things being equal, more frequent stimulation results in more rapid and/or more pronounced response decrement, and more rapid spontaneous recovery (if the decrement has reached asymptotic levels)."
  5. "Within a stimulus modality, the less intense the stimulus, the more rapid and/or more pronounced the behavioral response decrement. Very intense stimuli may yield no significant observable response decrement."
  6. "The effects of repeated stimulation may continue to accumulate even after the response has reached an asymptotic level (which may or may not be zero, or no response). This effect of stimulation beyond asymptotic levels can alter subsequent behavior, for example, by delaying the onset of spontaneous recovery."
  7. "Within the same stimulus modality, the response decrement shows some stimulus specificity. To test for stimulus specificity/stimulus generalization, a second, novel stimulus is presented, and a comparison is made between the changes in the responses to the habituated stimulus and the novel stimulus. In many paradigms (e.g. developmental studies of language acquisition), this test has been improperly termed a dishabituation test rather than a stimulus generalization test, its proper name."
  8. "Presentation of a different stimulus results in an increase of the decremented response to the original stimulus. This phenomenon is termed "dishabituation." It is important to note that the proper test for dishabituation is an increase in response to the original stimulus and not an increase in response to the dishabituating stimulus (see point #7 above). Indeed, the dishabituating stimulus by itself need not even trigger the response on its own."
  9. "Upon repeated application of the dishabituating stimulus, the amount of dishabituation produced decreases (this phenomenon can be called habituation of dishabituation)."
  10. 10. "Some stimulus repetition protocols may result in properties of the response decrement (e.g. more rapid rehabituation than baseline, smaller initial responses than baseline, smaller mean responses than baseline, less frequent responses than baseline) that last hours, days or weeks. This persistence of aspects of habituation is termed long-term habituation."

Within the proprieties of habituation, Lara et al. (1980) proposed a mathematical model of the phenomenon of habituation as a homosynaptic depression of the amount of transmitter release: “The model is based on the physiological studies of habituation in invertebrates and in the spinal cord of vertebrates, where a single synapse has been isolated and some of the physiological mechanisms of this process have been elucidated. The model simulates the following properties of habituation: (1) reduced amount of transmitter release attributed to a repetitive stimulus through changes in the membrane permeability to Ca2+ ions; (2) spontaneous recovery by rest; (3) the amplitude and frequency dependence of habituation; (4) modulation of habituation: sensitization, through an increase in membrane Ca2+ permeability, and presynaptic inhibition, through a reduced depolarization of the physiological stimulus; (5) long-term habituation attributed to repetitive trials of habituation and spontaneous recovery.”

Studies on Habituation

The work from Ezzeddine and Glanzman (2003), Leussis and Bolivar (2006), Engel and Wu (2009), Zaccardi (2012), and Typlt et al. (2013) shows common nervous system mechanisms involved in the habituation process, such as calcium and potassium channels, and genes involved in serotonin, dopamine, and glutamate neurotransmission. 

Daily, animals are exposed to aversive events that activate a complex stress response by the hypothalamic-pituitary-adrenal (HPA) axis, a response that seemingly shows habituation to the repeated presentation of the stressful event. Grissom and Bhatnagar (2009) concluded that "habituation of HPA activity meets many, but not all, important criteria for response habituation, supporting the use of this term within the context of repeated stress.”

Although habituation is a relatively simple phenomenon, variations in the stimulus used to elicit the response affect the rate of habituation. The study by Sharpless and Jasper (1956) showed the effects of loud noises on cats by recording their brain waves on an electroencephalograph (EEG). The EEG initially showed marked arousal, but the response declined continuously with each repetition of a given sound until the noise had almost no effect. PET scans have displayed changes in the cerebellum as a person's startle response to a loud noise habituates (Timmann et al., 1998). Growing evidence shows that many different brain and nervous system areas can undergo habituation when the same stimulus is repeatedly presented.

Studies in habituation in infants (Bridger, 1961) showed that when babies first heard a noise, they responded with increased heart rate. The change in heart rate became less noticeable with the repetition of the noise at regular intervals until the noise had no measurable effect. 

A study by Dielenberg and McGregor (1999) showed how animals could habituate to a fear-provoking stimulus if the stimulus repeatedly proves to be insignificant. Similarly, Fisher et al. (2003) conclude in their study of brain habituation during repeated exposure to fearful and neutral faces that “brain regions involved in novelty detection and memory processing habituate at similar rates regardless of whether the face in focus displays an aversive emotional expression or not.”.

The study by Leader (1995) demonstrated habituation even in the human fetus. A stimulus to the mother's abdomen during the last three months of pregnancy produced movement in the fetus. The fetal response became weaker when the stimulus was applied regularly. 

Laucht, Esser, and Schmidt (1994) found that infants who displayed faster habituation to repetitive stimuli at three months of age obtained, on average, slightly higher scores on intelligence tests when they were 41⁄2 years old.

Correlational studies compared rates of habituation in human adults who are or are not suffering from various psychological disorders such as schizophrenia or severe depression (Williams, Blackford, Luksik, Gauthier, & Heckers, 2013). Their findings showed that habituation in some brain areas, such as the cerebellum and the visual cortex, was slower in individuals with schizophrenia or depression than in the average population.

Habituation and Learning Theory

Habituation is typically associated with respondent rather than operant behavior. Habituation occurs when an unconditional stimulus (US) repeatedly elicits an unconditional response (UR). The frequent presentation of the US produces a gradual decline in the magnitude of the UR. When the UR is repeatedly elicited, it may eventually fail to occur at all. 

Learning theorists focus on the association between the conditional stimulus (CS) and the US as the ultimate of the conditional responses (CR), disregarding that a CR depends not only on CS-US but also on the associative strength of other CS present during the process. As a result, changing the latter may alter the CR. 

Acquired behavior depends on the context for the expression of learning. The context can enter into direct associations with the US but can also modulate the expression of CS-US associations (Urcelay and Miller, 2014). Finally, changes in the value of the US achieved through habituation or experience with the US of lower magnitude can also result in changes in CR (Davey, 1989). 

Opposite to habituation, sensitization is another form of nonassociative learning in which exposure to a stimulus, typically noxious, enhances the response (Groves and Thompson, 1970). The same stimulus that induces sensitization can also enhance habituated responses – dishabituation, currently recognized as a distinct form of learning (Antonov et al., 2010; Hawkins et al., 2006). 

The work of Colwill et al. (1988) and Hawkins et al. (1998) on long-term sensitization in Aplysia opens the discussion of always considering as nonassociative learning the behavioral change that involves the presentation of only one stimulus, disregarding the possible association with the context in which the stimulus is presented.

In behavior therapy, environmental enrichment may work as a function-based intervention because its effectiveness depends on a functional match or a substitutability relation between the reinforcers that environmental enrichment produces and those that maintain the problem behavior. Satiation or habituation alters the effectiveness of the reinforcer because the environmental enrichment has the same or similar reinforcement (Murphy et al., 2003). 

Murphy et al. (2003) reviewed research findings that support habituation accounting for many operant phenomena, including noncontingent reinforcement (NCR). Lloyd et al. (2014) propose an integrative model of habituation of reinforcer effectiveness (HRE) that links behavioral and neural-based reinforcement explanations. 

Fixed stimulus presentation schedules perform better on habituation, which predicts that fixed-time (FT) schedules are more effective in abolishing the effectiveness of the functional reinforcer than variable-time (VT) schedules. (e.g., Broster & Rankin, 1994)

Concerning punishments, a high-intensity stimulus may be ineffective as a punisher if the presented stimulus is initially low-intensity and increases gradually (Hineline & Rosales-Ruiz, 2013). The effectiveness of a punishing stimulus can decrease with repeated presentations of that stimulus. Using a variety of punishers may help to reduce habituation effects. In addition, using various punishers may increase the effectiveness of less intrusive punishers, as Charlop, Burgio, Iwata, and Ivancic (1988) published.

Reynolds (1961) refers to the behavioral contrast effect. The contrast refers to a negative correlation between the response rates in the two components of multiple schedules. There are two forms of behavioral contrast: Positive and Negative. Positive contrast occurs when the response rate increases in an unchanged component with a decreased behavior in the altered or manipulated component. Negative contrast occurs when the rate of response decreases in the unchanged component with an increase in response rate in the modified component. 

There are several alternative interpretations of behavioral contrast. For example, when the reinforcement is reduced in one component of two-component multiple schedules, habituation to the reinforcer is less, resulting in more effective reinforcement in the unchanged component (McSweeney & Weatherly, 1998). 

In the future, effectively studying habituation mechanisms systems can be done through general reviews and analyses of the previous studies to create a better overview of all the factors involved, as some authors show (Rankin et al., 2009; Schmid et al., 2014; McDiarmid et al., 2017; Hall & Rodríguez, 2020; Dissegna et al., 2021;).


Antonov, I., Kandel, E.R., Hawkins, R.D., 2010. Presynaptic and postsynaptic mechanisms of synaptic plasticity and metaplasticity during intermediate-term memory formation in Aplysia. J. Neurosci. 30 (16), 5781–5791.

Barlow, G. W. (1968): Ethological units of behavior. In: The Central Nervous System and Fish Behavior. (INGLE, D., ed.) Univ. of Chicago Press, Chicago, pp. 217-237

Barlow, G. W. (1977). Modal action patterns. In T. A. Sebeok (Ed.), How animals communicate (pp. 98–134). Bloomington: Indiana University Press.

Bridger, W. H. (1961). Sensory habituation and discrimination in the human neonate. American Journal of Psychiatry, 117, 991–996.

Charlop, M. H., Burgio, L. D., Iwata, B. A., & Ivancic, M. T. (1988). Stimulus variation as a means of enhancing punishment effects. Journal of Applied Behavior Analysis, 21, 89–95.

Colwill, R.M., Absher, R.A., Roberts, M.L., 1988. Context-US learning in Aplysia californica. J. Neurosci. 8, 4434–4439.

Davey, G.C., (1989). UCS revaluation and conditioning models of acquired fears. Behav. Res. Ther. 27, 521–528.

Dielenberg, R.A., & McGregor, I.S. (1999). Habituation of the hiding response to cat odor in rats (Rattus norvegicus). Journal of Comparative Psychology, 113, 376–387.

Dissegna, A., Turatto, M., & Chiandetti, C. (2021). Context-Specific Habituation: A Review. Animals: an open access journal from MDPI, 11(6), 1767.

Engel, J., Wu, C. (2009). Neurogenetic approaches to habituation and dishabituation in Drosophila. Neurobiology of Learning and Memory 92 (2), 166–175.

Ezzeddine, Y., Glanzman, D.L. (2003). Prolonged habituation of the gill-withdrawal reflex in Aplysia depends on protein synthesis, protein phosphatase activity, and postsynaptic glutamate receptors. The Journal of Neuroscience 23 (29), 9585–9594.

Fischer, H., Wright, C.I., Whalen, P.J., McInerney, S.C., Shin, L.M., & Rauch, S.L. (2003). Brain habituation during repeated exposure to fearful and neutral faces: A functional MRI study. Brain Research Bulletin, 59, 387–392.

Grissom, N., & Bhatnagar, S. (2009). Habituation to repeated stress: get used to it. Neurobiology of learning and memory, 92(2), 215–224.

Groves, P.M., Thompson, R.F., 1970. Habituation: a dual-process theory. Psychol. Rev. 77 (5), 419.

Hall, G., & Rodríguez, G. (2020). When the stimulus is predicted and what the stimulus predicts: Alternative accounts of habituation. Journal of Experimental Psychology: Animal Learning and Cognition, 46(3), 327–340.

Hawkins, R.D., Son, H., Arancio, O., 1998. Nitric oxide as a retrograde messenger during long-term potentiation in hippocampus. Prog. Brain Res. 118, 155–172.

Hawkins, R.D., Cohen, T.E., Kandel, E.R., 2006. Dishabituation in Aplysia can involve either reversal of habituation or superimposed sensitization. Learn. Mem. 13 (3), 397–403.

Hinde, R. A., & Tinbergen, N. (1958). The comparative study of species-specific behavior. In A. Roe & G. G. Simpson (eds.), Behavior and evolution. New Haven. CT: Vale University Press.

Hineline, P. N., & Rosales-Ruiz, J. (2013). Behavior in relation to aversive events: Punishment and negative reinforcement. In G. J. Madden (Ed.), APA handbook of behavior analysis, Vol. 1: Methods and principles (pp. 483–512). Washington, DC: American Psychological Association.

Lara, R., Tapia, R., Cervantes, F., Moreno, A., & Trujillo, H. (1980). Mathematical Model of Synaptic Plasticity: II. Habituation, Neurological Research, 2:1, 1-18, DOI: 10.1080/01616412.1980.11739568

Laucht, M., Esser, G., & Schmidt, M.H. (1994). Contrasting infant predictors of later cognitive functioning. Journal of Child Psychology and Psychiatry and Allied Disciplines, 35, 649–662.

Leader, L. R. (1995). The potential value of habituation in the prenate. In J.-P. Lecanuet, W. P. Fifer, N. A. Krasnegor, & W. P. Smotherman (Eds.), Fetal development: A psychobiological perspective (pp. 383–404). Hillsdale, NJ: Erlbaum.

Leaton, R. N. (1976). Long-term retention of the habituation of lick suppression and startle response produced by a single auditory stimulus. Journal of Experimental Psychology: Animal Behavior Processes, 2, 248–259.

Leussis, M.P., Bolivar, V.J. (2006). Habituation in rodents: A review of behavior, neurobiology, and genetics. Neuroscience and Biobehavioral Reviews 30 (7), 1045–1064.

Lloyd, D., Medina, D., Hawk, L., Fosco, W. and Richards, J. (2014). Habituation of reinforcer effectiveness. Front. Integr. Neurosci. 7:107. doi: 10.3389/fnint.2013.00107

Lorenz, K. Z., & Tinbergen, N. (1970). Taxis and instinctive behaviour pattern in egg-rolling by the Greylag goose (1938). In K. Lorenz (Ed.), Studies in animal and human behavior (Vol. 1, pp. 316–359). Cambridge: Harvard University Press.

McDiarmid, T.A., Bernardos, A.C., & Rankin, C.A. (2017). Habituation is altered in neuropsychiatric disorders—A comprehensive review with recommendations for experimental design and analysis. Neuroscience & Biobehavioral Reviews, Volume 80, 2017, Pages 286-305. ISSN 0149-7634.

McSweeney, F. K., & Weatherly, J. N. (1998). Habituation to the reinforcer may contribute to multiple-schedule behavioral contrast. Journal of the Experimental Analysis of Behavior, 69, 199–221.

Murphy, E. S., McSweeney, F. K., Smith, R. G., & Mc-Comas, J. J. (2003). Dynamic changes in reinforcer effectiveness: Theoretical, methodological, and practical implications for applied research. Journal of Applied Behavior Analysis, 36, 421–438.

Pavlov, I. P. (1927; reprint 1960). Conditioned reflexes: An investigation of the physiological activity of the cerebral cortex., trans. and ed. G. V. Anrep. New York: Dover.

Rankin, C. H., Abrams, T., Barry, R. J., Bhatnagar, S., Clayton, D. F., Colombo, J., Coppola, G., Geyer, M. A., Glanzman, D. L., Marsland, S., McSweeney, F. K., Wilson, D. A., Wu, C. F., & Thompson, R. F. (2009). Habituation revisited: an updated and revised description of the behavioral characteristics of habituation. Neurobiology of learning and memory, 92(2), 135–138.

Reynolds, G. S. (1961). An analysis of interactions in a multiple schedule. Journal of the Experimental Analysis of Behavior, 4, 107–117.

Schmid S., Wilson, D.A., & Rankin, C.H. (2015). Habituation mechanisms and their importance for cognitive function. Front. Integr. Neurosci. 8:97. doi: 10.3389/fnint.2014.00097

Sharpless, S. K., & Jasper, H. H. (1956). Habituation of the arousal reaction. Brain, 79, 655–680.

Thompson, R. F., & Spencer, W. A. (1966). Habituation: A model phenomenon for the study of neuronal substrates of behavior. Psychological Review, 73, 16–43.

Timmann, D., Musso, C., Kolb, F.P., Rijntjes, M., Jüptner, M., Müller, S.P., & Weiller, C.I. (1998). Involvement of the human cerebellum during habituation of the acoustic startle response: A PET study. Journal of Neurology, Neurosurgery & Psychiatry, 65, 771–773.

Typlt, M., Mirkowski, M., Azzopardi, E., Ruth, P., Pilz, PKD., and Schmid, S. (2013). Habituation of reflexive and motivated behavior in mice with deficient BK channel function. Front. Integr. Neurosci. 7:79. doi: 10.3389/fnint.2013.00079.

Urcelay, G.P., Miller, R.R., 2014. The functions of contexts in associative learning. Behav. Process. 104, 2–12.

Williams, L.E., Blackford, J.U., Luksik, A., Gauthier, I., & Heckers, S. (2013). Reduced habituation in patients with schizophrenia. Schizophrenia Research, 151, 124–132.

Zaccardi, M. (2012). Molecular mechanisms of short-term habituation in the leech Hirudo medicinalis. Behavioural Brain Research 229 (1), 235–243.