This is an excerpt from an assignment I wrote. We will dive into the topic of ‘Habituation’ regarding the psychological science of learning and how we can use this learning for our own benefit.

Introduction

Habituation is a modified variation of an elicited behaviour (Collett, 2025a). This results in the decrease of the elicited behaviour, where it is shown as a decrease in strength and/or frequency (Collett, 2025a). This typically does not occur due to sensory or motor fatigue (Ranken et al. 2009). This can occur for a variety of reasons, including, the over-repetition and overall complexity of a stimulus, however, it is stimulus specific and does not occur as effectively if the stimulus itself changes (Collett, 2025a).

Background Concepts

The ‘elicited behaviour’ which can be habituated is a set or pattern of response to a specific stimulus used to start the behaviour intentionally (Collett, 2025b). An example of this is when a puff of air is intentionally directed at an individual’s eye, and they blink; here the ‘blink’ being the elicited behaviour. While habituation relates to the decrease of an elicited behaviour, ‘sensitization’ shows an increase in the behaviour (Collett, 2025a). As a result, habituation and sensitization are not mutually exclusive, instead each being the sum of each other where one aspect will show more dominantly than the other (Collett, 2025a). This is explained using the dual-process theory which categorizes habituation to occur in the ‘S-R system’ (stimulus-response), and sensitization to occur in the ‘state system’ (Collett, 2025a). While the S-R system activates with every elicited stimulus, the state system only does so in ‘arousing’ events (Collett, 2025a).

Habituation occurs from “repeated stimulation” (Ranken et al. 2009), where the over-use of a specific stimulus causes an increase in the habituation’s effect. The S-R system has the shortest neural pathway connecting the sense organs to the muscles; due to this, each time the elicited stimulus presents, the S-R system activates as well which builds up the habituation effect (Collett, 2025a). Essentially, the more often a specific stimulus is presented, the more habituation occurs, which decreases the elicited behaviour in strength and/or frequency. 

While the on-set of the same specific stimulus may result in habituation over time, distraction can cause dishabituation, lowering if not diminishing the amount and rate that habituation occurs (Collett, 2025a). This causes an individual to not notice or register the stimulus as much, or at all, thus the behaviour’s not habituating to the same degree as without distractions.

Complexity of the stimulus also has an impact on how quickly, and to what degree, habituation occurs. Similar to the concept of distractions, habituation can be affected by the amount that the stimulus is registered. As the complexity increases, longer attention is provided to the stimulus, and thus habituation is decreased (Collett, 2025a).

Key Experiment – Stimulus Frequency and Distractors

A foundational experiment showcasing the effect of habituation due to stimulus frequency is the ‘lemon-lime’ experiment. In this experiment, 8 women, ages 18-20 years who reportedly liked the taste of lemons were divided into two groups; one group would taste a lemon, and the other would taste a lime (Collett, 2025a). Dental rolls were then placed on their tongues after tasting to absorb their saliva, quantifying the physiological response to the lemon or lime’s taste (Collett, 2025a). The taste of lemon or lime was the eliciting stimulus, and the amount of saliva was the elicited behaviour. It was observed that after a certain amount of trials, presented as the number of times the lemon or limes were tasted, habituation occurred. As the women tasted the lemon or lime’s taste respectively, their saliva would decrease, showcasing their decreased response to the taste of lemon / lime (Collett, 2025a). This demonstrated that as the stimulus was repeated over and over, eventually the responses to the stimulus, shown as the behavior of saliva, decreased. 

Furthermore, reversed habituation was observed when the same groups were given the other fruit, lemon to the lime group and lime to the lemon group. The amount of saliva was seen to go back to normal levels similar to the beginning of the original experiment (Collett, 2025a). This demonstrated that while lemon and lime are similar, it was the specific lemon taste stimulus that caused habituation for the lemon group, and vice-versa. 

In another experiment, a similar set-up was used to the lemon-lime experiment, however the topic of dishabituators was studied. This included playing a video game for a set amount of time before tasting the lemon, then collecting saliva (Collett, 2025a). It was observed that the habituation of the elicited behaviour, in this case saliva, can be dishabituated when distractions are used, such as video games in this case. Similarly, another experiment utilized chocolate in the place of video games, resulting in a similar observation and conclusion (Collett, 2025a).

Key Experiment – Habituation Complexity

The concept of habituation and how it is affected by complexity of the stimulus can be observed with the ‘baby and the checkerboard’ experiment. A baby went through three phases of each test, the first where it would observe a checkerboard for around 10 seconds, followed by 10 seconds of another board, and then finally 10 seconds of the original board (Collett, 2025a). With the stimulus being the checkerboard, the elicited behaviour being observed was how long the baby would keep attention on the board (Collett, 2025a). The shorter its attention, the quicker habituation was assumed. It was observed that the baby’s attention was greatest for more complex pattern checkerboards compared to more simple designs (Collett, 2025a). Thus, the conclusion from this experiment was that habituation itself be decreased by more complex stimuli. 

Application and Importance

The concept and topic of habituation is integral in many walks and fields of life. From the viewpoint of psychology, habituation is a fundamental aspect in how learning forms. In the experiments provided, habituation can occur easily if the stimulus, and thus behaviour trying to be learned, occur too close together in time and feels boring. This concept illustrates how learning effectively requires correct time management and needs to sway away from feeling mundane. 

It also lends an eye into how everyday behaviours, over time, can lose their importance to us, and make us more used to their stimuli. With the lemon-lime experiment, it showcases how our taste regarding a specific taste changes over time. Despite our appreciation of a specific taste, over time, if we taste the same stimulus repeatedly, our appreciation for it may decreases as well.

Having distractions in our stimuli can hold off habituation in a sense, as well as increasing the complexity. This is seen even in restaurants and cooking, where instead of using the same taste palate which would quickly result in habituation of the taste, interesting and unique taste palates are used in combination to increase the complexity, and thus making the taste more appreciative for longer. 

In sum, the topic of habituation has substantial importance in not only the world of psychology and research, but can be observed in our day-to-day lives as well. By learning and understanding this topic, we can further improve our own learning ability, as well as practical use in jobs, events and the like!

References

Collet H. (2025, November 21). Lecture 2 – Elicited behaviour, Habituation, and Sensitization [Lecture notes, PowerPoint slides] Courselink. file:///C:/Users/awadf/Downloads/Lecture%202-%20Elicited%20behaviour,%20Habituation,%20and%20Sensitization%20PSYC2330%20F25%20(3).pdf

Collet H. (2025, November 21). Lecture 1 – Introduction [Lecture notes, PowerPoint slides] Courselink. https://courselink.uoguelph.ca/d2l/le/content/993374/viewContent/4256136/View

Oakes L. M. (2010). Using Habituation of Looking Time to Assess Mental Processes in Infancy. Journal of cognition and development : official journal of the Cognitive Development Society, 11(3), 255–268. https://doi.org/10.1080/15248371003699977

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. https://doi.org/10.1016/j.nlm.2008.09.012