Habituation

Habituation is a decrement in response to repeated stimuli. It is a learning mechanism through which organisms are able to filter sensory inputs from their environment and thereby allocate scarce attentional resources to only the most relevant stimuli (Siddle 1991).

Habituation involves both peripheral and central nervous system processes. In the peripheral nervous system, the orienting response that alerts humans to novel stimuli originates in the reticular formation, a complex collection of nuclei in the upper brain stem with connections to the thalamus, hypothalamus and cortex. The orientation response explains reflexive physiological manifestations of attention – such as bodily reorientation toward the stimulus, elevated heart rate, accelerated eye blinking, and “sweaty palms” – in reaction to breaking news events, blaring commercial interruptions, or attention-grabbing sequences of violent or sexual activity. The orientation response must be suppressed, otherwise novel stimuli would never cease to be novel and completely occupy human attention, rendering the world a “buzzing confusion.” Habituation of the orienting response is associated with a diminution of the P300 component (a cortical response that follows exposure to an external stimulus by 300 milliseconds) of the event-related potential in the brain’s cortex. Functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) scan studies indicate that the amygdala, hippocampus, and medial/inferior temporal cortex are the locations in the central nervous system responsible for habituation in the higher brain centers (Fischer et al. 2003).

Affective habituation responses, or reductions in stimulus-evoked affective reactions as a result of previous exposure, may explain the “wear out” of popular media. Repeated exposure to unfamiliar stimuli produces an inverted U pattern. Pleasure initially increases from repeated exposure through reductions in fear and uncertainty, followed by a slow and linear decrease in pleasure with numerous repeated exposures, or habituation (Bornstein 1989). However, unlike the neutral and unfamiliar stimuli often used in habituation studies, highly valued and familiar stimuli, such as favorite songs or TV programs, habituate after only a few exposures and with no further increase in pleasure. Habituation of valenced, familiar stimuli is a conceptual process that readily generalizes to similar stimuli (Leventhal et al. 2007). Thus, the decline in the popularity of “reality programs” might be said to be the collective effect of individual-level affective habituation to individuals’ respective favorites from that genre.

Affective habituation to unpleasurable stimuli may explain desensitization to violence when narrowly defined as a reduction in emotion-related physiological reactivity to real violence (Carnagey et al. 2007). Within the general aggression model (GAM; Anderson & Bushman 2002), desensitization is thought to facilitate violent behavior as a result of suppressing initially fearful and anxious reactions to violence by repeatedly presenting violence in a positive context. In a controlled experiment, Carnagey et al. found attenuated physiological reactions to real life violence following a 20-minute exposure to a violent video game. Desensitization is also a factor in the effects of violent television (Bushman & Huesmann 2001).

Media habits, defined as media consumption behaviors that occur automatically without active self-instruction, are thought to result from the same economies of attention that drive other forms of habituation. While media consumers actively attend to initial media selections, they become inattentive to repeatedly enacted behaviors, diminish their self-regulation, and automatically repeat their media selections (LaRose & Eastin 2004). Media habits are found in uses and gratifications research as ritualized (as opposed to instrumental) gratifications (Rubin 1984). Excessive media habits have been characterized as addictions (Kubey & Csikszentmihalyi 2002), media habits that cause significant life crises. These studies have relied on self-reports of habit strength, while physiological measures of arousal are the norm in the psychological literature. Paper-and-pencil measures of habit strength that parallel those used by communication researchers have been validated against reaction-time measures that assess habit strength through word association tasks (Verplanken & Orbell 2003).

References:

1. Anderson, C. A., & Bushman, B. J. (2002). Human aggression. Annual Review of Psychology, 53, 27–51.
2. Bornstein, R. F. (1989). Exposure and affect: Overview and metaanalysis of research, 1968 –1987. Psychological Bulletin, 106(2), 265 –289.
3. Bushman, B. J., & Huesmann, L. R. (2001). Effects of televised violence on aggression. In D. G. Singer & J. L. Singer (eds.), Handbook of children and the media. Thousand Oaks, CA: Sage, pp. 223 –254.
4. Carnagey, N. L., Anderson, C. A., & Bushman, B. J. (2007). The effect of video game violence on physiological desensitization to real-life violence. Journal of Experimental Social Psychology, 43(3), 489 – 496.
5. 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(5), 387–392.
6. Kubey, R., & Csikszentmihalyi, M. (2002). Television addiction is no mere metaphor. Scientific American, 286(2), 74 – 81.
7. LaRose, R., & Eastin, M. S. (2004). A social cognitive theory of Internet uses and gratifications: Toward a new model of media attendance. Journal of Broadcasting and Electronic Media, 48(3), 358 –377.
8. Leventhal, A. M., Martin, R. L., Seals, R. W., Tapia, E., & Rehm, L. P. (2007). Investigating the dynamics of affect: Psychological mechanisms of affective habituation to pleasurable stimuli. Motivation and Emotion, 31(2), 145 –157.
9. Rubin, A. M. (1984). Ritualized and instrumental television viewing. Journal of Communication, 34(1), 67–77.
10. Siddle, D. A. T. (1991). Orienting, habituation, and resource allocation: An associative analysis. Psychophysiology, 28(3), 245 –259.
11. Verplanken, B., & Orbell, S. (2003). Reflections on past behavior: A self-report index of habit strength. Journal of Applied Social Psychology, 33(6), 1313 –1330.