Comment: Study demonstrating habituation (declining dopamine response) to the same sexual stimuli (film or fantasy), and an increase in sexual arousal (increased dopamine) when exposed to a novel sexual stimuli. This is an example of the Coolidge effect at work – more dopamine when presented with a novel sexual possibility. Novelty is what makes Internet porn different from porn of the past.

Behav Res Ther.

1993 Jul;31(6):575-85.

Koukounas E, Over R.

Source: Department of Psychology, La Trobe University, Bundoora, Victoria, Australia.


Sixteen men were tested under conditions where they viewed the same segment of erotic film on many occasions or engaged repeatedly in the same erotic fantasy. Decrements in penile tumescence and subjective sexual arousal over trials were accompanied by reports from Ss that they felt less absorbed in the events depicted in film or fantasy (and in the case of fantasy, that the images they formed became less vivid).

Analysis of covariance showed that habituation (reduction in physiological and subjective measures of sexual arousal over trials) was less when allowance was made for the manner in which absorption (and in vividness of imagery in the case of fantasy) changed during erotic stimulation. Increases in sexual arousal when novel erotic stimulation was introduced following habituation, as well as the dishabituation found when the original stimulus was reinstated, also correlated with the extent absorption and vividness of imagery shifted under these conditions. The results are discussed with reference to whether habituation of male sexual arousal is mediated by changes that occur in absorption and other aspects of information processing during repeated erotic stimulation. (emphasis supplied)