Subconscious learning shapes pain responses

Subconscious learning shapes pain responses
Karin Jensen, PhD. Credit: Stefan Zimmerman

In a new study led from Sweden's Karolinska Institutet, researchers report that people can be conditioned to associate images with particular pain responses – such as improved tolerance to pain – even when they are not consciously aware of the images.  The findings are being published in the journal PNAS.

Previous studies have shown that a person's can be increased or decreased by associating a specific cue, such as an image, with high or low intensity pain. However, until now it has been unclear if it is necessary to be consciously aware of the cue in order to learn the association. In this recent study, Dr Karin Jensen and colleagues tested whether unconscious learning affected pain responses, by using subliminal images and training participants to associate a certain image with high pain and another image with low pain.

The study involved 49 participants in all, randomly assigned into four experimental groups that would elucidate the impact of different levels of during the experiment. All participants were generally healthy, with no chronic illnesses or psychiatric diagnoses. None of the participants reported receiving any medication apart from hormonal contraceptives.

In the experiment, images of different faces were presented on a computer screen. To some of the participants the images were shown so quickly that they could not be consciously recognized. For each image exposure, participants were subjected to pain stimulation and asked to rate the pain according to a specific scale. As each image was repeatedly associated with either high or low pain, it turned into a high pain cue or a low pain cue that would affect the participants' expectations.

The results suggest that pain cues could be learned without conscious awareness, as participants reported increased pain when shown the high pain image and reduced pain when shown the low pain image during identical levels of pain stimulation, regardless of whether or not the images were shown subliminally,

 "These results demonstrate that responses can be shaped by learning that takes place outside conscious awareness, suggesting that unconscious learning may have an extensive effect on higher cognitive processes in general", says Karin Jensen.


Explore further

Impaired sleep linked to lower pain tolerance

More information: "Classical conditioning of analgesic and hyperalgesic pain responses without conscious awareness." PNAS, published ahead of print May 15, 2015, DOI: 10.1073/pnas.1504567112
Citation: Subconscious learning shapes pain responses (2015, May 22) retrieved 15 October 2019 from https://medicalxpress.com/news/2015-05-subconscious-pain-responses.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
151 shares

Feedback to editors

User comments

May 22, 2015
Wow, seriously, stunning. Oh yea the paper, good work everybody!

Jun 14, 2015
Interesting study! I curated it with my POV at:
http://surfaceyou...ealself/

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more