Jon May

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May, J. (2003) Images of Desire

Paper presented at the British Association for the Advancement of Science's Festival of Science, at Salford Univesity, UK, on September 11th 2003

FlickeryDots5 software to show Dynamic Visual Noise on a Mac (980k Stuffit archive)

Powerpoint slides from talk

See also our papers in Memory, Addictive Behaviors and Psychological Review

Abstract

This paper reports the results of a questionnaire study and two experiments that look at ways of reducing craving by interfering with cravers' thought processes.

Addiction is often thought of as a physiological problem, that people are literally helpless to resist. Chemical pathways used by addictive substances have been identified, and drugs have been developed that interfere with them, in the aim of disrupting addictive processes.

Theories of addiction concentrate on the causes in the world and in the body, but the subjective and mental components of addiction have been neglected.

The feelings of craving that accompany addiction are seen as resulting from addiction, not themselves having a causal role in leading people to use substances, yet even advocates of drug interventions recognize the power of mental states: adverts for nicotine patches always say that they also 'require willpower'.

We are examining the thought processes that occur while people are craving something, and hope that by interfering with these processes we can suppress craving, to help people quit using addictive substances.

We have carried out a questionnaire study to examine what people think causes an episode of craving, and what it feels like at the time. This is important, because asking people about craving when they are not craving just gets you information about what people expect craving to be like ('folk psychology'), not necessarily what it really feels like when it is actually happening.

We sent a questionnaire to 1500 students in late August, just before they began University. The questionnaire asked them to keep it nearby until they realised that they were craving something. It asked them what they were craving, and to rate twelve things that might have caused the craving, and ten descriptions of their craving.

We received 361 replies (24%), roughly equally distributed between cravers of chocolate, snacks, soft drinks, tobacco, and other foods, with a smaller number of alcohol cravers.

Overall, cravers tend not to attribute their craving to any identifiable cue in the environment, but report them as spontaneous, or due to physiological sensations in the body (hunger, thirst, etc) and imaginary smells, tastes and sights. These causes are all 'internal', and involve mental awareness of the self.

Surprisingly, neither seeing the substance, nor being bored, nor being in a place or time where it was habitually used, were rated as causing these real cravings, even though common-sense ideas about craving and existing theories of additcion say that they should have been.

Four of the six statements highly rated as describing the craving related to the reward or relief that was anticipated from using the substance. The other two are that people imagine the taste or smell and can visualise themselves using the substance. Imagining the sound, though, is rated as least descriptive.

We have developed a theory of the mental aspects of craving that explains this pattern of results, the Elaborated Intrusion Theory. It rests on the recognition that there are many aspects of our thoughts and sensations that we process mentally without being consciously aware of them. Only when they reach awareness can they be subjectively identified and reported.

As with other theories, the EI theory recognises that external cues in the world, and internal cues in the body, along with other thoughts about a substance and being in a bad mood, can all be triggers of thoughts about a substance, but because these are usually outside awareness at the time, people rarely report them.

The thoughts and associations that they trigger can break into awareness. When they do so, they are experienced as spontaneous Intrusive Thoughts, that apparently come into one's mind out of the blue. Suddenly, you are thinking about something that you desire.

The immediate mental sense is of the potential reward and relief that using the substance would provide. This motivates people to continue thinking about the substance, elaborating their thoughts by searching their memory and constructing mental images of the substance.

Visual images of what it looks like and where it might be found would be helpful in obtaining the substance, were they actually to try to use it. These elaborated thoughts then also contribute to cycles of reward and further elaboration, so that the craving comes to dominate one's thoughts.

After a short time, though, the elaborated thoughts make us even more aware that we don't actually have the substance, and so become aversive as our sense of being without it grows and grows. This is the point at which many people's resistance cracks and they give in to their craving.

With a cognitive description of the processes involved in craving, it is possible to identify ways of interfering and perhaps suppressing the cycle of elaboration before it dominates thoughts. One path we are exploring is interfering with mental imagery, to prevent the strongest class of elaborated thoughts.

In one experiment, we asked two groups of smokers not to have a cigarette between waking up and coming into our lab, where we gave them an imagery task to perform. Half of them had to imagine eighteen sounds (such as a telephone ringing, or a baby crying), for ten seconds each. The other half had to imagine visual scenes (such as 'a game of tennis'). We also tested two groups of smokers who were not asked to abstain, but could smoke as normal. We asked all four groups to rate their craving before, during, and after the imagery.

The abstaining smokers who had to imagine sounds craved at a moderate level throughout the study, but the cravings of those who were imagining visual scenes fell away after the first minute of imagery, and they ended the experiment with lower cravings than the groups who had been allowed to smoke normally. It did seem as if giving craving smokers a visual imagery task to perform had blocked the cognitive processes needed to construct elaborated images, and so had stopped their craving.

We followed this up with a less obvious imagery intervention, in which people had to watch a screen full of black and white squares which randomly changed colour. Known as the flickery dots display, this has been shown in previous research to make mental imagery less vivid, and to interfere with memory tasks that require imagery. We found the same pattern of results: watching the flickery dots reduced the cravings of smokers who had abstained prior to the study to the same level as smokers who had been allowed to smoke normally.

As yet, these results only show that we can reduce the reported strength of cravings, not that our smokers actually went on to smoke less. If we can confirm that it actually affects behaviour, then we will be able to develop a cheap and non-drug based intervention that can help provide people with the willpower necessary to quit smoking, and maybe also to stop using other addictive substances.

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