Playing ‘Tetris’ reduces the strength, frequency and vividness of naturally occurring cravings

Highlights

• Playing Tetris reduced craving compared with a ‘wait’ condition.

• Tetris reduced the vividness and frequency of craving imagery.

• In contrast to previous laboratory studies, we tested naturally occurring cravings.

Abstract

Elaborated Intrusion Theory (EI) postulates that imagery is central to craving, therefore a visually based task should decrease craving and craving imagery. This study provides the first laboratory test of this hypothesis in naturally occurring, rather than artificially induced, cravings. Participants reported if they were experiencing a craving and rated the strength, vividness and intrusiveness of their craving. They then either played ‘Tetris’ or they waited for a computer program to load (they were told it would load, but it was designed not to). Before task completion, craving scores between conditions did not differ; after, however, participants who had played ‘Tetris’ had significantly lower craving and less vivid craving imagery. The findings support EI theory, showing that a visuospatial working memory load reduces naturally occurring cravings, and that Tetris might be a useful task for tackling cravings outside the laboratory. Methodologically, the findings show that craving can be studied in the laboratory without using craving induction procedures.

Introduction

Although cravings are an everyday occurrence amongst the general population (Lafay et al., 2001) they are linked to a variety of negative effects, even when they are resisted; for example, by causing distress and distraction (Green, Rogers, & Elliman, 2000). Craving can also be a precursor to binge eating in the general population (Gendall, Joyce, Sullivan, & Bulik, 1998), early dropout from weight loss program’s (Sitton, 1991), and the development of obesity (Schlundt, Virts, Sbrocco, & Pope-Cordle, 1993).

Elaborated Intrusion Theory (Andrade et al., 2012, Kavanagh et al., 2005, May et al., 2012) conjectures that craving is principally a working memory process where affectively-charged sensory images are maintained primarily in the visuo-spatial sketchpad. An internal or external trigger leads to a spontaneous thought that, depending on its salience and on current cognitive demands, will either be elaborated or ignored. When elaboration occurs, images are developed, maintained and elaborated using internal and external information (for example, recalling memories of previously eating chocolate). Previous research has shown that visual images are central to craving imagery, although other senses are also involved. In Kavanagh, May, and Andrade’s (2009) study, respondents on an alcohol dependence programme reported an average of 2.3 sensory modalities in their alcohol craving imagery. May, Andrade, Panabokke, and Kavanagh (2004) found over 60% of respondents reported visualising or tasting the substance they were craving.

Visual and auditory imagery load the limited-capacity, modality-specific slave systems of working memory, the visuospatial sketchpad and phonological loop respectively (Baddeley & Andrade, 2000). Involvement of these slave systems in a task can be blocked by irrelevant task loads such a task involving spatial manipulation or visual distraction in the case of the visuospatial sketchpad, or a verbal task in the case of the phonological loop. In support of the EI theory hypothesis that visual imagery is a key component of craving, there is accumulating evidence that visuospatial loads or competing neutral visual images selectively reduce craving, for cigarettes (May et al., 2010, Versland and Rosenberg, 2007) and for food (Andrade, Pears, et al., 2012, Harvey et al., 2005, Kemps and Tiggeman, 2007, Kemps et al., 2005, Kemps et al., 2004, McClelland et al., 2006, Steel et al., 2006).

Van Dillen, Nordren, and Andrade (submitted for publication) used the visuospatial task of playing the computer game Tetris to block craving for food. Stuart, Holmes, and Brewin (2006) had used this task to block encoding of visual images while participants watched a traumatic film; in the week that followed the film, participants experienced fewer intrusive images from segments of the film during which they had played Tetris than from other segments of the film. Holmes, James, Coode-Bate, and Deeprose (2009) found similar reductions in intrusive imagery when Tetris was played after viewing the traumatic material. In Van Dillen et al.’s study, Tetris reduced attentional biases to food pictures, reduced craving, and led to fewer participants choosing chocolate or marzipan as a reward rather than a piece of fruit. Tetris is assumed to load heavily on visuospatial working memory because it requires the player to rotate and move geometric shapes rapidly in order to complete rows of shapes without leaving gaps. It is easy to access over the internet, giving it the potential to be used as a take-home task to help people manage craving or traumatic imagery.

We aimed to replicate Van Dillen et al.’s (submitted for publication) finding, with an important difference. Previous studies of craving in the laboratory, including those cited above, have induced cravings when participants have come into the laboratory. For example, Andrade, Pears, et al. (2012) asked participants to inspect and evaluate chocolates; Van Dillen et al. (submitted for publication) asked participants to select items from a menu. The reasoning behind craving inductions is that the novelty and cognitive demand of the laboratory setting may itself reduce cravings, even when participants have abstained from the substance prior to taking part in the study. There is a risk, though, that working memory loads are doing nothing more than removing an artificially induced desire. We therefore recruited an unselected sample and aimed to measure and manipulate any naturally occurring cravings that they were experiencing.

Naturally occurring cravings might be more resistant to intervention because they are triggered by physiological deficit or conditioned cues. We therefore wanted to maximize the chance of finding an effect of visuospatial interference by comparing Tetris against a condition with minimal working memory demands, but at the same time we needed a control condition that would ensure that participants did not become distracted by anything else in their environment and would not be aware that they were in the control group. We therefore followed Van Dillen et al. (submitted for publication) by using a ‘wait’ condition. Van Dillen et al. told participants that the computer was old and the programme might take a while to load. They looked at a blank screen while waiting. In our study, participants saw a fake load screen that appeared to be showing Tetris loading, but never actually loaded.

Van Dillen et al. (submitted for publication) used behavioural measures of craving, that is, response biases to tempting foods and food choices at the end of the experiment, and a four-item craving scale. We used the Craving Experience Questionnaire (CEQ; Andrade, Pears, et al., 2012, May et al., 2014) developed from the Alcohol Craving Experience questionnaire (Kavanagh et al., 2009, Statham et al., 2011), to assess craving phenomenology in the control and intervention conditions. The CEQ provides a measure of craving strength, imagery, and intrusiveness. We also asked participants if they were under the influence of alcohol (including being hung-over) to check if this was a confounding variable, because Burton and Tiffany (1997) found that when people had consumed alcohol they had a general increase in craving compared to when they had not.