A comparison of cognitive interference in restrained and unrestrained eaters using a modified Stroop task : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University
Cognitive factors are thought to play a primary role in the etiology and maintenance of eating disorders. Self-report measures used to assess people with eating disorders are prone to demand characteristics due to the secrecy and denial that are that are symptomatic of eating disorders. One measure with content which is difficult to fabricate is the Stroop test. The Stroop test is a colour naming task that involves a cognitive interference effect thought to occur when the words to be colour named are emotionally relevant to the subjects' concerns or worries. All studies assessing cognitive interference with a Stroop task among eating disordered populations have reported that such subjects have delayed response times to food, weight and shape words when compared to control subjects without eating disorders, and when compared to Stroop tasks using neutral stimuli. Women who continually attempt to restrict their food intake in order to conform to cultural ideals of physical beauty may become restrained eaters. There is some evidence that suggests restrained eaters also show cognitive interference on food, weight, and shape Stroop tasks. Anxiety and depression are common symptoms among individuals with eating disorders but little is known about the relative strength of these symptoms in restrained and unrestrained eaters. It is plausible that people with eating disorders, restrained and unrestrained eaters may fall along a continuum in relation to eating related pathologies such as interference on food, weight, and shape Stroop tasks, and anxiety and depression. In the present study the performance of female restrained (n = 21) and unrestrained eaters (n = 34) were compared on two Stroop tasks, one involving food, weight, and shape words and the other involving anxiety words. They were also compared on measures of trait anxiety and depression. Contrary to expectations no group differences were found on any of these measures. The lack of significant group effects was potentially explained by very low levels of eating related symptomatology and trait anxiety in the restrained eaters group compared to control and normative comparison groups. These results suggested that the process of subject recruitment in obtaining volunteers to complete the Stroop tasks may have produced artifacts. Possible causes for the inconclusive results are discussed and recommendations for future research proposed.