An Investigation of Attentional Biases for Food and Body Stimuli in Women with Overweight and Obesity Using a Visual-Search Paradigm
Creators: name: McFarlane, Kimberlee
Publisher: name: The Australian National University
Year: 2021

description: Selective attention to food and body stimuli have been proposed as vulnerability factors for weight gain leading to overweight and obesity, yet research on attentional biases in this population has produced mixed findings. To assist in clarifying the nature of these attentional biases as a function of weight category, the present research examined attentional subcomponents (i.e., speeded detection and increased distraction) using a novel paradigm in this context, namely, the visual-search task. The final sample included women in the healthy-weight (n = 50), overweight (n = 41), and obese (n = 46) weight ranges according to World Health Organization (2000) guidelines. Parts One and Two of this research assessed attentional biases for low- and high-calorie food stimuli in individuals with overweight and obesity. Part One of this research tested the hypothesis that the overweight and obese groups would display speeded detection for low- and high-calorie food versus non-food images (i.e., plants or animals) when compared with the healthy-weight group. When the target images were foods and plants, and the distractor images were animals, results indicated that all weight groups engaged in speeded detection for food versus non-food images. However, relative to the overweight group, the obese group unexpectedly displayed reduced speeded detection for food images, which could represent a degree of avoidance of food in early attentional processing among women with obesity. These findings were not replicated when the target images were foods and animals, and the distractor images were plants. This latter finding may have been due to the visual and/or thematic similarity between foods and plants, rendering it more difficult to discern food targets among plant distractors relative to food targets among animal distractors. Part Two investigated the hypothesis that the overweight and obese groups would display increased distraction by low- and high-calorie food versus non-food images (i.e., plants or animals) when compared with the healthy-weight group. When the distractor images were foods and plants, and the target images were animals, no weight group differences were observed in increased distraction. In contrast, when the distractor images were food and animals, and the target images were plants, the obese group showed increased distraction by low-calorie food images relative to the healthy-weight group. Moreover, all weight groups showed increased distraction by high-calorie food versus non-food images. However, relative to the healthy-weight group, the overweight group surprisingly displayed reduced distraction by high-calorie food images. Overall, the unexpected pattern of results observed across Parts One and Two raises questions about whether attention toward or away from food stimuli is adaptive or maladaptive. Parts Three and Four of this research assessed attentional biases for body shape and weight stimuli in individuals with overweight and obesity. Part Three examined the hypothesis that the overweight and obese groups would display speeded detection for low- and high-weight body versus non-body images (i.e., shoes and cars) when compared with the healthy-weight group. Regardless of whether the shoe or car images performed the role of the target or distractor, no weight group differences were observed in speeded detection. Finally, Part Four investigated the hypothesis that the overweight and obese groups would display increased distraction by low- and high-weight body versus non-body images (i.e., shoes and cars). Again, regardless of the role performed by the non-body images (i.e., target or distractor), no weight group differences were observed in level of distraction. While it is plausible that biased attention for body stimuli does not form part of the core difficulties that contribute to overweight and obesity, it is also possible that the visual-search tasks used in Parts Three and Four were subject to a floor effect.