Through the Frosted Glass Pane: Blunted Physiological Responses to Extremely Under- and Over-Sized Body Pictures in Female Adolescents with Obesity – An Experimental Pilot Study

Problematic weight control behaviors during adolescence are associated with an in-creased risk of chronic obesity. Understanding how adolescents with obesity respond to body-related visual cues may offer insights into underlying motivational deficits. This ex-perimental pilot study employed a peripherally measured startle reflex paradigm to as-sess the involuntary emotional responses to images of underweight, normal-weight, and overweight bodies. Twenty female adolescents with obesity and 21 normal-sized control subjects between 14 and 21 years of age were presented with photos of female bodies. Im-ages from the International Affective Picture System served as reference material. The Self-Assessment Manikin was used as subjective measure, while startle reflex magnitude and skin conductance response served as objective measures. A significant interaction emerged for body-related stimuli. In the normal-weight group, underweight and over-weight body images elicited increased skin conductance responses (indicative of height-ened attention) and potentiated startle reflexes (indicative of behavioral avoidance). In contrast, adolescents with obesity exhibited a general physiological down-regulation across all body image categories, suggesting a dysfunction in motivational processing. These findings may reflect reduced emotional salience of body-related cues, potentially undermining intrinsic weight loss motivation. Future research should investigate the neurobiological basis and clinical significance of this response pattern.