Schlezingerová Nicol, Málková Petra, Kocourek Martin, Telenský Petr
Department of Physiology, Faculty of Science, Charles University, Prague, Czechia.
Third Faculty of Medicine, Charles University, Prague, Czechia.
Front Psychol. 2024 Sep 9;15:1441184. doi: 10.3389/fpsyg.2024.1441184. eCollection 2024.
Food is a vital human need, and the human visual system is finely tuned to detect and respond to food cues in the environment. The omnipresence of food cues across various settings has been linked to the prevalence of obesity in susceptible populations. However, the influence of the post-prandial state on visual attention to food stimuli remains poorly understood. This study aimed to elucidate how a 12 hour fast affects visual attention to food and non-food stimuli in healthy, non-obese individuals.
Visual attention was assessed by measuring the total duration of visual fixations on stimuli presented on a computer screen, using a screen-based eye tracker (Tobii X2-60). Participants were divided into two groups: those who had fasted for 12 hours and those tested within two hours after consuming breakfast (satiated state). Additionally, performance on the Food Stroop task and electrodermal activity (EDA) responses were measured to evaluate attentional interference and physiological arousal, respectively. Salivary samples were also collected to assess levels of alpha-amylase and cortisol.
Fasted participants exhibited a progressive decline in visual attention toward food stimuli compared to satiated individuals, reflecting a satiated state. This effect was independent of the palatability of the depicted food items and was not observed with stimuli representing non-food items. The Food Stroop task revealed no differences between fasting and satiated participants, indicating that the presence of food-related stimuli does not differentially impact attentional interference under varying hunger states. Moreover, no significant variations were observed in EDA responses across participant groups and stimulus types, suggesting that the modulation of visual attention to food cues by hunger is independent of physiological arousal. Interestingly, satiated subjects exhibited higher levels of salivary alpha-amylase, which was inversely related to their subjective hunger ratings. No differences in salivary cortisol levels were found between groups.
The findings indicate a novel influence of mild hunger on the processing of visual food cues, independent of physiological arousal. The decline in visual attention to food stimuli in fasted individuals suggests that satiety modulates visual processing. The lack of differences in attentional interference and physiological arousal between fasting and satiated states further supports the notion that visual attention to food cues is primarily driven by hunger-related mechanisms rather than stress. Additionally, the inverse relationship between salivary alpha-amylase levels and hunger ratings implies that alpha-amylase may serve as a marker of satiety rather than stress.
食物是人类的一项基本需求，人类视觉系统经过精细调节，能够检测环境中的食物线索并做出反应。食物线索在各种环境中无处不在，这与易感人群中肥胖症的流行有关。然而，餐后状态对食物刺激视觉注意力的影响仍知之甚少。本研究旨在阐明12小时禁食如何影响健康、非肥胖个体对食物和非食物刺激的视觉注意力。
使用基于屏幕的眼动仪（Tobii X2 - 60），通过测量对电脑屏幕上呈现的刺激物的视觉注视总时长来评估视觉注意力。参与者被分为两组：禁食12小时的参与者和早餐后两小时内进行测试的参与者（饱腹状态）。此外，还测量了食物色词干扰任务的表现和皮肤电活动（EDA）反应，分别用于评估注意力干扰和生理唤醒。还收集了唾液样本以评估α - 淀粉酶和皮质醇水平。
与饱腹个体相比，禁食的参与者对食物刺激的视觉注意力逐渐下降，这反映了一种饱腹状态。这种效应与所描绘食物的可口性无关，在代表非食物项目的刺激物中未观察到这种效应。食物色词干扰任务显示禁食和饱腹参与者之间没有差异，这表明在不同饥饿状态下，与食物相关的刺激物的存在对注意力干扰没有差异影响。此外，在参与者组和刺激类型之间的EDA反应中未观察到显著差异，这表明饥饿对食物线索视觉注意力的调节与生理唤醒无关。有趣的是，饱腹的受试者唾液α - 淀粉酶水平较高，这与他们的主观饥饿评分呈负相关。两组之间唾液皮质醇水平没有差异。
研究结果表明，轻度饥饿对视觉食物线索处理有新的影响，且与生理唤醒无关。禁食个体对食物刺激的视觉注意力下降表明饱腹感调节视觉处理。禁食和饱腹状态之间在注意力干扰和生理唤醒方面缺乏差异，进一步支持了对食物线索的视觉注意力主要由饥饿相关机制而非压力驱动的观点。此外，唾液α - 淀粉酶水平与饥饿评分之间的负相关意味着α - 淀粉酶可能作为饱腹感而非压力的标志物。
