Visual Attention to Pictorial Food Stimuli in Individuals With Night Eating Syndrome: An Eye-Tracking Study

Abstract

Night eating syndrome (NES) is characterized by excessive evening and/or nocturnal eating episodes. Studies indicate an attentional bias towards food in other eating disorders. For NES, however, evidence of attentional food processing is lacking. Attention towards food and non-food stimuli was compared using eye-tracking in 19 participants with NES and 19 matched controls without eating disorders during a free exploration paradigm and a visual search task. In the free exploration paradigm, groups did not differ in initial fixation position or gaze duration. However, a significant orienting bias to food compared to non-food was found within the NES group, but not in controls. A significant attentional maintenance bias to non-food compared to food was found in both groups. Detection times did not differ between groups in the search task. Only in NES, attention to and faster detection of non-food stimuli were related to higher BMI and more evening eating episodes. The results might indicate an attentional approach-avoidance pattern towards food in NES. However, further studies should clarify the implications of attentional mechanisms for the etiology and maintenance of NES.

Eye‐tracking research in eating disorders: A systematic review

“…Firstly, those with BED showed more difficulty in inhibiting their automatic attention to both food and non-food stimuli compared to HC (Leehr et al, 2016(Leehr et al, , 2018Schag et al, 2013), as well as delayed disengagement to food stimuli, indicating increased food-related reward sensitivity (Schag et al, 2013;Schmidt et al, 2016;Sperling et al, 2017). The lack of group differences between those with NES and HCs suggests different attentional processes area associated with NES and BED (Baldofski et al, 2018). Difficulties in inhibitory control, a component of impulsivity, are likely to facilitate binge-eating behavior, therefore maintaining core psychopathology of the disorder (Balodis, Grilo, & Potenza, 2015).…”

“…For example, only three studies controlled for the effects of psychotropic medication on eye-movements (Fujiwara et al, 2017;Giel et al, 2011Giel et al, , 2013, while a further three only included participants who were medication free (Baldofski et al, 2018;Pallanti et al, 1998;Sperling et al, 2017). Atypical antipsychotics and benzodiazepines have been found to reduce saccadic velocity and increase latency in healthy individuals, due to their sedative effect on the central nervous system (Reilly, Lencer, Bishop, Keedy, & Sweeney, 2008).…”

“…Difficulties in inhibitory control, a component of impulsivity, are likely to facilitate binge-eating behavior, therefore maintaining core psychopathology of the disorder (Balodis, Grilo, & Potenza, 2015). The lack of group differences between those with NES and HCs suggests different attentional processes area associated with NES and BED (Baldofski et al, 2018). However, it is possible that the small sample size in the NES group (n = 19), especially when only full-syndrome cases were considered (n = 12), resulted in insufficient power to detect group differences.…”

“…Such factors may be important given the neural, cognitive, and low-level motor impairments that occur with malnutrition in AN (Joos et al, 2010;King et al, 2015;Titova et al, 2013;Zakzanis et al, 2010). Indeed, in the few studies that did report associations with clinical variables, higher BMI and ED psychopathology in those with BED or NES was found to be associated with shorter gaze duration to food stimuli (Baldofski et al, 2018;Schmidt et al, 2016). This pattern may reflect attentional avoidance or disengagement strategies being employed by those with more severe ED psychopathology.…”

“…All but one study (Watson et al, 2010) reported mean age of participants (range: 14.4-44.68 years), and only four studies did not report the mean BMI or % ideal body weight (IBW) of at least one participant group (Fujiwara et al, 2017;Stefano Pallanti et al, 1998;Pinhas et al, 2014;Watson et al, 2010). Most studies used exclusively female samples, however three studies examining either NES or BED included male participants (Baldofski et al, 2018;Schmidt et al, 2016;Sperling et al, 2017). A wide variety of tasks were employed, the most common being free-viewing, where participants are asked to simply view stimuli as if they were watching television.…”