Neuromodulation with Attention Bias Modification Training for Binge Eating Disorder

Recruitment rate/month over months will be assessed to demonstrate that recruitment targets for the main trial can be met within an adequate time-frame. An average of 3 patients per month must be recruited (randomised) over a consecutive 12 month period (a minimum of 36 patients) in order to demonstrate a 'steady state' of recruitment.

The Eating Disorder Examination Questionnaire (EDE-Q) will be used to assess eating disorders symptoms. The EDE-Q is a 36-item self-report quesitonnaire, and a higher global score indicates more severe eating disorder symptoms.

The Food Craving Questionnaire (FCQ) will be used to assess trait-level craving for food. Total scores can range between 15 and 90, with higher scores indicating more frequent and intense food cravings.

The Depression, Anxiety and Stress- Scale (DASS-21) is a 21-item self-report questionnaire which aims to evaluate mood, anxiety and stress levels over the previous week. Sum scores for the total DASS range between 0 and 120, with higher scores indicating more severe psychopathology. Sub-scales assess depression, anxiety and stress symptoms specifically, and scores range from 0 to 42, with higher scores indicating more severe symptoms.

Weight and height will be combined to report body mass index in kg/m^2

The Food Attention Network Task (Food-ANT) will be used to assess three components of attention (i.e. orienting, alerting and executive function) using food (low- and high-calorie) versus non-food pictures (neutral items). Change in reaction time will be used to assess change in orienting, alerting and executive function.

The Visual Probe Task (VP) will be used to assess visuo-spatial attention biases for food cues. Change in dwell time measured by eye tracking and reaction time will be used to assess change in attention bias for food cues.

Participants are presented with a continuous stream of stimuli (either faces or words), and for every stimulus, the participant must indicate (yes/no) whether or not the current stimulus is the same as the one presented three trials back. This is known as the N-Back and is a measure of working memory. Higher numbers of correct responses indicates superior working memory function.

Neuropsychological task measuring information processing biases for positive and negative facial expressions. The participant is told a target emotion and asked to press a button only when the target emotion is present. The task consists of six blocks, each of which presents a series of faces showing either the target emotion or a differently valenced distractor. Reaction times are calculated for correct responses for each condition. Affective bias scores are calculated by subtracting the sad target/happy distractor condition reaction time from the happy target/sad distractor condition reaction time.

In Wisconsin Card Sorting Test (WCST) participants are asked to sort 64 cards to match either color (red, blue, yellow, or green), form (crosses, circles, triangles, or stars), or number of figures (one, two, three, four). During the task, the sorting rule changes discreetly from color to form or number of figures without the participants being informed. The participants have to shift sets accordingly and sort cards following the new sorting rule. Set shifting difficulties are indicated by preservative errors; thus, higher scores on this test represent poorer cognitive flexibility.