Cognitive Evaluation of Patients With Eating Disorders

The Autism Spectrum Quotient (AQ) questionnarie has the purpose to evaluate the levels of autistic traits in each participant and permit to understand the differences between the groups.

The scoring of this questionnaire stays in the range 0-50, where 0 is the minimum and associated with less autistic traits and 50 is the maximum outcome possible, explaining elevated autistic traits. Usually, the cut-off is defined as 32, over that score is possible to define the presence of autistic traits.

The higher the percentage of perseverative errors out of the total errors made on the Wisconsin Card Sorting Test (WCST), the lower the subject's cognitive flexibility. The WCST assesses executive functions, particularly cognitive flexibility, set-shifting ability, and problem-solving strategies. Scoring is typically based on several indices, including number of categories completed, total errors, and perseverative errors, with perseverative errors often expressed as a percentage of total responses.

There is no universally accepted clinical cut-off for WCST performance, as interpretation is usually based on comparison with age-adjusted normative data; however, higher percentages of perseverative errors are generally interpreted as indicating greater executive dysfunction.

The scale starts at 0%, which indicates full cognitive flexibility, and increases accordingly torwards 100%, indicating cognitive rigidity.

The assessment of body representation is carried out through the scoring and comparison of participants' scores through the scoring of the Implicit Association Task (IAT), involving implicit associations with body images. Scores on the D-scores emerging as outcomes from the computerized IAT task will be evaluated. The interpretation of scoring has this pattern:

• +0.15 <: no implicit preference
• 0.16 - 0.35: weak preference
• 0.36 - 0.65: moderate preference
• > 0.65: strong preference

The theoretical range of D score is between -2 and 2, but in empirical practise it's moreover between -1,5 and 1,5.

The assessment of body representation is carried out through the scoring and comparison of participants' scores on one of the questionnaires included in the project, namely the Body Image Concern Inventory (BICI). It is a 19-item self-report questionnaire assessing dysmorphic concerns related to body image. Each item is rated on a 5-point Likert scale (1 = never, 5 = always). The total score is obtained by summing all items and ranges from 19 to 95, with higher scores indicating greater body image concern. A commonly used cut-off is ≥55 (95th percentile in normative samples), suggesting clinically relevant dysmorphic concern. The scale also includes two subscales: F1 - Dysmorphic Symptoms (preoccupation with perceived appearance flaws) and F2 - Symptom Interference (impact of these concerns on daily functioning).

The evaluation of inhibitory control capacity is carried out through a Go/No-go task. The test consists of high and low calorie food pictures or neutral stimuli (circles and squares). This kind of task presents two main outcomes: reaction time (RT) and accuracy.

Reaction time is recorded in milliseconds (ms) and has no theoretical maximum, but in this specific protocol the range of evaluations of answers is between 300 and 1000 ms, where stimuli under 300ms reflects a pattern of impulsivity and stimuli over 1000 ms of answers are not registred by the task, defining low reactivity.

Accuracy represents the percentage of correct responses (0-100%). The task does not have validated clinical cut-offs, as it is a continuous experimental measure rather than a diagnostic test. Normative interpretation is usually based on sample comparison or statistical ranges (e.g., mean ± 2 SD) rather than fixed thresholds.

The Eating Disorder Inventory-3 (EDI-3) is a self-report questionnaire used to assess psychological and behavioral traits associated with eating disorders and is commonly used in the differential diagnosis, particularly to evaluate body image disturbance. It includes 91 items rated on a 6-point Likert scale that are recoded from 0 to 4 and summed to produce 12 primary scales.

The instrument does not provide a single total score and cut-offs are not strictly diagnostic, although T-scores ≥60-65 are generally considered clinically elevated and ≥70 indicates high clinical concern.

Scales most relevant for research on body representation and differential diagnosis are Drive for Thinness, Body Dissatisfaction, and Bulimia, which form the Eating Disorder Risk Composite. Individuals with ARFID are expected to show low scores on these body-image related dimensions compared to those with Anorexia Nervosa or Bulimia Nervosa.