The Effect of Smartphone Addiction and Mental Fatigue on Working Memory in University Students

The Working Memory Questionnaire (WMQ) is a self-administered scale proposed by Vallat-Azouvi. It assesses the three different working memory domains (memory storage, attention, and executive functions). It consists of 30 questions, each scored on a five-point Likert-type scale ranging from 0 (not at all) to 4 (extremely). The total score varies between 0 and 120. Higher scores represent more memory difficulties/complaints.

This instrument to examine smartphone addiction was developed by Kwon et al. This scale consisted of six factors with ten items each, rated using the six-point Likert scale (1: strongly disagree, 2: disagree, 3: weakly disagree, 4: weakly agree, 5: agree, and 6: strongly agree).

The Mental Fatigue Scale (MFS) is a 15-item questionnaire that specifically evaluates mental fatigue. It includes affective, cognitive and sensory symptoms, duration of sleep and daytime variation in symptom severity. It has a 7-point Likert-type scale and is scored between 0 and 3. A rating of 0 indicates normal function, 1 slight problem, 2 significant problems and 3 maximum problems. There are also items such as 0.5, 1.5, 2.5 for marking when individuals fall between 2 items (0.5, 1.5, 2.5). The total score of the scale is obtained by summing the scores of the first 14 questions. The last question is evaluated as yes or no. The scores range from 0 to 42 and 0-10 indicates no mental fatigue problem, 10.5-14.5 indicates slight mental fatigue, 15-20 indicates fairly serious mental fatigue, and ≥ 20.5 indicates serious mental fatigue