Objectives:
The DEX-S Questionnaire is a tool often used in the self-report of executive difficulties. Numerous data demonstrate that the result of the DEX-S do not differentiate between healthy and clinical groups or people with different characteristics of brain pathology. Limited research taking into account lateralization of damage also did not provide the conclusive data. There were no relationships between the DEX-S result and the results of tasks evaluating cognitive function, including executive functions. There is an ongoing discussion on the clinical and ecological value of the DEX-S. In the face of inconclusive data, the own study was undertaken. The objective was: (1) to compare the overall result and the DEX-S profile of healthy people and people with brain pathology including the lateralization of brain pathology; and (2) determining the relationships between the result of the DEX-S and the level of selected cognitive competences. 115 people were enrolled in the study, including people without brain pathology (C; N = 74), people with damage to the left hemisphere (LH; N = 6), people with damage to the right hemisphere (RH, N = 12) and people with damage to both hemispheres (BH, N = 23).

Methods:
In the research the DEX-S, WAIS subtests: Vocabulary, Digit span forward and backwards, the MoCA test and the Affect Scale from the ProCog Questionnaire were applied.

Results:
The DEX-S overall result did not differentiate the groups. However, the RH and BH groups obtained the highest average scores and the LP group – the lowest. There were intergroup differences in the results of only a few DEX-S items. Patients with right and both hemispheres pathology reported a significantly higher level of difficulties in attention, greater susceptibility to distractors, deficits in planning, sequential operation and problem solving. The RH group performed poorer in tasks involving cognitive functions in comparison to other patients. All clinical groups differed from healthy persons in terms of results of tests/tasks evaluating selected cognitive functions. There were positive correlations between the DEX-S score and sense of anxiety, no association with age, and incidental correlations with the results of cognitive tasks in each research group.

Conclusions:
The results suggest that mechanisms of sense of executive deficits depend on lateralization of pathology. The higher sense of executive deficits in people with right hemisphere pathology may be due to the efficiency of delayed memory, and may reflect an adequate self-assessment of own competence. The low DEX-S result of the group with the left hemisphere pathology may result from reduced, despite the absence of aphasia, language /semantic skills and not from the lack of insight into executive deficits.