Abstract

The purpose of this research was to examine the role of cognitive estimation in patients with schizophrenia and Alzheimer disease (AD), and also to investigate the role of gender and levels of education in the cognitive estimation. Participants were 43 patients with AD, schizophrenia and controls that were selected through matching sampling method in Iran. A demographic questionnaire and cognitive estimation test (CET) were used in this study. Resulting data demonstrated that patients with schizophrenia and AD had significantly higher size and quality underestimation than normal individuals and the control group had significantly higher size and time overestimation than patients with schizophrenia and AD. However, there weren’t any significant group differences in weight under estimation and overestimation. Findings indicated that gender didn’t have a significant effect in cognitive estimation and its dimensions. Nevertheless, the levels of education play significant roles in size underestimation, size overestimation, quality underestimation and time overestimation.

Key words: Cognitive estimation test (CET), schizophrenia, Alzheimer disease, gender, level of education.