Time setting errors in the Clock Drawing Test are associated with both semantic and executive deficits.

Area of Science:

• Neuropsychology
• Cognitive Neuroscience
• Gerontology

Background:

• The Clock Drawing Test (CDT) is used to assess cognitive function.
• A specific CDT task aims to elicit stimulus-bound responses (SBRs), thought to indicate executive dysfunction.
• The validity of SBRs as markers of executive dysfunction requires further investigation.

Purpose of the Study:

• To compare SBRs and other time-setting errors on the CDT with performance on inhibitory control tests.
• To investigate the role of semantic dysfunction in the formation of time-setting errors.
• To test the hypothesis that SBRs and other time errors represent related constructs.

Main Methods:

• Examined baseline performance of 258 participants (Mild Cognitive Impairment, history of depression, controls) in a dementia prevention study.
• Categorized participants based on CDT performance: SBRs (n=16), other time errors (n=22), or no errors (n=42).
• Compared performance on executive function and semantic tests across these groups, controlling for covariates.

Main Results:

• No significant differences in executive test performance were found between the SBR and other time error groups.
• Both error groups performed significantly worse than the no error group on semantic tests.
• Statistical controls supported the contribution of both semantic and executive components to time-setting errors.

Conclusions:

• Time-setting errors on the CDT, including SBRs, are associated with semantic deficits.
• Both semantic and inhibitory control impairments may contribute to general time representation errors.
• The assumption that SBRs specifically mark executive dysfunction may not be valid.