Computerized Open-Source Navon Test (COSNaT): Normative data for the assessment of global processing abilities and...

Area of Science:

• Neuropsychology
• Cognitive Neuroscience
• Clinical Neurology

Background:

• Global processing deficits are linked to posterior cortical damage from lesions or neurodegenerative diseases like posterior cortical atrophy (PCA).
• Subtle impairments, such as those seen in multi-domain mild cognitive impairment (MCI), can precede severe symptoms like simultanagnosia.

Purpose of the Study:

• To establish normative data for the Computerized Open-Source Navon Test (COSNaT) within the Italian population.
• To validate the COSNaT's utility in identifying global processing deficits across diverse clinical groups.

Main Methods:

• Administered the COSNaT to 200 neurologically unimpaired Italian adults (mean age 57.2 years).
• Assessed performance based on errors and response times at global and local processing levels.
• Analyzed the impact of demographic factors (age, education, sex) on test results.

Main Results:

• Provided raw scores, regression-based adjustments for age and education, and equivalent scores for test indices.
• Demonstrated the COSNaT's sensitivity in detecting global processing impairments and simultanagnosia.
• Established population-specific norms for accurate clinical interpretation.

Conclusions:

• The COSNaT offers a valuable tool for the clinical characterization of neuropsychological profiles in patients with various etiologies.
• The test is effective in identifying deficits even in the early, prodromal stages of neurodegenerative diseases.
• Normative data supports the COSNaT's application in clinical settings for early detection and diagnosis.