The relationship between executive functions and fluid intelligence in early Parkinson’s disease

MARÍA ROCA; FACUNDO MANES; ANABEL CHADE; OSCAR GERSHANIK; ARÉVALO GONZALO; TERESA TORRALVA; JOHN DUNCAN

Buenos Aires

Congreso; 14th International Congress of Parkinson´s Disease and Movement Disorders; 2010

The Movement Disorder Society

OBJECTIVE: In the present study, we aimed to determine the role of fluid intelligence in frontal deficits shown by patients with Parkinson's Disease. BACKGROUND: Deficits in cognitive functions dependent upon the integrity of the prefrontal cortex are common in Parkinson's disease. In a recent study (Roca, 2009) we showed that fluid intelligence (g) is a substantial contributor to frontal deficits. For some classical executive tasks, frontal deficits were entirely explained by g. However, on a second set of frontal tasks, deficits remained even after fluid intelligence was statistically controlled. These latter tasks were associated particularly with anterior brain damage and included tests of Theory of Mind (Faux Pas) and Multitasking (Hotel Task). DESIGN/METHODS: We assesed a group of patients in the early stages of the disease (n= 32) and a group of control subjects (n= 22) with the aforementioned frontal tests, using the Raven Progressive Matrices to assess fluid intelligence.RESULTS: In line with our previous results, the significant differences found in some classical executive tests such as the WCST and Verbal Fluency became non-significant once fluid intelligence was introduced as a covariate. However, for tasks of Theory of Mind (Mind in the eyes) and multitasking (hotel task), deficits remained after fluid intelligence was statistically controlled. CONCLUSIONS: The present results suggest that clinical assessment of neuropsychological deficits in PD should include tests of fluid intelligence, supplemented with one or more specific tasks that allow for the assessment of residual frontal deficits associated with Theory of Mind and Multitasking.