BACKGROUND Schizophrenia is a severe mental disorder involving impairments in executive functioning, which are important cognitive processes that can be assessed by planning tasks such as the Stockings of Cambridge (SOC), and tasks of rule learning/abstraction such as the Wisconsin Card Sorting Test (WCST). We undertook this study to investigate the association between performance during separa...

PURPOSE Obstructive sleep apnea syndrome (OSAS) is associated with cognitive changes and executive functions are among the cognitive domains most affected. However, it is not completely understood which of the factor(s) among hypoxemia, repeated arousal, and sleepiness affect the executive functions. This study aims to evaluate the possible relationship between the executive functions and noctu...

The ability to adapt behavior in a changing environment is necessary for humans to achieve their goals and can be measured in the lab with tests of rule-based switching. Disease models, such as cocaine addiction, have revealed that alterations in dopamine interfere with adaptive set switching, culminating in perseveration. We explore perseverative behavior in individuals with cocaine use disord...

Objective: The Wisconsin Card Sorting Test (WCST) is often regarded as a prototypical neuropsychological test of set-shifting ability. However, it has been proposed that WCST performance involves cognitive processes other than set shifting, such as set maintenance and rule inference. Distinguishing between these processes is necessary for the meaningful interpretation of WCST performance defici...

BACKGROUND We studied relative cortical blood flow (relCBF) patterns associated to correct performance (CP) and perseverative error (PE) during Wisconsin Card Sorting Test (WCST) execution, in controls and patients with schizophrenia. SUBJECTS AND METHODS relCBF (regional cortical blood flow (rCBF) / whole cortex blood flow) of 10 well defined cortical regions was measured in 18 patients with...

We used PET to explore the neurophysiological changes that accompany cognitive disability in ageing, with a focus on the frontal lobe. Absolute regional cerebral blood flow (rCBF) was measured in 41 healthy volunteers, evenly distributed across an age range of 18-80 years, during two task paradigms: (i) the Wisconsin Card Sorting Test (WCST), which depends heavily on working memory and is parti...