Clinimetric Evaluation of the Experienced Communication in Dementia Questionnaire.

BACKGROUND AND OBJECTIVES: Tools to measure self-perceived communication between persons with early-stage dementia and their caregivers are lacking. Therefore, we developed a questionnaire for Experienced Communication in Dementia (ECD) with a patient version (ECD-P) and a caregiver version (ECD-C), which contains items on (a) caregiver competence, (b) social communication, (c) communication difficulties, and (d) experienced emotions. This article describes the feasibility and clinimetric evaluation of this instrument. RESEARCH DESIGN AND METHODS: A prospective observational cohort study was conducted with 57 dyads (community-dwelling person with dementia and primary caregiver). ECD-P, ECD-C, and measures on quality of life, caregiver burden, cognitive functioning, physical functioning, and functional independence were administered. After 2 weeks, the dyads filled out the ECD again. Feasibility (completion time and missing values per item), internal consistency (Cronbach's α), test-retest reliability (intraclass correlation coefficients [ICCs]), and construct validity (hypotheses testing with Spearman's r) were evaluated. RESULTS: Mean completion time was 10 min per questionnaire. ICCs for test-retest reliability ranged from 0.67 to 0.78, except for ECD-P2 (ICC = 0.31). Internal consistency ranged from α = 0.75 to 0.82 for ECD-P1 and all parts of ECD-C, except for ECD-P2 (α = 0.66). Correlation coefficients for convergent validity ranged from r = 0.31 to 0.69 and correlation coefficients for divergent validity were r < 0.20 and statistically insignificant. DISCUSSION AND IMPLICATIONS: Pending future research, the ECD, except part ECD-P2, seems to be a promising tool to measure experienced communication between persons with early-stage dementia and their caregivers.

Striatal dopamine dissociates methylphenidate effects on value-based versus surprise-based reversal learning.

Psychostimulants such as methylphenidate are widely used for their cognitive enhancing effects, but there is large variability in the direction and extent of these effects. We tested the hypothesis that methylphenidate enhances or impairs reward/punishment-based reversal learning depending on baseline striatal dopamine levels and corticostriatal gating of reward/punishment-related representations in stimulus-specific sensory cortex. Young healthy adults (N = 100) were scanned with functional magnetic resonance imaging during a reward/punishment reversal learning task, after intake of methylphenidate or the selective D2/3-receptor antagonist sulpiride. Striatal dopamine synthesis capacity was indexed with [18F]DOPA positron emission tomography. Methylphenidate improved and sulpiride decreased overall accuracy and response speed. Both drugs boosted reward versus punishment learning signals to a greater degree in participants with higher dopamine synthesis capacity. By contrast, striatal and stimulus-specific sensory surprise signals were boosted in participants with lower dopamine synthesis. These results unravel the mechanisms by which methylphenidate gates both attention and reward learning.