TY  - JOUR
PY  - 2010//
TI  - Effects of modafinil and methylphenidate on visual attention capacity: a TVA-based study
JO  - Psychopharmacology
A1  - Finke, Kathrin
A1  - Dodds, Chris M.
A1  - Bublak, Peter
A1  - Regenthal, Ralf
A1  - Baumann, Frank
A1  - Manly, Tom
A1  - Müller, U.
SP  - 317
EP  - 329
VL  - 210
IS  - 3
N2  - INTRODUCTION: Theory of visual attention (TVA; Bundesen 1990) whole report tasks allow the independent measurement of visual perceptual processing speed and visual short-term memory (vSTM) storage capacity, unconfounded by motor speed. This study investigates how cognitive enhancing effects of psychostimulants depend on baseline performance and individual plasma levels. MATERIALS AND METHODS: Eighteen healthy volunteers (aged 20-35 years) received single oral doses of either 40 mg methylphenidate, 400 mg modafinil or placebo in a counterbalanced, double-blind crossover design. A whole report of visually presented letter arrays was performed 2.5-3.5 h after drug administration, and blood samples for plasma level analysis were taken. RESULTS: Methylphenidate and modafinil both enhanced perceptual processing speed in participants with low baseline (placebo) performance. These improvements correlated with subjective alertness. Furthermore, we observed differential plasma level-dependent effects of methylphenidate in lower and higher performing participants: higher plasma levels led to a greater improvement in low-performing participants and to decreasing improvement in high-performing participants. Modafinil enhanced visual short-term memory storage capacity in low-performing participants. CONCLUSIONS: This is the first pharmacological investigation demonstrating the usefulness of a TVA task for high-resolution and repeated cognitive parameter estimation after cognitive-enhancing medication. Our results confirm previous findings of attentional capacity improvements in low performers and extend the baseline dependency model to methylphenidate. Plasma level-dependent effects of psychostimulants can be modelled on an inverted U-shaped dose-response relationship, which is highly relevant to predict cognitive enhancing and detrimental effects of psychostimulants in patients with cognitive deficits (e.g., attention deficit hyperactivity disorder) and healthy volunteers (e.g., self-medicating academics).<p />  <p>Language: en</p>
LA  - en
SN  - 0033-3158
UR  - http://dx.doi.org/10.1007/s00213-010-1823-x
ID  - ref1
ER  -