Die Neurowissenschaften als Herausforderung und Chance der Psychologie

Functional magnetic resonance imaging (fMRI) studiesofemotion, personality, and social cognition have drawn much attention in recent years, with high-profile studies frequently reporting extremely high (e.g., >.8) correlations between brain activation and personality measures. We show that these correlations are higher than should be expected given the (evidently limited) reliability of both fMRI and personality measures. The high correlations are all the more puzzling because method sections rarely contain much detail about how the correlations were obtained. We surveyed authors of 55 articles that reported findings of this kind to determine a few details on how these correlations were computed. More than half acknowledged using a strategy that computes separate correlations for individual voxels and reports means of only those voxels exceeding chosen thresholds. We show how this nonindependent analysis inflates correlations while yielding reassuring-looking scattergrams. This analysis technique was used to obtain the vast majority of the implausibly high correlations in our survey sample. In addition, we argue that, in some cases, other analysis problems likely created entirely spurious correlations. We outline how the data from these studies could be reanalyzed with unbiased methods to provide accurate estimates of the correlations in question and urge authors to perform such reanalyses. The underlying problems described here appear to be common in fMRI research of many kinds-not just in studies of emotion, personality, and social cognition.

Molecular-imaging studies of dopaminergic neurotransmission measure biomarkers of dopamine (DA), such as the DA transporter and D(1) and D(2) receptor densities in the living brain. These studies indicate that individual differences in DA functions are linked to cognitive performance irrespective of age, and serve as powerful mediators of age-related decline in executive functioning, episodic memory, and perceptual speed. This focused review targets several recent findings pertaining to these relationships. Specifically, we discuss novel evidence concerning (a) the role of DA in within-person cognitive variability; (b) age-related differences in DA release during cognitive processing; (c) DA release following cognitive training in younger and older adults; and (d) the relationship between DA and task-induced functional brain activity. Based on these lines of empirical inquiry, we outline a series of avenues for future research on aging, DA, and cognition. Copyright 2009 Elsevier Ltd. All rights reserved.

Many cognitive tasks have been developed by basic scientists to isolate and measure specific cognitive processes in healthy young adults, and these tasks have the potential to provide important information about cognitive dysfunction in psychiatric disorders, both in psychopathology research and in clinical trials. However, several practical and conceptual challenges arise in translating these tasks for patient research. Here we outline a paradigm development strategy--which involves iteratively testing modifications of the tasks in college students, in older healthy adults, and in patients--that we have used to successfully translate a large number of cognitive tasks for use in schizophrenia patients. This strategy makes it possible to make the tasks patient friendly while maintaining their cognitive precision. We also outline several measurement issues that arise in these tasks, including differences in baseline performance levels and speed-accuracy trade-offs, and we provide suggestions for addressing these issues. Finally, we present examples of 2 experiments, one of which exemplifies our recommendations regarding measurement issues and was a success and one of which was a painful but informative failure.