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Copyright of Zeitschrift für Neuropsychologie is the property of Hogrefe AG and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Among patients with multiple sclerosis (MS), fatigue is the most commonly reported symptom. It can be subdivided into an effort-dependent (fatigability) and an effort-independent component (trait-fatigue). Objective: The objective was to disentangle activity changes associated with effort-independent "traitfatigue" from those associated with effort-dependent fatigability in MS patients. Methods: This study employed behavioral measures and functional magnetic imaging to investigate neural changes in MS patients associated with fatigue. A total of 40 MS patients and 22 age-matched healthy controls performed in a fatigue-inducing N-back task. Effort-independent fatigue was assessed using the Fatigue Scale of Motor and Cognition (FSMC) questionnaire. Results: Effort-independent fatigue was observed to be reflected by activity increases in fronto-striatalsubcortical networks primarily involved in the maintenance of homeostatic processes and in motor and cognitive control. Effort-dependent fatigue (fatigability) leads to activity decreases in attention-related cortical and subcortical networks. Conclusion: These results indicate that effort-independent (fatigue) and effort-dependent fatigue (fatigability) in MS patients have functionally related but fundamentally different neural correlates. Fatigue in MS as a general phenomenon is reflected by complex interactions of activity increases in control networks (effort-independent component) and activity reductions in executive networks (effort-dependent component) of brain areas. [ABSTRACT FROM AUTHOR]

The article discusses if both action observation (AO) and action imagery should be used as options for stroke rehabilitation. Results showed that AO induced blood oxygenation level dependent (BOLD) signal increased in areas including the occipital, superior parietal cortex, and the prefrontal cortex. Addition of imagery increased activation in areas including both cerebellar hemispheres, inferior parietal cortex, and the supplementary motor area, which revealed that both be used in conjunction.

Purpose: Recent evidence from neuroimaging studies using visual tasks suggests that the right superior parietal cortex plays a pivotal role for the recovery of neglect. Importantly, neglect-related deficits are not limited to the visual system and have a rather multimodal nature. We employed somatosensory stimulation in patients with neglect in order to analyze activity changes in networks that are presumably associated with this condition. Methods: Eleven chronic neglect patients with right hemispherical stroke were investigated with a fMRI paradigm in which the affected and unaffected hand were passively moved. Results: Brain activation was correlated with the performance in clinical neglect tests. Significant positive correlations with brain activation were found for the lesion duration, the performance in bells and letter cancellation tests and the line bisection test. These activated areas formed a distributed pattern in the right superior parietal cortex. Conclusions: The results suggest a shared representation of visual and somatosensory networks in the right superior parietal cortex in patients with right hemispherical strokes and neglect. The spatial pattern of activity in the superior parietal cortex points out to a different representation of changes related to lesion duration and neglect. [ABSTRACT FROM AUTHOR]

Purpose: Recent studies have found age-related BOLD signal changes in several areas of the human brain. We investigated whether such changes also occur in brain areas involved in the processing of motor action observation and imagery. Methods: Functional magnetic resonance imaging with an experimental paradigm in which motor acts had to be observed and/or imagined from a first person perspective was performed in twenty-six subjects. Results: In line with previous work action observation and imagery induced BOLD signal increases in similar areas, predominantly in the premotor and parietal cortex. In contrast to young subjects the elderly displayed a stronger activity in most activated brain areas indicative of compensatory activity for the age-related decline of neural structures. Importantly, activity in the ventrolateral premotor cortex and inferior parietal cortex, seminal areas of the mirror neuron system, did not exhibit activity changes as a function of age. Conclusion: These findings suggest that activity within the mirror neuron system is not age dependent and provide a neural basis for therapeutical interventions and novel rehabilitation treatments such as video therapy. [ABSTRACT FROM AUTHOR]