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The "intentional stance" is the disposition to treat an entity as a rational agent, possessing particular beliefs, desires, and intentions, in order to interpret and predict it's behavior. The intentional stance is a component of a broader social cognitive function, mentalizing. Here we report a study that investigates the neural substrates of "on-line" mentalizing, using PET, by asking volunteers to second-guess an opponent. In order to identify brain activity specifically associated with adoption of an intentional stance, we used a paradigm that allowed tight control of other cognitive demands. Volunteers played a computerised version of the children's game "stone, paper, scissors." In the mentalizing condition volunteers believed they were playing against the experimenter. In the comparison condition, volunteers believed they were playing against a computer. In fact, during the actual scanning, the "opponent" produced a random sequence in both conditions. The only difference was the attitude, or stance, adopted by the volunteer. Only one region was more active when volunteers adopted the intentional stance. This was in anterior paracingulate cortex (bilaterally). This region has been activated in a number of previous studies involving mentalizing. However, this is the first study suggesting a specific link between activity in this brain region and the adoption of an intentional stance.

Objectives-Since Devic's original description of neuromyelitis optica in 1894 there has been much debate regarding its aetiology. A specific cause has been identified in a minority of cases but in most the question has arisen whether or not Devic's neuromyelitis optica is a variant of multiple sclerosis. This study was undertaken to help clarify this issue. Methods-Neuromyelitis optica was defined as (1) a severe transverse myelitis; (2) an acute unilateral or bilateral optic neuropathy; (3)

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Objective-The serial quantification of MRI lesion load in multiple sclerosis provides an eVective tool for monitoring disease progression and this has led to its increasing use as an outcome measure in treatment trials. Segmentation techniques must display a high degree of precision and reliability if they are to be responsive to small changes over time. This study has evaluated the performance of two such techniques, the manual outlining and contour methods, in serial lesion load quantification. Methods-Sixteen patients with clinically definite multiple sclerosis were scanned at baseline and after two years. Scan analysis was performed twice, independently by three observers using each technique. Results-For the absolute lesion volumes the median intrarater coeYcient of variation (CV) was 3.2% for the contour technique and 7.6% for the manual outlining method (p<0.005), the interrater CVs were 3.8% and 6.1% respectively (p<0.01) and the reliability of both techniques was very high. For the change in lesion volume the intrarater and interrater repeatability coeYcients were respectively 2.6 cm 3 and 2.8 cm 3 for the contour technique, and 3.3 cm 3 and 3.7 cm 3 for the manual outlining method (lower values reflect higher precision). The values for intrarater and interrater reliability for measuring change in lesion volume were respectively, 0.945 and 0.944 for the contour technique, and 0.939 and 0.921 for the manual outline method (perfect reliability = 1.0). Conclusions-With such high values for reliability, the impact of measurement error in lesion segmentation on sample size requirements in multiple sclerosis treatment trials is minor. This study shows that a change in lesion volume can be measured with a higher level of precision and reliability with the contour technique and this supports its further application in serial studies. (J Neurol Neurosurg Psychiatry 1998;65:42-47)

BackgroundBilateral training (BT) of the upper limb (UL) might enhance recovery of arm function after stroke. To better understand the therapeutic potential of BT, this study aimed to determine the correlation between arm motor behavior and brain structure/function as a result of bilateral arm training poststroke.MethodsA systematic review of quantitative studies of BT evaluating both UL motor behavior and neuroplasticity was conducted. Eleven electronic databases were searched. Two reviewers independently selected studies, extracted data and assessed methodological quality, using the Effective Public Health Practice Project (EPHPP) tool.ResultsEight studies comprising 164 participants met the inclusion criteria. Only two studies rated “strong” on the EPHPP tool. Considerable heterogeneity of participants, BT modes, comparator interventions and measures contraindicated pooled outcome analysis. Modes of BT included: in‐phase and anti‐phase; functional movements involving objects; and movements only. Movements were mechanically coupled, free, auditory‐cued, or self‐paced. The Fugl‐Meyer Assessment (UL section) was used in six of eight studies, however, different subsections were used by different studies. Neural correlates were measured using fMRI and TMS in three and five studies, respectively, using a wide variety of variables. Associations between changes in UL function and neural plasticity were inconsistent and only two studies reported a statistical correlation following BT.ConclusionsNo clear pattern of association between UL motor and neural response to BT was apparent from this review, indicating that the neural correlates of motor behavior response to BT after stroke remain unknown. To understand the full therapeutic potential of BT and its different modes, further investigation is required.

Serial MRI is an important measure of disease progression in evaluating the treatment of multiple sclerosis (MS). Accurate comparisons of scans for lesion activity and lesion volume require precise repositioning of patients. A simple, reproducible repositioning method is described. In a multicenter treatment trial of MS using beta-interferon-1b, this method has been successful, with only 1.1% of scans being rejected because of poor repositioning.