Lyman‐α imaging of the SO 2 distribution on Io

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94916/1/grl12620.pd

Role of Basal Ganglia Circuits in Resisting Interference by Distracters: A swLORETA Study

BACKGROUND: The selection of task-relevant information requires both the focalization of attention on the task and resistance to interference from irrelevant stimuli. Both mechanisms rely on a dorsal frontoparietal network, while focalization additionally involves a ventral frontoparietal network. The role of subcortical structures in attention is less clear, despite the fact that the striatum interacts significantly with the frontal cortex via frontostriatal loops. One means of investigating the basal ganglia's contributions to attention is to examine the features of P300 components (i.e. amplitude, latency, and generators) in patients with basal ganglia damage (such as in Parkinson's disease (PD), in which attention is often impaired). Three-stimulus oddball paradigms can be used to study distracter-elicited and target-elicited P300 subcomponents. METHODOLOGY/PRINCIPAL FINDINGS: In order to compare distracter- and target-elicited P300 components, high-density (128-channel) electroencephalograms were recorded during a three-stimulus visual oddball paradigm in 15 patients with early PD and 15 matched healthy controls. For each subject, the P300 sources were localized using standardized weighted low-resolution electromagnetic tomography (swLORETA). Comparative analyses (one-sample and two-sample t-tests) were performed using SPM5® software. The swLORETA analyses showed that PD patients displayed fewer dorsolateral prefrontal (DLPF) distracter-P300 generators but no significant differences in target-elicited P300 sources; this suggests dysfunction of the DLPF cortex when the executive frontostriatal loop is disrupted by basal ganglia damage. CONCLUSIONS/SIGNIFICANCE: Our results suggest that the cortical attention frontoparietal networks (mainly the dorsal one) are modulated by the basal ganglia. Disruption of this network in PD impairs resistance to distracters, which results in attention disorders

The public life of the Swahili stonehouse, 14th - 15th centuries AD

Houses are an important subject of archaeological research, normally explored through the households they contain. This has established a deliberately social agenda for the archaeology of houses, yet has had the unintended consequence of creating bounded worlds for study. Although household archaeologies explore the ways that households contributed to broader social and economic realms, it is rare to think through the public role of houses for non-residents and the larger population of the settlement. This paper seeks to explore this more public aspect of houses using the data from archaeology at Songo Mnara, a 14th–15th century Swahili town on the southern Tanzanian coast. This was a time when stone-built domestic architecture was first emerging in this region. The archaeology of the houses provides data for a series of ways that the house was at the heart of the economic and political life of the town, as well as demonstrating a spatial continuity between indoor and outdoor spaces. It is therefore suggested that the domestic and residential functions of the house for a particular household should be balanced with an appreciation of the broader world of the house itself