Trinity College (Connecticut)

Abstract: Objective: The “default mode” has been defined as a baseline condition of brain function and is of interest because its component brain regions are believed to be abnormal in schizophrenia. It was hypothesized that the default mode network would show abnormal activation and connectivity in patients with schizophrenia. Method: Patients with schizophrenia (N=21) and healthy comparison subjects (N=22) performed an auditory oddball task during functional magnetic resonance imaging (fMRI). Independent component analysis was used to identify the default mode component. Differences in the spatial and temporal aspects of the default mode network were examined in patients versus comparison subjects. Results: Healthy comparison subjects and patients had significant spatial differences in the default mode network, most notably in the frontal, anterior cingulate, and parahippocampal gyri. In addition, activity in patients in the medial frontal, temporal, and cingulate gyri correlated with severity of positive symptoms. The patients also showed significantly higher frequency fluctuations in the temporal evolution of the default mode. Conclusions: Schizophrenia is associated with altered temporal frequency and spatial location of the default mode network. The authors hypothesized that this network may be under- or overmodulated by key regions, including the anterior and posterior cingulate cortex. In addition, the altered temporal fluctuations in patients may result from a change in the connectivity of these regions with other brain networks.

Abstract: Although numerous authorities have addressed the question, ‘What is a nation?’, far less attention has been paid to the question, ‘At what point in its development does a nation come into being?’ Evidence is offered that Europe's currently recognized nations emerged only very recently, often centuries later than the dates customarily assigned. In some cases, it is problematic whether nationhood has even yet been achieved. Four problems involved in dating the emergence of a nation are: (1) national consciousness is a mass not an elite phenomenon, and the masses, until quite recently semi‐ or totally illiterate, were quite mute with regard to their sense of group identity(ies); (2) nation‐formation is a process, not an occurrence, and the point in the process at which a sufficient number has internalized the national identity in order to cause nationalism to become an effective force for mobilizing the masses does not lend itself to precise calculation; (3) the process of nation‐formation is not se...