SummaryBackground Patients diagnosed as vegetative have periods of wakefulness, but seem to be unaware of themselves or their environment. Although functional MRI (fMRI) studies have shown that some of these patients are consciously aware, issues of expense and accessibility preclude the use of fMRI assessment in most of these individuals. We aimed to assess bedside detection of awareness with an electroencephalography (EEG) technique in patients in the vegetative state.

Objective: Functional connectivity in the default mode network (DMN) is known to be reduced in patients with disorders of consciousness, to a different extent depending on their clinical severity. Nevertheless, the integrity of the structural architecture supporting this network and its relation with the exhibited functional disconnections are very poorly understood. We investigated the structural connectivity and white matter integrity of the DMN in patients with disorders of consciousness of varying clinical severity. Methods: Fifty-two patients-19 in a vegetative state (VS), 27 in a minimally conscious state (MCS), and 6 emerging from a minimally conscious state (EMCS)-and 23 healthy volunteers participated in the study. Structural connectivity was assessed by means of probabilistic tractography, and the integrity of the resulting fibers was characterized by their mean fractional anisotropy values. Results: Patients showed significant impairments in all of the pathways connecting cortical regions within this network, as well as the pathway connecting the posterior cingulate cortex/precuneus with the thalamus, relative to the healthy volunteers. Moreover, the structural integrity of this pathway, as well as that of those connecting the posterior areas of the network, was correlated with the patients' behavioral signs for awareness, being higher in EMCS patients than those in the upper and lower ranges of the MCS patients, and lowest in VS patients. Interpretation: These results provide a possible neural substrate for the functional disconnection previously described in these patients, and reinforce the importance of the DMN in the genesis of awareness and the neural bases of its disorders. ANN NEUROL 2012;72:335-343 P atients with disorders of consciousness (DOC) show metabolic impairments and functional disconnections within corticocortical and thalamic-cortical areas of the default mode network (DMN) [1][2][3][4] to an extent that appears to correspond to clinical severity. 5 Thus, poorer functional connectivity is observed in vegetative state (VS) patients (who show no behavioral signs of awareness) 6 than in minimally conscious state (MCS) patients (who show intermittent behavioral signs of awareness). 7It is generally assumed that functional connectivity within intrinsic networks reflects structural connectivity. A plausible hypothesis, then, is that the reduced functional connectivity observed in the DMN of DOC patients reflects structural disconnections within this network, providing anatomical support for the description of these patients as suffering from ''disconnection syndromes.'' 8 However, the relationship between structure and function in the DMN is not straightforward. 9 It has View this article online at wileyonlinelibrary.com.

Cognitive Linguistics argues that language is governed by general cognitive principles, rather than by a special-purpose language module. This introductory textbook surveys the field of cognitive linguistics as a distinct area of study, presenting its theoretical foundations and the arguments supporting it. Clearly organised and accessibly written, it provides a useful introduction to the relationship between language and cognitive processing in the human brain. It covers the main topics likely to be encountered in a course or seminar, and provides a synthesis of study and research in this fast-growing field of linguistics. The authors begin by explaining the conceptual structures and cognitive processes governing linguistic representation and behaviour, and go on to explore cognitive approaches to lexical semantics, as well as syntactic representation and analysis, focusing on the closely related frameworks of cognitive grammar and construction grammar. This much-needed introduction will be welcomed by students in linguistics and cognitive science.

Highlights d Narrative stimuli can synchronize fluctuations of heart rate between individuals d This interpersonal synchronization is modulated by attention and predicts memory d These effects on heart rate cannot be explained by modulation of respiratory patterns d Synchrony is lower in patients with disorders of consciousness

Patients in the Vegetative State (VS) do not produce overt motor behavior to command and are therefore considered to be unaware of themselves and of their environments. However, we recently showed that high-density electroencephalography (EEG) can be used to detect covert command-following in some VS patients. Due to its portability and inexpensiveness, EEG assessments of awareness have the potential to contribute to a standard clinical protocol, thus improving diagnostic accuracy. However, this technique requires refinement and optimization if it is to be used widely as a clinical tool. We asked a patient who had been repeatedly diagnosed as VS for 12-years to try to move his left and right hands, between periods of rest, while EEG was recorded from four scalp electrodes. We identified appropriate and statistically reliable modulations of sensorimotor beta rhythms following commands to try to move, which could be significantly classified at a single-trial level. These reliable effects indicate that the patient attempted to follow the commands, and was therefore aware, but was unable to execute an overtly discernable action. The cognitive demands of this novel task are lower than those used previously and, crucially, allow for awareness to be determined on the basis of a 20-minute EEG recording made with only four electrodes. This approach makes EEG assessments of awareness clinically viable, and therefore has potential for inclusion in a standard assessment of awareness in the VS.