Temporal Deployment of Attention by Mental Training: an fMRI Study.

In this study, we employed a visuo-motor imagery task of alertness as a mental training to examine temporal processing of motor responses within healthy young adults. Participants were divided into two groups (group 1; n = 20 who performed the mental training before the real physical task and a control group who performed the physical task without mental training). We vary the time interval between the imperative stimulus and the preceding one (fore-period) in which temporal preparation and arousal increase briefly. Our behavioural results provide clear evidence that mental training reinforces both temporal preparation and arousal, by shortening reaction time (RT), especially for the shortest fore-periods (FP) within exogenous "FP 250 ms" (p = 0.008) and endogenous alertness "FP 650 ms" (p = 0.001). We investigated how the brain controls such small temporal changes. We focus our neural hypothesis on three brain regions: anterior insula, dorsolateral prefrontal cortex, and anterior cingulate cortex and three putative circuits: one top-down (from dorsolateral prefrontal cortex to anterior cingulate cortex) and two bottom-up (from anterior insula to dorsolateral prefrontal cortex and anterior cingulate cortex). In fMRI, effective connectivity is strengthened during exogenous alertness between anterior insula and dorsolateral prefrontal cortex (p = 0.001), between anterior insula and cingulate cortex (p = 0.01), and during endogenous alertness between dorsolateral prefrontal cortex and anterior cingulate cortex (p = 0.05). We suggest that attentional reinforcement induced by an intensive and short session of mental training induces a temporal deployment of attention and allow optimizing the time pressure by maintaining a high state of arousal and ameliorating temporal preparation.

Neurophysiology of CSWS-associated cognitive dysfunction.

The phenomenon of continuous spikes and waves during slow-wave sleep (CSWS) is associated with a number of epileptic syndromes, which share a behavioral phenotype characterized by deterioration of cognitive, behavioral, or sensorimotor functions. Available evidence seems to suggest that spike-wave activity is a result of a complex interaction between cortical and subcortical inhibitory networks and can "per se" produce a transient loss of underlying cortical functions. Syndromes like Landau-Kleffner syndrome, CSWS, and phenomena such as negative myoclonus could share in common--at least at the neurophysiological level--some similarities. Differences in behavioral phenotypes could be explained in term of maturational and genetic differences, as well as by the functional specificity of the involved areas.

Pre-attentive auditory sensory processing in autistic spectrum disorder. Are electromagnetic measurements telling us a coherent story?

Sensory processing is a crucial underpinning of the development of social cognition, a function which is compromised in variable degree in patients with pervasive developmental disorders (PDD). In this manuscript, we review some of the most recent and relevant contributions, which have looked at auditory sensory processing derangement in PDD. The variability in the clinical characteristics of the samples studied so far, in terms of severity of the associated cognitive deficits and associated limited compliance, underlying aetiology and demographic features makes a univocal interpretation arduous. We hypothesise that, in patients with severe mental deficits, the presence of impaired auditory sensory memory as expressed by the mismatch negativity could be a non-specific indicator of more diffuse cortical deficits rather than causally related to the clinical symptomatology. More consistent findings seem to emerge from studies on less severely impaired patients, in whom increased pitch perception has been interpreted as an indicator of increased local processing, probably as compensatory mechanism for the lack of global processing (central coherence). This latter hypothesis seems extremely attractive and future trials in larger cohorts of patients, possibly standardising the characteristics of the stimuli are a much-needed development. Finally, specificity of the role of the auditory derangement as opposed to other sensory channels needs to be assessed more systematically using multimodal stimuli in the same patient group.

Carbon Dioxide Insufflation During Cardiac Surgery: A Meta-analysis of Randomized Controlled Trials.

Despite the widespread use of carbon dioxide insufflation (CDI) in cardiac surgery, there is still paucity of evidence to prove its benefit in terms of neurologic protection. Therefore, we conducted a meta-analysis of available randomized controlled trials comparing CDI vs standard de-airing maneuvers. Electronic searches were performed to identify relevant randomized controlled trials. Primary outcomes investigated were postoperative stroke, neurocognitive deterioration, and in-hospital mortality. Risk difference (RD) was used as summary statistic. Pooled estimates were obtained by means of random-effects model to account for possible clinical diversity and methodological variation between studies. Eight studies were identified with 668 patients randomized to CDI (n = 332) vs standard de-airing maneuvers (n = 336). In-hospital mortality was 2.1% vs 3.0% in the CDI and control group, respectively (RD 0%; 95% confidence interval [CI] -2% to 2%; P = 0.87; I2 = 0%). Incidence of stroke was similar between the 2 groups (1.0% vs 1.2% in the CDI and control group, respectively; RD 0%; 95% CI -1% to 2%; P = 0.62; I2 = 0%). Neurocognitive deterioration rate was 12% vs 21% in the CDI and control group, respectively, but this difference was not statistically significant (RD: -7%; 95% CI -0.22% to 8%; P = 0.35; I2 = 0%). The present meta-analysis did not find any significant protective effect from the use of CDI when compared with manual de-airing maneuvers in terms of clinical outcomes, including postoperative neurocognitive decline.