The Past, Present, and Future of the Brain Imaging Data Structure (BIDS).

The Brain Imaging Data Structure (BIDS) is a community-driven standard for the organization of data and metadata from a growing range of neuroscience modalities. This paper is meant as a history of how the standard has developed and grown over time. We outline the principles behind the project, the mechanisms by which it has been extended, and some of the challenges being addressed as it evolves. We also discuss the lessons learned through the project, with the aim of enabling researchers in other domains to learn from the success of BIDS.

Increased Entropic Brain Dynamics during DeepDream-Induced Altered Perceptual Phenomenology.

In recent years, the use of psychedelic drugs to study brain dynamics has flourished due to the unique opportunity they offer to investigate the neural mechanisms of conscious perception. Unfortunately, there are many difficulties to conduct experiments on pharmacologically-induced hallucinations, especially regarding ethical and legal issues. In addition, it is difficult to isolate the neural effects of psychedelic states from other physiological effects elicited by the drug ingestion. Here, we used the DeepDream algorithm to create visual stimuli that mimic the perception of hallucinatory states. Participants were first exposed to a regular video, followed by its modified version, while recording electroencephalography (EEG). Results showed that the frontal region's activity was characterized by a higher entropy and lower complexity during the modified video, with respect to the regular one, at different time scales. Moreover, we found an increased undirected connectivity and a greater level of entropy in functional connectivity networks elicited by the modified video. These findings suggest that DeepDream and psychedelic drugs induced similar altered brain patterns and demonstrate the potential of adopting this method to study altered perceptual phenomenology in neuroimaging research.

A Joint Modelling Approach to Analyze Risky Decisions by Means of Diffusion Tensor Imaging and Behavioural Data.

Understanding dependencies between brain functioning and cognition is a challenging task which might require more than applying standard statistical models to neural and behavioural measures to be accomplished. Recent developments in computational modelling have demonstrated the advantage to formally account for reciprocal relations between mathematical models of cognition and brain functional, or structural, characteristics to relate neural and cognitive parameters on a model-based perspective. This would allow to account for both neural and behavioural data simultaneously by providing a joint probabilistic model for the two sources of information. In the present work we proposed an architecture for jointly modelling the reciprocal relation between behavioural and neural information in the context of risky decision-making. More precisely, we offered a way to relate Diffusion Tensor Imaging data to cognitive parameters of a computational model accounting for behavioural outcomes in the popular Balloon Analogue Risk Task (BART). Results show that the proposed architecture has the potential to account for individual differences in task performances and brain structural features by letting individual-level parameters to be modelled by a joint distribution connecting both sources of information. Such a joint modelling framework can offer interesting insights in the development of computational models able to investigate correspondence between decision-making and brain structural connectivity.

Brain-Machine Interface Induced Morpho-Functional Remodeling of the Neural Motor System in Severe Chronic Stroke.

Brain-machine interfaces (BMI) permit bypass motor system disruption by coupling contingent neuroelectric signals related to motor activity with prosthetic devices that enhance afferent and proprioceptive feedback to the somatosensory cortex. In this study, we investigated neural plasticity in the motor network of severely impaired chronic stroke patients after an EEG-BMI-based treatment reinforcing sensorimotor contingency of ipsilesional motor commands. Our structural connectivity analysis revealed decreased fractional anisotropy in the splenium and body of the corpus callosum, and in the contralesional hemisphere in the posterior limb of the internal capsule, the posterior thalamic radiation, and the superior corona radiata. Functional connectivity analysis showed decreased negative interhemispheric coupling between contralesional and ipsilesional sensorimotor regions, and decreased positive intrahemispheric coupling among contralesional sensorimotor regions. These findings indicate that BMI reinforcing ipsilesional brain activity and enhancing proprioceptive function of the affected hand elicits reorganization of contralesional and ipsilesional somatosensory and motor-assemblies as well as afferent and efferent connection-related motor circuits that support the partial re-establishment of the original neurophysiology of the motor system even in severe chronic stroke.

First-ever stroke incidence and 30-day case fatality in the Sicilian Aeolian archipelago, Italy.

BACKGROUND AND PURPOSE: Not many data on stroke epidemiology come from studies on islands. This is the first report on a Mediterranean archipelago population. METHODS: Using recommended criteria, from July 1, 1999, to June 30, 2002, information was collected on first-ever stroke and 30-day case fatality in Aeolian island residents (13,431). RESULTS: The overall crude incidence rate was 154 of 100,000 (95% CI, 118 to 197; 128 in men and 180 in women) or 180, 154, and 87, if adjusted to the Italian, European, and world populations, respectively. The 30-day case fatality rate was 24.2% (95% CI, 14.22 to 36.75). CONCLUSIONS: Besides genetic or dietary factors, our results may reflect local, limited possibilities of diagnosis and management for stroke patients.

Ischaemic stroke in young people: a prospective and long-term follow-up study.

BACKGROUND: A few studies have comprehensively assessed the epidemiology, aetiology, prognosis, and secondary prevention of ischaemic stroke in young adults. To gain further information on this field, we have prospectively studied a hospital-based series of young adults with a first-ever episode of cerebral ischaemia (CI). METHODS: Sixty consecutive patients aged 17-45 with ischaemic stroke (55 patients) or transient ischaemic attack within 24 h before hospital admission were recruited and investigated by a standardized rigorous protocol. The patients were followed up for >or=1 year after hospital discharge. Arbitrary doses of aspirin 100 mg/d or ticlopidine 250 mg b.i.d. in case of intolerance to aspirin were given for the secondary prevention. Adjusted-dose oral anticoagulation (INR target 2.5) was used in the presence of cardioembolism or hypercoagulable states. Endpoints included the residual disability, rated by modified Rankin Scale (RS) and Barthel Index (BI), and poststroke recurrence. RESULTS: CI was associated with two or more risk factors in 61.6% of patients. Cigarette smoking was more frequently associated with male gender (p < 0.05) and migraine history with female sex (p < 0.05). The atherothrombotic diagnostic subtype and the subtype from 'other cause' predominated significantly among patients >or=35 years old (p < 0.05) and <35 years (p < 0.025), respectively. The 'other cause' subset was more frequent in female gender (p < 0.05). Transoesophageal echocardiography (TEE) detected potential cardiac sources of emboli (PCSE) at an extent 3 times higher (p < 0.0001) than transthoracic echocardiography. Congenital heart defects were nearly threefold more frequent than acquired ones, with a prevalence of patent foramen ovale. At a mean of 6.1 +/- 2.6 years (confidence interval 5.4 to 6.8), follow-up data were available for only 54 patients, since five patients were lost and one died in the acute phase. Poststroke recurrence rate was low (7.4%) and no event was fatal. General handicap was severe to moderately severe (RS>3) in 11% of the patients, slight to moderate (1>or=RSor=95), 38.9% partially dependent (BI 60 to 86), and 11.1% fully dependent (BI <60). Thirty-seven (68.5%) patients returned to work, although adjustments (other job or part-time employment) were necessary for 10 out of them (27%). CONCLUSIONS: The present study, though limited by the relatively small number of subjects, suggests that the overall prognosis of ischaemic stroke in young adults is good. We strongly recommend TEE in all patients with ischaemic stroke as an essential tool to increase the detection of PCSE and make the therapeutic approach more efficient.