scholarly journals Neurobiology of Consciousness: Current Research and Perspectives

Studia Humana ◽  
2015 ◽  
Vol 4 (4) ◽  
pp. 23-38 ◽  
Author(s):  
Beata Płonka
Keyword(s):  
Experimental Data ◽  
Brain Function ◽  
Brain Connectivity ◽  
Brain Activity ◽  
Neural Correlates ◽  
Philosophical Tradition ◽  
Scientific Objective ◽  
Philosophical Approach ◽  
Philosophical Perspective ◽  
Neurobiological Research

Abstract Scientific, objective approach to consciousness has allowed to obtain some experimental data concerning brain activity, ignoring, however, the longstanding philosophical tradition. Spectacular development of neuroscience which has been observed recently made this dissonance particularly noticeable. The paper addresses the main problems of discrepancy between neurobiological research and philosophical perspective. Current opinions concerning neural correlates and models of consciousness are discussed, as well as the problems of working memory, attention, self, and disorders of consciousness. A new neurobiological approach to describe brain function in terms of brain connectivity (so-called connectome) is also presented. Finally, the need to introduce at least some aspects of philosophical approach directly into neurobiological research of consciousness is postulated.

scholarly journals Integrating TMS, EEG, and MRI as an Approach for Studying Brain Connectivity

2020 ◽  
Vol 26 (5-6) ◽  
pp. 471-486
Author(s):  
Romina Esposito ◽  
Marta Bortoletto ◽  
Carlo Miniussi
Keyword(s):  
Brain Function ◽  
Closed Loop ◽  
Current Knowledge ◽  
Brain Connectivity ◽  
Brain Activity ◽  
Brain Regions ◽  
Integrative Approach ◽  
Resonance Imaging ◽  
Neural Communication ◽  
Neural Interactions

The human brain is a complex network in which hundreds of brain regions are interconnected via thousands of axonal pathways. The capability of such a complex system emerges from specific interactions among smaller entities, a set of events that can be described by the activation of interconnections between brain areas. Studies that focus on brain connectivity have the aim of understanding and modeling brain function, taking into account the spatiotemporal dynamics of neural communication between brain regions. Much of the current knowledge regarding brain connectivity has been obtained from stand-alone neuroimaging methods. Nevertheless, the use of a multimodal approach seems to be a powerful way to investigate effective brain connectivity, overcoming the limitations of unimodal approaches. In this review, we will present the advantages of an integrative approach in which transcranial magnetic stimulation–electroencephalography coregistration is combined with magnetic resonance imaging methods to explore effective neural interactions. Moreover, we will describe possible implementations of the integrative approach in open- and closed-loop frameworks where real-time brain activity becomes a contributor to the study of cognitive brain networks.

Abstract W P387: Neurological Correlates Of Brain Function After Acute Stroke--A Dense Array EEG Study

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Jennifer Wu ◽  
Ramesh Srinivasan ◽  
Ana Solodkin ◽  
Steven L Small ◽  
Steven C Cramer
Keyword(s):  
Motor Cortex ◽  
Acute Stroke ◽  
Brain Function ◽  
Brain Connectivity ◽  
Brain Activity ◽  
Dense Array ◽  
Whole Brain ◽  
Regional Brain ◽  
Eeg Connectivity ◽  
Regional Brain Activity

INTRODUCTION: Measures of brain function can complement assessment of injury to inform clinical decision-making after stroke, but the most useful metrics remain uncertain. An acute stroke alters brain function in widespread areas. We therefore reasoned that a whole brain measure of brain function would be better related to behavioral deficits than a regional measure of brain function. METHODS: In 24 patients hospitalized for acute stroke, resting EEG (256 leads) was recorded for 3 min at the bedside and analyzed offline. Two EEG measures of brain function were extracted: [1] whole brain connectivity, which found the EEG frequency (from 1-30 Hz) and seed point (from among the 256 leads) that best fit whole brain coherence with total NIHSS scores, using a partial least squares regression model; and [2] regional brain activity, which found the EEG frequency and lead where spectral power was most strongly correlated with total NIHSS scores. Analyses were repeated focused on NIHSS motor subscores (Q4-6). All models were validated using a leave-one-out approach. RESULTS: The 24 patients were age 60.9±13.1yr, 3.5 ± 2.9 d post-onset (range 3hr-12d), and were studied in settings that included ER, ICU, and stroke ward. Whole brain EEG connectivity explained a large fraction of the variance in total NIHSS scores (r^2=0.72); this was achieved in the 2-4 Hz range, with seed over ipsilesional motor cortex, and with model predicting higher NIHSS score when this seed had greater coherence with contralesional frontal/motor regions. Regional brain activity, by comparison, explained a smaller fraction of variance (r^2=0.51), with maximal correlation between total NIHSS and regional EEG power found using a lead over contralesional motor cortex, at 2 Hz. Similar results for whole brain EEG connectivity were obtained when modeling NIHSS motor subscores in the 14 subjects with motor deficits (validated r^2=0.71). CONCLUSIONS: Dense array EEG recordings could be obtained early after stroke, rapidly and reliably, and at the bedside in widespread hospital settings. Whole brain connectivity measures corresponded to behavioral state better than measures of regional brain activity do. Results support the utility of EEG as a bedside method for evaluating brain functional status after stroke.

Simulated Driving and Brain Imaging: Combining Behavior, Brain Activity, and Virtual Reality

CNS Spectrums ◽  
2006 ◽  
Vol 11 (1) ◽  
pp. 52-62 ◽  
Author(s):  
Kara N. Carvalho ◽  
Godfrey D. Pearlson ◽  
Robert S. Astur ◽  
Vince D. Calhoun
Keyword(s):  
Virtual Reality ◽  
Brain Function ◽  
Driving Simulator ◽  
Alcohol Intoxication ◽  
Brain Activity ◽  
Neural Correlates ◽  
Brain Regions ◽  
Blood Levels ◽  
Imaging Data ◽  
Simulated Driving

ABSTRACTIntroduction:Virtual reality in the form of simulated driving is a useful tool for studying the brain. Various clinical questions can be addressed, including both the role of alcohol as a modulator of brain function and regional brain activation related to elements of driving.Objective:We reviewed a study of the neural correlates of alcohol intoxication through the use of a simulated-driving paradigm and wished to demonstrate the utility of recording continuous-driving behavior through a new study using a programmable driving simulator developed at our center.Methods:Functional magnetic resonance imaging data was collected from subjects while operating a driving simulator. Independent component analysis (ICA) was used to analyze the data. Specific brain regions modulated by alcohol, and relationships between behavior, brain function, and alcohol blood levels were examined with aggregate behavioral measures. Fifteen driving epochs taken from two subjects while also recording continuously recorded driving variables were analyzed with ICA.Results:Preliminary findings reveal that four independent components correlate with various aspects of behavior. An increase in braking while driving was found to increase activation in motor areas, while cerebellar areas showed signal increases during steering maintenance, yet signal decreases during steering changes. Additional components and significant findings are further outlined.Conclusion:In summary, continuous behavioral variables conjoined with ICA may offer new insight into the neural correlates of complex human behavior.

scholarly journals Interactions between sleep disturbances and Alzheimer’s disease on brain function: a preliminary study combining the static and dynamic functional MRI

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kaicheng Li ◽  
Xiao Luo ◽  
Qingze Zeng ◽  
Yerfan Jiaerken ◽  
Shuyue Wang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Risk Factor ◽  
Sleep Disturbance ◽  
Brain Function ◽  
Sleep Disturbances ◽  
Brain Activity ◽  
Vascular Risk Factor ◽  
Underlying Mechanism ◽  
Amyloid Pet

AbstractThough sleep disturbance constitutes the risk factor for Alzheimer’s disease (AD), the underlying mechanism is still unclear. This study aims to explore the interaction between sleep disturbances and AD on brain function. We included 192 normal controls, 111 mild cognitive impairment (MCI), and 30 AD patients, with either poor or normal sleep (PS, NS, respectively). To explore the strength and stability of brain activity, we used static amplitude of low-frequency fluctuation (sALFF) and dynamic ALFF (dALFF) variance. Further, we examined white matter hyperintensities (WMH) and amyloid PET deposition, representing the vascular risk factor and AD-related hallmark, respectively. We observed that sleep disturbance significantly interacted with disease severity, exposing distinct effects on sALFF and dALFF variance. Interestingly, PS groups showed the dALFF variance trajectory of initially increased, then decreased and finally increased along the AD spectrum, while showing the opposite trajectory of sALFF. Further correlation analysis showed that the WMH burden correlates with dALFF variance in PS groups. Conclusively, our study suggested that sleep disturbance interacts with AD severity, expressing as effects of compensatory in MCI and de-compensatory in AD, respectively. Further, vascular impairment might act as important pathogenesis underlying the interaction effect between sleep and AD.

scholarly journals DOES BRAIN ACTIVATION DURING FUNCTIONAL MOVEMENT TASKS DIFFERENTIATE BETWEEN GOOD AND BAD MOVERS? AN INTEGRATED NEUROIMAGING ASSESSMENT OF MOTOR CONTROL IN YOUNG ATHLETES

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0013
Author(s):  
Manish Anand ◽  
Jed A. Diekfuss ◽  
Dustin R. Grooms ◽  
Alexis B. Slutsky-Ganesh ◽  
Scott Bonnette ◽  
...  
Keyword(s):  
Motor Control ◽  
Range Of Motion ◽  
Brain Function ◽  
Sagittal Plane ◽  
Brain Activity ◽  
Frontal Plane ◽  
Acl Injury ◽  
Timing Error ◽  
Lingual Gyrus ◽  
Increased Activity

Background: Aberrant frontal and sagittal plane knee motor control biomechanics contribute to increased anterior cruciate ligament (ACL) injury risk. Emergent data further indicates alterations in brain function may underlie ACL injury high risk biomechanics and primary injury. However, technical limitations have limited our ability to assess direct linkages between maladaptive biomechanics and brain function. Hypothesis/Purpose: (1) Increased frontal plane knee range of motion would associate with altered brain activity in regions important for sensorimotor control and (2) increased sagittal plane knee motor control timing error would associate with altered activity in sensorimotor control brain regions. Methods: Eighteen female high-school basketball and volleyball players (14.7 ± 1.4 years, 169.5 ± 7 cm, 65.8 ± 20.5 kg) underwent brain functional magnetic resonance imaging (fMRI) while performing a bilateral, combined hip, knee, and ankle flexion/extension movements against resistance (i.e., leg press) Figure 1(a). The participants completed this task to a reference beat of 1.2 Hz during four movement blocks of 30 seconds each interleaved in between 5 rest blocks of 30 seconds each. Concurrent frontal and sagittal plane range of motion (ROM) kinematics were measured using an MRI-compatible single camera motion capture system. Results: Increased frontal plane ROM was associated with increased brain activity in one cluster extending over the occipital fusiform gyrus and lingual gyrus ( p = .003, z > 3.1). Increased sagittal plane motor control timing error was associated with increased brain activity in multiple clusters extending over the occipital cortex (lingual gyrus), frontal cortex, and anterior cingulate cortex ( p < .001, z > 3.1); see Figure 1 (b). Conclusion: The associations of increased knee frontal plane ROM and sagittal plane timing error with increased activity in regions that integrate visuospatial information may be indicative of an increased propensity for knee injury biomechanics that are, in part, driven by reduced spatial awareness and an inability to adequately control knee abduction motion. Increased activation in these regions during movement tasks may underlie an impaired ability to control movements (i.e., less neural efficiency), leading to compromised knee positions during more complex sports scenarios. Increased activity in regions important for cognition/attention associating with motor control timing error further indicates a neurologically inefficient motor control strategy. [Figure: see text]

scholarly journals A Fast Transform for Brain Connectivity Difference Evaluation

2021 ◽  
Author(s):  
Massimiliano Zanin ◽  
Ilinka Ivanoska ◽  
Bahar Güntekin ◽  
Görsev Yener ◽  
Tatjana Loncar-Turukalo ◽  
...  
Keyword(s):  
Brain Function ◽  
Functional Significance ◽  
Brain Connectivity ◽  
Network Reconstruction ◽  
Auxiliary Space ◽  
Fast Transform

AbstractAnatomical and dynamical connectivity are essential to healthy brain function. However, quantifying variations in connectivity across conditions or between patient populations and appraising their functional significance are highly non-trivial tasks. Here we show that link ranking differences induce specific geometries in a convenient auxiliary space that are often easily recognisable at mere eye inspection. Link ranking can also provide fast and reliable criteria for network reconstruction parameters for which no theoretical guideline has been proposed.

scholarly journals Brain hemodynamic response in Examiner–Examinee dyads during spatial short-term memory task: an fNIRS study

2021 ◽  
Author(s):  
Francesco Panico ◽  
Stefania De Marco ◽  
Laura Sagliano ◽  
Francesca D’Olimpio ◽  
Dario Grossi ◽  
...  
Keyword(s):  
Working Memory ◽  
Cognitive Processes ◽  
Short Term Memory ◽  
Spatial Working Memory ◽  
Brain Activity ◽  
Memory Task ◽  
Neural Correlates ◽  
Short Term ◽  
Term Memory ◽  
The Real

AbstractThe Corsi Block-Tapping test (CBT) is a measure of spatial working memory (WM) in clinical practice, requiring an examinee to reproduce sequences of cubes tapped by an examiner. CBT implies complementary behaviors in the examiners and the examinees, as they have to attend a precise turn taking. Previous studies demonstrated that the Prefrontal Cortex (PFC) is activated during CBT, but scarce evidence is available on the neural correlates of CBT in the real setting. We assessed PFC activity in dyads of examiner–examinee participants while completing the real version of CBT, during conditions of increasing and exceeding workload. This procedure allowed to investigate whether brain activity in the dyads is coordinated. Results in the examinees showed that PFC activity was higher when the workload approached or reached participants’ spatial WM span, and lower during workload conditions that were largely below or above their span. Interestingly, findings in the examiners paralleled the ones in the examinees, as examiners’ brain activity increased and decreased in a similar way as the examinees’ one. In the examiners, higher left-hemisphere activity was observed suggesting the likely activation of non-spatial WM processes. Data support a bell-shaped relationship between cognitive load and brain activity, and provide original insights on the cognitive processes activated in the examiner during CBT.

Error-related Persistence of Motor Activity in Resting-state Networks

2018 ◽  
Vol 30 (12) ◽  
pp. 1883-1901 ◽  
Author(s):  
Nicolò F. Bernardi ◽  
Floris T. Van Vugt ◽  
Ricardo Ruy Valle-Mena ◽  
Shahabeddin Vahdat ◽  
David J. Ostry
Keyword(s):  
Motor Learning ◽  
Resting State ◽  
Brain Connectivity ◽  
Brain Activity ◽  
Brain Networks ◽  
Neural Activation ◽  
Resting State Functional Connectivity ◽  
Movement Training ◽  
Movement Error ◽  
Human Participants

The relationship between neural activation during movement training and the plastic changes that survive beyond movement execution is not well understood. Here we ask whether the changes in resting-state functional connectivity observed following motor learning overlap with the brain networks that track movement error during training. Human participants learned to trace an arched trajectory using a computer mouse in an MRI scanner. Motor performance was quantified on each trial as the maximum distance from the prescribed arc. During learning, two brain networks were observed, one showing increased activations for larger movement error, comprising the cerebellum, parietal, visual, somatosensory, and cortical motor areas, and the other being more activated for movements with lower error, comprising the ventral putamen and the OFC. After learning, changes in brain connectivity at rest were found predominantly in areas that had shown increased activation for larger error during task, specifically the cerebellum and its connections with motor, visual, and somatosensory cortex. The findings indicate that, although both errors and accurate movements are important during the active stage of motor learning, the changes in brain activity observed at rest primarily reflect networks that process errors. This suggests that error-related networks are represented in the initial stages of motor memory formation.

Neuroplasticity in Music Learning

2018 ◽  
pp. 545-563
Author(s):  
Vesa Putkinen ◽  
Mari Tervaniemi
Keyword(s):  
Speech Processing ◽  
Cognitive Functions ◽  
Brain Function ◽  
Musical Training ◽  
Event Related Potentials ◽  
Training Transfer ◽  
Neural Correlates ◽  
Music Learning ◽  
Functional Brain ◽  
Related Potentials

Studies conducted during the last three decades have identified numerous differences between musicians and non-musicians in neural correlates of sensory, motor, and higher-order cognitive functions. Research employing event-related potentials/fields has been particularly important in this framework. This chapter reviews the evidence that has emerged from these studies with emphasis on longitudinal studies comparing functional brain development in children taking music lessons and those engaged in non-musical activities. The literature provides empirical and theoretical grounds for concluding that musical training enhances sound encoding skills that are relevant for both music and speech processing. The question whether the benefits of musical training transfer to more distantly related cognitive functions remains controversial, however. Finally, it appears likely that training-induced plasticity alone does not account for the differences in brain function between musicians and non-musicians and, conversely, that predisposing factors also play a role.

scholarly journals Physical exercise increases overall brain oscillatory activity but does not influence inhibitory control in young adults

2018 ◽  
Author(s):  
Luis F. Ciria ◽  
Pandelis Perakakis ◽  
Antonio Luque-Casado ◽  
Daniel Sanabria
Keyword(s):  
Physical Exercise ◽  
Inhibitory Control ◽  
Frequency Band ◽  
Brain Function ◽  
Acute Exercise ◽  
Brain Activity ◽  
Oscillatory Activity ◽  
Power Increase ◽  
Oscillatory Brain Activity ◽  
Exercise Induced

AbstractExtant evidence suggests that acute exercise triggers a tonic power increase in the alpha frequency band at frontal locations, which has been linked to benefits in cognitive function. However, recent literature has questioned such a selective effect on a particular frequency band, indicating a rather overall power increase across the entire frequency spectrum. Moreover, the nature of task-evoked oscillatory brain activity associated to inhibitory control after exercising, and the duration of the exercise effect, are not yet clear. Here, we investigate for the first time steady state oscillatory brain activity during and following an acute bout of aerobic exercise at two different exercise intensities (moderate-to-high and light), by means of a data-driven cluster-based approach to describe the spatio-temporal distribution of exercise-induced effects on brain function without prior assumptions on any frequency range or site of interest. We also assess the transient oscillatory brain activity elicited by stimulus presentation, as well as behavioural performance, in two inhibitory control (flanker) tasks, one performed after a short delay following the physical exercise and another completed after a rest period of 15’ post-exercise to explore the time course of exercise-induced changes on brain function and cognitive performance. The results show that oscillatory brain activity increases during exercise compared to the resting state, and that this increase is higher during the moderate-to-high intensity exercise with respect to the light intensity exercise. In addition, our results show that the global pattern of increased oscillatory brain activity is not specific to any concrete surface localization in slow frequencies, while in faster frequencies this effect is located in parieto-occipital sites. Notably, the exercise-induced increase in oscillatory brain activity disappears immediately after the end of the exercise bout. Neither transient (event-related) oscillatory activity, nor behavioral performance during the flanker tasks following exercise showed significant between-intensity differences. The present findings help elucidate the effect of physical exercise on oscillatory brain activity and challenge previous research suggesting improved inhibitory control following moderate-to-high acute exercise.

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