Behavior in the Brain

2010 ◽  
Vol 24 (2) ◽  
pp. 76-82 ◽  
Author(s):  
Martin M. Monti ◽  
Adrian M. Owen
Keyword(s):  
Motor Behavior ◽  
Functional Neuroimaging ◽  
Brain Activity ◽  
Motor Output ◽  
The Unconscious ◽  
Ethical Implications ◽  
Brain Responses ◽  
Minimally Conscious ◽  
Brain Insults ◽  
Brain Behavior

Recent evidence has suggested that functional neuroimaging may play a crucial role in assessing residual cognition and awareness in brain injury survivors. In particular, brain insults that compromise the patient’s ability to produce motor output may render standard clinical testing ineffective. Indeed, if patients were aware but unable to signal so via motor behavior, they would be impossible to distinguish, at the bedside, from vegetative patients. Considering the alarming rate with which minimally conscious patients are misdiagnosed as vegetative, and the severe medical, legal, and ethical implications of such decisions, novel tools are urgently required to complement current clinical-assessment protocols. Functional neuroimaging may be particularly suited to this aim by providing a window on brain function without requiring patients to produce any motor output. Specifically, the possibility of detecting signs of willful behavior by directly observing brain activity (i.e., “brain behavior”), rather than motoric output, allows this approach to reach beyond what is observable at the bedside with standard clinical assessments. In addition, several neuroimaging studies have already highlighted neuroimaging protocols that can distinguish automatic brain responses from willful brain activity, making it possible to employ willful brain activations as an index of awareness. Certainly, neuroimaging in patient populations faces some theoretical and experimental difficulties, but willful, task-dependent, brain activation may be the only way to discriminate the conscious, but immobile, patient from the unconscious one.

Why the Assessment of Causality in Brain–Behavior Relations Requires Brain Stimulation

2012 ◽  
Vol 24 (4) ◽  
pp. 775-777 ◽  
Author(s):  
Juha Silvanto ◽  
Alvaro Pascual-Leone
Keyword(s):  
Opposite Direction ◽  
Brain Stimulation ◽  
Cognitive Neuroscience ◽  
Neural Activity ◽  
Functional Neuroimaging ◽  
Brain Activity ◽  
Causal Link ◽  
And Behavior ◽  
Brain Behavior

A central aim in cognitive neuroscience is to explain how neural activity gives rise to perception and behavior; the causal link of paramount interest is thus from brain to behavior. Functional neuroimaging studies, however, tend to provide information in the opposite direction by informing us how manipulation of behavior may affect neural activity. Although this may provide valuable insights into neuronal properties, one cannot use such evidence to make inferences about the behavioral significance of the observed activations; if A causes B, it does not necessarily follow that B causes A. In contrast, brain stimulation techniques enable us to directly modulate brain activity as the source of behavior and thus establish causal links.

scholarly journals Concurrent MEG-articulography for investigating neuromotor control of speech articulation

2020 ◽  
Author(s):  
Blake Johnson ◽  
Qinqing Meng ◽  
Ioanna Anastasopoulou ◽  
Louise Ratko ◽  
Tunde Szalay ◽  
...  
Keyword(s):  
Speech Production ◽  
Functional Neuroimaging ◽  
Brain Activity ◽  
Typically Developing ◽  
Facial Movements ◽  
Electromagnetic Articulography ◽  
Neuromotor Control ◽  
Brain Responses ◽  
First Time ◽  
Speech Kinematics

AbstractArticulography and functional neuroimaging are two major tools for studying the neurobiology of speech production. Until now, however, it has generally not been possible to use both in the same experimental setup because of technical incompatibilities between the two methodologies. Here we describe results from a novel articulography system dubbed Magneto-articulography for the Assessment of Speech Kinematics (MASK), used for the first time to obtain kinematic profiles of oro-facial movements during speech together with concurrent magnetoencephalographic (MEG) measurements of neuromotor brain activity. MASK was used to characterise speech kinematics in a healthy adult, and the results were compared to measurements from the same participant with a conventional electromagnetic articulography (EMA) setup. We also characterised speech movement kinematics with MASK in a group of ten typically developing children, aged 8-12 years. Analyses targeted the gestural landmarks of the utterances /ida/, /ila/ and reiterated productions of /pataka/. These results demonstrate that the MASK technique can be used to reliably characterise movement profiles and kinematic parameters that reflect development of speech motor control, together with MEG measurements of brain responses from speech sensorimotor cortex. This new capability sets the stage for cross-disciplinary efforts to understand the developmental neurobiology of human speech production.

Zinc, brain, behavior

2021 ◽  
Vol 19 (1) ◽  
pp. 23-35
Author(s):  
Аndrey F. Yakimovskii
Keyword(s):  
Zinc Concentration ◽  
Motor Behavior ◽  
Brain Activity ◽  
Human Cognition ◽  
Zinc Metabolism ◽  
Essential Trace Element ◽  
Mode Of Entry ◽  
Neurologic Disorders ◽  
Brain Behavior

The purpose of the review was to analyze current notions about role of essential trace element zinc in brain activity and therefore in behavior. At the beginning of the review the basic data about zinc metabolism was described. The facts of zinc involvement into neurologic disorders and human cognition were represented. The results of the own investigation, devoted zinc peroral treatment and intrabrain microinjections influence on rats normal and pathological motor behavior were described. In particular, it is shown that zinc, depending on the dose and its mode of entry into the organism, can weaken and prevent the development of picrotoxin-induced neostriatal hyperkinesis (human Huntington horea analog), but it may aggravate hyperkinesis symptoms and even independently cause the motor stereotypy. On the basis of their own data and literary, it was suggested that neurons membranes structures are different sensitive to a certain zinc concentration and what does the specific way of behavior realization is ultimately depend.

scholarly journals Brainwide organization of neuronal activity and convergent sensorimotor transformations in larval zebrafish

2018 ◽  
Author(s):  
Xiuye Chen ◽  
Yu Mu ◽  
Yu Hu ◽  
Aaron T. Kuan ◽  
Maxim Nikitchenko ◽  
...  
Keyword(s):  
Neuronal Activity ◽  
Motor Behavior ◽  
Brain Activity ◽  
Motor Output ◽  
Larval Zebrafish ◽  
Sensorimotor Transformations ◽  
Concerted Activity ◽  
Large Populations ◽  
Regression Techniques ◽  
Novel Model

AbstractSimultaneous recordings of large populations of neurons in behaving animals allow detailed observation of high-dimensional, complex brain activity. However, experimental design and analysis approaches have not sufficiently evolved to fully realize the potential of these methods. We recorded whole-brain neuronal activity for larval zebrafish presented with a battery of visual stimuli while recording fictive motor output. These data were used to develop analysis methods including regression techniques that leverage trial-to-trial variations and unsupervised clustering techniques that organize neurons into functional groups. We used these methods to obtain brain-wide maps of concerted activity, which revealed both known and heretofore uncharacterized brain nuclei. We also identified neurons tuned to each stimulus type and motor output, and revealed nuclei in the anterior hindbrain that respond to multiple stimuli that elicit the same behavior. However, these convergent sensorimotor representations were only weakly correlated to instantaneous motor behavior, suggesting that they inform, but do not directly generate, behavioral output. These findings motivate a novel model of sensorimotor transformation spanning distinct behavioral contexts, within which these hindbrain convergence neurons likely constitute a key step.

Functional Neuroimaging, Free Will, and Privacy

2010 ◽  
pp. 233-251 ◽  
Author(s):  
Nada Gligorov ◽  
Stephen C. Krieger
Keyword(s):  
Magnetic Resonance Imaging ◽  
Free Will ◽  
Ethical Issues ◽  
Functional Neuroimaging ◽  
Brain Activity ◽  
Moral Issues ◽  
Ethical Implications ◽  
Technological Advances ◽  
Brain States ◽  
The Impact

Technological advances in neuroscience have made inroads on the localization of identifiable brain states, in some instances purporting the individuation of particular thoughts. Brain imaging technology has given rise to what seem to be novel ethical issues. This chapter will assess the current abilities and limitations of functional neuroimaging and examine its ethical implications. The authors argue that currently there are limitations of fMRI (functional magnetic resonance imaging) and its ability to capture ongoing brain processes. They also examine the impact of neuroimaging on free will and privacy. The degree of variability of brain function precludes drawing meaningful conclusions about an individual’s thoughts solely from images of brain activity. The authors argue that neuroimaging does not raise novel challenges to privacy and free will, but is a recapitulation of traditional moral issues in a novel context.

scholarly journals Tracking attention in a visual active paradigm for the diagnosis of disorders of consciousness

2019 ◽  
Author(s):  
Damien Lesenfants ◽  
Camille Chatelle ◽  
Steven Laureys ◽  
Quentin Noirhomme
Keyword(s):  
Behavioral Response ◽  
Brain Activity ◽  
Minimally Conscious State ◽  
Conscious State ◽  
Disorders Of Consciousness ◽  
Unresponsive Wakefulness Syndrome ◽  
Attention Task ◽  
Attentional Processes ◽  
Brain Responses ◽  
Minimally Conscious

AbstractBackgroundClinical assessment of patients with disorders of consciousness (DOC) relies on the clinician’s ability to detect a behavioral response to an instruction (e.g., “squeeze my hand”). However, recent studies have shown that some of these patients can produce volitional brain responses to command while no behavioral response is present. This highlights the importance of developing motor-independent diagnostic tool for this population, complementing standardized behavioral evaluation. We here evaluate the ability of a novel gaze-independent attention-based EEG paradigm to detect volitional attentional processes in patients with disorders of consciousness.MethodsThirty patients with DOC were included in the study: 12 with an unresponsive wakefulness syndrome, 16 in a minimally conscious state (MCS), two who emerged from a MCS. Patients were randomly instructed to either concentrate on a task or rest while brain activity was recorded using EEG during a gaze-independent paradigm.ResultsOne of two EMCS, one of 16 MCS and one of 12 UWS patients showed a response to command using the attention task. Interestingly, this method could detect a brain-based response to command in one MCS patient who did not present a behavioral response to command at the bedside the day of the assessment.ConclusionThis study show that task-related variation of attention during an active task could help to objectively detect response to command in patients with DOC.

scholarly journals Delta band activity contributes to the identification of command following in disorder of consciousness

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gonzalo Rivera-Lillo ◽  
Emmanuel A. Stamatakis ◽  
Tristan A. Bekinschtein ◽  
David K. Menon ◽  
Srivas Chennu
Keyword(s):  
Functional Neuroimaging ◽  
Brain Activity ◽  
Disorder Of Consciousness ◽  
Fine Grained ◽  
Electrical Brain Activity ◽  
Delta Band ◽  
Delta Modulation ◽  
Command Following ◽  
Band Activity

AbstractThe overt or covert ability to follow commands in patients with disorders of consciousness is considered a sign of awareness and has recently been defined as cortically mediated behaviour. Despite its clinical relevance, the brain signatures of the perceptual processing supporting command following have been elusive. This multimodal study investigates the temporal spectral pattern of electrical brain activity to identify features that differentiated healthy controls from patients both able and unable to follow commands. We combined evidence from behavioural assessment, functional neuroimaging during mental imagery and high-density electroencephalography collected during auditory prediction, from 21 patients and 10 controls. We used a penalised regression model to identify command following using features from electroencephalography. We identified seven well-defined spatiotemporal signatures in the delta, theta and alpha bands that together contribute to identify DoC subjects with and without the ability to follow command, and further distinguished these groups of patients from controls. A fine-grained analysis of these seven signatures enabled us to determine that increased delta modulation at the frontal sensors was the main feature in command following patients. In contrast, higher frequency theta and alpha modulations differentiated controls from both groups of patients. Our findings highlight a key role of spatiotemporally specific delta modulation in supporting cortically mediated behaviour including the ability to follow command. However, patients able to follow commands nevertheless have marked differences in brain activity in comparison with healthy volunteers.

scholarly journals Peripheral BDNF: a candidate biomarker of healthy neural activity during learning is disrupted in schizophrenia

2014 ◽  
Vol 45 (4) ◽  
pp. 841-854 ◽  
Author(s):  
A. J. Skilleter ◽  
C. S. Weickert ◽  
A. Vercammen ◽  
R. Lenroot ◽  
T. W. Weickert
Keyword(s):  
Functional Neuroimaging ◽  
Brain Activity ◽  
Healthy Adults ◽  
Enzyme Linked Immunosorbent Assay ◽  
Association Learning ◽  
Healthy Humans ◽  
Important Regulator ◽  
Learning Test ◽  
Parietal Cortices ◽  
And Task

Background.Brain-derived neurotrophic factor (BDNF) is an important regulator of synaptogenesis and synaptic plasticity underlying learning. However, a relationship between circulating BDNF levels and brain activity during learning has not been demonstrated in humans. Reduced brain BDNF levels are found in schizophrenia and functional neuroimaging studies of probabilistic association learning in schizophrenia have demonstrated reduced activity in a neural network that includes the prefrontal and parietal cortices and the caudate nucleus. We predicted that brain activity would correlate positively with peripheral BDNF levels during probabilistic association learning in healthy adults and that this relationship would be altered in schizophrenia.Method.Twenty-five healthy adults and 17 people with schizophrenia or schizo-affective disorder performed a probabilistic association learning test during functional magnetic resonance imaging (fMRI). Plasma BDNF levels were measured by enzyme-linked immunosorbent assay (ELISA).Results.We found a positive correlation between circulating plasma BDNF levels and brain activity in the parietal cortex in healthy adults. There was no relationship between plasma BDNF levels and task-related activity in the prefrontal, parietal or caudate regions in schizophrenia. A direct comparison of these relationships between groups revealed a significant diagnostic difference.Conclusions.This is the first study to show a relationship between peripheral BDNF levels and cortical activity during learning, suggesting that plasma BDNF levels may reflect learning-related brain activity in healthy humans. The lack of relationship between plasma BDNF and task-related brain activity in patients suggests that circulating blood BDNF may not be indicative of learning-dependent brain activity in schizophrenia.

scholarly journals Humans with obesity have disordered brain responses to food images during physiological hyperglycemia

2018 ◽  
Vol 314 (5) ◽  
pp. E522-E529 ◽  
Author(s):  
Renata Belfort-DeAguiar ◽  
Dongju Seo ◽  
Cheryl Lacadie ◽  
Sarita Naik ◽  
Christian Schmidt ◽  
...  
Keyword(s):  
Brain Activity ◽  
Blood Oxygen Level Dependent ◽  
Normal Weight ◽  
Self Control ◽  
Food Cues ◽  
Brain Response ◽  
Glucose Levels ◽  
Hyperglycemic Clamp ◽  
Brain Responses ◽  
Food Images

Blood glucose levels influence brain regulation of food intake. This study assessed the effect of mild physiological hyperglycemia on brain response to food cues in individuals with obesity (OB) versus normal weight individuals (NW). Brain responses in 10 OB and 10 NW nondiabetic healthy adults [body mass index: 34 (3) vs. 23 (2) kg/m2, means (SD), P < 0.0001] were measured with functional MRI (blood oxygen level-dependent contrast) in combination with a two-step normoglycemic-hyperglycemic clamp. Participants were shown food and nonfood images during normoglycemia (~95 mg/dl) and hyperglycemia (~130 mg/dl). Plasma glucose levels were comparable in both groups during the two-step clamp ( P = not significant). Insulin and leptin levels were higher in the OB group compared with NW, whereas ghrelin levels were lower (all P < 0.05). During hyperglycemia, insula activity showed a group-by-glucose level effect. When compared with normoglycemia, hyperglycemia resulted in decreased activity in the hypothalamus and putamen in response to food images ( P < 0.001) in the NW group, whereas the OB group exhibited increased activity in insula, putamen, and anterior and dorsolateral prefrontal cortex (aPFC/dlPFC; P < 0.001). These data suggest that OB, compared with NW, appears to have disruption of brain responses to food cues during hyperglycemia, with reduced insula response in NW but increased insula response in OB, an area involved in food perception and interoception. In a post hoc analysis, brain activity in obesity appears to be associated with dysregulated motivation (striatum) and inappropriate self-control (aPFC/dlPFC) to food cues during hyperglycemia. Hyperstimulation for food and insensitivity to internal homeostatic signals may favor food consumption to possibly play a role in the pathogenesis of obesity.

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