scholarly journals Neural Correlates of Passive Position Finger Sense After Stroke

2019 ◽  
Vol 33 (9) ◽  
pp. 740-750 ◽  
Author(s):  
Morgan L. Ingemanson ◽  
Justin R. Rowe ◽  
Vicky Chan ◽  
Jeff Riley ◽  
Eric T. Wolbrecht ◽  
...  
Keyword(s):  
Primary Motor Cortex ◽  
Clinical Status ◽  
Sensory System ◽  
Somatosensory System ◽  
Neural Correlates ◽  
Neural Function ◽  
Neural Basis ◽  
Behavioral Measures ◽  
Neural Injury ◽  
Secondary Somatosensory Cortex

Background. Proprioception of fingers is essential for motor control. Reduced proprioception is common after stroke and is associated with longer hospitalization and reduced quality of life. Neural correlates of proprioception deficits after stroke remain incompletely understood, partly because of weaknesses of clinical proprioception assessments. Objective. To examine the neural basis of finger proprioception deficits after stroke. We hypothesized that a model incorporating both neural injury and neural function of the somatosensory system is necessary for delineating proprioception deficits poststroke. Methods. Finger proprioception was measured using a robot in 27 individuals with chronic unilateral stroke; measures of neural injury (damage to gray and white matter, including corticospinal and thalamocortical sensory tracts), neural function (activation of and connectivity of cortical sensorimotor areas), and clinical status (demographics and behavioral measures) were also assessed. Results. Impairment in finger proprioception was present contralesionally in 67% and bilaterally in 56%. Robotic measures of proprioception deficits were more sensitive than standard scales and were specific to proprioception. Multivariable modeling found that contralesional proprioception deficits were best explained ( r2= 0.63; P = .0006) by a combination of neural function (connectivity between ipsilesional secondary somatosensory cortex and ipsilesional primary motor cortex) and neural injury (total sensory system injury). Conclusions. Impairment of finger proprioception occurs frequently after stroke and is best measured using a quantitative device such as a robot. A model containing a measure of neural function plus a measure of neural injury best explained proprioception performance. These measurements might be useful in the development of novel neurorehabilitation therapies.

scholarly journals Somatosensory system integrity explains differences in treatment response after stroke

Neurology ◽  
2019 ◽  
Vol 92 (10) ◽  
pp. e1098-e1108 ◽  
Author(s):  
Morgan L. Ingemanson ◽  
Justin R. Rowe ◽  
Vicky Chan ◽  
Eric T. Wolbrecht ◽  
David J. Reinkensmeyer ◽  
...  
Keyword(s):  
Treatment Response ◽  
Motor Behavior ◽  
Hand Function ◽  
Sensory System ◽  
Somatosensory System ◽  
Proprioceptive Feedback ◽  
Neural Function ◽  
Neural Basis ◽  
Motor Systems ◽  
System Integrity

ObjectiveTo test the hypothesis that, in the context of robotic therapy designed to enhance proprioceptive feedback via a Hebbian model, integrity of both somatosensory and motor systems would be important in understanding interparticipant differences in treatment-related motor gains.MethodsIn 30 patients with chronic stroke, behavioral performance, neural injury, and neural function were quantified for somatosensory and motor systems. Patients then received a 3-week robot-based therapy targeting finger movements with enhanced proprioceptive feedback.ResultsHand function improved after treatment (Box and Blocks score increase of 2.8 blocks, p = 0.001) but with substantial variability: 9 patients showed improvement exceeding the minimal clinically important difference (6 blocks), while 8 patients (all of whom had >2-SD greater proprioception deficit compared to 25 healthy controls) showed no improvement. In terms of baseline behavioral assessments, a somatosensory measure (finger proprioception assessed robotically) best predicted treatment gains, outperforming all measures of motor behavior. When the neural basis underlying variability in treatment response was examined, somatosensory-related variables were again the strongest predictors. A multivariate model combining total sensory system injury and sensorimotor cortical connectivity (between ipsilesional primary motor and secondary somatosensory cortices) explained 56% of variance in treatment-induced hand functional gains (p = 0.002).ConclusionsMeasures related to the somatosensory network best explained interparticipant differences in treatment-related hand function gains. These results underscore the importance of baseline somatosensory integrity for improving hand function after stroke and provide insights useful for individualizing rehabilitation therapy.ClinicalTrials.gov identifier:NCT02048826.

scholarly journals Neural basis of somatosensory target detection independent of uncertainty, relevance, and reports

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Pia Schröder ◽  
Timo Torsten Schmidt ◽  
Felix Blankenburg
Keyword(s):  
Somatosensory Cortex ◽  
Target Detection ◽  
Cognitive Processes ◽  
Neural Correlates ◽  
Perceptual Awareness ◽  
Stimulus Uncertainty ◽  
Neural Basis ◽  
Secondary Somatosensory Cortex ◽  
Frontoparietal Network

Research on somatosensory awareness has yielded highly diverse findings with putative neural correlates ranging from activity within somatosensory cortex to activation of widely distributed frontoparietal networks. Divergent results from previous studies may reside in cognitive processes that often coincide with stimulus awareness in experimental settings. To scrutinise the specific relevance of regions implied in the target detection network, we used functional magnetic resonance imaging (n = 27) on a novel somatosensory detection task that explicitly controls for stimulus uncertainty, behavioural relevance, overt reports, and motor responses. Using Bayesian Model Selection, we show that responses reflecting target detection are restricted to secondary somatosensory cortex, whereas activity in insular, cingulate, and motor regions is best explained in terms of stimulus uncertainty and overt reports. Our results emphasise the role of sensory-specific cortex for the emergence of perceptual awareness and dissect the contribution of the frontoparietal network to classical detection tasks.

scholarly journals Limited memory optimizes cooperation in social dilemma experiments

2021 ◽  
Vol 8 (8) ◽  
pp. 210653
Author(s):  
Shuangmei Ma ◽  
Boyu Zhang ◽  
Shinan Cao ◽  
Jun S. Liu ◽  
Wen-Xu Wang
Keyword(s):  
Working Memory ◽  
Replicator Dynamics ◽  
Working Memory Capacity ◽  
Social Dilemma ◽  
Cultural Influences ◽  
Memory Capacity ◽  
Neural Function ◽  
Human Society ◽  
Neural Basis ◽  
Conditional Cooperation

Cooperation is one of the key collective behaviours of human society. Despite discoveries of several social mechanisms underpinning cooperation, relatively little is known about how our neural functions affect cooperative behaviours. Here, we study the effect of a main neural function, working-memory capacity, on cooperation in repeated Prisoner's Dilemma experiments. Our experimental paradigm overcomes the obstacles in measuring and changing subjects' working-memory capacity. We find that the optimal cooperation level occurs when subjects remember two previous rounds of information, and cooperation increases abruptly from no memory capacity to minimal memory capacity. The results can be explained by memory-based conditional cooperation of subjects. We propose evolutionary models based on replicator dynamics and Markov processes, respectively, which are in good agreement with experimental results of different memory capacities. Our experimental findings differ from previous hypotheses and predictions of existent models and theories, and suggest a neural basis and evolutionary roots of cooperation beyond cultural influences.

scholarly journals Early changes in corticomotor excitability underlie proactive inhibitory control of error correction

2021 ◽  
Author(s):  
Borja Rodriguez Herreros ◽  
Julia L Amengual ◽  
Jimena Lucrecia Vazquez-Anguiano ◽  
Silvio Ionta ◽  
Carlo Miniussi ◽  
...  
Keyword(s):  
Inhibitory Control ◽  
Time Course ◽  
Decisive Role ◽  
Neural Correlates ◽  
Proactive Inhibition ◽  
Conclusive Evidence ◽  
Inhibitory Mechanism ◽  
Neural Basis ◽  
Corticomotor Excitability ◽  
Control Of Error

Converging evidence indicates that response inhibition may arise from the interaction of effortful proactive and reflexive reactive mechanisms. However, the distinction between the neural basis sustaining proactive and reactive inhibitory processes is still unclear. To identify reliable neural markers of proactive inhibition, we examined the behavioral and electrophysiological correlates elicited by manipulating the degree of inhibitory control in a task that involved the detection and amendment of errors. Restraining or encouraging the correction of errors did not affect the time course of the behavioral and neural correlates associated to reactive inhibition. We rather found that a bilateral and sustained decrease of corticomotor excitability was required for an effective proactive inhibitory control, whereas selective strategies were associated with defective response suppression. Our results provide behavioral and electrophysiological conclusive evidence of a comprehensive proactive inhibitory mechanism, with a distinctive underlying neural basis, governing the commission and amendment of errors. Together, these findings hint at a decisive role for changes in corticomotor excitability in determining whether an action will be successfully suppressed.

scholarly journals Neural Correlates of Theory of Mind Are Preserved in Young Women With Anorexia Nervosa

2020 ◽  
Vol 11 ◽  
Author(s):  
Monica Leslie ◽  
Daniel Halls ◽  
Jenni Leppanen ◽  
Felicity Sedgewick ◽  
Katherine Smith ◽  
...  
Keyword(s):  
Anorexia Nervosa ◽  
Prefrontal Cortex ◽  
Theory Of Mind ◽  
Social Interactions ◽  
Young Women ◽  
Inferior Frontal Gyrus ◽  
Reliability And Validity ◽  
Neural Correlates ◽  
Neural Activation ◽  
Neural Basis

People with anorexia nervosa (AN) commonly exhibit social difficulties, which may be related to problems with understanding the perspectives of others, commonly known as Theory of Mind (ToM) processing. However, there is a dearth of literature investigating the neural basis of these differences in ToM and at what age they emerge. This study aimed to test for differences in the neural correlates of ToM processes in young women with AN, and young women weight-restored (WR) from AN, as compared to healthy control participants (HC). Based on previous findings in AN, we hypothesized that young women with current or prior AN, as compared to HCs, would exhibit a reduced neural response in the medial prefrontal cortex (mPFC), the inferior frontal gyrus, and the temporo-parietal junction (TPJ) whilst completing a ToM task. We recruited 73 young women with AN, 45 WR young women, and 70 young women without a history of AN to take part in the current study. Whilst undergoing a functional magnetic resonance imaging (fMRI) scan, participants completed the Frith-Happé task, which is a commonly used measure of ToM with demonstrated reliability and validity in adult populations. In this task, participants viewed the movements of triangles, which depicted either action movements, simple interactions, or complex social interactions. Viewing trials with more complex social interactions in the Frith-Happé task was associated with increased brain activation in regions including the right TPJ, the bilateral mPFC, the cerebellum, and the dorsolateral prefrontal cortex. There were no group differences in neural activation in response to the ToM contrast. Overall, these results suggest that the neural basis of spontaneous mentalizing is preserved in most young women with AN.

scholarly journals Neural correlates of spatial orienting in the human superior colliculus

2011 ◽  
Vol 106 (5) ◽  
pp. 2273-2284 ◽  
Author(s):  
Elaine J. Anderson ◽  
Geraint Rees
Keyword(s):  
Superior Colliculus ◽  
High Speed ◽  
Neural Correlates ◽  
Inhibitory Response ◽  
Neural Basis ◽  
Spatial Orienting ◽  
Visual Areas ◽  
Oculomotor Responses ◽  
Salient Event ◽  
Cortical Visual Areas

A natural visual scene contains more information than the visual system has the capacity to simultaneously process, requiring specific items to be selected for detailed analysis at the expense of others. Such selection and inhibition are fundamental in guiding search behavior, but the neural basis of these mechanisms remains unclear. Abruptly appearing visual items can automatically capture attention, but once attention has been directed away from the salient event, return to that same location is slowed. In non-human primates, signals associated with attentional capture (AC) and subsequent inhibition of return (IOR) have been recorded from the superior colliculus (SC)—a structure known to play a pivotal role in reflexive spatial orienting. Here, we sought to establish whether similar signals could be recorded from the human SC, as well as early retinotopic cortical visual areas, where signals associated with AC and IOR have yet to be investigated with respect to oculomotor responses. Using an optimized oculomotor paradigm together with high-field, high-spatial resolution functional magnetic resonance imaging and high-speed eye tracking, we demonstrate that BOLD signal changes recorded from the human SC correlate strongly with our saccadic measures of AC and IOR. A qualitatively similar pattern of responses was found for V1, but only the inhibitory response associated with IOR persisted through V2 and V3. Although the SC plays a role in mediating these automatic attentional biasing signals, the source of these signals is likely to lie in higher cortical areas.

scholarly journals A roadmap for the study of conscious audition and its neural basis

2017 ◽  
Vol 372 (1714) ◽  
pp. 20160103 ◽  
Author(s):  
Andrew R. Dykstra ◽  
Peter A. Cariani ◽  
Alexander Gutschalk
Keyword(s):  
Auditory Perception ◽  
Neural Correlates ◽  
Scene Analysis ◽  
Conscious Perception ◽  
Neural Basis ◽  
Or Groups ◽  
Neural Processes ◽  
Auditory Scenes ◽  
Shed Light

How and which aspects of neural activity give rise to subjective perceptual experience—i.e. conscious perception—is a fundamental question of neuroscience. To date, the vast majority of work concerning this question has come from vision, raising the issue of generalizability of prominent resulting theories. However, recent work has begun to shed light on the neural processes subserving conscious perception in other modalities, particularly audition. Here, we outline a roadmap for the future study of conscious auditory perception and its neural basis, paying particular attention to how conscious perception emerges (and of which elements or groups of elements) in complex auditory scenes. We begin by discussing the functional role of the auditory system, particularly as it pertains to conscious perception. Next, we ask: what are the phenomena that need to be explained by a theory of conscious auditory perception? After surveying the available literature for candidate neural correlates, we end by considering the implications that such results have for a general theory of conscious perception as well as prominent outstanding questions and what approaches/techniques can best be used to address them. This article is part of the themed issue ‘Auditory and visual scene analysis’.

Neural Correlates of Subjective Awareness and Unconscious Processing: An ERP Study

2009 ◽  
Vol 21 (7) ◽  
pp. 1435-1446 ◽  
Author(s):  
Dominique Lamy ◽  
Moti Salti ◽  
Yair Bar-Haim
Keyword(s):  
Event Related Potentials ◽  
Neural Correlates ◽  
Choice Response ◽  
Backward Masking ◽  
Unconscious Perception ◽  
Behavioral Measures ◽  
Subjective Awareness ◽  
Related Potentials ◽  
Physically Identical ◽  
P3 Component

The aim of the present study was to dissociate the ERP (Event Related Potentials) correlates of subjective awareness from those of unconscious perception. In a backward masking paradigm, participants first produced a forced-choice response to the location of a liminal target presented for an individually calibrated duration, and then reported on their subjective awareness of the target's presence. We recorded (Event-Related Potentials) ERPs and compared the ERP waves when observers reported being aware vs. unaware of the target but localized it correctly, thereby isolating the neural correlates of subjective awareness while controlling for differences in objective performance. In addition, we compared the ERPs when participants were subjectively unaware of the target's presence and localized it correctly versus incorrectly, thereby isolating the neural correlates of unconscious perception. All conditions involved stimuli that were physically identical and were presented for the same duration. Both behavioral measures were associated with modulation of the amplitude of the P3 component of the ERP. Importantly, this modulation was widely spread across all scalp locations for subjective awareness, but was restricted to the parietal electrodes for unconscious perception. These results indicate that liminal stimuli that do not affect performance undergo considerable processing and that subjective awareness is associated with a late wave of activation with widely distributed topography.

scholarly journals Changes in corticospinal excitability during reach adaptation in force fields

2013 ◽  
Vol 109 (1) ◽  
pp. 124-136 ◽  
Author(s):  
Jean-Jacques Orban de Xivry ◽  
Mohammad Ali Ahmadi-Pajouh ◽  
Michelle D. Harran ◽  
Yousef Salimpour ◽  
Reza Shadmehr
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Motor Evoked Potentials ◽  
Corticospinal Excitability ◽  
Neural Basis ◽  
Key Factor ◽  
Gradual Group ◽  
Specific Increase ◽  
Stimulation Of

Both abrupt and gradually imposed perturbations produce adaptive changes in motor output, but the neural basis of adaptation may be distinct. Here, we measured the state of the primary motor cortex (M1) and the corticospinal network during adaptation by measuring motor-evoked potentials (MEPs) before reach onset using transcranial magnetic stimulation of M1. Subjects reached in a force field in a schedule in which the field was introduced either abruptly or gradually over many trials. In both groups, by end of the training, muscles that countered the perturbation in a given direction increased their activity during the reach (labeled as the on direction for each muscle). In the abrupt group, in the period before the reach toward the on direction, MEPs in these muscles also increased, suggesting a direction-specific increase in the excitability of the corticospinal network. However, in the gradual group, these MEP changes were missing. After training, there was a period of washout. The MEPs did not return to baseline. Rather, in the abrupt group, off direction MEPs increased to match on direction MEPs. Therefore, we observed changes in corticospinal excitability in the abrupt but not gradual condition. Abrupt training includes the repetition of motor commands, and repetition may be the key factor that produces this plasticity. Furthermore, washout did not return MEPs to baseline, suggesting that washout engaged a new network that masked but did not erase the effects of previous adaptation. Abrupt but not gradual training appears to induce changes in M1 and/or corticospinal networks.

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