neurophysiological studies
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Author(s):  
Juliusz Huber ◽  
Katarzyna Kaczmarek ◽  
Katarzyna Leszczyńska ◽  
Przemysław Daroszewski

The aim of this study was to determine the sustained influence of personalized neuromuscular functional electrical stimulation (NMFES) combined with kinesiotherapy (mainly, proprioceptive neuromuscular facilitation (PNF)) on the activity of muscle motor units acting antagonistically at the wrist and the ankle in a large population of post-stroke patients. Clinical evaluations of spasticity (Ashworth scale), manual muscle testing (Lovett scale), and surface electromyography recordings at rest (rEMG) and during attempts of maximal muscle contraction (mcEMG) were performed three times in 120 post-stroke patients (T0: up to 7 days after the incidence; T1: after 21 days of treatment; T2: after 60 days of treatment). Patients (N = 120) were divided into two subgroups—60 patients received personalized NMFES and PNF treatment (NMFES+K), and the other 60 received only PNF (K). The NMFES+K therapy resulted in a decrease in spasticity and an increase in muscle strength of mainly flexor muscles, in comparison with the K group. A positive correlation between the increase of rEMG amplitudes and high Ashworth scale scores and a positive correlation between low amplitudes of mcEMG and low Lovett scale scores were found in the wrist flexors and calf muscles on the paretic side. Negative correlations were found between the rEMG and mcEMG amplitudes in the recordings. The five-grade alternate activity score of the antagonists’ actions improved in the NMFES+K group. These improvements in the results of controlled NMFES treatment combined with PNF in patients having experienced an ischemic stroke, in comparison to the use of kinesiotherapy alone, might justify the application of conjoined rehabilitation procedures based on neurophysiological approaches. Considering the results of clinical and neurophysiological studies, we suppose that NMFES of the antagonistic muscle groups acting at the wrist and the ankle may evoke its positive effects in post-stroke patients by the modulation of the activity more in the spinal motor centers, including the level of Ia inhibitory neurons, than only at the muscular level.


Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 440
Author(s):  
Anup Vanarse ◽  
Adam Osseiran ◽  
Alexander Rassau ◽  
Peter van der Made

Current developments in artificial olfactory systems, also known as electronic nose (e-nose) systems, have benefited from advanced machine learning techniques that have significantly improved the conditioning and processing of multivariate feature-rich sensor data. These advancements are complemented by the application of bioinspired algorithms and architectures based on findings from neurophysiological studies focusing on the biological olfactory pathway. The application of spiking neural networks (SNNs), and concepts from neuromorphic engineering in general, are one of the key factors that has led to the design and development of efficient bioinspired e-nose systems. However, only a limited number of studies have focused on deploying these models on a natively event-driven hardware platform that exploits the benefits of neuromorphic implementation, such as ultra-low-power consumption and real-time processing, for simplified integration in a portable e-nose system. In this paper, we extend our previously reported neuromorphic encoding and classification approach to a real-world dataset that consists of sensor responses from a commercial e-nose system when exposed to eight different types of malts. We show that the proposed SNN-based classifier was able to deliver 97% accurate classification results at a maximum latency of 0.4 ms per inference with a power consumption of less than 1 mW when deployed on neuromorphic hardware. One of the key advantages of the proposed neuromorphic architecture is that the entire functionality, including pre-processing, event encoding, and classification, can be mapped on the neuromorphic system-on-a-chip (NSoC) to develop power-efficient and highly-accurate real-time e-nose systems.


2021 ◽  
Vol 27 (4) ◽  
pp. 3-9
Author(s):  
Yurii V. Zavaliy ◽  
Oleksandr S. Solonovych ◽  
Vadym V. Biloshitsky ◽  
Albina I. Trеtiakova ◽  
Lidia L. Chebotariova ◽  
...  

Hostilities in the East of Ukraine are characterized by the use of new weapons, including rocket artillery, rocket-propelled grenades and landmines. This has led to an increase in the number of victims with blast mild traumatic brain injury (BMTBI) and the need to provide them with effective assistance and rehabilitation. An important task is to improve the BMTBI diagnosis by specifying the objective criteria for structural and functional disorders of the central nervous system. This will improve the prognosis of the course of BMTBI in the injured and the treatment program, including personalized, to prevent the development of persistent neurological deficit. Objective: to investigate the possibilities of the cognitive evoked potentials (CEP) method for the objective diagnosis of cognitive disorders in post-concussion syndrome (PCS) BMTBI. Materials and methods. The study involved 115 men with PCS (main group) and 30 healthy individuals (control group). The cognitive functions of the study participants were studied using the questionnaire "Cicerone". The neurophysiological method for assessing the functional state of the brain involved the registration of CEP, event-related (P300 CEP). Results. The selection of a subgroup of patients with PCS, characterized by a predominance of cognitive impairments, allowed us to trace the relationship between the results of neurophysiological studies with the cognitive indicators of patients with BMTBI. P300 latency indices are inversely proportional to cognitive assessment the questionnaire "Cicerone" and statistically significantly depend on the severity of cognitive impairment. Conclusions. The CEP P300 method can be an effective means of objectifying the degree of cognitive impairment in patients with PCS due to BMTBI.


2021 ◽  
Author(s):  
Petar Gabrić ◽  
Marko Banda ◽  
Ivor Karavanić

Abstract Experimental data suggesting a co-evolutionary relationship between Palaeolithic stone toolmaking, and cognition and language remain limited to indirect findings of neurophysiological studies. Furthermore, retouch and quartz flaking remain uninvestigated. We recruited thirteen subjects and taught them to produce quartz choppers and chert sidescrapers in either a verbal or gestural condition. Two raters rated on a 5-point scale the subjects’ performances on specific steps of the two stone toolmaking tasks. Subjects also performed on a neuropsychological battery encompassing visuospatial, executive functioning, and linguistic tasks. Given the small sample size, the results should be regarded as exploratory and preliminary. There was only limited evidence that verbal compared to gestural teaching facilitated acquisition. Quartz chopper manufacture was not associated with cognitive performance. Conversely, chert flaking and retouch were moderately and strongly associated with visuospatial working memory and executive functioning. Specific aspects of chert flaking were also associated with verbal fluency performance, showing, among others, moderate and strong positive associations with the productivity and rate of production of syntactically transitive verbs on action fluency. Controversially assuming similar results would have been obtained by testing extinct hominins, our results possibly suggest Oldowan hominins relied on modern-like visuospatial working memory and executive functioning during chert knapping. Furthermore, some prerequisites for aspects of action language and syntactic transitivity in modern humans might have been to some degree present in Oldowan hominin populations. We conclude by proposing that the quality of performance on Oldowan knapping may not reflect the full level of cognitive capacities of Oldowan populations.


2021 ◽  
Vol 15 ◽  
Author(s):  
Moïra-Phoebé Huet ◽  
Christophe Micheyl ◽  
Etienne Parizet ◽  
Etienne Gaudrain

During the past decade, several studies have identified electroencephalographic (EEG) correlates of selective auditory attention to speech. In these studies, typically, listeners are instructed to focus on one of two concurrent speech streams (the “target”), while ignoring the other (the “masker”). EEG signals are recorded while participants are performing this task, and subsequently analyzed to recover the attended stream. An assumption often made in these studies is that the participant’s attention can remain focused on the target throughout the test. To check this assumption, and assess when a participant’s attention in a concurrent speech listening task was directed toward the target, the masker, or neither, we designed a behavioral listen-then-recall task (the Long-SWoRD test). After listening to two simultaneous short stories, participants had to identify keywords from the target story, randomly interspersed among words from the masker story and words from neither story, on a computer screen. To modulate task difficulty, and hence, the likelihood of attentional switches, masker stories were originally uttered by the same talker as the target stories. The masker voice parameters were then manipulated to parametrically control the similarity of the two streams, from clearly dissimilar to almost identical. While participants listened to the stories, EEG signals were measured and subsequently, analyzed using a temporal response function (TRF) model to reconstruct the speech stimuli. Responses in the behavioral recall task were used to infer, retrospectively, when attention was directed toward the target, the masker, or neither. During the model-training phase, the results of these behavioral-data-driven inferences were used as inputs to the model in addition to the EEG signals, to determine if this additional information would improve stimulus reconstruction accuracy, relative to performance of models trained under the assumption that the listener’s attention was unwaveringly focused on the target. Results from 21 participants show that information regarding the actual – as opposed to, assumed – attentional focus can be used advantageously during model training, to enhance subsequent (test phase) accuracy of auditory stimulus-reconstruction based on EEG signals. This is the case, especially, in challenging listening situations, where the participants’ attention is less likely to remain focused entirely on the target talker. In situations where the two competing voices are clearly distinct and easily separated perceptually, the assumption that listeners are able to stay focused on the target is reasonable. The behavioral recall protocol introduced here provides experimenters with a means to behaviorally track fluctuations in auditory selective attention, including, in combined behavioral/neurophysiological studies.


2021 ◽  
Vol 14 (12) ◽  
pp. e246187
Author(s):  
Sadia Tariq ◽  
Sameh Jonny ◽  
Hanadi Asalieh

We present here an interesting case of a 67-year-old man with 3 weeks history of lethargy, loss of appetite, generalised weakness and weight loss. Following thorough investigations, occult malignancy was ruled out. Hyponatraemia was a consistent finding which needed further classification. Additional workup including cerebral imaging and neurophysiological studies excluded cerebral vascular events and myopathies. Vasculitis screening was undertaken, and the diagnostic dilemma was revealed by the temporal arteries Doppler ultrasound which showed classical ‘halo sign’. Diagnosis of temporal arteritis was made and linked with syndrome of inappropriate antidiuretic hormone secretion, which appears to be a rare association with few instances on record. Patient was treated with high dose of prednisolone with marked improvement of clinical features.


2021 ◽  
Author(s):  
Laurianne Cabrera ◽  
Bonnie K. Lau

The processing of auditory temporal information is important for the extraction of voice pitch, linguistic information, as well as the overall temporal structure of speech. However, many aspects regarding its early development remains not well understood. This paper reviews the development of different aspects of auditory temporal processing during the first year of life when infants are acquiring their native language. First, potential mechanisms of neural immaturity are discussed in the context of neurophysiological studies. Next, what is known about infant auditory capabilities is considered with a focus on psychophysical studies involving non-speech stimuli to investigate the perception of temporal fine structure and envelope cues. This is followed by a review of studies involving speech stimuli, including those that present vocoded signals as a method of degrading the spectro-temporal information available to infant listeners. Finally, we highlight key findings from the cochlear implant literature that illustrate the importance of temporal cues in speech perception.


2021 ◽  
Vol 12 ◽  
Author(s):  
Elisa Micalizzi ◽  
Anna Elisabetta Vaudano ◽  
Giada Giovannini ◽  
Giulia Turchi ◽  
Leandra Giunta ◽  
...  

Ictal respiratory changes have been mainly described following generalized tonic-clonic seizures and recently considered to be a biomarker to assess the risk of sudden unexplained death in epilepsy (SUDEP). Nonetheless, modification of respiratory pattern can be related also to focal seizures, especially arising from the temporal lobe. Changes in cardiac function such as tachycardia or bradycardia could be often associated. We report a short case series of four patients with temporal lobe epilepsy admitted to our Epilepsy Monitoring Unit (EMU) presenting with an ictal central apnea as the first clinical manifestation of their seizures. None of these patients was aware of the occurrence of respiratory arrest. Age at onset ranged from 15 to 29 years. One patient had seizures with prolonged central apnea accompanied by a significant decrease in oxygen saturation. Neuroimaging in two patients showed alterations of mesial temporal lobe structures, including the amygdala. Recent neurophysiological studies supported the existence of a cortical network involving the limbic system that modulates downstream brainstem respiratory centers. Monitoring for respiratory changes and oxygen saturation in focal seizures is warranted for their potential value in identifying the epileptogenic zone and for a better understanding of ictal respiratory changes that could potentially define a subgroup of patients with high risk of seizure-related autonomic changes.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Hari Teja Kalidindi ◽  
Kevin P Cross ◽  
Timothy P Lillicrap ◽  
Mohsen Omrani ◽  
Egidio Falotico ◽  
...  

Recent studies have identified rotational dynamics in motor cortex (MC) which many assume arise from intrinsic connections in MC. However, behavioural and neurophysiological studies suggest that MC behaves like a feedback controller where continuous sensory feedback and interactions with other brain areas contribute substantially to MC processing. We investigated these apparently conflicting theories by building recurrent neural networks that controlled a model arm and received sensory feedback from the limb. Networks were trained to counteract perturbations to the limb and to reach towards spatial targets. Network activities and sensory feedback signals to the network exhibited rotational structure even when the recurrent connections were removed. Furthermore, neural recordings in monkeys performing similar tasks also exhibited rotational structure not only in MC but also in somatosensory cortex. Our results argue that rotational structure may also reflect dynamics throughout the voluntary motor system involved in online control of motor actions.


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