Validation of a sleep staging classification model for healthy adults based on two combinations of a single-channel EEG headband and wrist actigraphy.

STUDY OBJECTIVES: The aim of this study was to develop a sleep staging classification model capable of accurately performing on different wearable devices. METHODS: Twenty-three healthy participants underwent a full-night type I polysomnography and used two device combinations: (A) flexible single-channel electroencephalogram (EEG) headband + actigraphy (n = 12) and (B) rigid single-channel EEG headband + actigraphy (n = 11). The signals were segmented into 30-second epochs according to polysomnographic stages (scored by a board-certified sleep technologist; model ground truth) and 18 frequency and time features were extracted. The model consisted of an ensemble of bagged decision trees. Bagging refers to bootstrap aggregation to reduce overfitting and improve generalization. To evaluate the model, a training dataset under 5-fold cross-validation and an 80-20% dataset split was used. The headbands were also evaluated without the actigraphy feature. Participants also completed a usability evaluation (comfort, pain while sleeping, and sleep disturbance). RESULTS: Combination A had an F1-score of 98.4% and the flexible headband alone of 97.7% (error rate for N1: combination A = 9.8%; flexible headband alone = 15.7%). Combination B had an F1-score of 96.9% and the rigid headband alone of 95.3% (error rate for N1: combination B = 17.0%; rigid headband alone = 27.7%); in both, N1 was more confounded with N2. CONCLUSIONS: We developed an accurate sleep classification model based on a single-channel EEG device, and actigraphy was not an important feature of the model. Both headbands were found to be useful, with the rigid one being more disruptive to sleep. Future research can improve our results by applying the developed model in a population with sleep disorders. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Actigraphy, Wearable EEG Band and Smartphone for Sleep Staging; URL: https://clinicaltrials.gov/study/NCT04943562; Identifier: NCT04943562. CITATION: Melo MC, Vallim JRS, Garbuio S, et al. Validation of a sleep staging classification model for healthy adults based on 2 combinations of a single-channel EEG headband and wrist actigraphy. J Clin Sleep Med. 2024;20(6):983-990.

Development of eight wireless automated cages system with two lick-o-meters each for rodents.

Drinking behavior has been used in basic research to study metabolism, motivation, decision-making and different aspects of health problems, such as anhedonia and alcohol use disorders. In the majority of studies, liquid intake is measured by weighing the bottles before and after the experiment. This method does not tell much about the drinking microstructure, e.g., licking bouts and periods of preference for each liquid, which could be valuable to understand drinking behavior. To improve the data acquisition of drinking microstructure, companies have developed lick-o-meters devices that acquire timestamps when animals approach or drink from a specific sipper. Nevertheless, commercially available devices have elevated costs. Here, we present a low-cost alternative for a lick-o-meter system that allows wireless data acquisition of licking from eight cages with two sippers each. We run a three-phase validation protocol to ensure 1) proper choice of the sensor to detect licks; 2) adaptation of the device to a wireless transmission and realistic in silico tests; and 3) in vivo tests to correlate the amount of licks measured by the prototype and the bottle weight. The capacitive sensor presented appropriate recall and precision for our device. After adaptation to wireless transmission, the in silico validation demonstrated low reading and transmission errors for the device even when tested in extreme simultaneous licking conditions. Finally, a positive correlation between volume consumption and lick's count in the in vivo test was observed, showing that the prototype can be used for in vivo studies interested in rodent drinking microstructure.Significant StatementThis study presents an innovative and low-cost solution for drinking behavioral studies: a lick-o-meter system based on an open-source hardware platform with a user-friendly interface software, capable of simultaneously receiving data from eight automated cages with two drinking bottles each. The lick-o-meter brings an accessible device to acquire high-quality and detailed data. This device also has the possibility to be adaptable to new types of sensors or other neuroscience tools capable of measuring brain activity simultaneously to the behavior.

Weak central coherence in adults with ASD: Evidence from eye-tracking and thematic content analysis of social scenes.

Central Coherence Weakness has been defined as a tendency for local rather than global processing that may underlie core deficits in Autism Spectrum Disorder (ASD). In social contexts it may be expressed in difficulties to integrate social cues arising from the recognition of emotions in faces or from the environment in order to understand people's interactions. A sample of 28 adults diagnosed with ASD Level 1 and 25 controls was submitted to a cartoon-like task with the instruction to describe social scenes and to Navon letter stimuli. Both quantitative measures and qualitative (thematic content analysis) procedures were used to assess performance. Heatmap and fixation preferences according to the stimuli quadrants were used to investigate eye-tracking patterns. A tendency to local processing, independently of the stimuli type, in the ASD participants was observed. Data from visual tracking by quadrants and from verbal reports suggest loss of social cues important for understanding context. Their reaction time and response duration were increased in relation to controls. The findings corroborate the idea that weak central coherence may be part of the cognitive phenotype in ASD.

Autistic adults often report difficulties in interpreting social situations. These difficulties are commonly associated with a tendency to visually focus on specific parts of the situation (known as local processing) to the detriment of the whole situation. This way of looking at things has been given the name "weak central coherence," and may result in difficulties in understanding a situation or other people's behaviors. A group of ASD and controls were asked to describe two different types of image, one showing a common social situation, the other Navon figure. Eye-tracking technology was used to analyze how the participants looked at the images (which part of the image and for how long) and asked about what they had seen. The results showed that in the group of autistic participants there was a tendency to focus on the details in both types of images. The analysis of the verbal reports revealed that the interpretation of the social contexts by those with ASD was not what was expected, associated with a specific focus on details. These findings may be useful for a better understanding of some difficulties experienced by ASD in social contexts and contribute to therapeutic treatments.

Divergent Findings in Brain Reorganization After Spinal Cord Injury: A Review.

Spinal cord injury (SCI) leads to a general lack of sensory and motor functions below the level of injury and may promote deafferentation-induced brain reorganization. Functional magnetic resonance imaging (fMRI) has been established as an essential tool in neuroscience research and can precisely map the spatiotemporal distribution of brain activity. Task-based fMRI experiments associated with the tongue, upper limbs, or lower limbs have been used as the primary paradigms to study brain reorganization following SCI. A review of the current literature on the subject shows one common trait: while most articles agree that brain networks are usually preserved after SCI, and that is not the case as some articles describe possible alterations in brain activation after the lesion. There is no consensus if those alterations indeed occur. In articles that show alterations, there is no agreement if they are transient or permanent. Besides, there is no consensus on which areas are most prone to activation changes, or on the intensity and direction (increase vs. decrease) of those possible changes. In this article, we present a critical review of the literature and trace possible reasons for those contradictory findings on brain reorganization following SCI. fMRI studies based on the ankle dorsiflexion, upper-limb, and tongue paradigms are used as case studies for the analyses.

Effect of myofeedback on the threshold of the stretch reflex response of post-stroke spastic patients.

Purpose We propose a visual myofeedback protocol as a coadjuvant therapy to standard rehabilitation of post-stroke spastic patients. We also argue in favor of the tonic stretch reflex threshold (TSRT) as a more sensitive unit for quantifying subtle changes in the spastic response that may be induced by biofeedback training. Method Sixteen volunteers with ischaemic stroke were divided into an experimental group (EG), subjected to myofeedback training in parallel with conventional physical therapy and a control group (CG), receiving only conventional physical therapy. The EG subjects underwent a six-week myofeedback training, with two sessions weekly. Both groups followed the same treatment schedule for physical therapy. The TSRTs of the volunteers' spastic muscles were assessed before the beginning of the experimental protocol and 3 weeks after it ended. Results Both groups showed some degree of improvement in the level of spasticity when the final TSRT values were compared to the initial values. However, the percentage of improvement (after-before) of the experimental group (38.59%) was significantly higher than that in the control group (18.58%). Conclusion The myofeedback training provided a significant contribution to conventional treatment, allowing for a better improvement of the spastic condition. Implications for rehabilitation Biofeedback is an effective means of improving motor control of post-stroke spastic patients. The Tonic Stretch Reflex Threshold is a more sensitive quantitative measure to assess upper-limb post-stroke spasticity. Spastic patients who participate in myofeedback training along with physical therapy can improve faster then those who participate only in traditional physical therapy rehabilitation protocols.

Bruxismo do sono e o padrão neurocomportamental – proposta de protocolo de biofeedback multimodal / Sleep bruxism and its neurobehavioral pattern – a proposal of a multimodal biofeedback protocol

O bruxismo do sono (BS) é uma manifestação intensa da atividade muscular mastigatória rítmica, caracterizado pelo ranger e apertar dos dentes durante o sono. Sua etiologia ainda não foi definida, o que dificulta o diagnóstico e, consequentemente, o plano de tratamento. As abordagens terapêuticas convencionais são o uso de placas e fármacos, questionadas por serem padronizadas, sem abordagem individualizada e com efeitos colaterais adversos. Conforme revisões da literatura, hipóteses etiológicas apontam a participação expressiva do sistema nervoso central (SNC), especialmente do sistema límbico (SL), sistema nervoso autônomo (SNA) e do reflexo vago-trigeminal, na origem do BS. Um postulado consistente relaciona o BS como um ajuste para o estresse. Estudos demonstram que o BS pode ser um mecanismo fisiológico de autorregulação do sistema autonômico, como resposta para estabelecer alostasia do sistema corporal frente a ocorrências noturnas de taquicardias decorrentes da atividade cerebral, quando ocorrem microdespertares fisiológicos de sentinela, durante o sono. Este estudo apresentou um protocolo com instrumentos para coleta e retroalimentação de sinais biológicos, com a finalidade de identificar alterações fisiológicas que sejam compatíveis ou não com alterações emocionais, que possam desencadear o bruxismo. Esses instrumentos possibilitam a autorregulação dos eventos psicofisiológicos e o desenvolvimento de habilidades pelo próprio indivíduo, permitindo o controle de suas emoções e comportamento. Esse processo terapêutico é conhecido como biofeedback (BF). O treinamento com o BF permite regularizar rítmos internos, propiciando desaceleração das funções neurofisiológicas, atenuando os efeitos desta atividade não funcional...

Sleep bruxism (SB) is a severe manifestation of rhythmic masticatory muscle activity characterized by grinding and clenching of teeth during sleep. Its etiology has not been set yet which complicates the diagnosis and therefore the treatment plan. The more conventional therapeutic approaches are the use of intra oral plates and drugs, that are being questioned for being a standardized approach and not individualized, with adverse side effects. Describe in the literature, etiological hypotheses suggest significant participation of the central nervous system (CNS), especially the limbic system (LS), autonomous nervous system (ANS) and the vague-trigeminal reflex, in the SB source. A consistent postulate relates SB to a mechanism for adjustment to stress. Some studies show that BS may be a physiological mechanism of self-regulation of the autonomic system, as a response to establish body system alostasia when tachycardia occurs during sleep associated to physiological sentinel microarousals. This work is meant to provide information to assist health professionals to assess the behavioral and emotional relation with BS. Furthermore, this study presents a protocol with instruments to collect and feedback data related to biological signals, in order to identify physiological changes which are compatible or not with emotional changes that may trigger bruxism. These instruments, allow self-regulation of psychophysiological events by the individual and the development of habilities that enables to control of emotions and behavior. This therapeutic process is known as Biofeedback (BF). Training with the BF allows to regularize the heart and respiratory rate, providing deceleration of neurophysiological functions, mitigating the effects of this nonfunctional activity...