Wearable strain sensor suit for infants to measure limb movements under interaction with caregiver

Development of motion capture technology has enabled the measurement of body movements over long periods of time in daily life. Although accelerometers have been used as primary sensors, problems arise when they are used to measure the movements of infants. Because infants and caregivers interact frequently, accelerometer data from infants may be significantly distorted by a caregiver’s movement. To overcome this problem, a strain sensor suit was developed for infants to measure flexion and extension movements of the limbs. A case study was performed to analyze the strain sensor data of an infant in relation to the accelerometer data of the infant’s and a caregiver’s body under various types of infant–caregiver interaction. The results demonstrated that the strain sensor data had low correlation with the accelerometer data of the infant and caregiver while the accelerometer data between infant and caregiver had higher correlation. This suggests that the strain sensor is suitable to detect limbs’ angular displacements mostly independent from the translational body movements exerted by a caregiver.     

Mental time travel to the future might be reduced in sleep

We present a quantitative study of mental time travel to the future in sleep. Three independent, blind judges analysed a total of 563 physiology-monitored mentation reports from sleep onset, REM sleep, non-REM sleep, and waking. The linguistic tool for the mentation report analysis is based on established grammatical and cognitive-semantic theories and has been validated in previous studies. Our data indicate that REM and non-REM sleep must be characterized by a reduction in mental time travel to the future, which would support earlier physiological evidence at the level of brain function.     

Blind Speakers Show Language‐Specific Patterns in Co‐Speech Gesture but Not Silent Gesture

Sighted speakers of different languages vary systematically in how they package and order components of a motion event in speech. These differences influence how semantic elements are organized in gesture, but only when those gestures are produced with speech (co‐speech gesture), not without speech (silent gesture). We ask whether the cross‐linguistic similarity in silent gesture is driven by the visuospatial structure of the event. We compared 40 congenitally blind adult native speakers of English or Turkish (20/language) to 80 sighted adult speakers (40/language; half with, half without blindfolds) as they described three‐dimensional motion scenes. We found an effect of language on co‐speech gesture, not on silent gesture—blind speakers of both languages organized their silent gestures as sighted speakers do. Humans may have a natural semantic organization that they impose on events when conveying them in gesture without language—an organization that relies on neither visuospatial cues nor language structure.     

Evaluation of upper limb movements in children with Down’s syndrome: A systematic review

The aim of the present study was to perform a review of the literature on current quantitative clinical methods for the evaluation of upper limb movements in children and adolescents with Down syndrome, with a focus on describing the variables, protocols, motor function and motor control.MethodsA survey of PubMed, Scielo, BVS Bireme and PEDro databases using the following key words: upper limb and EMG and Down syndrome; upper limb and kinematics and Down syndrome; upper limb and motion analysis and Down syndrome; movement and upper limb and Down syndrome; upper limb and Down syndrome; reach and Down syndrome.ResultsIn all, 344 articles and five were selected to compose the present systematic review. No standardization was found among the studies analyzed with regard to data collection, data processing or procedures for the evaluation of the variables.ConclusionA kinematic evaluation is effective for the discussion of the results, but methodological differences among the studies and inconsistent results exert a negative influence on clinical interpretations and the possibility of reproducibility. The standardization of an upper limb movement evaluation protocol using kinematic analysis is important, as it would provide the basis for comparable, reproducible results and facilitate the planning of treatment interventions.     

The relationship between simulator sickness and driving performance in a high-fidelity simulator

Driving simulators are highly valuable tools for various applications such as research, training, and rehabilitation. However, they are also known to cause simulator sickness, a special form of traditional motion sickness. Common side effects of simulator sickness include nausea, headache, dizziness, eye-strain, and/or disorientation, all symptoms which may negatively impact driving performance. The goal of the present study was to investigate the relationship between simulator sickness and driving performance obtained in a high-fidelity driving simulator. Twenty-one healthy participants were engaged in a simulated driving task containing rural, city, and highway sections for approx. 25 min. Participants were asked to drive naturally while obeying traffic rules and completing common driving maneuvers (including reactions to sudden events). Driving performance was evaluated based on various driving measures, such as lane positioning, speed measures, following distance, or the number of steering reversals. Simulator sickness was measured before, during, and after the simulated drive using a combination of the Simulator Sickness Questionnaire and the Fast Motion Sickness scale. Overall, correlations between the level of simulator sickness and driving performance measures were low to moderate (r’s from -0.37 to 0.40) and were not significant. Additionally, participants who reported higher levels of simulator sickness did not differ with regards to their driving performance from those who reported lower simulator sickness scores. Our results suggest that the presence of simulator sickness is not strongly related to performance in a driving simulator.     

Spatial and Temporal Processing in Healthy Aging: Implications for Perceptions of Driving Skills

ABSTRACT

Sensitivity to the attributes of a stimulus (form or motion) and accuracy when detecting rapidly presented stimulus information were measured in older (N?=?36) and younger (N?=?37) groups. Before and after practice, the older group was significantly less sensitive to global motion (but not to form) and less accurate on a rapid sequencing task when detecting the individual elements presented in long but not short sequences. These effect sizes produced power for the different analyses that ranged between 0.5 and 1.00. The reduced sensitivity found among older individuals to temporal but not spatial stimuli, adds support to previous findings of a selective age-related deficit in temporal processing. Older women were significantly less sensitive than older men, younger men and younger women on the global motion task. Gender effects were evident when, in response to global motion stimuli, complex extraction and integration processes needed to be undertaken rapidly. Significant moderate correlations were found between age, global motion sensitivity and reports of perceptions of other vehicles and road signs when driving. These associations suggest that reduced motion sensitivity may produce functional difficulties for the older adults when judging speeds or estimating gaps in traffic while driving.     

Synchronising self-displacement with a cross-traffic gap: How does the size of traffic vehicles impact continuous speed regulations?

In this article, we investigated what visual information is used by drivers at a road crossing when they want to synchronize their displacement with that of an incoming traffic train. We made the hypothesis that synchronizing self-displacement with that of a traffic gap shares the same perceptual-motor basis as interception tasks. While a large body of literature demonstrates that bearing angle is used to control interception, another range of studies points to optical size and expansion as playing a critical role in collision avoidance. In order to test the hypothesis of the exclusive use of bearing angle in road crossing task, we manipulated the optical size and expansion of oncoming traffic elements independently of bearing angle variations. We designed a driving simulator study in which participants were to adjust their approach speed in order to cross a road junction within a moving traffic gap. We manipulated the initial offset of participants with the traffic gap, the geometry of the road junction and the way optical size of oncoming traffic elements evolves over the course of a trial. Our results showed an effect of optical size and optical expansion manipulations eventhough, we also found similar displacement profiles as in interception studies. This demonstrates that bearing angle could not explain alone the control of such a complex perceptual-motor task. We discuss these results with regard to similar results in other fields of literature.     

Sudden onset of excessive repetitions in the speech of a patient with multiple sclerosis: A case report

This report provides a detailed analysis of excessive part- and whole-word repetitions in the speech of a 36-year-old male patient hospitalized for treatment of multiple sclerosis (MS) who also exhibited concurrent language and prosodic disturbances. Shortly following his hospitalization, a magnetic resonance imaging examination revealed plaques in the white matter of the medulla, cerebellum, basal ganglion, and periventricular white matter. His speech strongly resembled apractic speech patterns, chiefly syllable segregation. The source of data collected for this study was seven tape-recorded speech samples containing 2536 words spoken in 32.75 min, diagnostic reports, and clinical notes of 27 biweekly speech therapy sessions across a 5-month period. This report focused on an analysis of variables associated with the patient's part- and whole-word repetitions, and it was concluded that they were used as a compensatory device to procure additional time to articulate complex syllables. A brief critique of the therapeutic procedures used for treating his speech problem is also presented.

Educational objectives: The reader will learn about and be able to describe (1) the effects of MS on speech and language; (2) the kinds of data that were gathered to account for this patient's sudden onset of speech and language disorders; and (3) the findings that led them to conclude that his excessive repetitions were compensatory behaviors.     

Bottom-up and top-down factors of motion direction learning transfer

Perceptual learning of motion discrimination has long been believed to be motion direction specific. However, recent studies using a double-training paradigm, in which the to-be-transferred condition was experienced through practicing an irrelevant task, found that perceptual learning in various visual tasks, including motion direction discrimination, can transfer completely to new conditions. This transfer occurred when the transfer stimulus was subconsciously presented, or when top-down attention was allocated to the transfer stimulus (which was absent). In the current study, observers were exposed subconsciously, or directed top-down attention, to the transfer motion direction, either simultaneously or successively with training. Data showed that motion direction learning transferred to the transfer direction, and suggest that motion direction learning specificity may result from under-activations of untrained visual neurons due to insufficient bottom-up stimulation and/or lack of top-down attention during training. These results shed new light on the neural mechanisms underlying motion perceptual learning and provide a constraint for models of motion perceptual learning.