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PloS One 2024Whether a saccade is accurate and has reached the target cannot be evaluated during its execution, but relies on post-saccadic feedback. If the eye has missed the target...
Whether a saccade is accurate and has reached the target cannot be evaluated during its execution, but relies on post-saccadic feedback. If the eye has missed the target object, a secondary corrective saccade has to be made to align the fovea with the target. If a systematic post-saccadic error occurs, adaptive changes to the oculomotor behavior are made, such as shortening or lengthening the saccade amplitude. Systematic post-saccadic errors are typically attributed internally to erroneous motor commands. The corresponding adaptive changes to the motor command reduce the error and the need for secondary corrective saccades, and, in doing so, restore accuracy and efficiency. However, adaptive changes to the oculomotor behavior also occur if a change in saccade amplitude is beneficial for task performance, or if it is rewarded. Oculomotor learning thus is more complex than reducing a post-saccadic position error. In the current study, we used a novel oculomotor learning paradigm and investigated whether human participants are able to adapt their oculomotor behavior to improve task performance even when they attribute the error externally. The task was to indicate the intended target object among several objects to a simulated human-machine interface by making eye movements. The participants were informed that the system itself could make errors. The decoding process depended on a distorted landing point of the saccade, resulting in decoding errors. Two different types of visual feedback were added to the post-saccadic scene and we compared how participants used the different feedback types to adjust their oculomotor behavior to avoid errors. We found that task performance improved over time, regardless of the type of feedback. Thus, error feedback from the simulated human-machine interface was used for post-saccadic error evaluation. This indicates that 1) artificial visual feedback signals and 2) externally caused errors might drive adaptive changes to oculomotor behavior.
Topics: Humans; Saccades; Adult; Male; Female; Eye Movements; Young Adult; Psychomotor Performance; Learning
PubMed: 38768134
DOI: 10.1371/journal.pone.0302872 -
Journal of Neuroengineering and... May 2024Proprioceptive impairments are common after stroke and are associated with worse motor recovery and poor rehabilitation outcomes. Motor learning may also be an important...
BACKGROUND
Proprioceptive impairments are common after stroke and are associated with worse motor recovery and poor rehabilitation outcomes. Motor learning may also be an important factor in motor recovery, and some evidence in healthy adults suggests that reduced proprioceptive function is associated with reductions in motor learning. It is unclear how impairments in proprioception and motor learning relate after stroke. Here we used robotics and a traditional clinical assessment to examine the link between impairments in proprioception after stroke and a type of motor learning known as visuomotor adaptation.
METHODS
We recruited participants with first-time unilateral stroke and controls matched for overall age and sex. Proprioceptive impairments in the more affected arm were assessed using robotic arm position- (APM) and movement-matching (AMM) tasks. We also assessed proprioceptive impairments using a clinical scale (Thumb Localization Test; TLT). Visuomotor adaptation was assessed using a task that systematically rotated hand cursor feedback during reaching movements (VMR). We quantified how much participants adapted to the disturbance and how many trials they took to adapt to the same levels as controls. Spearman's rho was used to examine the relationship between proprioception, assessed using robotics and the TLT, and visuomotor adaptation. Data from healthy adults were used to identify participants with stroke who were impaired in proprioception and visuomotor adaptation. The independence of impairments in proprioception and adaptation were examined using Fisher's exact tests.
RESULTS
Impairments in proprioception (58.3%) and adaptation (52.1%) were common in participants with stroke (n = 48; 2.10% acute, 70.8% subacute, 27.1% chronic stroke). Performance on the APM task, AMM task, and TLT scores correlated weakly with measures of visuomotor adaptation. Fisher's exact tests demonstrated that impairments in proprioception, assessed using robotics and the TLT, were independent from impairments in visuomotor adaptation in our sample.
CONCLUSION
Our results suggest impairments in proprioception may be independent from impairments in visuomotor adaptation after stroke. Further studies are needed to understand factors that influence the relationship between motor learning, proprioception and other rehabilitation outcomes throughout stroke recovery.
Topics: Humans; Male; Female; Proprioception; Middle Aged; Adaptation, Physiological; Stroke; Stroke Rehabilitation; Aged; Psychomotor Performance; Robotics; Adult
PubMed: 38762552
DOI: 10.1186/s12984-024-01360-7 -
Cognition Aug 2024Eyes are active in memory recall and visual imagination, yet our grasp of the underlying qualities and factors of these internally coupled eye movements is limited. To...
Eyes are active in memory recall and visual imagination, yet our grasp of the underlying qualities and factors of these internally coupled eye movements is limited. To explore this, we studied 50 participants, examining how workload, spatial reference availability, and imagined movement direction influence internal coupling of eye movements. We designed a visuospatial working memory task in which participants mentally moved a black patch along a path within a matrix and each trial involved one step along this path (presented via speakers: up, down, left, or right). We varied workload by adjusting matrix size (3 × 3 vs. 5 × 5), manipulated availability of a spatial frame of reference by presenting either a blank screen (requiring participants to rely solely on their mental representation of the matrix) or spatial reference in the form of an empty matrix, and contrasted active task performance to two control conditions involving only active or passive listening. Our findings show that eye movements consistently matched the imagined movement of the patch in the matrix, not driven solely by auditory or semantic cues. While workload influenced pupil diameter, perceived demand, and performance, it had no observable impact on internal coupling. The availability of spatial reference enhanced coupling of eye movements, leading more frequent, precise, and resilient saccades against noise and bias. The absence of workload effects on coupled saccades in our study, in combination with the relatively high degree of coupling observed even in the invisible matrix condition, indicates that eye movements align with shifts in attention across both visually and internally represented information. This suggests that coupled eye movements are not merely strategic efforts to reduce workload, but rather a natural response to where attention is directed.
Topics: Humans; Memory, Short-Term; Adult; Male; Female; Young Adult; Space Perception; Eye Movements; Imagination; Visual Perception; Psychomotor Performance
PubMed: 38761645
DOI: 10.1016/j.cognition.2024.105815 -
Developmental Cognitive Neuroscience Jun 2024This study aimed to clarify the psychometric properties and development of Go/No-Go (GNG) task-related neural activation across critical periods of neurobiological...
Clarifying the longitudinal factor structure, temporal stability, and construct validity of Go/No-Go task-related neural activation across adolescence and young adulthood.
This study aimed to clarify the psychometric properties and development of Go/No-Go (GNG) task-related neural activation across critical periods of neurobiological maturation by examining its longitudinal stability, factor structure, developmental change, and associations with a computational index of task-general cognitive control. A longitudinal sample (N=289) of adolescents from the Michigan Longitudinal Study was assessed at four time-points (mean number of timepoints per participant=2.05; standard deviation=0.89) spanning early adolescence (ages 10-13) to young adulthood (22-25). Results suggested that regional neural activations from the "successful inhibition" (SI>GO) and "failed inhibition" (FI>GO; error-monitoring) contrasts are each described well by a single general factor. Neural activity across both contrasts showed developmental increases throughout adolescence that plateau in young adulthood. Neural activity metrics evidenced low temporal stability across this period of marked developmental change, and the SI>GO factor showed no relations with a behavioral index of cognitive control. The FI>GO factor displayed stronger criterion validity in the form of significant, positive associations with behaviorally measured cognitive control. Findings emphasize the utility of well-validated psychometric methods and longitudinal data for clarifying the measurement properties of functional neuroimaging metrics and improving measurement practices in developmental cognitive neuroscience.
Topics: Humans; Adolescent; Male; Longitudinal Studies; Female; Young Adult; Child; Adult; Magnetic Resonance Imaging; Inhibition, Psychological; Psychometrics; Executive Function; Adolescent Development; Brain; Neuropsychological Tests; Psychomotor Performance; Reproducibility of Results; Cognition
PubMed: 38759528
DOI: 10.1016/j.dcn.2024.101390 -
Journal of Neuroengineering and... May 2024Individuals with a moderate-to-severe traumatic brain injury (m/sTBI), despite experiencing good locomotor recovery six months post-injury, face challenges in adapting...
BACKGROUND
Individuals with a moderate-to-severe traumatic brain injury (m/sTBI), despite experiencing good locomotor recovery six months post-injury, face challenges in adapting their locomotion to the environment. They also present with altered cognitive functions, which may impact dual-task walking abilities. Whether they present collision avoidance strategies with moving pedestrians that are altered under dual-task conditions, however, remains unclear. This study aimed to compare between individuals with m/sTBI and age-matched control individuals: (1), the locomotor and cognitive costs associated with the concurrent performance of circumventing approaching virtual pedestrians (VRPs) while attending to an auditory-based cognitive task and; (2) gaze behaviour associated with the VRP circumvention task in single and dual-task conditions.
METHODOLOGY
Twelve individuals with m/sTBI (age = 43.3 ± 9.5 yrs; >6 mo. post injury) and 12 healthy controls (CTLs) (age = 41.8 ± 8.3 yrs) were assessed while walking in a virtual subway station viewed in a head-mounted display. They performed a collision avoidance task with VRPs, as well as auditory-based cognitive tasks (pitch discrimination and auditory Stroop), both under single and dual-task conditions. Dual-task cost (DTC) for onset distance of trajectory deviation, minimum distance from the VRP, maximum lateral deviation, walking speed, gaze fixations and cognitive task accuracy were contrasted between groups using generalized estimating equations.
RESULTS
In contrast to CTLs who showed locomotor DTCs only, individuals with m/sTBI displayed both locomotor and cognitive DTCs. While both groups walked slower under dual-task conditions, only individuals with m/sTBI failed to modify their onset distance of trajectory deviation and maintained smaller minimum distances and smaller maximum lateral deviation compared to single-task walking. Both groups showed shorter gaze fixations on the approaching VRP under dual-task conditions, but this reduction was less pronounced in the individuals with m/sTBI. A reduction in cognitive task accuracy under dual-task conditions was found in the m/sTBI group only.
CONCLUSION
Individuals with m/sTBI present altered locomotor and gaze behaviours, as well as altered cognitive performances, when executing a collision avoidance task involving moving pedestrians in dual-task conditions. Potential mechanisms explaining those alterations are discussed. Present findings highlight the compromised complex walking abilities in individuals with m/sTBI who otherwise present a good locomotor recovery.
Topics: Humans; Male; Adult; Female; Pedestrians; Brain Injuries, Traumatic; Middle Aged; Virtual Reality; Psychomotor Performance; Walking; Cognition; Avoidance Learning; Attention
PubMed: 38755606
DOI: 10.1186/s12984-024-01378-x -
PloS One 2024When older adults step over obstacles during multitasking, their performance is impaired; the impairment results from central and/or sensory interference. The purpose...
When older adults step over obstacles during multitasking, their performance is impaired; the impairment results from central and/or sensory interference. The purpose was to determine if sensory interference alters performance under low levels of cognitive, temporal, and gait demand, and if the change in performance is different for younger versus older adults. Participants included 17 younger adults (20.9±1.9 years) and 14 older adults (69.7±5.4 years). The concurrent task was a single, simple reaction time (RT) task: depress button in response to light cue. The gait task was stepping over an obstacle (8 m walkway) in three conditions: (1) no sensory interference (no RT task), (2) low sensory interference (light cue on obstacle, allowed concurrent foveation of cue and obstacle), or (3) high sensory interference (light cue away from obstacle, prevented concurrent foveation of cue and obstacle). When standing, the light cue location was not relevant (no sensory interference). An interaction (sensory interference by task, p<0.01) indicated that RT was longer for high sensory interference during walking, but RT was not altered for standing, confirming that sensory interference increased RT during obstacle approach. An interaction (sensory interference by age, p<0.01) was observed for foot placement before the obstacle: With high sensory interference, younger adults placed the trail foot closer to the obstacle while older adults placed it farther back from the obstacle. The change increases the likelihood of tripping with the trail foot for younger adults, but with the lead limb for older adults. Recovery from a lead limb trip is more difficult due to shorter time for corrective actions. Overall, visual sensory interference impaired both RT and gait behavior with low levels of multitask demand. Changes in foot placement increased trip risk for both ages, but for different limbs, reducing the likelihood of balance recovery in older adults.
Topics: Humans; Aged; Male; Female; Reaction Time; Young Adult; Gait; Adult; Psychomotor Performance; Aging; Cues; Walking; Middle Aged; Age Factors
PubMed: 38753863
DOI: 10.1371/journal.pone.0302838 -
PloS One 2024Soccer heading is adversely associated with neurocognitive performance, but whether greater neck strength or anthropometrics mitigates these outcomes is controversial....
OBJECTIVES
Soccer heading is adversely associated with neurocognitive performance, but whether greater neck strength or anthropometrics mitigates these outcomes is controversial. Here, we examine the effect of neck strength or anthropometrics on associations of soccer heading with neurocognitive outcomes in a large cohort of adult amateur players.
METHODS
380 adult amateur league soccer players underwent standardized measurement of neck strength (forward flexion, extension, left lateral flexion, right lateral flexion) and head/neck anthropometric measures (head circumference, neck length, neck circumference and neck volume). Participants were assessed for heading (HeadCount) and cognitive performance (Cogstate) on up to 7 visits over a period of two years. Principal components analysis (PCA) was performed on 8 neck strength and anthropometric measures. We used generalized estimating equations to test the moderation effect of each of the three PCs on 8 previously identified adverse associations of 2-week and 12-month heading estimates with cognitive performance (psychomotor speed, immediate verbal recall, verbal episodic memory, attention, working memory) and of unintentional head impacts on moderate to severe central nervous system symptoms.
RESULTS
3 principal components (PC's) account for 80% of the variance in the PCA. In men, PC1 represents head/neck anthropometric measures, PC2 represents neck strength measures, and PC3 represents the flexor/extensor (F/E) ratio. In women, PC1 represents neck strength, PC2 represents anthropometrics, and PC3 represents the F/E ratio. Of the 48 moderation effects tested, only one showed statistical significance after Bonferroni correction, which was not robust to extensive sensitivity analyses.
CONCLUSION
Neither neck strength nor anthropometrics mitigate adverse associations of soccer heading with cognitive performance in adult amateur players.
Topics: Humans; Soccer; Male; Adult; Cognition; Female; Muscle Strength; Neck; Young Adult; Principal Component Analysis; Neck Muscles; Athletes
PubMed: 38753699
DOI: 10.1371/journal.pone.0302463 -
Nature May 2024Working memory, the process through which information is transiently maintained and manipulated over a brief period, is essential for most cognitive functions. However,...
Working memory, the process through which information is transiently maintained and manipulated over a brief period, is essential for most cognitive functions. However, the mechanisms underlying the generation and evolution of working-memory neuronal representations at the population level over long timescales remain unclear. Here, to identify these mechanisms, we trained head-fixed mice to perform an olfactory delayed-association task in which the mice made decisions depending on the sequential identity of two odours separated by a 5 s delay. Optogenetic inhibition of secondary motor neurons during the late-delay and choice epochs strongly impaired the task performance of the mice. Mesoscopic calcium imaging of large neuronal populations of the secondary motor cortex (M2), retrosplenial cortex (RSA) and primary motor cortex (M1) showed that many late-delay-epoch-selective neurons emerged in M2 as the mice learned the task. Working-memory late-delay decoding accuracy substantially improved in the M2, but not in the M1 or RSA, as the mice became experts. During the early expert phase, working-memory representations during the late-delay epoch drifted across days, while the stimulus and choice representations stabilized. In contrast to single-plane layer 2/3 (L2/3) imaging, simultaneous volumetric calcium imaging of up to 73,307 M2 neurons, which included superficial L5 neurons, also revealed stabilization of late-delay working-memory representations with continued practice. Thus, delay- and choice-related activities that are essential for working-memory performance drift during learning and stabilize only after several days of expert performance.
Topics: Animals; Female; Male; Mice; Calcium; Choice Behavior; Memory Consolidation; Memory, Short-Term; Mice, Inbred C57BL; Motor Cortex; Motor Neurons; Odorants; Optogenetics; Practice, Psychological; Psychomotor Performance; Smell; Time Factors
PubMed: 38750359
DOI: 10.1038/s41586-024-07425-w -
Research in Developmental Disabilities Jul 2024Physically active learning (PAL) is a potentially valuable method to stimulate academic performance and physical activity (PA) in children with learning disorders (LD)...
BACKGROUND
Physically active learning (PAL) is a potentially valuable method to stimulate academic performance and physical activity (PA) in children with learning disorders (LD) attending special-needs schools. It is yet unknown whether PAL can be successfully implemented in special-needs schools.
AIMS
This study aimed to evaluate a PAL-program in special-needs schools by examining teacher's dose delivered, children's dose received, and associations of children's characteristics with dose received.
METHODS
Children (N = 37) from two special-needs schools participated in a six-week PAL-program. Dose delivered was evaluated based on PAL-lessons' implementation rate and duration. Dose received was assessed through time-on-task observations (n = 23) and PA (n = 37). To assess the association between dose received and children's characteristics (sex, behavioral disorders, motor skills, and physical fitness), Mann-Whitney U tests and Spearman's rho correlations were used.
RESULTS
For teacher's dose delivered, the implementation rate exceeded 95%, and the PAL-lessons lasted the intended 12 minutes. For dose received, children's on-task behavior was above 79%, and children spent 43% of the time in moderate-to-vigorous PA during PAL. Motor skills were positively related to on-task behavior related to the movements, and physical fitness was positively related to moderate-to-vigorous PA.
CONCLUSIONS
PAL was successfully implemented in terms of dose delivered and dose received for children with LD attending special-needs schools.
Topics: Humans; Child; Male; Female; Learning Disabilities; Program Evaluation; Exercise; Schools; Education, Special; Motor Skills; Physical Fitness; Academic Performance; Learning
PubMed: 38749230
DOI: 10.1016/j.ridd.2024.104749 -
PloS One 2024Cognitive Arousal, frequently elicited by environmental stressors that exceed personal coping resources, manifests in measurable physiological markers, notably in...
Cognitive Arousal, frequently elicited by environmental stressors that exceed personal coping resources, manifests in measurable physiological markers, notably in galvanic skin responses. This effect is prominent in cognitive tasks such as composition, where fluctuations in these biomarkers correlate with individual expressiveness. It is crucial to understand the nexus between cognitive arousal and expressiveness. However, there has not been a concrete study that investigates this inter-relation concurrently. Addressing this, we introduce an innovative methodology for simultaneous monitoring of these elements. Our strategy employs Bayesian analysis in a multi-state filtering format to dissect psychomotor performance (captured through typing speed), galvanic skin response or skin conductance (SC), and heart rate variability (HRV). This integrative analysis facilitates the quantification of expressive behavior and arousal states. At the core, we deploy a state-space model connecting one latent psychological arousal condition to neural activities impacting sweating (inferred through SC responses) and another latent state to expressive behavior during typing. These states are concurrently evaluated with model parameters using an expectation-maximization algorithms approach. Assessments using both computer-simulated data and experimental data substantiate the validity of our approach. Outcomes display distinguishable latent state patterns in expressive typing and arousal across different computer software used in office management, offering profound implications for Human-Computer Interaction (HCI) and productivity analysis. This research marks a significant advancement in decoding human productivity dynamics, with extensive repercussions for optimizing performance in telecommuting scenarios.
Topics: Humans; Arousal; Galvanic Skin Response; Heart Rate; Cognition; Male; Bayes Theorem; Female; Adult; Psychomotor Performance; Teleworking; Efficiency; Algorithms; Young Adult
PubMed: 38748663
DOI: 10.1371/journal.pone.0300786