scholarly journals Differences in Mechanical Parameters of Keyboard Switches Modulate Motor Preparation: A Wearable EEG Study

2021 ◽  
Vol 2 ◽  
Author(s):  
Hiroki Watanabe ◽  
Kae Nakajima ◽  
Shunsuke Takagi ◽  
Ryo Mizuyama ◽  
Mayumi Saito ◽  
...  
Keyword(s):  
Information Processing ◽  
Motor Preparation ◽  
Objective Evaluation ◽  
Mechanical Parameters ◽  
Response Preparation ◽  
Subjective Evaluations ◽  
Wearable Eeg ◽  
Free Position ◽  
Psychological Sense ◽  
Parameter Values

The mechanical parameters of keyboard switches affect the psychological sense of pressing. The effects of different mechanical parameters on psychological sense have been quantified using questionnaires, but these subjective evaluations are unable to fully clarify the modulation of information processing in the brain due to these differences. This study aimed to elucidate the ability of electroencephalography (EEG) measurements to detect the modulation of subconscious information processing according to mechanical parameter values. To this end, we prepared five mechanical switches with linearly increasing values of pretravel (PT: the distance from the free position until the operating position). We hypothesized that the differences in PTs would subconsciously affect the motor preparation prior to pressing switches because switches with PTs that deviated from those commonly used were predicted to increase the users' attention level when pressing. Differences in motor preparation were quantified using the mean amplitudes of the late contingent negative variation (CNV). We recorded EEGs of 25 gamers during a reaction task for fast switch pressing after a response cue preceded by a pre-cue for response preparation; we also measured the reaction time feedback on each switch pressing trial. Participants performed five sessions (60 trials per session) in total. For the analysis, trials were divided into first (session 1, 2, and 3) and second half sessions (session 4 and 5). In the latter session, CNV amplitudes were significantly higher for the switch with the highest PT than for that with a medium PT, which is closest to that commonly used in commercial mechanical switches. On the other hand, the questionnaire did not detect any significant differences between PTs in their subjective rankings of the psychological effects of switch pressing. These results suggest that differences in PTs modulate motor preparation to press switches, and that EEG measurements may provide a novel objective evaluation of the mechanical parameters of keyboard switches.

scholarly journals Frontal and motor cortex contributions to response inhibition: evidence from electrocorticography

2016 ◽  
Vol 115 (4) ◽  
pp. 2224-2236 ◽  
Author(s):  
Yvonne M. Fonken ◽  
Jochem W. Rieger ◽  
Elinor Tzvi ◽  
Nathan E. Crone ◽  
Edward Chang ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Response Inhibition ◽  
Motor Preparation ◽  
Relevant Information ◽  
Stop Signal ◽  
Response Preparation ◽  
Time Frequency ◽  
Beta Power ◽  
High Gamma ◽  
Stop Signal Reaction Time

Changes in the environment require rapid modification or inhibition of ongoing behavior. We used the stop-signal paradigm and intracranial recordings to investigate response preparation, inhibition, and monitoring of task-relevant information. Electrocorticographic data were recorded in eight patients with electrodes covering frontal, temporal, and parietal cortex, and time-frequency analysis was used to examine power differences in the beta (13–30 Hz) and high-gamma bands (60–180 Hz). Over motor cortex, beta power decreased, and high-gamma power increased during motor preparation for both go trials (Go) and unsuccessful stops (US). For successful stops (SS), beta increased, and high-gamma was reduced, indexing the cancellation of the prepared response. In the middle frontal gyrus (MFG), stop signals elicited a transient high-gamma increase. The MFG response occurred before the estimated stop-signal reaction time but did not distinguish between SS and US trials, likely signaling attention to the salient stop stimulus. A postresponse high-gamma increase in MFG was stronger for US compared with SS and absent in Go, supporting a role in behavior monitoring. These results provide evidence for differential contributions of frontal subregions to response inhibition, including motor preparation and inhibitory control in motor cortex and cognitive control and action evaluation in lateral prefrontal cortex.

Assessment of Muscle Spasticity by a Simple Pendulum Test and Modeling

2006 ◽  
Vol 321-323 ◽  
pp. 1008-1011
Author(s):  
Jae Hoon Jun ◽  
Se Jin Kong ◽  
Chul Seung Kim ◽  
Gwang Moon Eom ◽  
Soon Hyuck Lee ◽  
...  
Keyword(s):  
Muscle Length ◽  
Severity Index ◽  
Objective Evaluation ◽  
Study Data ◽  
Nonlinear Feedback ◽  
Modeling Error ◽  
Simple Pendulum ◽  
Subjective Evaluations ◽  
Pendulum Test ◽  
Reflex System

The quantitative and objective evaluation of spasticity is desirable in rehabilitation and orthopedics where subjective evaluations are mostly used. In the present study, data from a simple pendulum test are used for the evaluation of the spasticity with the help of biomechanical modeling. The spasticity of a knee joint is modeled as nonlinear feedback of muscle lengthening velocity and the muscle length. Through the optimization of the modeling error, the feedback parameters are determined. The threshold of muscle lengthening velocity in the reflex system is suggested as a severity index of the spasticity.

scholarly journals Assessment of Personal Relaxation in Indoor-Air Environments: Study in Real Full-Scale Laboratory Houses

2021 ◽  
Vol 18 (19) ◽  
pp. 10246
Author(s):  
Yoshitake Nakayama ◽  
Norimichi Suzuki ◽  
Hiroko Nakaoka ◽  
Kayo Tsumura ◽  
Kohki Takaguchi ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Indoor Air ◽  
Subjective Evaluation ◽  
Objective Evaluation ◽  
Subjective Evaluations ◽  
Volatile Organic ◽  
The Relationship ◽  
Electroencephalogram Eeg ◽  
Human Sense

The relationship between chemical concentrations in indoor air and the human sense of comfort and relaxation have been reported. We investigated the effect of the sum of volatile organic compounds (ΣVOCs; sum of 79 VOCs) on the level of relaxation in two laboratory houses with almost identical interior and exterior appearances. The electroencephalogram (EEG) was monitored to evaluate the degree of personal relaxation objectively. The experiments were conducted in laboratory houses (LH) A and B with lower and higher levels of ΣVOCs, respectively. A total of 168 healthy volunteers participated, who each performed the task for 20 min, followed by a 10-min break, and EEG was measured during the break. Simultaneously as subjective evaluations, the participants were asked to fill a questionnaire regarding the intensity of odor and preference for the air quality in each LH. The subjective evaluation showed a significant association between ΣVOCs and participants’ relaxation (OR: 2.86, 95%CI: 1.24–6.61), and the objective evaluation indicated that the participants were more relaxed in the LH with lower levels of ΣVOCs than that with higher levels (OR: 3.03, 95%CI: 1.23–7.50). Therefore, the reduction of ΣVOCs and odors in indoor air would have an effect, which is the promotion of relaxation.

scholarly journals Generating Artificial Reverberation via Genetic Algorithms for Real-Time Applications

Entropy ◽  
2020 ◽  
Vol 22 (11) ◽  
pp. 1309
Author(s):  
Edward Ly ◽  
Julián Villegas
Keyword(s):  
Real World ◽  
Subjective Evaluation ◽  
Weighted Average ◽  
Objective Evaluation ◽  
Physical World ◽  
Impulse Responses ◽  
Audio Signals ◽  
Left And Right ◽  
Parameter Values ◽  
Crossover And Mutation

We introduce a Virtual Studio Technology (VST) 2 audio effect plugin that performs convolution reverb using synthetic Room Impulse Responses (RIRs) generated via a Genetic Algorithm (GA). The parameters of the plugin include some of those defined under the ISO 3382-1 standard (e.g., reverberation time, early decay time, and clarity), which are used to determine the fitness values of potential RIRs so that the user has some control over the shape of the resulting RIRs. In the GA, these RIRs are initially generated via a custom Gaussian noise method, and then evolve via truncation selection, random weighted average crossover, and mutation via Gaussian multiplication in order to produce RIRs that resemble real-world, recorded ones. Binaural Room Impulse Responses (BRIRs) can also be generated by assigning two different RIRs to the left and right stereo channels. With the proposed audio effect, new RIRs that represent virtual rooms, some of which may even be impossible to replicate in the physical world, can be generated and stored. Objective evaluation of the GA shows that contradictory combinations of parameter values will produce RIRs with low fitness. Additionally, through subjective evaluation, it was determined that RIRs generated by the GA were still perceptually distinguishable from similar real-world RIRs, but the perceptual differences were reduced when longer execution times were used for generating the RIRs or the unprocessed audio signals were comprised of only speech.

Synthetic Video Generation for Evaluation of Sprite Generation

2012 ◽  
pp. 160-187
Author(s):  
Yi Chen ◽  
Ramazan S. Aygün
Keyword(s):  
Ground Truth ◽  
Objective Evaluation ◽  
Camera Motion ◽  
Generation Algorithm ◽  
Motion Patterns ◽  
Subjective Evaluations ◽  
Sprite Generation ◽  
Ground Truth Image ◽  
Motion Parameters ◽  
Synthetic Video

Sprite generation is the process of aligning, warping, and blending of pixels that belong to an object in a video. The evaluation of the correctness of a sprite is usually accomplished by a combination of objective and subjective evaluations. Availability of ground-truth image would help mere objective evaluation. In this paper, the authors present video generation from an image based on various camera motion parameters to be used as ground-truth for the sprite evaluation. This paper introduces a framework for evaluation of sprite generation algorithms. Experiments under the proposed framework were performed on the synthetic videos of different camera motion patterns to reveal the components of the sprite generation algorithm to be improved.

scholarly journals Inter-Individual Variability in The Joint Negative Work During Running

2018 ◽  
Vol 02 (05) ◽  
pp. E157-E162
Author(s):  
Satoru Hashizume ◽  
Hiroaki Hobara ◽  
Yoshiyuki Kobayashi ◽  
Mitsunori Tada ◽  
Masaaki Mochimaru
Keyword(s):  
Regression Analysis ◽  
Lower Extremity ◽  
Linear Regression Analysis ◽  
Young Male ◽  
Multiple Linear Regression Analysis ◽  
Individual Variability ◽  
Mechanical Parameters ◽  
Negative Work ◽  
The Moment ◽  
Parameter Values

AbstractThe inter-individual variability of running technique is an important factor affecting the negative work of lower extremity joints that leads to muscle damage. Our study examines the relationships between the negative work of the lower extremity joints and the associated mechanical parameters that account for inter-individual variability in the negative work. Twenty-four young male adults were asked to run on a runway at a speed of 3.0 m·s−1. Multiple linear regression analysis was conducted to examine the relationships between the negative work and the associated mechanical parameters for each lower extremity joint. With regards to the results, 76.3% of inter-individual variability in the negative work of the hip joint was accounted for by inter-individual variabilities in the corresponding moment (25.4%) and duration (50.9%). For the knee joint, the inter-individual variabilities in the moment (40.6%), angular velocity (24.5%), and duration (23.8%) accounted for 88.9% of inter-individual variability in the negative work. The inter-individual variability in the moment of the ankle joint alone accounted for 89.3% of the inter-individual variability in the corresponding negative work. These results suggest that runners can change the negative work by adapting their running techniques to influence the relevant mechanical parameter values; however, major parameters corresponding to the change in the negative work are not the same among the lower extremity joints.

Actions speak louder than words: Enhanced action tendencies in obsessive-compulsive disorder: An ERP study

2016 ◽  
Vol 33 (S1) ◽  
pp. S89-S89
Author(s):  
A. Dayan Riva ◽  
A. Berger ◽  
G. Anholt
Keyword(s):  
Obsessive Compulsive Disorder ◽  
Response Inhibition ◽  
Motor Preparation ◽  
Event Related Potential ◽  
Stop Signal Task ◽  
Response Preparation ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Competing Interest ◽  
Action Tendencies

Obsessive-compulsive disorder (OCD) is characterized by repeated thoughts and behaviors. Several studies have detected deficient response inhibition ability in individuals with OCD, leading researchers to suggest this deficit as an endophenotype of OCD. However, other researchers maintain that the effect size of this deficit is modest and that it lacks clinical significance. The current investigation examines a potential alternative explanation for difficulties in response inhibition, namely enhanced action tendencies in response to stimuli. Therefore, early processes of motor response preparation preceding action performance (or inhibition) were studied with the event-related potential (ERP) component of readiness potential (RP). RP measures brain reactions related to motor activity in response to external stimuli. ERPs were recorded while 15 participants with OCD and 16 healthy controls performed a variation of a go/no-go task and a stop-signal task using schematic faces (angry and neutral). The OCD group presented with a greater RP slope gradient and amplitude over bilateral parietal areas corresponding to the motor cortex. The amplitude effect was further enhanced under negative valence, compared with the neutral condition. Differences in RP between the OCD and control groups remained significant when controlling for levels of trait anxiety. Results support the hypothesis that a stronger readiness for action might characterize OCD, especially in the presence of threatening stimuli. This finding, specific to OCD and not to anxiety symptoms, may underlie habitual tendencies in OCD. This study suggests that early-stages of motor preparation might be important to the etiology and maintenance of OCD.Disclosure of interestThe authors have not supplied their declaration of competing interest.

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