Kinetic and Frequency-Domain Properties of Reflex and Conditioned Eyelid Responses in the Rabbit

2000 ◽  
Vol 83 (2) ◽  
pp. 836-852 ◽  
Author(s):  
Agnès Gruart ◽  
Bernard G. Schreurs ◽  
Eduardo Domínguez del Toro ◽  
JoséMaría Delgado-García
Keyword(s):  
Power Spectrum ◽  
Peak Velocity ◽  
Maximum Amplitude ◽  
Reflex Response ◽  
Neural Oscillator ◽  
Electromyographic Activity ◽  
Onset Latency ◽  
Stimulus Interval ◽  
Time To Peak ◽  
Reflex Blinks

Eyelid position and the electromyographic activity of the orbicularis oculi muscle were recorded unilaterally in rabbits during reflex and conditioned blinks. Air-puff–evoked blinks consisted of a fast downward phase followed sometimes by successive downward sags. The reopening phase had a much longer duration and slower peak velocity. Onset latency, maximum amplitude, peak velocity, and rise time of reflex blinks depended on the intensity and duration of the air puff–evoking stimulus. A flashlight focused on the eye also evoked reflex blinks, but not flashes of light, or tones. Both delayed and trace classical conditioning paradigms were used. For delayed conditioning, animals were presented with a 350-ms, 90-dB, 600-Hz tone, as conditioned stimulus (CS). For trace conditioning, animals were presented with a 10-ms, 1-k/cm2 air puff, as CS. The unconditioned stimulus (US) consisted of a 100-ms, 3-k/cm2 air puff. The stimulus interval between CS and US onsets was 250 ms. Conditioned responses (CRs) to tones were composed of downward sags that increased in number through the successive conditioning sessions. The onset latency of the CR decreased across conditioning at the same time as its maximum amplitude and its peak velocity increased, but the time-to-peak of the CR remained unaltered. The topography of CRs evoked by short, weak air puffs as the CS showed three different components: the alpha response to the CS, the CR, and the reflex response to the US. Through conditioning, CRs showed a decrease in onset latency, and an increase in maximum amplitude and peak velocity. The time-to-peak of the CR remained unchanged. A power spectrum analysis of reflex and conditioned blink acceleration profiles showed a significant ≈8-Hz oscillation within a broadband of frequencies between 4 and 15 Hz. Nose and mandible movements presented power spectrum profiles different from those characterizing reflex and conditioned blinks. It is concluded that eyelid reflex responses in the rabbit present significant differences from CRs in their profiles and metric properties, suggesting different neural origins, but that a common ≈8-Hz neural oscillator underlies lid motor performance. According to available data, the frequency of this putative oscillator seems to be related to the species size.

scholarly journals The StartReact Effect on Self-Initiated Movements

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
J. M. Castellote ◽  
M. E. L. Van den Berg ◽  
J. Valls-Solé
Keyword(s):  
Reaction Time ◽  
Time Window ◽  
Peak Velocity ◽  
Movement Time ◽  
Reaction Time Task ◽  
Electromyographic Activity ◽  
Wrist Extension ◽  
Time To Peak ◽  
Movement Kinematic ◽  
Preparatory Activity

Preparation of the motor system for movement execution involves an increase in excitability of motor pathways. In a reaction time task paradigm, a startling auditory stimulus (SAS) delivered together with the imperative signal (IS) shortens reaction time significantly. In self-generated tasks we considered that an appropriately timed SAS would have similar effects. Eight subjects performed a ballistic wrist extension in two blocks: reaction, in which they responded to a visual IS, and action, in which they moved when they wished within a predetermined time window. In 20–25% of the trials, a SAS was applied. We recorded electromyographic activity of wrist extension and wrist movement kinematic variables. No effects of SAS were observed in action trials when movement was performed before or long after SAS application. However, a cluster of action trials was observed within 200 ms after SAS. These trials showed larger EMG bursts, shorter movement time, shorter time to peak velocity, and higher peak velocity than other action trials (P<0.001for all), with no difference from Reaction trials containing SAS. The results show that SAS influences the execution of self-generated human actions as it does with preprogrammed reaction time tasks during the assumed building up of preparatory activity before execution of the willed motor action.

Quantal Organization of Reflex and Conditioned Eyelid Responses

1997 ◽  
Vol 78 (5) ◽  
pp. 2518-2530 ◽  
Author(s):  
José A. Domingo ◽  
Agnes Gruart ◽  
José M. Delgado-García
Keyword(s):  
Conditioned Stimulus ◽  
Unconditioned Stimulus ◽  
Conditioned Response ◽  
Total Duration ◽  
Maximum Amplitude ◽  
Dominant Frequency ◽  
Time Interval ◽  
Electromyographic Activity ◽  
Conditioned Eyelid ◽  
Reflex Blinks

Domingo, José A., Agnes Gruart, and José M. Delgado-Garcı́a. Quantal organization of reflex and conditioned eyelid responses. J. Neurophysiol. 78: 2518–2530, 1997. Upper lid movements and the electromyographic activity of the orbicularis oculi muscle were recorded in behaving cats during spontaneous and experimentally evoked reflex blinks, and conditioned eyelid responses. Reflex blinks evoked by the presentation of air puffs, flashes, or tones consisted of a fast downward lid movement followed by late, small downward waves, recurring at ≈50-ms intervals. The latency, maximum amplitude, peak velocity, and number of late waves depended on the modality, intensity, and duration of the evoking stimulus. The power spectra of acceleration records indicated a dominant frequency of ≈20 Hz for air puff–evoked blinks. Flashes and tones usually evoked small and easily fatigable reflex responses of lower dominant frequencies (14–17 and 9–11 Hz, respectively). A basic ≈20-Hz oscillation was also noticed during lid fixation, and ramplike lid displacements evoked by optokinetic stimuli. Five classical conditioning paradigms were used to analyze the frequency-domain properties of conditioned eyelid responses. These learned lid movements differed in latency, maximum amplitude, and profile smoothness depending on the modality (air puff, tone), intensity (weak, strong), and presentation site (ipsi-, contralateral to the unconditioned stimulus) of the conditioned stimulus. It was found that the characteristic ramplike profile of a conditioned response was not smooth, but appeared to be formed by a succession of small waves at a dominant frequency of ≈20 Hz. The amplitude (and number) of the constituting waves depended on the characteristics of the conditioned stimulus and on the time interval until unconditioned stimulus presentation. Thus conditioned responses seemed to be formed from lid displacements of 2–6° in amplitude and ≈50 ms in duration, which increased in number throughout conditioning sessions, until a complete (i.e., lid closing) conditioned response was reached. It is suggested that a ≈20-Hz oscillator underlies the generation of reflex and conditioned eyelid responses. The oscillator is susceptible to being neurally modulated to modify the velocity of a given quantum of movement, and the total duration of the lid response. Learned eyelid movements are probably the result of a successively longer release of the oscillator as a function of the temporal-spatial needs of the motor response.

scholarly journals P802 Delayed time to peak left ventricular outflow tract velocity is associated with symptomatic status in patients with hypertrophic obstructive cardiomyopathy

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
R Huurman ◽  
A Schinkel ◽  
D Bowen ◽  
A Hirsch ◽  
M Michels
Keyword(s):  
Regression Models ◽  
Peak Velocity ◽  
Ventricular Outflow Tract ◽  
Hypertrophic Obstructive Cardiomyopathy ◽  
Left Ventricular ◽  
Outflow Tract ◽  
Ejection Time ◽  
Logistic Regression Models ◽  
Time To Peak ◽  
Left Ventricular Outflow

Abstract Funding Acknowledgements None. The presence and magnitude of left ventricular outflow tract (LVOT) obstruction in hypertrophic obstructive cardiomyopathy (HOCM) patients is weakly associated with presence of symptoms. The factors underlying this are not well understood. We hypothesize that time to peak velocity (TPV) of LVOT flow is associated with symptomatic status. We included 136 HOCM patients (58% men, mean age 55 ± 14 years) with peak gradients ≥30 mmHg at rest or during Valsalva without aortic valve stenosis. At rest and during Valsalva, continuous wave Doppler tracings from 3 consecutive beats were used to assess peak velocity (PV), left ventricular ejection time (LVET) and TPV, which was defined as the time interval between the onset of flow over the LVOT and the moment of PV. Differences were compared between asymptomatic and symptomatic patients (defined as New York Heart Association class I vs. II-IV). The relation between symptom status and TPV was investigated using logistic regression models. A random sample of 20 patients was examined by 2 observers and reproducibility was assessed using the intraclass correlation coefficient (ICC). Symptomatic patients were more often female (table) and had significantly higher mean TPV values (figure). In multivariable logistic regression models, TPV was an independent predictor of symptomatic status after correction for PV, LVOT diameter, heart rate and age (odds ratio 1.02 per 1 ms, p &lt; 0.001). The ICC was 0.99 with a mean difference of 0.28 ± 8.5 ms. Delayed TPV is associated with symptomatic status in HOCM patients, after adjustment for heart rate, peak velocity, LVOT diameter and age, and is an easily measured echocardiographic variable with excellent inter-reader reproducibility. The clinical implications of delayed TPV, particularly in the context risk prediction and clinical decision making, remain to be determined. Characteristics per group Asymptomatic HOCM patients n = 47 Symptomatic HOCM patients n = 89 p value Age, y 55 ± 14 55 ± 14 0.99 Male gender 34 (72%) 45 (51%) 0.01 Body mass index, kg/m&sup2; 27 ± 5 28 ± 5 0.08 Left atrial diameter, mm 46 ± 7 47 ± 7 0.64 Septal wall thickness, mm 18 ± 4 19 ± 5 0.58 LV outflow tract diameter, mm 22 ± 3 21 ± 3 0.001 Peak velocity, cm/s 403 ± 86 434 ± 79 0.03 LV ejection time, ms 316 ± 44 340 ± 42 0.002 Time to peak velocity, ms 157 ± 32 178 ± 32 &lt;0.001 HOCM = hypertrophic obstructive cardiomyopathy, LV = left ventricular. Abstract P802 Figure. Time to peak velocity per NYHA class

scholarly journals Detecting Mind-Wandering from Eye Movement and Oculomotor Data during Learning Video Lecture

2020 ◽  
Vol 10 (3) ◽  
pp. 51
Author(s):  
DongMin Jang ◽  
IlHo Yang ◽  
SeoungUn Kim
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Fixation Duration ◽  
Peak Velocity ◽  
Eye Gaze ◽  
Sampling Rate ◽  
Maximum Amplitude ◽  
Mind Wandering ◽  
Video Lecture ◽  
Video Lectures

The purpose of this study was to detect mind-wandering experienced by pre-service teachers during a video learning lecture on physics. The lecture was videotaped and consisted of a live lecture in a classroom. The lecture was about Gauss's law on physics. We investigated whether oculomotor data and eye movements could be used as a marker to indicate the learner’s mind-wandering. Each data was collected in a study in which 24 pre-service teachers (16 females and 8 males) reported mind-wandering experience through self-caught method while learning physics video lecture during 30 minutes. A Tobii Pro Spectrum (sampling rate: 300 Hz) was used to capture their eye-gaze during learning Gauss's law through a course video. After watching the video lecture, we interviewed pre-service teachers about their mind-wandering experience. We first used the self-caught method to capture the mind-wandering timing of pre-service teachers while learning from video lectures. We detected more accurate mind-wandering segments by comparing fixation duration and saccade count. We investigated two types of oculomotor data (blink count, pupil size) and nine eye movements (average peak velocity of saccades; maximum peak velocity of saccades; standard deviation of peak velocity of saccades; average amplitude of saccades; maximum amplitude of saccades; total amplitude of saccades; saccade count/s; fixation duration; fixation dispersion). The result was that the blink count could not be used as a marker for mind-wandering during learning video lectures among them (oculomotor data and eye movements), unlike previous literatures. Based on the results of this study, we identified elements that can be used as mind-wandering markers while learning from video lectures that are similar to real classes, among the oculomotor data and eye movement mentioned in previous literatures. Additionally, we found that most participants focused on past thoughts and felt unpleasant after experiencing mind-wandering through interview analysis.

scholarly journals Developmental Differences in the Prospective Organisation of Goal-Directed Movement Between Children with Autism and Typically Developing Children: A Smart Tablet Serious Game Study

2021 ◽  
Author(s):  
Yu Wei Chua ◽  
Szu-Ching Lu ◽  
Anna Anzulewicz ◽  
Krzysztof Sobota ◽  
Christos Tachtatzis ◽  
...  
Keyword(s):  
Peak Velocity ◽  
Movement Time ◽  
Developmental Differences ◽  
Serious Game ◽  
Movement Kinematics ◽  
Directed Movement ◽  
Mixed Effect ◽  
Feedback Mechanisms ◽  
Time To Peak ◽  
Movement Unit

Movement is prospective. It structures self-generated engagement with objects and social partners and is fundamental to children’s learning and development. In autistic children, previous reports of differences in movement kinematics compared to neurotypical peers suggest its prospective organisation might be disrupted. Here, we employed a smart tablet serious game paradigm to assess differences in the feedforward and feedback mechanisms of prospective action organisation, between autistic and neurotypical preschool children. We analysed 3926 goal-directed finger movements made during smart-tablet ecological gameplay, from 28 children with Childhood Autism (ICD-10; ASD) and 43 neurotypical children (TD), aged 3-6 years old. Using linear and generalised linear mixed-effect models, we found the ASD group executed movements with longer Movement Time (MT) and Time to Peak Velocity (TTPV), lower Peak Velocity (PV), with peak velocity less likely to occur in the first movement unit, and with a greater number of Movement Units After Peak Velocity (MU-APV). Interestingly, compared to the TD group, the ASD group showed smaller increases in PV, TTPV and MT with an increase in Age (ASD x Age interaction), together with a smaller reduction in MU-APV and an increase in MU-APV at shorter target distances (ASD x Dist interaction). Our results are the first to highlight different developmental trends in anticipatory feedforward and compensatory feedback mechanisms of control, contributing to differences in movement kinematics observed between autistic and neurotypical children. These findings point to differences in integration of prospective perceptuomotor information, with implications for embodied cognition and learning from self-generated action in autism.

scholarly journals Correlation between temporal-spatial parameters and manual ability of adults with dyskinetic cerebral palsy

2014 ◽  
Vol 21 (2) ◽  
pp. 120-126
Author(s):  
Mariana Cunha Artilheiro ◽  
Danielli Souza Speciali ◽  
Bárbara Alves Lopes ◽  
João Carlos Ferrari Correa ◽  
Paulo Roberto Garcia Lucareli
Keyword(s):  
Cerebral Palsy ◽  
Average Velocity ◽  
Peak Velocity ◽  
Movement Speed ◽  
Mean Velocity ◽  
Spatial Variables ◽  
Time To Peak ◽  
Spatial Parameters ◽  
Manual Ability Classification System

The aim of this study was to verify relation between kinematic variables of temporal-spatial parameters and manual ability and between own temporal-spatial variables during the movement of bring a mug to the mouth in adults with dyskinetic cerebral palsy (DCP). Sixteen adults with DCP were evaluated by MACS (Manual Ability Classification System), and by temporal-spatial variables of tridimensional kinematics of the movement to bring a bug to the mouth by means of 9 cameras infra-red Vicon(r) MX 40 (Oxford Metrics Group, Oxford, UK). The Spearman correlation coefficient (ρ) was used to correlate variables. As a result, we found weak correlation between the classification of manual ability and the adjusting phase (ρ=0.219), the velocity variables - average velocity (ρ=-0.313), peak velocity (ρ=-0.282) and time to peak velocity (ρ=-0.250). No correlation was found between the variables going and returning phase and MACS. Moderate correlation was found between going and returning phase (ρ=0.559), between the going phase and time to peak velocity (ρ=0.518) and between the adjusting phase and peak velocity (ρ=-0.562). A strong correlation was found between the mean velocity and peak velocity (ρ=0.947) and between the adjusting phase and average velocity (ρ=-0.635). In conclusion, functional impairment may be related to longer adjusting phase and decrease of movement speed in subjects with PCD. Kinematic variables were related to each other in moderate and strong way and indicated that the phases runtime influences the movement speed.

Windup of Flexion Reflexes in Chronic Human Spinal Cord Injury: A Marker for Neuronal Plateau Potentials?

2003 ◽  
Vol 89 (1) ◽  
pp. 416-426 ◽  
Author(s):  
T. G. Hornby ◽  
W. Z. Rymer ◽  
E. N. Benz ◽  
B. D. Schmit
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Reflex Response ◽  
Electromyographic Activity ◽  
Plateau Potentials ◽  
Physiological Basis ◽  
Human Spinal Cord ◽  
Reflex Responses ◽  
Flexion Reflex ◽  
Cord Injury

The physiological basis of flexion spasms in individuals after spinal cord injury (SCI) may involve alterations in the properties of spinal neurons in the flexion reflex pathways. We hypothesize that these changes would be manifested as progressive increases in reflex response with repetitive stimulus application (i.e., “windup”) of the flexion reflexes. We investigated the windup of flexion reflex responses in 12 individuals with complete chronic SCI. Flexion reflexes were triggered using trains of electrical stimulation of plantar skin at variable intensities and inter-stimulus intervals. For threshold and suprathreshold stimulation, windup of both peak ankle and hip flexion torques and of integrated tibialis anterior electromyographic activity was observed consistently in all patients at inter-stimulus intervals ≤3 s. For subthreshold stimuli, facilitation of reflexes occurred only at intervals ≤1 s. Similarly, the latency of flexion reflexes decreased significantly at intervals ≤1 s. Patients that were receiving anti-spasticity medications (e.g., baclofen) had surprisingly larger windup of reflex responses than those who did not take such medications, although this difference may be related to differences of spasm frequency between the groups of subjects. The results indicate that the increase in spinal neuronal excitability following a train of electrical stimuli lasts for ≤3 s, similar to previous studies of nociceptive processing. Such long-lasting increases in flexion reflex responses suggest that cellular mechanisms such as plateau potentials in spinal motoneurons, interneurons, or both, may partially mediate spinal cord hyperexcitability in the absence of descending modulatory input.

Factors Underlying Tongue Articulation in Speech

1987 ◽  
Vol 30 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Eric Keller
Keyword(s):  
Peak Velocity ◽  
Additive Models ◽  
Distance Measures ◽  
Linguistic Context ◽  
Movement Onset ◽  
Canonical Correlations ◽  
Time To Peak ◽  
Onset Delay ◽  
Two Factors ◽  
Interarticulatory Coordination

A factor analysis of 11 measures of lingual activity involved in the production of the syllable /ka/ showed that three factors can explain about 75% of the variance in the data. Measures of displacement and velocity loaded strongly on the first factor, durational measures loaded strongly on the second factor, and midsyllable durational and distance measures loaded on the third factor. This three-factor solution emerged from each of four conditions involving manipulations of speed of delivery and linguistic context. Canonical correlations showed that the best of four linear additive models involving 3 of the 11 variables was able to explain 45% of the variance in the remaining 8 variables. The three best predictor variables were (a) descending movement displacement, (b) linguo laryngeal movement onset delay, and (c) time to peak velocity for the ascending movement. It is argued that these variables represent the speech system's control over the articulatory distinction of different sounds, interarticulatory coordination, and, perhaps, rhythm adjustment, and that the first two factors correspond to central variables of breakdown in Broca's aphasia.

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