Effects Of Visual Input Research Articles

Effect of visual input on gait stability using immersive virtual reality in children with cerebral palsy

Effect of visual input on gait stability using immersive virtual reality in children with cerebral palsy

Effects of Visual Input Absence on Balance Recovery Responses to Lateral Standing Surface Perturbations in Older and Younger Adults

Although the ability to recover balance in the lateral direction has important implications with regard to fall risk in older adults, the effect of visual input on balance recovery in response to lateral perturbation and the effect of age are not well studied. We investigated the effect of visual input on balance recovery response to unpredictable lateral surface perturbations and its age-related changes. Ten younger and 10 older healthy adults were compared during balance recovery trials performed with the eyes open and eyes closed (EC). Compared with younger adults, older adults showed increased electromyography (EMG) peak amplitude of the soleus and gluteus medius, reduced EMG burst duration of the gluteus maximus and medius, and increased body sway (SD of the body's center of mass acceleration) in EC. In addition, older adults exhibited a smaller % increase (EC-eyes open) of the ankle eversion angle, hip abduction torque, EMG burst duration of the fibularis longus, and a greater % increase of body sway. All kinematics, kinetics, and EMG variables were greater in EC compared with eyes open in both groups. In conclusion, the absence of visual input negatively affects the balance recovery mechanism more in older adults compared with younger adults.

The Effects of Visual Input and Text Types on the Listening Comprehension of EFL Students in China

In recent years, there has been an interest in using visual input in multimodal applications for language learning. However, the effects of visual input in listening materials remain to be discussed. Past literature has shown no unified answer to the effects of video input in improving listening comprehension scores. Since there are many proposals for the diversified reform of English teaching methods, it is worth examining whether using traditional audio listening only or using different video inputs can bring more significant benefits to students. The subjects of this study are 30 non-English majors in Chinese universities. This paper applied the quantitative research method, testing students’ performance using different listening visual inputs (content, context, and audio only) and different listening text types (monologue and dialogue). Data were analysed using the two-way repeated measures within groups ANOVA. The interaction effects and the main effect of variables on listening performance were examined to explore the impact of visual input and text types on English listening comprehension. The following conclusions are drawn from the data analysis: (1) The interaction effect shows that video and text types significantly affect students’ listening scores. Videos that contain authentic listening scenes and content elements are beneficial to promote listening comprehension as they support students’ interpretation and understanding of what they hear, and (2) It was noted that grouping students by listening proficiency and examining their cultural background would expand the study in the future.

Effects of visual input on changes in the bioelectrical activity of the cervical and masticatory muscles in myopic subjects.

The study aimed to analyze the changes within the bioelectrical activity of the cervical spine and masticatory muscles during the change of visual stimulus—open and closed eyes test. After applying the inclusion criteria, 50 subjects were included in the study, with visual impairment ranging from −0.5 to −5.75 Diopters. Four muscle pairs were analyzed: the anterior part of the temporalis muscle (TA), the superficial part of the masseter muscle (MM), the anterior belly of the digastric muscle (DA), and the middle part of the sternocleidomastoid muscle (SCM) belly during rest, teeth clenching, teeth clenching on dental cotton rollers, and active mouth opening. Statistical analysis showed a significant decrease in the bioelectrical activity during teeth clenching of all analyzed muscles during the closed eyes test. Significant decreases of electromyographic values were also observed during resting activity within TA muscles, during teeth clenching with dental cotton rollers within SCM and DA muscles, and during active mouth opening within the right masseter. Changing the visual stimulus from open eyes to closed eyes in people with myopia affects the bioelectrical activity of the masticatory and cervical spine muscles.

Effect of visual input on syllable parsing in a computational model of a neural microcircuit for speech processing

Objective. Seeing a person talking can help us understand them, particularly in a noisy environment. However, how the brain integrates the visual information with the auditory signal to enhance speech comprehension remains poorly understood. Approach. Here we address this question in a computational model of a cortical microcircuit for speech processing. The model consists of an excitatory and an inhibitory neural population that together create oscillations in the theta frequency range. When stimulated with speech, the theta rhythm becomes entrained to the onsets of syllables, such that the onsets can be inferred from the network activity. We investigate how well the obtained syllable parsing performs when different types of visual stimuli are added. In particular, we consider currents related to the rate of syllables as well as currents related to the mouth-opening area of the talking faces. Main results. We find that currents that target the excitatory neuronal population can influence speech comprehension, both boosting it or impeding it, depending on the temporal delay and on whether the currents are excitatory or inhibitory. In contrast, currents that act on the inhibitory neurons do not impact speech comprehension significantly. Significance. Our results suggest neural mechanisms for the integration of visual information with the acoustic information in speech and make experimentally-testable predictions.

Dynamics of postural control in individuals with ankle instability: Effect of visual input and orthotic use

The present study investigated the effect of visual deprivation and the use of an ankle orthosis on the dynamics of center of pressure (COP) trajectories during unilateral stance in individuals with ankle instability (AI). Sixteen individuals with AI and nine healthy individuals performed four trials of 30s unilateral stance on a force platform with 1) eyes open wearing no orthosis, 2) eyes closed wearing no orthosis, 3) eyes open wearing orthosis, and 4) eyes closed wearing orthosis. The anterior-posterior and mediolateral COP trajectory were extracted. Regularity was quantified by sample entropy, dimensionality was quantified by correlation dimension and level of time dependency was quantified by entropic half-life. The AI individuals had lower sample entropy and longer entropic half-life in their COP trajectories. The effect of visual deprivation did not differ between groups. Wearing an ankle orthosis increased the sample entropy in the anterior-posterior direction and decreased the correlation dimension in the mediolateral direction for the AI group only. Individuals with AI have higher COP trajectory regularity and higher level of time dependency compared to healthy individuals. Additionally, individuals with AI do not alter the dynamics of their postural control during unilateral stance with visual deprivation compared to healthy individuals. This suggests that alterations in visual or somatosensory information differently affect the executed postural movement pattern. Finally, wearing an orthosis significantly alters the COP dynamics of individuals with AI.

The Effect of Visual Input in Athletes With Chronic Ankle Instability

The Effect of Visual Input in Athletes With Chronic Ankle Instability

Activation of Auditory Centers during Freezing Response Depends on Visual Afferentation in Course of the Development of Pied Flycatcher Nestlings

The study of defense behavior development in pied flycatcher altricial nestlings has shown that preceding visual deprivation decreased the capability to freeze in the young. At the same time, auditory thresholds of deprived nestlings were lower than those of the nestlings developing in unaltered visual environment. Our goal in the present work was to study effects of visual input on the functional development of neural circuitry for flycatcher’s acoustically-guided defensive behavior. We compared the immunohistochemical response of transcription factors ZENK and c-Fos in the nestlings’ auditory telencephalic structures in visually deprived and non-deprived flycatcher nestlings to alarm calls emitted by adult birds. We have demonstrated that the development of flycatcher nestlings under the conditions of limited visual afferentation results in the decrease of induction of the immediate-early genes c-Fos and ZENK in auditory structures of 9-day-old nestlings performing auditory-guided defense behavior. The most marked decrease of induction of both genes is observed in Field L. Our data suggest that visual afferentation affects neuronal activations in higher auditory structures of nestlings’ brain that, in turn, may increase the efficiency of species-typical alarm call. Thus, the work demonstrated for the first time that visual affererntation facilitates the growth of efficiency of alarm call affecting the activity of neurons in auditory integrative structures.

Automatic analysis of human posture equilibrium using empirical mode decomposition

The present study proposes a new approach for the assessment of the human balance control. This approach is based on the decomposition of the center of pressure displacement using empirical mode decomposition (EMD) that provides an effective time-frequency analysis of non-stationary signals. Twenty-eight healthy subjects performed quiet standing in four conditions—feet apart/together with respect to eyes open/closed—while recording the stabilometric signals in the anteroposterior (AP) and mediolateral (ML) directions. The EMD method decomposes each stabilometric signal into several subsignals called intrinsic mode functions (IMFs). Stabilogram-diffusion analysis technique is applied to generate the diffusion curve of each IMF signal. Each diffusion curve is modeled as a second-order system and provides representative features, such as the gain parameter. Analysis of the gain parameter shows the major effect of visual input and feet conditions on the strategy to control/stabilize the balance. Significant differences were found between young and elderly, and between women and men. In addition, the impact of feet position seems to be higher in ML direction than in AP direction.

Effect of visual input on postural stability in young adults with chronic motion sensitivity: A controlled cross-sectional study.

Chronic motion sensitivity (CMS) has been defined as a feeling of un-wellness elicited by either actual or perceived motion. CMS is a common condition and is more prevalent in females than in males. In addition to a variety of symptoms, young adults with CMS have less postural stability than those without CMS. To determine whether dependence on visual cues for postural stability is different between young adults with and without CMS, and whether it differs by gender within each group. Sixty young adults (30 females and 30 males) were assigned to one of two groups (CMS or non-CMS) using the Motion Sickness Susceptibility Questionnaire-Short Form. Postural stability was measured for all participants using the Bertec Balance Advantage-Computerized Dynamic Posturography with Immersion Virtual Reality. A significant difference was found in mean postural stability scores during immersion virtual reality between the CMS and non-CMS groups (p < 0.001); however, no significant difference was shown in mean postural stability between males and females within the CMS and non-CMS groups (p = 0.10 and p = 0.97, respectively). The results suggest that young adults with CMS are over-reliant on visual cues for postural stability, and that visual dependence is not influenced by gender.

The Effects of Visual Input on Scoring a Speaking Achievement Test

The Effects of Visual Input on Scoring a Speaking Achievement Test

Effect of Visual Input and Foam Rubber on Leg-Joint Angles and Sway of Center of Pressure during Stepping on the Spot

Dynamic balance has frequently been evaluated by using center of pressure (COP) during stepping movement. COP sway may be greater during stepping on foam rubber, which is a kind of external load. This study aimed to examine the effect of leg-joint angles and COP sway during stepping on a spot in 13 young male adults (mean age 25.6 ± 4.8 years, mean height 170.6 ± 5.2 cm, mean mass 69.1 ± 8.2 kg), with or without foam rubber and with eyes open or closed. When subjects stepped on foam rubber placed on two force plates (right and left), while matching a tempo of 100 bpm for 20 s under the above four conditions, characteristics such as mean angles of hip, knee, and ankle joints and COP sway were measured. In the results of two-way ANOVA (rubber condition × eye condition) and post-hoc tests, the hip-joint angle was significantly greater with eyes open, regardless of with or without foam rubber. The knee-joint angle was significantly greater in eyes closed with off-foam-rubber than on-foam-rubber. The ankle-joint angle was significantly greater in off- foam-rubber, regardless of eyes open or closed, and with eyes open than with eyes closed, regardless of with or without foam rubber. The total trace length and velocity were significantly greater in off-foam-rubber with eyes open, and on-foam-rubber with eyes closed than on-foam-rubber with eyes open. The other sway parameters were significantly greater with eyes open than with eyes closed regardless of with or without foam rubber. The hip-joint angle was significantly greater with eyes open regardless of with or without foam rubber. In conclusion, the COP sway during stepping with a stipulated tempo is less with eyes open than eyes closed, but the motion of knee and ankle joints is greater with eyes open. The sway distance and velocity during stepping with eyes open and motion of knee and ankle joints during stepping with eyes closed are both affected by the foam-rubber load. When stepping on the foam rubber, movement of the knee joints relates to distance and velocity of COP regardless of open or closed eyes. The findings in this study will be used to evaluate balance functions that are closely related to basic movements.

An Easy Platform for Postural Balance Analysis by the Evaluation of Instantaneous Center of Gravity

The aim of this paper is to present an easy instrument and method for postural balance analysis based on evaluation of instantaneous center of gravity (COG) were the subject is stand on innovative force platform. The instrument is realized with three identical composite sensor supporting a feet plate were used to measure the ground reaction force applied by subject during postural balance analysis. A Microsystems based on microcontroller was built in order to drive the instrumentation and a graphical user interface was realized. The signals acquisitions are displayed on the PC screen when the COG moves in the xy plan. After the calculation and programming of the COG coordinates point, the plot of the XG and YG time series of the COG position during a postural balance analysis is easily obtained and recording. The effect of visual input is studied by performing the test with eyes open and then closed. The dynamic parameters show clear indicator of the postural balance. Objective method of diagnosis is to access to postural stability for identifying persons at risk of falling.

Effect of visual input on normalized standing stability in subjects with recurrent low back pain

Although a number of studies have evaluated kinematic stability changes in subjects with low back pain (LBP), the combined sensitivity of normalized standing stability from the ground force and kinematic rotational angle of the body segment were not carefully examined for postural responses. The purpose of this study was to evaluate normalized standing stability in subjects with and without recurrent LBP while they stood quietly with the tested foot parallel to the other lower extremity at hip width. The subjects were then instructed to stand freely on one leg for 25s with the contra lateral hip flexed 90° based on dominance side (dominant leg vs. non-dominant lower extremity) and visual condition (eyes open vs. eyes closed). A total of 42 subjects (27 subjects without LBP and 15 subjects with LBP) participated in the study. The dominant leg standing stability was significantly different during the eyes closed condition (0.68±0.30 for control vs. 0.37±0.32 for LBP, T=−3.23, p=0.002) compared to the eyes open condition. The standing kinematic stability, especially of the dominant thigh, was greater in the control subjects than in the subjects with LBP (T=−2.43, p=0.02). This sensitive detection of kinematic imbalance with postural stability is important for effective rehabilitation strategies and to understanding compensatory mechanisms in subjects with recurrent LBP.

Effect of anxiety on antero-posterior postural stability in patients with dizziness

The purpose of this study was to investigate the effect of anxiety on the postural stability of a variety of dizzy patients during upright standing. To address this issue, 54 patients complaining of dizziness were enrolled in this study. The degree of anxiety in patients was evaluated on the basis of a routine vestibular examination together with their dizziness handicap inventory (DHI) scores as well as the hospital anxiety and depression scale (HADS). The patients were divided into 3 groups. If there was no vestibular dysfunction, they were defined as psychogenic (PSY) ( N = 16). The remaining subjects were further divided on the basis of their HADS score. If the score of A (anxiety) was less than 5, they are defined as organic (ORG) ( N = 25), and the rest were defined as a combination of psychogenic and organic (PSY + ORG) ( N = 13). Posturographic measurements were performed in a quiet and stable standing position on a force platform, as one of the vestibular examinations. The total length, the area of body sway, and the ratio of maximum perturbation of antero-posterior axis (A/P ratio) were registered. Spectrum analyses of the left–right axis and antero-posterior axis were also performed by using the fast Fourier transform (FFT) method of body sway. We found a significant correlation between anxiety and postural instability in the antero-posterior axis in all subjects as a group and in either group PSY or PSY + ORG. However, no significant correlation was found in group ORG. Using power spectrum analysis (FFT), we identified 3 frequency components of postural sway: group A (0.02–0.21 Hz), group B (0.22–2.01 Hz), and group C (2.01–10 Hz). Statistical significance of the data was examined by ANOVA. Group C reflected somatosensory inputs, and group A reflected vestibular inputs. The power of group C decreased in the high anxiety group, whereas the power of group A increased in the high anxiety group. These phenomena disappeared in the eyes-closed condition. Our study shows that the effect of visual input on vestibular and somatosensory input is affected by anxiety. In conclusion, our results indicate that anxiety affects the postural perturbation in the antero-posterior axis and that anxiety possibly affects the interactions of visual inputs with vestibular and somatosensory inputs in the maintenance of postural balance in patients complaining of dizziness.

Effects of myogenous facial pain on muscle activity of head and neck

This study evaluated the effects of visual input on surface electromyography (sEMG) of some stomathognatic and neck muscles (anterior temporalis, masseter, anterior digastric and sternocleidomastoid muscles) in patients experiencing myogenous facial pain compared with healthy volunteers. All subjects kept the mandible at rest with teeth apart and underwent a 15-s sEMG recording of anterior temporalis, masseter, digastric and sternocleidomastoid muscles. Each recording was carried out with closed and then open eyes. The sEMG activity of each muscle was compared between the two groups. In the study group, anterior temporalis, masseter and sternocleidomastoid sEMG with closed eyes showed higher values compared with controls (p<0.05). In the study group, left and right anterior temporalis (p<0.003) and right digastric (p<0.03) sEMG with open eyes showed higher values than sEMG with closed eyes. In the control group no significant differences were observed between closed and open eyes. In patients with myogenous facial pain, visual input appears to be associated with a significant increase in the sEMG activity of some head and neck muscles.

The effects of visual input on the separability of volume and mass

The effects of visual input on the separability of volume and mass

Auditory-Visual Integration for Speech by Children With and Without Specific Language Impairment

It has long been known that children with specific language impairment (SLI) can demonstrate difficulty with auditory speech perception. However, speech perception can also involve the integration of both auditory and visual articulatory information. Fifty-six preschool children, half with and half without SLI, were studied in order to examine auditory-visual integration. Children watched and listened to video clips of a woman speaking [bi] and [gi]. They also listened to audio clips of [bi], [di], and [gi], produced by the same woman. The effect of visual input on speech perception was tested by presenting an auditory [bi] combined with a visually articulated [gi], which tends to alter the phoneme percept (the McGurk effect). Both groups of children performed at ceiling when asked to identify speech tokens in auditory-only and congruent auditory-visual modalities. In the incongruent auditory-visual condition, a stronger McGurk effect was found for the normal language group compared with the children with SLI. Responses by the children with SLI indicated less impact of visual processing on speech perception than was seen with their normal peers. These results demonstrate that the difficulties with speech perception by SLI children extend beyond the auditory-only modality to include auditory-visual processing as well.

Modification of human postural responses to soleus muscle vibration by rotation of visual scene

Sensory interaction in posture control in 20 healthy subjects was investigated by postural responses to differently timed proprioceptive and visual stimulation. As proprioceptive stimulation was used both soleus muscles vibration. Visual stimulation was rotating disc moving in forward and backward direction. Centre of foot pressure (CoP) and trunk tilts in antero-posterior (AP) direction were measured during stance by two accelerometers on the upper and the lower trunk level. Subjects performed four series of eight trials lasted 20s: vibration with eyes open and closed, visual scene motion forward or backward, vibration together with scene motion forward or backward, scene motion forward or backward 3s before vibration. The results showed that early velocities and final angles of body tilt induced by soleus muscle vibration were modified by motion of visual scene. Early part of postural responses was changed slightly if sensory stimulation starts together. When visual stimulation started 3s before muscle vibration, the induced early CoP and trunk tilt records of postural response to vibration occurred with the faster slope similar for both directions of scene motion and for condition of vibration alone with eyes closed. Significantly different final CoP shifts and trunk angles were measured between condition with visual scene motion forward and backward. The effect of visual input on posture control was two times enhanced in paired sensory stimulation. The results indicated an important influence of unstable visual field on posture response to somatosensory stimulation where the early part of postural reaction indicated absence of visual influence.

Subjective somatosensory vertical during dynamic tilt is dependent on task, inertial condition, and multisensory concordance

To investigate how visual and vestibular cues are integrated for the perception of gravity during passive self-motion, we measured the ability to maintain a handheld object vertical relative to gravity without visual feedback during sinusoidal roll-tilt stimulation. Visual input, either concordant or discordant with actual dynamic roll-tilt, was delivered by a head-mounted display showing the laboratory. The four visual conditions were darkness, visual-vestibular concordance, stationary visual scene, and a visual scene 180 degrees phase-shifted relative to actual tilt. Tilt-indication performance using a solid, cylindrical joystick was better in the presence of concordant visual input relative to the other visual conditions. In addition, we compared performance when indicating the vertical by the joystick or a full glass of water. Subjects indicated the direction of gravity significantly better when holding the full glass of water than the joystick. Matching the inertial characteristics, including fluid properties, of the handheld object to the glass of water did not improve performance. There was no effect of visual input on tilt performance when using the glass of water to indicate gravitational vertical. The gain of object tilt motion did not change with roll-tilt amplitude and frequency (+/-7.5 degrees at 0.25 Hz, +/-10 degrees at 0.16 Hz, and +/-20 degrees at 0.08 Hz), however, the phase of object tilt relative to subject tilt showed significant phase-leads at the highest frequency tested (0.25 Hz). Comparison of the object and visual effects observed suggest that the task-dependent behavior change may be due to an attentional shift and/or shift in strategy.