Visual Color and Form Perception

Introduction. Piriformis syndrome (PS) is a condition accompanied by tension of the piriformis muscle and followed then by compression of the sciatic nerve passing through the piriformis muscle. According to statistics, PS occurs in 6–35 % of patients with lower back pain. Practitioners still face difficulties in treating patients with PS, and it necessitates the searching of new therapy methods and assessment of their compatibility.The goal of research — to study the clinical efficacy of the combined use of manual therapy and visual colorimpulse therapy in patients with piriformis syndrome.Materials and methods. A prospective, controlled, randomized study was conducted in 2019 at the Department of Sports Medicine and Medical Rehabilitation of I. M. Sechenov First Moscow Medical State University. In accordance with the inclusion criteria, 40 patients participated in the study. All participants, depending on the used treatment methodology, were divided by the method of simple randomization using envelopes into two equal groups. In the main group (group I), an integrated approach to treatment was tested: manual therapy in combination with visual color-impulse therapy (CIT); and in the other group (group II) only manual therapy was used.Results. The combined use of manual therapy and CIT in patients with piriformis syndrome leads to a significantly more pronounced decrease in the pain degree and normalization of impaired muscle tone. Also, an integrated approach helps to eliminate existing angiospastic disorders of the lower extremities.Conclusion. The study shows a clear positive dynamics in the integrated use of manual therapy methods in combination with visual color-impulse therapy in the treatment of patients with piriformis syndrome. It is planned to continue the study and assess the possibilities of using the combined technique in different groups of patients (athletes, pregnant women) with this syndrome.

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Color and Form Perception: Straddling the Boundary

10.3389/978-2-88919-857-3 ◽

2016 ◽

Keyword(s):

Form Perception

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Temporal coherency of mechanical stimuli modulates tactile form perception

Scientific Reports ◽

10.1038/s41598-021-90661-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Masashi Nakatani ◽

Yasuaki Kobayashi ◽

Kota Ohno ◽

Masaaki Uesaka ◽

Sayako Mogami ◽

...

Keyword(s):

Sensory Neuron ◽

Sensory Neurons ◽

Contact Surface ◽

Relative Magnitude ◽

Form Perception ◽

Tangential Displacement ◽

Surface Geometry ◽

Tactile Stimuli ◽

Surface Patterns ◽

Temporal Coherency

AbstractThe human hand can detect both form and texture information of a contact surface. The detection of skin displacement (sustained stimulus) and changes in skin displacement (transient stimulus) are thought to be mediated in different tactile channels; however, tactile form perception may use both types of information. Here, we studied whether both the temporal frequency and the temporal coherency information of tactile stimuli encoded in sensory neurons could be used to recognize the form of contact surfaces. We used the fishbone tactile illusion (FTI), a known tactile phenomenon, as a probe for tactile form perception in humans. This illusion typically occurs with a surface geometry that has a smooth bar and coarse textures in its adjacent areas. When stroking the central bar back and forth with a fingertip, a human observer perceives a hollow surface geometry even though the bar is physically flat. We used a passive high-density pin matrix to extract only the vertical information of the contact surface, suppressing tangential displacement from surface rubbing. Participants in the psychological experiment reported indented surface geometry by tracing over the FTI textures with pin matrices of the different spatial densities (1.0 and 2.0 mm pin intervals). Human participants reported that the relative magnitude of perceived surface indentation steeply decreased when pins in the adjacent areas vibrated in synchrony. To address possible mechanisms for tactile form perception in the FTI, we developed a computational model of sensory neurons to estimate temporal patterns of action potentials from tactile receptive fields. Our computational data suggest that (1) the temporal asynchrony of sensory neuron responses is correlated with the relative magnitude of perceived surface indentation and (2) the spatiotemporal change of displacements in tactile stimuli are correlated with the asynchrony of simulated sensory neuron responses for the fishbone surface patterns. Based on these results, we propose that both the frequency and the asynchrony of temporal activity in sensory neurons could produce tactile form perception.

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Motor Adaptation to Cognitive Challenges and Destabilizing Treadmill Walking in Healthy Older Adults

Innovation in Aging ◽

10.1093/geroni/igaa057.1687 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

pp. 523-523

Author(s):

Pei-Chun Kao ◽

Michaela Pierro

Keyword(s):

Older Adults ◽

Cognitive Task ◽

Daily Lives ◽

Healthy Older Adults ◽

Trunk Motion ◽

Visual Color ◽

Stability Data ◽

Serial Addition ◽

Task Conditions ◽

Perturbed Walking

Abstract To develop effective fall prevention intervention, it is necessary to understand how older adults respond to challenges that demand cognitive-motor dual-tasking capability, an important capability in the daily lives. The purpose of this study is to investigate how older adults adjust their motor responses when encountering cognitive and walking perturbations simultaneously. We recorded kinematic data as subjects walked on a treadmill with or without 1) continuous random-amplitude treadmill platform sways (Perturbed vs. No-perturbed walking); and 2) each of the four cognitive tasks: Paced Auditory Serial Addition test (PASAT), clock test, visual color-word incongruent test (V-stroop), and auditory pitch-word incongruent test (A-stroop). We computed dynamic margins of stability (MOS), gait variability, and short-term local divergence exponent (LDE) of the trunk motion (local stability). Data of ten older subjects (age: 72.2±4.9) show that cognitive performance did not differ between standing, Perturbed or No-perturbed walking. Subjects demonstrated significantly greater local instability and variability in step measures, joint angle and MOS during Perturbed than No-perturbed walking (p<0.001). During dual-task conditions, subjects walked with significantly larger medio-lateral MOS (MOSML) compared to walking only, especially during early phase of the trial. During Perturbed walking, subjects had significantly larger MOSML during PASAT and Vstroop than walking only. Our data showed that subjects tried to increase their dynamic MOS during Perturbed walking or a cognitive task more difficult or taxing visual attention. However, the adjustments do not sustain throughout the trial. These findings suggest older adults tend to prioritize cognitive over walking tasks even when encountering walking perturbations.

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