The Effect of Oral Tactile Sensitivity on Texture Perception and Mastication Behavior in Humans

AbstractMastication behavior is a notable source of interindividual variation in texture perception and could be linked to oral sensitivity. As oral sensitivity declines so does the amount of tactile feedback relayed to the brain, resulting in less effective manipulation or food and a reduced ability to discriminate differences. To address these hypotheses, we measured masticatory behavior and related this to texture discrimination and oral sensitivity. The study was performed on 41 participants in two groups, with high (n = 20) or low (n=21) sensitivity. Oral sensitivity was measured using a battery of tests that included: oral stereognosis, lingual tactile acuity, and bite force sensitivity. Sensitivity to texture changes was measured using a series of triangle tests with confectionaries of different hardness, with masticatory patterns and behaviors being video recorded and analyzed using jaw tracking software. Overall, there was no significant difference between high and low sensitivity participants and their ability to distinguish texture changes. But, there were significantly different trends found between the groups based on their masticatory behaviors including chewing pattern and overall number of chews. But, it was found that multiple masticatory behaviors were being modulated by oral sensitivity, including overall chewing cycles used (p < 0.0001). More, specifically those in the high sensitivity group used more stochastic chewing movements, while those in the low sensitivity group were found to use crescent-shaped chewing cycles. It was also noted that in the high sensitivity group the jaw moved further distances (p < 0.0001) in all phases and moved at a higher velocity when opening (p < 0.0001) but not when closing, when compared to the low sensitivity group. These results help bolster evidence that mastication and oral sensitivity are related.

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Vestibuloocular Reflex Adaptation Investigated With Chronic Motion-Modulated Electrical Stimulation of Semicircular Canal Afferents

Journal of Neurophysiology ◽

10.1152/jn.00241.2009 ◽

2010 ◽

Vol 103 (2) ◽

pp. 1066-1079 ◽

Cited By ~ 44

Author(s):

Richard F. Lewis ◽

Csilla Haburcakova ◽

Wangsong Gong ◽

Chadi Makary ◽

Daniel M. Merfeld

Keyword(s):

Electrical Stimulation ◽

High Sensitivity ◽

Rotational Axis ◽

Vestibuloocular Reflex ◽

Chronic Stimulation ◽

Unilateral Stimulation ◽

Electrical Pulses ◽

Vor Adaptation ◽

Low Sensitivity ◽

The Brain

To investigate vestibuloocular reflex (VOR) adaptation produced by changes in peripheral vestibular afference, we developed and tested a vestibular “prosthesis” that senses yaw-axis angular head velocity and uses this information to modulate the rate of electrical pulses applied to the lateral canal ampullary nerve. The ability of the brain to adapt the different components of the VOR (gain, phase, axis, and symmetry) during chronic prosthetic electrical stimulation was studied in two squirrel monkeys. After characterizing the normal yaw-axis VOR, electrodes were implanted in both lateral canals and the canals were plugged. The VOR in the canal-plugged/instrumented state was measured and then unilateral stimulation was applied by the prosthesis. The VOR was repeatedly measured over several months while the prosthetic stimulation was cycled between off, low-sensitivity, and high-sensitivity stimulation states. The VOR response initially demonstrated a low gain, abnormal rotational axis, and substantial asymmetry. During chronic stimulation the gain increased, the rotational axis improved, and the VOR became more symmetric. Gain changes were augmented by cycling the stimulation between the off and both low- and high-sensitivity states every few weeks. The VOR time constant remained low throughout the period of chronic stimulation. These results demonstrate that the brain can adaptively modify the gain, axis, and symmetry of the VOR when provided with chronic motion-modulated electrical stimulation by a canal prosthesis.

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Characterization of Oral Tactile Sensitivity and Chewing Efficiency Across Adulthood

10.1101/333674 ◽

2018 ◽

Author(s):

Grace E. Shupe ◽

Zoe N. Resmondo ◽

Curtis R. Luckett

Keyword(s):

Linear Trend ◽

Age Groups ◽

Bite Force ◽

Tactile Sensitivity ◽

Texture Perception ◽

Tactile Acuity ◽

Force Sensitivity ◽

Age Related ◽

Chewing Efficiency ◽

Oral Processing

AbstractTexture perception is one of the most important factors in food acceptance, yet population-wide differences in texture sensations are not well understood. The variation in texture perception across populations is thought to depend on oral tactile sensitivity and oral processing behaviors. To address this hypothesis, we aimed to measure tactile acuity with a battery of tests and quantitate the relationship to oral processing. The study was performed on 98 participants, in 3 age groups (20-25, 35-45, or over 62). Two main measures of oral sensitivity were performed: to assess bite force, subjects were asked to discriminate between foam samples of varying hardness. Secondly, to assess lingual sensitivity the subjects were asked to identify 3D printed shapes, ranging from 3mm to 8mm, using their tongue, as well as identify confectionary letters. Additionally, chewing efficiency was measured through assessing each participants ability to mix two-colored chewing gum. In general, we found that sensitivity and chewing efficiency in the younger age groups was superior to that of older adults (p<0.0001). We also found a positive linear trend between bite force sensitivity and chewing efficiency with younger participants, a trend not found in older participants. We found no significant relationship between age groups for bite force and chewing efficiency, suggesting that age-related declines in bite force sensitivity are not a significant cause of altered oral processing ability. These results help bolster evidence that sensitivity and oral processing are related, as well previously reported declines in both as people age.

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Measurement of Adult Human Brain Responses to Breath-Holding by Multi-Distance Hyperspectral Near-Infrared Spectroscopy

Applied Sciences ◽

10.3390/app12010371 ◽

2021 ◽

Vol 12 (1) ◽

pp. 371

Author(s):

Zahida Guerouah ◽

Steve Lin ◽

Vladislav Toronov

Keyword(s):

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Near Infrared ◽

High Sensitivity ◽

Breath Holding ◽

Brain Responses ◽

Adult Humans ◽

Using Data ◽

Low Sensitivity ◽

The Brain

A major limitation of near-infrared spectroscopy (NIRS) is its high sensitivity to the scalp and low sensitivity to the brain of adult humans. In the present work we used multi-distance hyperspectral NIRS (hNIRS) to investigate the optimal source-detector distances, wavelength ranges, and analysis techniques to separate cerebral responses to 30 s breath-holds (BHs) from the responses in the superficial tissue layer in healthy adult humans. We observed significant responses to BHs in the scalp hemodynamics. Cerebral responses to BHs were detected in the cytochrome C oxidase redox (rCCO) at 4 cm without using data from the short-distance channel. Using the data from the 1 cm channel in the two-layer regression algorithm showed that cerebral hemodynamic and rCCO responses also occurred at 3 cm. We found that the waveband 700–900 nm was optimal for the detection of cerebral responses to BHs in adults.

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The Preventive Value of Acupoint Sensitization for Patients with Stable Angina Pectoris: A Randomized, Double-Blind, Positive-Controlled, Multicentre Trial

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2021/7228033 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Shourui Huang ◽

Ling Li ◽

Jiali Liu ◽

Xiujuan Li ◽

Qingyang Shi ◽

...

Keyword(s):

Angina Pectoris ◽

Stable Angina ◽

High Sensitivity ◽

Stable Angina Pectoris ◽

Double Blind ◽

Significant Difference ◽

N 93 ◽

Low Sensitivity ◽

Sensitivity To Pain ◽

Nitroglycerin Consumption

Background. Acupoint sensitization is considered an important factor in the efficacy of acupoint therapy. This study aimed to evaluate the efficacy of acupressure in the prevention of stable angina pectoris using acupoints with different pressure-pain sensitivities. Methods. A total of 202 patients were enrolled and randomly assigned to a high-sensitivity group (HSG) (n = 109) in which patients received acupressure at the five acupoints with the highest sensitivity to pain and a low-sensitivity group (LSG) (n = 93) in which patients received acupressure at the five acupoints with the lowest sensitivity to pain. The duration of acupressure treatment was 4 weeks, and the patients were evaluated at baseline, week 4, and week 8. The primary outcome was a change in the frequency of angina attacks from baseline. The secondary outcomes included nitroglycerin consumption, the Canadian Cardiovascular Society classification, and the Seattle Angina Questionnaire score. Adverse events such as bleeding and subcutaneous haemorrhage were recorded in both groups. Results. The effect of acupressure compared with baseline on the prevention of angina pectoris in HSG was better than that in LSG at week 4 (incidence rate ratio (IRR): 0.691 and 95% confidence interval (CI): [0.569, 0.839]) and week 8 (IRR: 0.692 and 95% CI: [0.569, 0.839]). No significant difference between groups was found in the frequency of nitroglycerin consumption at week 4 (odds ratio (OR) = 0.863 and 95% CI: [0.147, 5.077]) or week 8 (OR = 1.426 and 95% CI: [0.211, 9.661]). Two themes in the questionnaire showed significantly different changes from baseline between the two groups. Scores on the angina frequency (AF) subscale had changed more from the baseline in the HSG at week 8 than in the LSG (mean difference (MD) = 3.807 and 95% CI: [0.673, 6.942]). Scores on the treatment satisfaction (TS) subscale had also changed more in the HSG than in the LSG at week 4 (MD = 3.651 and 95% CI: [0.327, 7.327]) and week 8 (MD = 4.220 and 95% CI: [0.347, 7.346]). One patient in the LSG reported bruising at the acupoint. No unexpected safety problems arose. Conclusions. This study showed that acupressure at acupoints with high sensitivity to pain may effectively reduce the frequency of stable angina pectoris episodes. This trial is registered with NCT03975140.

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Measurement of Adult Human Brain Responses to Breath Holding by Multi-Distance Hyperspectral Near-Infrared Spectroscopy

10.20944/preprints202109.0487.v1 ◽

2021 ◽

Author(s):

Zahida Guerouah ◽

Steve Lin ◽

Vladislav Toronov

Keyword(s):

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Near Infrared ◽

High Sensitivity ◽

Breath Holding ◽

Brain Responses ◽

Adult Humans ◽

Using Data ◽

Low Sensitivity ◽

The Brain

A major limitation of near-infrared spectroscopy (NIRS) is its high sensitivity to the scalp and low sensitivity to the brain of adult humans. In the present work we use multi-distance hyperspectral NIRS (hNIRS) to investigate the optimal source-detector distances, range of wavelengths, and analysis techniques to separate cerebral responses to 30-s breath holds (BHs) from the responses in the superficial tissue layer in healthy adult humans. We observed significant responses to BHs in the scalp hemodynamics. Cerebral responses to BHs were detected in the cytochrome C oxidase redox (rCCO) at 4 cm without using data from the short-distance channel. Using the data from the 1 cm channel in the two-layer regression algorithm showed that hemodynamic and rCCO responses also occurred at 3cm. We found that the waveband 700-900 nm was optimal for the detection of cerebral responses to BHs in adults.

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Ultraviolet Radiation Effect on Seed Germination and Seedling Growth of Common Species from Northeastern Mexico

Agronomy ◽

10.3390/agronomy9060269 ◽

2019 ◽

Vol 9 (6) ◽

pp. 269

Author(s):

Rahim Foroughbakhch Pournavab ◽

Elly Bacópulos Mejía ◽

Adalberto Benavides Mendoza ◽

Lidia Salas Cruz ◽

Maginot Ngangyo Heya

Keyword(s):

Germination Rate ◽

Accelerated Aging ◽

High Sensitivity ◽

Common Species ◽

Pests And Diseases ◽

Significant Difference ◽

Key Factor ◽

Northeastern Mexico ◽

Low Sensitivity ◽

Uv C

Light is the only key factor essential for plant growth, and ultraviolet (UV) rays, the harmful part of solar radiation, have the ability to decrease the metabolic rate in photosynthesis, causing deterioration in their growth. Accurate handling of the ultraviolet light that reaches the crops allows the improvement of different aspects of production, such as the shape and color of the plants, the precocity of the crops, and an improvement in the control of pests and diseases. The present study was carried out with the purpose of studying the responses in terms of germination and growth of four plant species—Glycine max, Triticum aestivum, Helianthus annuus, and Pinus maximartinezii—exposed to different doses of UV-C and UV-B radiation, for evaluation through the standard germination and accelerated aging tests, registering the germination rate (GR) and vigor (V), the number of normal seedlings (NS), and the average lengths of radicle (ALR) and plumule (ALP). Seeds treated with UV-C radiation showed a significant difference (p <0.05) between treatments (doses) and species, both in the standard germination and accelerated aging tests for the ALR and ALP variables. Seeds of G. max showed low sensitivity in both tests, with the dose 43.20 kJ/m2/day. The seeds of H. annuus and P. maximartinezii showed high sensitivity in both tests under UV-C radiation, with the doses 8.64 kJ/m2/day and 0.864 kJ/m2/day, respectively. Both tests under UV-B radiation showed a significant difference (p < 0.01) between species and treatments in the variables NS and ALP, with the minimum dose (T2).

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Comparison of Cytocidal Activities of L-DOPA and Dopamine in S. cerevisiae and C. glabrata

Current Bioactive Compounds ◽

10.2174/1573407214666180108144216 ◽

2020 ◽

Vol 16 (1) ◽

pp. 90-93

Author(s):

Carmen E. Iriarte ◽

Ian G. Macreadie

Keyword(s):

Saccharomyces Cerevisiae ◽

Parkinson’S Disease ◽

Parkinson's Disease ◽

Dopaminergic Neurons ◽

Candida Glabrata ◽

High Sensitivity ◽

Time Dependent ◽

Colony Forming Units ◽

Dependent Cell ◽

The Brain

Background: Parkinson's Disease results from a loss of dopaminergic neurons, and reduced levels of the neurotransmitter dopamine. Parkinson's Disease treatments involve increasing dopamine levels through administration of L-DOPA, which can cross the blood brain barrier and be converted to dopamine in the brain. The toxicity of dopamine has previously studied but there has been little study of L-DOPA toxicity. Methods: We have compared the toxicity of dopamine and L-DOPA in the yeasts, Saccharomyces cerevisiae and Candida glabrata by cell viability assays, measuring colony forming units. Results: L-DOPA and dopamine caused time-dependent cell killing in Candida glabrata while only dopamine caused such effects in Saccharomyces cerevisiae. The toxicity of L-DOPA is much lower than dopamine. Conclusion: Candida glabrata exhibits high sensitivity to L-DOPA and may have advantages for studying the cytotoxicity of L-DOPA.

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Optical Imaging of Beta-Amyloid Plaques in Alzheimer’s Disease

Biosensors ◽

10.3390/bios11080255 ◽

2021 ◽

Vol 11 (8) ◽

pp. 255

Author(s):

Ziyi Luo ◽

Hao Xu ◽

Liwei Liu ◽

Tymish Y. Ohulchanskyy ◽

Junle Qu

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Optical Imaging ◽

Imaging Techniques ◽

High Sensitivity ◽

Pathological Feature ◽

Promising Tool ◽

Abnormal Accumulation ◽

Accumulation Mechanism ◽

The Brain

Alzheimer’s disease (AD) is a multifactorial, irreversible, and incurable neurodegenerative disease. The main pathological feature of AD is the deposition of misfolded β-amyloid protein (Aβ) plaques in the brain. The abnormal accumulation of Aβ plaques leads to the loss of some neuron functions, further causing the neuron entanglement and the corresponding functional damage, which has a great impact on memory and cognitive functions. Hence, studying the accumulation mechanism of Aβ in the brain and its effect on other tissues is of great significance for the early diagnosis of AD. The current clinical studies of Aβ accumulation mainly rely on medical imaging techniques, which have some deficiencies in sensitivity and specificity. Optical imaging has recently become a research hotspot in the medical field and clinical applications, manifesting noninvasiveness, high sensitivity, absence of ionizing radiation, high contrast, and spatial resolution. Moreover, it is now emerging as a promising tool for the diagnosis and study of Aβ buildup. This review focuses on the application of the optical imaging technique for the determination of Aβ plaques in AD research. In addition, recent advances and key operational applications are discussed.

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Second harmonic generation correlation spectroscopy for characterizing translationally diffusing protein nanocrystals

Acta Crystallographica Section D Structural Biology ◽

10.1107/s205979831600841x ◽

2016 ◽

Vol 72 (7) ◽

pp. 849-859

Author(s):

Ximeng Y. Dow ◽

Christopher M. Dettmar ◽

Emma L. DeWalt ◽

Justin A. Newman ◽

Alexander R. Dow ◽

...

Keyword(s):

Second Harmonic Generation ◽

Harmonic Generation ◽

Unit Volume ◽

Second Harmonic ◽

Incident Beam ◽

High Sensitivity ◽

Correlation Spectroscopy ◽

Optical Process ◽

Active Nanoparticles ◽

Low Sensitivity

Second harmonic generation correlation spectroscopy (SHG-CS) is demonstrated as a new approach to protein nanocrystal characterization. A novel line-scanning approach was performed to enable autocorrelation analysis without sample damage from the intense incident beam. An analytical model for autocorrelation was developed, which includes a correction for the optical scattering forces arising when focusing intense, infrared beams. SHG-CS was applied to the analysis of BaTiO3nanoparticles ranging from 200 to ∼500 nm and of photosystem I nanocrystals. A size distribution was recovered for each sample and compared with the size histogram measured by scanning electron microscopy (SEM). Good agreement was observed between the two independent measurements. The intrinsic selectivity of the second-order nonlinear optical process provides SHG-CS with the ability to distinguish well ordered nanocrystals from conglomerates and amorphous aggregates. Combining the recovered distribution of particle diameters with the histogram of measured SHG intensities provides the inherent hyperpolarizability per unit volume of the SHG-active nanoparticles. Simulations suggest that the SHG activity per unit volume is likely to exhibit relatively low sensitivity to the subtle distortions within the lattice that contribute to resolution loss in X-ray diffraction, but high sensitivity to the presence of multi-domain crystals.

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Adaptation and Validation of the Mini-Addenbrooke’s Cognitive Examination in Dementia in Arabic Speakers in Egypt

Dementia and Geriatric Cognitive Disorders ◽

10.1159/000513411 ◽

2020 ◽

Vol 49 (6) ◽

pp. 611-616

Author(s):

Tarik Qassem ◽

Mohamed S. Khater ◽

Tamer Emara ◽

Doha Rasheedy ◽

Heba M. Tawfik ◽

...

Keyword(s):

Screening Tool ◽

Characteristic Curve ◽

High Sensitivity ◽

Receiver Operator Characteristic Curve ◽

Cutoff Score ◽

Arabic Speakers ◽

Dementia Patients ◽

Significant Difference ◽

Sensitivity Specificity ◽

Addenbrooke’S Cognitive Examination

Background: The mini-Addenbrooke’s Cognitive Examination (m-ACE) is a brief cognitive battery that assesses 5 subdomains of cognition (attention, memory, verbal fluency, visuospatial abilities, and memory recall). It is scored out of 30 and can be administered in under 5 min providing a quick screening tool for assessment of cognition. Objectives: We aimed to adapt the m-ACE in Arabic speakers in Egypt and to validate it in dementia patients to provide cutoff scores. Methods: We included 37 patients with dementia (Alzheimer’s disease [n = 25], vascular dementia [n = 8], and dementia with Lewy body [n = 4]) and 43 controls. Results: There was a statistically significant difference (p < 0.001) on the total m-ACE score between dementia patients (mean 10.54 and standard deviation [SD] 5.83) and controls (mean 24.02 and SD 2.75). There was also a statistically significant difference between dementia patients and controls on all sub-score domains of the m-ACE (p < 0.05). Performance on the m-ACE significantly correlated with both the Mini-Mental State Examination (MMSE) and the Addenbrooke’s Cognitive Examination-III (ACE-III). Using a receiver operator characteristic curve, the optimal cutoff score for dementia on the m-ACE total score was found to be 18 (92% sensitivity, 95% specificity, and 94% accuracy). Conclusions: We adapted the m-ACE in Arabic speakers in Egypt and provided objective validation of it as a screening tool for dementia, with high sensitivity, specificity, and accuracy.

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