Search results for "SENSORY THRESHOLD"

Luminance threshold for stereopsis.

1981

Rod-cone based color vision in seals under photopic conditions

2016

Marine mammals have lost the ability to express S-cone opsin, and possess only one type of M/L-cone in addition to numerous rods. As they are cone monochromats they should be color blind. However, early behavioral experiments with fur seals and sea lions indicated discrimination ability between many shades of grey and blue or green. On the other hand, most recent training experiments with harbor seals under "mesopic" conditions demonstrated rod based color blindness (Scholtyssek et al., 2015). In our experiments we trained two harbor seals (Phoca vitulina) and two South African fur seals (Arctocephalus pusillus) with surface colors under photopic conditions. The seals had to detect a triang…

The influence of local capsaicin treatment on small nerve fibre function and neurovascular control in symptomatic diabetic neuropathy.

2002

Topical treatment with capsaicin cream has been shown to be successful in the treatment of different symptomatic nerve disorders like diabetic neuropathy. Conflicting data exist on the effect of capsaicin on nerve function and neurovascular control especially in patients with diabetic neuropathy. The aim of this pilot study was to investigate the impact of topical capsaicin application on small nerve fibre function and neurovascular control. Capsaicin cream was applied to the feet of 13 patients with symptomatic diabetic neuropathy over a period of 8 weeks. Before and during the treatment period, we investigated the total symptoms score, the vibration, thermal (heat and cold) and pain perce…

A cohort study found good respiratory, sensory and motor functions decreased mortality risk in older people

2003

Abstract Background and Objective The main aims of this study were to evaluate the separate and joint effects of respiratory, sensory, and psychomotor function, muscle strength, and mobility in predicting mortality in older men and women, and to find a way to control multicollinearity in a multivariate Cox regression model. Methods Mortality was followed for 10 years (1990–2000) in an entire cohort of 75-year-old residents of the city of Jyvaskyla, Finland (born in 1914; N =388). Cox regression models and principal component estimation were employed to study the association between the covariates and mortality. Results The study indicated that, after adjustment for fatal diseases and cognit…

Decreasing prevalence of specific anosmia to non-steroid odorants from childhood to adolescence

2020

International audience; Specific anosmia is defined as the inability to detect a particular odorant, despite a normal olfactory function. Previous studies reported sex-related difference in detection threshold to steroid odorants, like androstenone or androstadienone during adolescence, and boys showed an increased detection threshold with age. However, such investigations have not been performed for non-steroid odorants. Hence, the current study investigated sex- and age-related effects on the prevalence of specific anosmia in children/adolescents aged 5-14 years (n = 800) to non-steroid odorants. The detection thresholds of three non-steroid odorants (bacdanol, methylsalicylate, and 3-hyd…

Olfaction in chemotherapy for head and neck malignancies

2015

Abstract Objective Systemic chemotherapy for different malignancies occurs alongside various side effects, including reduced sensory function. To date, little is known about the effect of chemotherapeutic agents on olfaction. The aim of this study was to provide new data about changes in sense of smell during chemotherapy among patients with advanced squamous cell carcinomas of the head and neck region. Methods In a prospective, controlled cohort study of patients undergoing up to three courses of chemotherapy (cis- or carboplatin, 5-fluorouracil and docetaxel), olfaction was evaluated prior to and directly following completing a cycle, as well as 3 weeks later with the beginning of the nex…

Thermal Thresholds Predict Painfulness of Diabetic Neuropathies

2004

OBJECTIVE—Pathophysiology explaining pain in diabetic neuropathy (DN) is still unknown. RESEARCH DESIGN AND METHODS—Thirty patients with peripheral DN (17 men and 13 women; mean age 52.4 ± 2.5 years) were investigated. Fifteen patients had neuropathic pain, and 15 patients were free of pain. Patients were followed over 2 years and examined at the beginning and thereafter every 6 months. Clinical severity and painfulness of the DN were assessed by the neuropathy impairment score and visual analog scales (VASs). Cold and warm perception thresholds as well as heat pain thresholds were obtained for evaluation of Aδ- and C-fibers. Nerve conduction velocities (NCVs) and vibratory thresholds were …

Thermal hypoaesthesia differentiates secondary restless legs syndrome associated with small fibre neuropathy from primary restless legs syndrome.

2010

This study aimed to assess thermal and mechanical perception and pain thresholds in primary idiopathic restless legs syndrome and secondary restless legs syndrome associated with small fibre neuropathy. Twenty-one patients (age: 53.4 + or - 8.4, n = 3, male) with primary restless legs syndrome and 13 patients (age: 63.0 + or - 8.2, n = 1, male) with secondary restless legs syndrome associated with small fibre neuropathy were compared with 20 healthy subjects (age: 58.0 + or - 7.0; n = 2, male). Differential diagnosis of secondary restless legs syndrome associated with small fibre neuropathy was based on clinical symptoms and confirmed with skin biopsies in all patients. A comprehensive quan…

Influence of the contrast sensitivity function on the reaction time

1993

The reaction time (RT) vs spatial frequency (SF) curve is determined, using gratings from 1 to 40 c/deg, at seven different contrast levels between 0.95 and 0.02. The form of the RT/SF function: (a) replicated the inverse of the contrast sensitivity function (CSF) at near threshold contrast levels; (b) behaved differently at higher contrasts, exhibiting two branches at contrast close to 1. The interpretation is that there are two factors determining this function: (1) the transition from the operation of fast transient channels at low SF to the operation of slow sustained channels at high SF, the transition taking place within a narrow SF band close to 6 or 8 c/deg (depending on the subject…

Nasal tactile sensitivity in elderly

2010

Conclusion: Although older people varied widely in tactile sensitivity, our results show that tactile thresholds increased with age. Objectives: The aim of this study was to evaluate the effects of aging on nasal tactile sensitivity. Methods: A total of 160 healthy patients aged between 50 and 90 years were included. According to their age, patients were divided into groups (A, B, C, D, E, F, G, and H). From the age of 50, each group included subjects with an age range of 5 years (i.e. group A, 50-55 years; group B, 56-60 years, etc.). Each patient's outcome was assessed through the nasal monofilament test: a set of 20 Semmes-Weinstein monofilaments was used to detect nasal sensitivity for …