Search results for "NEUROSCIENCE"
showing 10 items of 8040 documents
Mentally represented motor actions in normal aging. I. Age effects on the temporal features of overt and covert execution of actions.
2005
The present study examines the temporal features of overt and covert actions as a function of normal aging. In the first experiment, we tested three motor tasks (walking, sit-stand-sit, arm pointing) that did not imply any particular spatiotemporal constraints, and we compared the duration of their overt and covert execution in three different groups of age (mean ages: 22.5, 66.2 and 73.4 years). We found that the ability of generating motor images did not differentiate elderly subjects from young subjects. Precisely, regarding overt and covert durations, subjects presented similarities for the walking and pointing tasks and dissimilarities for the stand-sit-stand task. Furthermore, the tim…
Contrast sensitivity and glare disability by halogen light after monofocal and multifocal lens implantation
2000
BACKGROUND—Standard examination of contrast sensitivity under conditions of glare disability is performed with incandescent light. A new halogen glare test that simulates glare as seen with oncoming vehicle headlights was used to measure glare disability in patients implanted with multifocal and monofocal intraocular lenses (IOLs). METHODS—28 patients with an average age of 69 years (SD 12 years) were implanted with a monofocal IOL (SI-40NB, Allergan) and 28 patients with an average of 66 years (12 years) were implanted with a refractive multifocal IOL (Array-SA-40N, Allergan). All patients were followed for 5 months postoperatively. Contrast sensitivity at four spatial frequencies (3, 6, 1…
Heat-evoked vasodilatation in human hairy skin: axon reflexes due to low-level activity of nociceptive afferents.
1996
1. Spreading vasodilatation of the axon reflex type was evoked by contact heat stimulation of the hairy skin in the human forearm (13.3 cm2 stimulus area) and was detected by laser Doppler flowmetry at 8, 19 and 30 mm distance. 2. From a base temperature of 35 degrees C, rapidly rising short heat stimuli (4 degrees C s-1, 2 s plateau) elicited vasodilatation at an average threshold of 39.4 degrees C. For slowly rising sustained heat stimuli (64 s duration) the average threshold was 39.6 degrees C (n.s.) Laser Doppler flowmetry revealed a rapid onset within about 4 s, a long duration of several minutes beyond the end of the stimulus, and a rapid spread of vasodilatation to remote skin areas.…
Salivary alpha-amylase response to acute psychosocial stress: The impact of age
2011
a b s t r a c t The impact of stress on health varies across the different stages of human life. Aging is associated with psychobiological changes that could limit our ability to cope with stressors. Therefore, it is crucial to clarify the physiological mechanisms that underlie the stress response and the changes that occur in them as we age. Our aim was to investigate age differences in the salivary alpha amylase (sAA) response to stress, and its relationship with other typical stress biomarkers such as cortisol and heart rate (HR). Sixty-two participants divided into two age groups (younger group: N = 31, age range: 18-35 years; older group: N = 31, age range: 54-71 years) were exposed to…
Do healthy elders, like young adults, remember animates better than inanimates? An adaptive view
2016
International audience; Background/Study Context: It has been found that young adults remember animates better than inanimates. According to the adaptive view of human memory, this is due to the fact that animates are more important for fitness purposes than inanimates. This effect has been ascribed to episodic memory, where older people exhibit difficulties. Methods: Here the authors investigated whether the animacy effect in memory also occurs for healthy older adults. Older and young adults categorized words for their animacy characteristics and were then given an unexpected recognition test on the words using the Remember/Know paradigm. Executive functions were also evaluated using seve…
The effect of age on cognitive performance of frontal patients
2015
Age is known to affect prefrontal brain structure and executive functioning in healthy older adults, patients with neurodegenerative conditions and TBI. Yet, no studies appear to have systematically investigated the effect of age on cognitive performance in patients with focal lesions. We investigated the effect of age on the cognitive performance of a large sample of tumour and stroke patients with focal unilateral, frontal (n=68), or non-frontal lesions (n=45) and healthy controls (n=52). We retrospectively reviewed their cross sectional cognitive and imaging data. In our frontal patients, age significantly predicted the magnitude of their impairment on two executive tests (Raven's Advanc…
Mentally represented motor actions in normal agingII. The influence of the gravito-inertial context on the duration of overt and covert arm movements
2007
Here, we address the question of whether normal aging influences action representation by comparing the ability of 14 young (age: 23.6 +/- 2.1 years) and 14 older (age: 70.1 +/- 4.5 years) adults to mentally simulate arm movements under a varying dynamic context. We conducted two experiments in which we experimentally manipulated the gravity and inertial components of arm dynamics: (i) unloaded and loaded vertical arm movements, rotation around the shoulder joint, (ii) unloaded and loaded horizontal arm movements, rotations around the shoulder and elbow joints, in two directions (inertial anisotropy phenomenon). The main findings indicated that imagery ability was equivalent between the two…
Differential effects of age on subcomponents of response inhibition.
2013
Inhibitory deficits contribute to cognitive decline in the aging brain. Separating subcomponents of response inhibition may help to resolve contradictions in the existing literature. A total of 49 healthy participants underwent functional magnetic resonance imaging (fMRI) while performing a Go/no-go-, a Simon-, and a Stop-signal task. Regression analyses were conducted to identify correlations of age and activation patterns. Imaging results revealed a differential effect of age on subcomponents of response inhibition. In a simple Go/no-go task (no spatial discrimination), aging was associated with increased activation of the core inhibitory network and parietal areas. In the Simon task, whi…
Two Italian kindreds with familial amyotrophic lateral sclerosis due to FUS mutation
2009
Recently, fused in sarcoma/translated in liposarcoma (FUS/TLS) gene, located on chromosome 16p11.2, has been identified as a disease gene in familial amyotrophic lateral sclerosis (FALS). We have analyzed FUS/TLS in a cohort of 52 index cases from seven Italian regions with non-SOD1 and non-TARDBP FALS. We identified a heterozygous c.G1542C missense mutation in a family of northern Italian origin, and a heterozygous c.C1574T missense mutation in a family of Sicilian origin. Both variants are located in exon 15 encoding the RNA-recognition motif, and result in a substitution of an arginine with a serine in position 514 (p.R514S) and substitution of a proline with a leucine at position 525 (p…
Asymmetry in dopamine D2/3 receptors of caudate nucleus is lost with age
2007
Molecular and functional imaging techniques reveal evidence for lateralization of human cerebral function. Based on animal data, we hypothesized that asymmetry in dopamine neurotransmission declines during normal aging. In order to test this hypothesis, we measured dopamine D2/3 receptor availability with [18F]desmethoxyfallypride-PET (DMFP) in putamen and caudate nucleus (NC) of 21 healthy, right-handed males (24-60 years; 35+/-10). For volumetric analysis, high-resolution T1-weighted MR-images were obtained in 18 of the PET-subjects in order to assess possible age-related decreases in NC and putamen volume. The calculated DMFP binding potentials (BP) showed a right-ward asymmetry in NC of…