Search results for "Sensory"
showing 10 items of 2427 documents
Speed on the dance floor : auditory and visual cues for musical tempo
2016
Musical tempo is most strongly associated with the rate of the beat or “tactus,” which may be defined as the most prominent rhythmic periodicity present in the music, typically in a range of 1.67–2 Hz. However, other factors such as rhythmic density, mean rhythmic inter-onset interval, metrical (accentual) structure, and rhythmic complexity can affect perceived tempo (Drake et al., 1999 and London, 2011Drake, Gros, & Penel, 1999; London, 2011). Visual information can also give rise to a perceived beat/tempo (Iversen, et al., 2015), and auditory and visual temporal cues can interact and mutually influence each other (Soto-Faraco and Kingstone, 2004 and Spence, 2015). A five-part experiment w…
Reproducibility of optical biometry using partial coherence interferometry: intraobserver and interobserver reliability
2001
Abstract Purpose: To evaluate the intraobserver and interobserver variability in axial length (AL), anterior chamber depth (ACD), and corneal radius measurements using an optical biometry instrument based on partial coherence interferometry (PCI). Setting: Johannes Gutenberg University, Mainz, Germany. Methods: In this observational case series and interobserver reliability trial, 30 healthy, emmetropic to moderately myopic eyes of 15 volunteers were evaluated. The AL, ACD, and corneal radius were measured 20 times in 10 eyes by 1 observer to evaluate the intraobserver variability. To evaluate the interobserver variability, the measurements were taken in 20 eyes by 5 different observers. Me…
Scalp, earlobe and nasopharyngeal recordings of the median nerve somatosensory evoked P14 potential in coma and brain death
1996
Median nerve somatosensory evoked potentials (SEPs) were recorded in a total of 181 patients in coma and brain death. Special attention was paid to derivation of P14 (the positive potential occurring approximately 14 ms after median nerve stimulation) with different electrode montages, using midfrontal scalp (Fz), linked earlobe (A1/2), median nasopharyngeal (Pgz) and non-cephalic reference (NC) electrodes. The P14 amplitude (and, to a lesser extent, latency) were invariably lower in brain death than in coma. The potential was preserved in coma in all patients, but lost in brain death in 9.8% in Fz-NC and Pgz-NC recordings, in 23.2% in Fz-A1/2, and in 100% in Fz-Pgz. Thus, Fz-Pgz was the de…
Contrast-enhanced transcranial Doppler ultrasonography in the diagnosis of brain death
2013
The diagnosis of brain death (BD) is based on clinical criteria including deep coma, brain stem areflexia and apnoea. Depending on different local guidelines, confirmatory technical tests are sometimes mandatory.1 Since the 1990s, transcranial Doppler sonography (TCD) has found its place in these circumstances and fulfils most of the criteria of an ‘ideal test’ in confirming BD. To confirm intracranial circulatory arrest (CA) with Doppler sonography, typical flow patterns must be recorded in bilateral intracranial and extracranial brain-supplying arteries.2 A completely absent intracranial flow signal is not a reliable sign to determine CA because this can be due to transmission problems. I…
fMRI characterization of visual working memory recognition
2013
Encoding and maintenance of information in visual working memory have been extensively studied, highlighting the crucial and capacity-limiting role of fronto-parietal regions. In contrast, the neural basis of recognition in visual working memory has remained largely unspecified. Cognitive models suggest that recognition relies on a matching process that compares sensory information with the mental representations held in memory. To characterize the neural basis of recognition we varied both the need for recognition and the degree of similarity between the probe item and the memory contents, while independently manipulating memory load to produce load-related fronto-parietal activations. fMR…
CATCHING FALLING OBJECTS: THE ROLE OF THE CEREBELLUM IN PROCESSING SENSORY-MOTOR ERRORS THAT MAY INFLUENCE UPDATING OF FEEDFORWARD COMMANDS. AN fMRI …
2011
Import JabRef | WosArea Neurosciences and Neurology; International audience; The human motor system continuously adapts to changes in the environment by comparing differences between the brain's predicted outcome of a certain behavior and the observed outcome. This discrepancy signal triggers a sensory-motor error and it is assumed that the cerebellum is a key structure in updating this error and associated feedforward commands. Using fMRI, the aim of the present study was to determine the main cerebellar structures that are involved in the processing of sensory-motor errors and in updating feedforward commands when simply catching a falling ball without displacement of the hand. Subjects o…
Acute Alcohol Effects on Neuronal and Attentional Processing: Striatal Reward System and Inhibitory Sensory Interactions under Acute Ethanol Challenge
2004
The acute influence of ethanol on cerebral activity induces complex psycho-physiological effects that are considerably more pronounced during acute ethanol influx than during maximal blood alcohol concentration (elimination phase). Despite the psychiatric and forensic relevance of these different ethanol effects, the underlying neuronal mechanisms are still unclear. In total, 20 male healthy volunteers were investigated each with three different experimental conditions in a randomized order using an intravenous ethanol challenge (40 g bolus infusion): during influx phase, elimination phase, and under placebo condition. During and after the ethanol (or placebo) infusion, neuropsychological t…
Cognitive and Motor Loops of the Human Cerebro-cerebellar System
2010
Abstract We applied fMRI and diffusion-weighted MRI to study the segregation of cognitive and motor functions in the human cerebro-cerebellar system. Our fMRI results show that a load increase in a nonverbal auditory working memory task is associated with enhanced brain activity in the parietal, dorsal premotor, and lateral prefrontal cortices and in lobules VII–VIII of the posterior cerebellum, whereas a sensory-motor control task activated the motor/somatosensory, medial prefrontal, and posterior cingulate cortices and lobules V/VI of the anterior cerebellum. The load-dependent activity in the crus I/II had a specific relationship with cognitive performance: This activity correlated negat…
Role of the cerebellum in time perception: A TMS study in normal subjects
2007
The aim of this study was to investigate the role of the cerebellum in a temporal-discrimination task without movement production in healthy subjects. Ten healthy subjects underwent a time-perception task with somatosensory stimuli. Two pairs of electrical stimuli: the first considered the reference pair (rp) with a standard interval of 400 ms and the second, the test pair (tp), with variable intervals ranging from 300 to 500 ms, were applied by surface electrodes on the right forearm. Subjects were instructed to compare time intervals of rp and tp and to estimate whether the tp interval was shorter than, equal to, or longer than that of rp. The task was performed in baseline and after 1 Hz…
Neurophysiological changes associated with implant placement
2016
Objectives The objective of the study was to evaluate the feasibility of a standardized Quantitative Sensory Testing (QST) protocol extra- and intraoral in patients to detect and quantify sensory disturbances of the inferior alveolar nerve due to the proximity of implantation procedures to the inferior alveolar nerve canal. Material and Methods Patients who had obtained an implant placement were examined by implementing a comprehensive QST protocol for extra- and intraoral use. The study included 33 patients after implant placement in the lower jaw and one patient suffering from an inferior alveolar nerve injury. Patients were tested bilaterally (chin and mucosal lower lip). Results Compari…