Search results for "quiet"

Messages beyond the phone: Processing variable message signs while attending hands-free phone calls.

2021

We examined the effects of different types of cognitive distraction coming from a hands-free phone conversation on the processing of information provided by variable message signs (VMS), on driving performance indicators, and on a physiological index of mental effort (heart rate). Participants drove a route in a driving simulator and had to respond to VMS messages under three conditions: no-distraction, visuospatial distraction (attending phone calls with questions inducing visuospatial processing), and conceptual distraction (attending phone calls with questions requiring semantic memory). Results showed more errors responding to VMS messages in the visuospatial distraction condition. In a…

Connotative meaning of travel modes and activity-travel behavior

2018

Abstract This paper aims to present results of a study regarding how the meaning of travel modes influences on the performance of activities and trips. Connotative meaning of travel modes was measured using semantic differential scales, which collect the suggestive significance of the terms used to name current travel modes. More than 400 people provided that information together with values and other types of attitudes, characteristics of their usual companions, socio-demographics, and 2-days activity-travel diary that includes a weekend day and a weekday. Descriptive analysis, which include frequency distributions, Factor Analysis, and correlations, have been developed to find potential r…

The difficulty of the postural control task affects multi-muscle control during quiet standing

2016

The aim of this study was to compare the electromyographic (EMG) coherence between the lower limb and the core muscles when carrying out two postural tasks at different difficulty levels. EMG was recorded in 20 healthy male subjects while performing two independent quiet standing tasks. The first one involved a bipedal stance with the eyes open, while the second consisted of a dominant unipedal stance also with the eyes open. The obtained EMG signals were analysed by computing estimations of EMG–EMG coherence between muscle pairs, both singly (single-pair estimations) and combined (pooled estimations). Pooled and single coherence of anterior, posterior, core, antagonist and mixed pairs of m…

Sequential grouping modulates the effect of non-simultaneous masking on auditory intensity resolution.

2012

The presence of non-simultaneous maskers can result in strong impairment in auditory intensity resolution relative to a condition without maskers, and causes a complex pattern of effects that is difficult to explain on the basis of peripheral processing. We suggest that the failure of selective attention to the target tones is a useful framework for understanding these effects. Two experiments tested the hypothesis that the sequential grouping of the targets and the maskers into separate auditory objects facilitates selective attention and therefore reduces the masker-induced impairment in intensity resolution. In Experiment 1, a condition favoring the processing of the maskers and the targ…

Analyzing gastrocnemius EMG-activity and sway data from quiet and perturbed standing.

2007

In an experiment, we combined force plate measurements and surface EMG in studying quiet and perturbed standing, involving MS (Multiple sclerosis) and controls. The aim of this paper is to report the results thus obtained on the relation between filtered gastrocnemius (GA) EMG and the anterior-posterior center-of-pressure (A/P COP) coordinate. The main finding is the good correspondence between A/P COP and the filtered GA EMG in the low frequency range. The EMG envelope was calculated using a zero-lag filter. Combining this with time shifts around 250-350 ms produced a high correlation (85.5+/-8.4%) between the GA-EMG envelope and the A/P COP. This EMG-COP relation was closest when using a …

Sensory strategies of postural sway during quiet stance in patients with haemophilic arthropathy.

2017

Introduction: The sensory strategies of postural control in adult haemophilic arthropathy patients are still poorly understood. Aim: To determine sensorial posture-control strategies through postural sway frequency analysis when in a bipedal quiet stance with and without visual stimulus deprivation in healthy subjects and patients with haemophilic arthropathy. Secondarily, to determine the irregularity of postural balance control through sample entropy (SampEn). Methods: A triaxial accelerometer attached at the L3 level determined the displacement and acceleration of the centre of mass (DCoM and ACoM, respectively) under open-and closed-eyes conditions. Sensorial strategies were studied by …

Elderly adults delay proprioceptive reweighting during the anticipation of collision avoidance when standing.

2012

The ability to reweight visual and proprioceptive information is critical for maintaining postural stability in a dynamic environment. In this study, we examined whether visual anticipation of collision avoidance (AV) while standing could facilitate the down-weighting of altered proprioception in young and elderly adults. Twelve young (24.91 ± 6.44 years) and 12 elderly (74.8 ± 6.42 years) participants stood upright for 180 s under two task conditions: (a) quiet stance (QS) and (b) standing while anticipating virtual objects to be avoided. In order to disrupt the accuracy of proprioceptive input participants were exposed to bilateral Achilles tendon vibration during the middle 60 s of stand…

Alveolar Gas Mixing in Chronic Pulmonary Hyperinflation

1991

It is well known that in chronic pulmonary hyperinflation defects in intrapulmo-nary gas mixing and in V/Q ratio are likely to occur.

2013

To identify factors limiting performance in multitone intensity discrimination, we presented sequences of five pure tones alternating in level between loud (85 dB SPL) and soft (30, 55, or 80 dB SPL). In the “overall-intensity task”, listeners detected a level increment on all of the five tones. In the “masking task”, the level increment was imposed only on the soft tones, rendering the soft tones targets and loud tones task-irrelevant maskers. Decision weights quantifying the importance of the five tone levels for the decision were estimated using methods of molecular psychophysics. Compatible with previous studies, listeners placed higher weights on the loud tones than on the soft tones i…

Cerebral Dynamics during the Observation of Point-Light Displays Depicting Postural Adjustments

2017

Objective: As highly social creatures, human beings rely part of their skills of identifying, interpreting, and predicting the actions of others on the ability of perceiving biological motion. In the present study, we aim to investigate the electroencephalographic (EEG) cerebral dynamics involved in the coding of postural control and examine whether upright stance would be codified through the activation of the temporal-parietal cortical network classically enrolled in the coding of biological motion. Design: We registered the EEG activity of 12 volunteers while they passively watched point light displays (PLD) depicting quiet stable (QB) and an unstable (UB) postural situations and their r…