Search results for "perception."
showing 10 items of 3582 documents
Impact of olfactory and auditory priming on the attraction towards foods with high energy density
2015
\]\Recent research suggests that non-attentively perceived stimuli may significantly influence consumers' food choices. The main objective of the present study was to determine whether an olfactory prime (a sweet-fatty odour) and a semantic auditory prime (a nutritional prevention message), both presented incidentally, either alone or in combination can influence subsequent food choices. The experiment included 147 participants who were assigned to four different conditions: a control condition, a scented condition, an auditory condition or an auditory-scented condition. All participants remained in the waiting room during15 min while they performed a 'lure' task. For the scented condition,…
Does gender really matter? A structural equation model to explain risky and positive cycling behaviors
2018
Abstract Introduction While the use of bicycles as mean of transport is growing worldwide, the increasing rates of traffic crashes involving cyclists have turned into a relevant scientific, public health, and road safety concern. According to several studies, and despite the fact that some countries are taking part in preventive actions, the data indicate that the problem of cycling injuries implies high costs for the community welfare, for the economy, and for healthcare systems, thus proving a clear need for solutions. In this regard, and considering the available empirical evidence, risky and positive riding behaviors have gained significant weight in terms of explaining, intervening in,…
Alliesthesia in visual and auditory sensations from environmental signals.
2007
'Alliesthesia' describes the fact that sensory stimuli can arouse pleasant or unpleasant sensations according to the internal state of a person. In the present work, the hedonicity aroused by stimuli from the environment in visual and auditory sensations was evaluated in 5 situations: 1) daytime without sensory stimulations (no video-tape); 2) daytime with poor sensory stimulations (uninteresting video-tape film); 3) daytime with rich sensory stimulations (interesting chosen movie on video-tape); 4) night-time without sensory stimulations (no video-tape); 5) night-time with poor sensory stimulations (uninteresting video-tape). During the day, hedonic ratings decreased with time in the no- a…
Subjective, behavioral, and physiological responses to the rubber hand illusion do not vary with age in the adult phase.
2018
[EN] The Rubber Hand Illusion (RHI) is a perceptual illusion that enables integration of artificial limbs into the body representation through combined multisensory integration. Most previous studies investigating the RHI have involved young healthy adults within a very narrow age range (typically 20-30 years old). The purpose of this paper was to determine the influence of age on the RHI. The RHI was performed on 93 healthy adults classified into three groups of age (20-35 years old, N = 41; 36-60 years old, N = 28; and 61-80 years old, N = 24), and its effects were measured with subjective (Embodiment of Rubber Hand Questionnaire), behavioral (proprioceptive drift), and physiological (cha…
Effects of instruction on acquisition and extinction of electrodermal responses to fear-relevant stimuli.
1977
In the present study we examined the hypothesis that electrodermal responses conditioned to fear-relevant stimuli are insensitive to verbal instructions. In the first experiment, different groups of subjects were conditioned to fear-relevant and fear-irrelevant control stimuli in a long interstimulus interval differential paradigm with shock as the unconditioned stimulus. Then half of the subjects were informed that no more shocks would be presented, and a number of extinction trials followed. The instruction completely abolished responding to fear-irrelevant stimuli, while leaving responses to the fear-relevant stimuli unaffected. In the second experiment, subjects were "conditioned" to fe…
Perceptual Performance as a Function of Intra-Cycle Cardiac Activity
1975
The purpose of the experiment was to test the hypothesis of a systematic change in perceptual performance within a single cardiac cycle due to the activity of the baroreceptors in carotid sinus. As an index of perceptual performance the ds-parameter from signal detection theory (TSD) was used. A 1000 Hz sine tone had to be detected in a background of white noise. Each of 4 subjects received on the average 4605 noise or noise plus tone stimuli distributed over 10 experimental sessions. When comparing performance during time intervals before and after baroreceptor activity onset no significant difference was found. Also, when tracing perceptual performance over the whole cardiac cycle in step…
Distraction effects in vision: behavioral and event-related potential indices.
2004
Evidence is presented which shows that slight changes in serially presented visual input can be detected automatically and may result in behavioral distraction. In two experiments, reaction times on a two-alternative, forced-choice duration discrimination task were prolonged in trials where a task-irrelevant change in the location of the stimulus occurred. The P1 and N1 components of the event-related potential were enhanced in such trials. However, electrophysiological and behavioral effects were not affected when the duration discrimination was made more difficult and the N1 amplitude increase and RT prolongation were confined to situations where task-irrelevant location changes were infr…
Representation of time intervals in the right posterior parietal cortex: implications for a mental time line
2009
Space and time interact with each other in the cognitive system. Recent studies indicate the posterior parietal cortex (PPC) as the neural correlate of spatial-temporal interactions. We studied whether the contribution of the PPC becomes critical in tasks requiring the performance of spatial computations on time intervals. We adopted an integrated neuropsychological and transcranial magnetic stimulation (rTMS) approach, presenting behavioural timing tasks to both healthy subjects and right-brain-damaged patients with and without evidence of spatial neglect. rTMS of the right PPC of healthy subjects induced a lateralised bias during a task requiring setting the midpoint of a time interval. T…
Functional MRI of galvanic vestibular stimulation with alternating currents at different frequencies.
2004
Abstract Functional MRI was performed in 28 healthy volunteers to study the effects of galvanic vestibular stimulation with alternating currents (AC-GVS) of different frequencies on brain activation patterns. The aims of this study were (1) to identify specific areas within the vestibular cortical network that are involved in the processing of frequency-specific aspects by correlation analyses, (2) to determine the optimal frequency for stimulation of the vestibular system with respect to perception, and (3) to analyze whether different frequencies of AC-GVS are mediated in different cortical areas or different sites within the vestibular cortex. AC-GVS was performed using sinusoidal stimul…
Perceiving numbers alters time perception.
2008
The representation of time, space and numbers are strictly linked in the primate's cognitive system. Here we show that merely looking at number symbols biases a temporal judgment on their duration depending upon the number's magnitude. In a first experiment, a group of healthy subjects was submitted to a time estimation task, requiring to judge whether the duration of a test stimulus was longer or shorter than that of a previous reference fixed stimulus (digit 5; duration 300 ms). Test stimuli were the digits 1, 5 and 9 ranging between 250 and 350 ms. The main results showed that temporal perception was biased according to the magnitude expressed by the digit: low digits (i.e. 1) leading to…