Search results for "Photic stimulation"
showing 10 items of 307 documents
Emotion recognition from facial expressions: a normative study of the Ekman 60-Faces Test in the Italian population.
2013
The Ekman 60-Faces (EK-60F) Test is a well-known neuropsychological tool assessing emotion recognition from facial expressions. It is the most employed task for research purposes in psychiatric and neurological disorders, including neurodegenerative diseases, such as the behavioral variant of Frontotemporal Dementia (bvFTD). Despite its remarkable usefulness in the social cognition research field, to date, there are still no normative data for the Italian population, thus limiting its application in a clinical context. In this study, we report procedures and normative data for the Italian version of the test. A hundred and thirty-two healthy Italian participants aged between 20 and 79 years…
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…
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…
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…
Dissociation of emotional processes in response to visual and olfactory stimuli following frontotemporal damage.
2005
Contemporary neuropsychological studies have stressed the widely distributed and multicomponential nature of human affective processes. Here, we examined facial electromyographic (EMG) (zygomaticus and corrugator muscle activity), autonomic (skin conductance and heart rate) and subjective measures of affective valence and arousal in patient TG, a 30 year-old man with left anterior mediotemporal and left orbitofrontal lesions resulting from a traumatic brain injury. Both TG and a normal control group were exposed to hedonically valenced visual and olfactory stimuli. In contrast with control subjects, facial EMG and electrodermal activity in TG did not differentiate among pleasant, unpleasant…
Prism adaptation and neck muscle vibration in healthy individuals: Are two methods better than one?
2013
Studies involving therapeutic combinations reveal an important benefit in the rehabilitation of neglect patients when compared to single therapies. In light of these observations our present work examines, in healthy individuals, sensorimotor and cognitive after-effects of prism adaptation and neck muscle vibration applied individually or simultaneously. We explored sensorimotor after-effects on visuo-manual open-loop pointing, visual and proprioceptive straight-ahead estimations. We assessed cognitive after-effects on the line bisection task. Fifty-four healthy participants were divided into six groups designated according to the exposure procedure used with each: 'Prism' (P) group; 'Vibra…
Distraction of task-relevant information processing by irrelevant changes in auditory, visual, and bimodal stimulus features: A behavioral and event-…
2009
Distractibility with auditory, visual, and bimodal stimulus changes was investigated using an audio-visual distraction paradigm. Participants were asked to discriminate between equiprobable short and long audio-visual stimuli. Infrequently, the auditory, the visual, or both parts of the stimuli changed. These rare deviations (deviants) were irrelevant for the actual task. The influence of the three types of deviant stimuli on the processing of task-relevant information was assessed with behavioral and event-related potential (ERP) measures assuming that bimodal deviants would lead to an increase in distraction. Behavioral and ERP results did not support this assumption, as reaction time (RT…
Cue exposure in alcohol dependent patients: preliminary evidence for different types of cue reactivity.
2000
Craving is considered to be an important phenomenon in addictive behaviours. However, there is still an unresolved debate on what craving for alcohol means, how it is best measured and which clinical and therapeutical consequences its presence or absence may imply. Cue reactivity paradigms have been developed to elicit craving under standardized experimental conditions. Here we present preliminary results characterizing alcohol-dependent patients with regard to subjective and psychophysiological aspects of exposure to alcohol-associated cues in a cue reactivity paradigm. Thirty-six patients fulfilling at least 5 criteria of alcohol dependence according to DSM-IV criteria were studied after …
Optokinetic stimulation affects temporal estimation in healthy humans
2007
The representation of time and space are closely linked in the cognitive system. Optokinetic stimulation modulates spatial attention in healthy subjects and patients with spatial neglect. In order to evaluate whether optokinetic stimulation could influence time perception, a group of healthy subjects performed "time-comparison" tasks of sub- and supra-second intervals before and after leftward or rightward optokinetic stimulation. Subjective time perception was biased by the direction of optokinetic stimulation. Rightward optokinetic stimulation induced an overestimation of time perception compared with baseline and leftward optokinetic stimulation. These results indicate a directional bias…
The influence of lorazepam medication upon the transfer properties of the brain during sleep in man
1993
In order to get better insight into the principles of information processing by the brain during sleep and its alterations under the influence of drugs we applied some tools from linear system theory to sleep EEG data. We investigated late components of auditory and visually evoked potentials (AEPs and VEPs) during different sleep stages and calculated from these the so-called amplitude-frequency characteristics (AFC). The main advantage of this analysis is that it enables one to detect functional differences during different sleep stages. This information can hardly be obtained by conventional spectral analysis. The result of our investigation was that the transfer properties of the brain …