Search results for "physiologic"
showing 10 items of 2593 documents
The time line of threat processing and vagal withdrawal in response to a self-threatening stressor in cognitive avoidant copers: evidence for vigilan…
2010
Using a spatial cueing paradigm with emotional and neutral facial expressions as cues, we examined early and late patterns of information processing in cognitive avoidant coping (CAV). Participants were required to detect a target that appeared either in the same location as the cue (valid) or in a different location (invalid). Cue–target onset asynchrony (CTOA) was manipulated to be short (250 ms) or long (750 ms). CAV was associated with early facilitation and faster disengagement from angry faces. No effects were found for happy or neutral faces. After completing the spatial cueing task, participants prepared and delivered a public speech and heart rate variability (HRV) was recorded. Di…
Musical familiarity in congenital amusia: Evidence from a gating paradigm
2013
Congenital amusia has been described as a lifelong deficit of music perception and production, notably including amusic individuals' difficulties to recognize a familiar tune without the aid of lyrics. The present study aimed to evaluate whether amusic individuals might have acquired long-term knowledge of familiar music, and to test for the minimal amount of acoustic information necessary to access this knowledge (if any) in amusia. Segments of familiar and unfamiliar instrumental musical pieces were presented with increasing duration (250, 500, 1000 msec etc.), and participants provided familiarity judgments for each segment. Results showed that amusic individuals succeeded in differentia…
Both contextual regularity and selective attention affect the reduction of precision‐weighted prediction errors but in distinct manners
2020
Predictive coding model of perception postulates that the primary objective of the brain is to infer the causes of sensory inputs by reducing prediction errors (i.e., the discrepancy between expected and actual information). Moreover, prediction errors are weighted by their precision (i.e., inverse variance), which quantifies the degree of certainty about the variables. There is accumulating evidence that the reduction of precision-weighted prediction errors can be affected by contextual regularity (as an external factor) and selective attention (as an internal factor). However, it is unclear whether the two factors function together or separately. Here we used electroencephalography (EEG) …
The influence of rTMS over prefrontal and motor areas in a morphological task: grammatical vs. semantic effects
2008
We investigated the differential role of two frontal regions in the processing of grammatical and semantic knowledge. Given the documented specificity of the prefrontal cortex for the grammatical class of verbs, and of the primary motor cortex for the semantic class of action words, we sought to investigate whether the prefrontal cortex is also sensitive to semantic effects, and whether the motor cortex is also sensitive to grammatical class effects. We used repetitive transcranial magnetic stimulation (rTMS) to suppress the excitability of a portion of left prefontal cortex (first experiment) and of the motor area (second experiment). In the first experiment we found that rTMS applied to t…
An approach to single trial analysis of event-related potentials based on signal detection theory.
1996
Abstract The aim of the present paper was to introduce a single trial analysis to event-related potential measurement in order to illuminate the mechanisms behind an impaired P300 amplitude occurring under certain experimental conditions. For this purpose we applied tools from linear system theory and signal detection theory to single trials in an oddball paradigm in order to estimate the amplitude of the positive deflection around the P300 latency following target and nontarget stimuli. According to the density functions of these amplitude distributions we operationally defined ‘P300 absent in target’ (P300 amplitude smaller than an individual threshold under target conditions) as well as …
Testosterone responses to competition: the opponent’s psychological state makes it challenging
2010
Testosterone (T) increases after competition have typically been attributed to winning, yet there is also evidence that being victorious is not in itself sufficient to provoke a T response. Instead, it has been proposed that T responses are moderated by psychological processes. Here, we investigated whether the opponent's psychological state affected hormonal changes in men competing face to face on a rigged computer task. The results show that, irrespective of outcome, the competition led to increases in heart rate and T levels. We found that the T levels of the participants increased more when their opponents had high self-efficacy and that T levels were not influenced by participants' ow…
Sex differences in autonomic response and situational appraisal of a competitive situation in young adults.
2017
Competition is a social stressor capable of eliciting physiological responses modulated by the outcome. The main objective of this study was to analyze the psychophysiological changes associated with competition and its outcome in men and women, taking into account the role of situational appraisal. To this end, 112 young people (46 men and 66 women) participated in a laboratory task in a competitive or non-competitive condition, while Blood Pressure (BP), Heart Rate Variability (HRV), and Skin Conductance (SC) responses were measured. Our results indicate that competition elicits higher systolic blood pressure (SBP) than a non-competitive task; in addition, winners presented a greater R-R …
Exploring the switching of the focus of attention within working memory: A combined event-related potential and behavioral study.
2018
Abstract Working memory enables humans to maintain selected information for cognitive processes and ensures instant access to the memorized contents. Theories suggest that switching the focus of attention between items within working memory realizes the access. This is reflected in object-switching costs in response times when the item for the task processing is to be changed. Another correlate of attentional allocation in working memory is the P3a-component of the human event-related potential. The aim of this study was to demonstrate that switching of attention within working memory is a separable processing step. Participants completed a cued memory-updating task in which they were instr…
Sensor acceptance model:measuring patient acceptance of wearable sensors
2008
Summary Objectives: This project focuses on how patients respond to wearable biomedical sensors, since patient acceptance of this type of monitoring technology is essential for enhancing the quality of the data being measured. There is a lack of validated questionnaires measuring patient acceptance of telemedical solutions, and little information is known of how patients evaluate the use of wearable sensors. Methods: In information systems research, surveys are commonly used to evaluate the user satisfaction of software programs. Based on this tradition and adding measures of patient satisfaction and health-related quality of life (HRQoL), a Sensor Acceptance Model is developed. The model i…
Confabulation: damage to a specific inferior medial prefrontal system
2008
Confabulation, the pathological production of false memories, occurs following a variety of aetiologies involving the frontal lobes, and is frequently held to be underpinned by combined memory and executive deficits. However, the critical frontal regions and specific cognitive deficits involved are unclear. Studies in amnesic patients have associated confabulation with damage to the orbital and ventromedial prefrontal cortices. However, neuroimaging studies have associated memory-control processes which are assumed to underlie confabulation with the right lateral prefrontal cortex. We used a confabulation battery to investigate the occurrence and localisation of confabulation in an unselect…