12 research outputs found
Self-focused attention enhances tactile sensitivity in women at risk from eating disorders
We examined whether alterations in body perception in EDs extend to the integration of exteroceptive visual and tactile information. Moreover, we investigated the effect of self-focused attention on the ability to correctly detect tactile stimuli. Twenty-seven women reporting low ED symptoms, versus 26 women reporting high ED symptoms, undertook a modified version of the Somatic Signal Detection Task (SSDT), which involved detecting tactile stimuli on the cheek in the presence or absence of a concomitant light. The SSDT was completed while looking at a photograph of one’s own face, another female face, and a scrambled face. Heart rate and skin conductance were recorded continuously during the SSDT. Although ED symptoms were not associated with an overall increased tendency to misperceive touch in the presence of a light, High ED participants were differentially affected by self-focused attention. For the High ED group, physiological arousal, and tactile sensitivity (d′) were increased when self-focused attention was augmented. For the Low ED group, sensitivity (d′) and physiological arousal were higher in the control conditions. We suggest that in those with High ED symptoms, attention to the bodily self may exacerbate a predisposition to focusing on external rather than internal bodily information
The relationship between pain induced autonomic arousal and perceived duration
Emotional distortions of the perceived duration of events are often explained in terms of increases and decreases in arousal. Whilst this explanation is theoretically plausible, there is a lack of evidence for a direct relationship between physiological arousal and perceived duration. The aim of the current study was to investigate whether physiological arousal, defined by autonomic nervous system (ANS) activity is directly related to perceived duration. In two experiments we measured skin conductance level (SCL) and high frequency heart rate variability (HF HRV) during verbal estimation tasks. In Experiment 1, participants estimated the duration of electro-cutaneous stimuli previously rated as inducing no pain, low pain and high pain. High intensity stimuli were perceived as lasting for longer than low intensity stimuli, and these changes in duration estimation were associated with changes in ANS activity. In Experiment 2, participants estimated the duration of a neutral visual stimulus whilst experiencing different intensities of background thermal pain (no pain, low pain, and high pain), to determine whether task-irrelevant arousal also affects time perception. Duration estimations for the neutral stimulus did not increase with pain intensity despite significant increases in SCL. Furthermore, there was no association between ANS activity and time estimation in Experiment 2. These findings suggest that the relationship between physiological arousal and time perception is more complex than previously described. Whilst physiological arousal can influence the perceived duration of events, it appears to have a greater capacity to do so when the to-be-timed stimulus is itself the source of arousal. ©American Psychological Association, 201
I feel bad and look worse than you: Social comparisons moderate the effect of mood on face health judgement
Mood can bias the judgements people make about themselves and how people compare themselves to others. However, it is not yet clear whether mood also affects appearance-based self-evaluations and social comparisons. Given the importance of perceived health status for well-being, we investigated the effect of mood on self-image and social comparisons of healthiness during two versions of a face health judgement task. Thirty participants judged how they felt compared to healthy and unhealthy looking versions of their own (self version) and a stranger’s face (stranger version), after a positive, negative and neutral mood induction. The effect of mood was dependent on self/stranger task order. Although mood did not affect face health judgement for participants who initially judged themselves against their own face, it did affect face health judgement for participants who initially judged themselves in comparison to a stranger’s face. After the positive and negative mood inductions, these participants judged themselves as equivalent to healthier/unhealthier looking versions of their own and stranger’s faces, respectively. Thus, social comparisons of facial healthiness could provide a perceptual measure of state well-being
In your eyes: vision of the body alters touch perception in women with eating disorder symptoms
We investigated the effects of non-informative vision of the body on exteroceptive multisensory integration and touch perception in participants presenting with different levels of eating disorder (ED) symptoms. The study employed a sample of women reporting low (low ED; n = 31) vs high (high ED; n = 34) levels of subclinical ED symptoms who undertook the Somatic Signal Detection task (SSDT). During the SSDT, participants are required to detect near-threshold tactile stimulation at their fingertip with and without a simultaneous light flash next to the stimulated fingertip. Previous research has found that participants have a tendency to erroneously report touch sensations in the absence of the stimulation, and especially when the light flash is presented. In this study, participants completed the SSDT under two conditions: while their hand was visible (non-informative vision), and while their hand was hidden from sight (no vision). Non-informative vision of the hand was found to have a different effect on SSDT performances according to participants’ levels of ED symptoms. High ED participants were better able to correctly detect the touch during the SSDT when their hand was visible. Conversely, for low ED participants, vision of the body was linked to a greater effect of the light in inducing false reports of touch. We suggest that in those with high ED symptoms, vision of the body may exacerbate a predisposition to focusing on external rather than internal bodily information
The effect of pain on reference memory for duration
Previous research has consistently reported that pain related stimuli are perceived as lasting longer than non-pain related ones, suggesting that pain lengthens subjective time. However, to date the investigation has been limited to the immediate effects of pain on time perception. The current study aims to investigate whether pain affects how a duration is recalled after a period of delay. In two experiments, participants were asked to complete four temporal generalisation tasks where they were required first to remember the duration of a standard tone (learning phase) and then to compare the standard duration to a series of comparison durations (testing phase). Using a 2x2 design, the four tasks differed in terms of whether participants were exposed to a painful or non-painful stimulus during the learning phase, and whether the testing phase started immediately or 15 minutes after the learning phase. Participants were exposed to low pain in Experiment 1 and high pain in Experiment 2. Two possible results were expected: pain could decrease temporal accuracy because pain disrupts cognitive processes required for accurate timing, or pain could increase temporal accuracy because pain facilitates memory consolidation. Contrary to expectations, results from both Experiments indicated that participants’ temporal performances were similar in the pain and no-pain conditions when testing occurred 15 minutes after the learning phase. Findings therefore suggest that pain neither disrupts nor enhances long-term memory representations of duration
The off-line effect of affective touch on multisensory integration and tactile perceptual accuracy during the somatic signal detection task
Affective touch refers to the emotional and motivational facets of tactile sensation and has been linked to the activation of a specialised system of mechanosensory afferents (the CT system), that respond optimally to slow caress-like touch. Affective touch has been shown to play an important role in the building of the bodily self: the multisensory integrated global awareness of one’s own body. Here we investigated the effects of affective touch on subsequent tactile awareness and multisensory integration using the Somatic Signal Detection Task (SSDT). During the SSDT, participants were required to detect near-threshold tactile stimulation on their cheek, in the presence/absence of a concomitant light. Participants repeated the SSDT twice, before and after receiving a touch manipulation. Participants were divided into two groups: one received affective touch (CT optimal; n = 32), and the second received non-affective touch (non-CT optimal; n = 34). Levels of arousal (skin conductance levels, SCLs) and mood changes after the touch manipulation were also measured. Affective touch led to an increase in tactile accuracy, as indicated by less false reports of touch and a trend towards higher tactile sensitivity during the subsequent SSDT. Conversely, non-affective touch was found to induce a partial decrease in the correct detection of touch possibly due to a desensitization of skin mechanoreceptors. Both affective and non-affective touch induced a more positive mood and higher SCLs in participants. The increase in SCLs was greater after affective touch. We conclude that receiving affective touch enhances the sense of bodily self therefore increasing perceptual accuracy and awareness. Higher SCLs are suggested to be a possible mediator linking affective touch to a greater tactile accuracy. Clinical implications are discussed
Comparison of McMaster and FECPAKG2 methods for counting nematode eggs in the faeces of alpacas
Spectroscopic and Mechanistic Studies of Co(II) Phosphoesterase and Metallo-β-lactamase Biomimetics
Computational models in cardiology
The treatment of individual patients in cardiology practice increasingly relies on advanced imaging, genetic screening and devices. As the amount of imaging and other diagnostic data increases, paralleled by the greater capacity to personalize treatment, the difficulty of using the full array of measurements of a patient to determine an optimal treatment seems also to be paradoxically increasing. Computational models are progressively addressing this issue by providing a common framework for integrating multiple data sets from individual patients. These models, which are based on physiology and physics rather than on population statistics, enable computational simulations to reveal diagnostic information that would have otherwise remained concealed and to predict treatment outcomes for individual patients. The inherent need for patient-specific models in cardiology is clear and is driving the rapid development of tools and techniques for creating personalized methods to guide pharmaceutical therapy, deployment of devices and surgical interventions