Attention, unpredictability, and reports of physical symptoms: eliminating the benefits of predictability

Individual differences show that only some bats can cope with noise-induced masking and distraction

Anthropogenic noise is a widespread pollutant that has received considerable recent attention. While alarming effects on wildlife have been documented, we have limited understanding of the perceptual mechanisms of noise disturbance, which are required to understand potential mitigation measures. Likewise, individual differences in response to noise (especially via perceptual mechanisms) are likely widespread, but lacking in empirical data. Here we use the echolocating bat Phyllostomus discolor, a trained discrimination task, and experimental noise playback to explicitly test perceptual mechanisms of noise disturbance. We demonstrate high individual variability in response to noise treatments and evidence for multiple perceptual mechanisms. Additionally, we highlight that only some individuals were able to cope with noise, while others were not. We tested for changes in echolocation call duration, amplitude, and peak frequency as possible ways of coping with noise. Although all bats strongly increased call amplitude and showed additional minor changes in call duration and frequency, these changes could not explain the differences in coping and non-coping individuals. Our understanding of noise disturbance needs to become more mechanistic and individualistic as research knowledge is transformed into policy changes and conservation action.

The effects of auditory background noise and virtual reality technology on video game distraction analgesia

Background and aims

The present study was designed to evaluate the relative efficacy of two video game display modalities – virtual reality (VR) assisted video game distraction, in which the game is presented via a VR head-mounted display (HMD) helmet, versus standard video game distraction, in which the game is projected on a television – and to determine whether environmental context (quiet versus noisy) moderates the relative efficacy of the two display modalities in reducing cold pressor pain in healthy college students.

Methods

Undergraduate students (n=164) were stratified by sex and self-reported video game skill and were randomly assigned to a quiet or a noisy environment. Participants then underwent three cold pressor trials consisting of one baseline followed by two distraction trials differing in display modality (i.e. VR-assisted or standard distraction) in counter-balanced order.

Results

Participants experienced improvement in pain tolerance from baseline to distraction in both display modality conditions (p<0.001, partial η2=0.41), and there was a trend toward greater improvement in pain tolerance from baseline to distraction when using the VR HMD helmet than during standard video game distraction (p=0.057, partial η2=0.02). Participants rated pain as more intense when experienced with concurrent experimental background noise (p=0.047, partial η2=0.02). Pain tolerance was not influenced by the presence or absence of background noise, and there was not a significant interaction between display modality and noise condition. Though exploratory sex analyses demonstrated a significant three-way interaction between noise condition, sex, and display modality on pain intensity (p=0.040, partial η2=0.040), follow-up post-hoc analyses conducted for males and females separately did not reveal significant differences in pain intensity based on the interaction between noise condition and display modality.

Conclusions

As expected, video game distraction both with and without an HMD helmet increased pain tolerance; however, the two display modalities only marginally differed in efficacy within the population under study. The effect of auditory background noise on pain was mixed; while pain tolerance did not vary as a function of the presence or absence of background noise, the addition of noise increased pain intensity ratings. The interaction between participant sex, noise condition, and distraction modality on pain intensity trended toward significance but would require replication in future research.

Implications

Results suggest that video game distraction via HMD helmet may be superior to standard video game distraction for increasing pain tolerance, though further research is required to replicate the trending findings observed in this study. Though it does not appear that background noise significantly impacted the relative efficacy of the two different video game display modalities, the presence of noise does appear to alter the pain response through amplified pain intensity ratings. Further research utilizing more sophisticated VR technology and clinically relevant background auditory stimuli is necessary in order to better understand the impact of these findings in real-world settings and to test the clinical utility of VR technology for pain management relative to standard video game distraction.

When Information Fails

We exposed 72 subjects to 23 95d BA unpredictable noise bursts, and assigned them to one of four experimental conditions: full information-perceived control, standard information-perceived control, full information-no control, and standard information-no control. All subjects completed arithmetic problems during the noise exposure and attempted Feather's (1961) line puzzles after hearing the noise. Contrary to predictions, the data revealed that subjects given full information about the experimental procedures experienced more frustration than subjects given standard information. The control manipulation decreased frustration only for subjects given full information. Possible explanations to account for the present findings are discussed.

The effects of cell phone conversations on the attention and memory of bystanders

The pervasive use of cell phones impacts many people–both cell phone users and bystanders exposed to conversations. This study examined the effects of overhearing a one-sided (cell phone) conversation versus a two-sided conversation on attention and memory. In our realistic design, participants were led to believe they were participating in a study examining the relationship between anagrams and reading comprehension. While the participant was completing an anagram task, the researcher left the room and participants overheard a scripted conversation, either two confederates talking with each other or one confederate talking on a cell phone. Upon the researcher’s return, the participant took a recognition memory task with words from the conversation, and completed a questionnaire measuring the distracting nature of the conversation. Participants who overheard the one-sided conversation rated the conversation as significantly higher in distractibility than those who overheard the two-sided conversation. Also, participants in the one-sided condition scored higher on the recognition task. In particular they were more confident and accurate in their responses to words from the conversation than participants in the two-sided condition. However, participants’ scores on the anagram task were not significantly different between conditions. As in real world situations, individual participants could pay varying amounts of attention to the conversation since they were not explicitly instructed to ignore it. Even though the conversation was irrelevant to the anagram task and contained less words and noise, one-sided conversations still impacted participants’ self-reported distractibility and memory, thus showing people are more attentive to cell phone conversations than two-sided conversations. Cell phone conversations may be a common source of distraction causing negative consequences in workplace environments and other public places.

Impact of stressors in a natural context on release of cortisol in healthy adult humans: a meta-analysis

Increased hypothalamic-pituitary-adrenal (HPA) activation, culminating in elevated circulating cortisol levels is a fundamental response to stressors. In animals, this neuroendocrine change is highly reliable and marked (approximately 5-10-fold elevations), whereas in humans, the increase of cortisol release is less pronounced, and even some potent life-threatening events (anticipation of surgery) only elicit modest cortisol increases. Meta-analysis of factors that influenced the increase of cortisol release in a laboratory context pointed to the importance of social evaluative threats and stressor controllability in accounting for the cortisol rise. The present meta-analysis, covering the period from 1978 through March 2007, was undertaken to identify the factors most closely aligned with cortisol increases in natural settings. It appeared that stressor chronicity was fundamental in predicting cortisol changes; however, this variable is often confounded by the stressor type, the stressor's controllability, as well as contextual factors, making it difficult to disentangle their relative contributions to the cortisol response. Moreover, several experiential factors (e.g. previous stressor experiences) may influence the cortisol response to ongoing stressors, but these are not readily deduced through a meta-analysis. Nevertheless, there are ample data suggesting that stressful events, through their actions on cortisol levels and reactivity, may influence psychological and physical pathology.

The context of a noxious stimulus affects the pain it evokes

The influence of contextual factors on the pain evoked by a noxious stimulus is not well defined. In this study, a -20 degrees C rod was placed on one hand for 500 ms while we manipulated the evaluative context (or 'meaning') of, warning about, and visual attention to, the stimulus. For meaning, a red (hot, more tissue damaging) or blue (cold, less tissue damaging) visual cue was used. For warning, the stimulus occurred after the cue or they occurred together. For visual attention, subjects looked towards the stimulus or away from it. Repeated measures ANCOVA was significant (alpha=0.0125). Stimuli associated with a red cue were rated as hot, with the blue cue as cold (difference on an 11 point scale approximately 5.5). The red cue also meant the pain was rated as more unpleasant (difference approximately 3.5) and more intense (difference approximately 3). For stimuli associated with the red cue only, the pain was more unpleasant when the stimulus occurred after the cue than when it didn't (difference approximately 1.1). Pain was rated as more intense, and the stimulus as hotter, when subjects looked at the red-cued stimulus than when they didn't (difference approximately 0.9 for pain intensity and approximately 2 for temperature). We conclude that meaning affects the experience a noxious stimulus evokes, and that warning and visual attention moderate the effects of meaning when the meaning is associated with tissue-damage. Different dimensions of the stimulus' context can have differential effects on sensory-discriminative and affective-emotional components of pain.

Emotional experience in sheep: Predictability of a sudden event lowers subsequent emotional responses

The study of emotions in animals can be approached thanks to a framework derived from appraisal theories developed in cognitive psychology, according to which emotions are triggered when the individual evaluates challenging events. This evaluation is based on a limited number of criteria such as the familiarity and the predictability of an event. If animals are able to experience emotions rather than simply displaying reflex responses to their environment, then their appraisal of events should, as in humans, modulate their emotional responses. We tested this hypothesis by comparing vocalisations, feeding behaviour, and the startle and cardiac responses of lambs submitted to a sudden event that could or could not be predicted. Lambs able to predict the sudden event thanks to a light cue (associative predictability) showed weaker suddenness-induced startle and cardiac responses and spent more time feeding than their counterparts, thus supporting the existence of an emotional experience in these animals. Furthermore, lambs submitted to the regular appearance of the sudden event (temporal regularity) vocalised less and left less unconsumed food deliveries than lambs submitted to random appearances of the sudden event (controls). These results underline that the cognitive abilities of animals should be taken into account when assessing their emotional experiences and more generally their mood states, which are underlying factors of animal welfare.

Social defeat increases food intake, body mass, and adiposity in Syrian hamsters

Overeating and increases in body and fat mass are the most common responses to day-to-day stress in humans, whereas stressed laboratory rats and mice respond oppositely. Group housing of Syrian hamsters increases body mass, adiposity, and food intake, perhaps due to social confrontation-induced stress. In experiment 1 we asked, Does repeated social defeat increase food intake, body mass, and white adipose tissue (WAT) mass in Syrian hamsters? Male hamsters subjected to the resident-intruder social interaction model and defeated intermittently 15 times over 34 days for 7-min sessions significantly increased their food intake, body mass, and most WAT masses compared with nondefeated controls. Defeat significantly increased terminal adrenal norepinephrine, but not epinephrine, content. In experiment 2 we asked, Are 15 intermittent resident-intruder interactions necessary to increase body mass and food intake? Body mass and food intake of subordinate hamsters defeated only once were similar to those of nondefeated controls, but four or eight defeats similarly and significantly increased these responses. In experiment 3 we asked, Do intermittent defeats increase adiposity and food intake more than consecutive defeats? Four intermittent or consecutive defeats similarly and significantly increased food intake and body mass compared with nondefeated controls, but only intermittent defeats significantly increased all WAT masses. Consecutive defeats significantly increased mesenteric and inguinal WAT masses. Plasma leptin, but not insulin, concentrations were similarly and significantly increased compared with nondefeated controls. Collectively, social defeat, a natural stressor, significantly increased food intake, body mass, and adiposity in Syrian hamsters and may prove useful in determining mechanisms underlying human stress-induced obesity.

Stress, depression, and anhedonia: caveats concerning animal models

Numerous animal models of depression have been advanced, each having multiple attributes and some limitations. This review provides caveats concerning etiologically valid animal models of depression, focusing on characteristics of the depressive subtype being examined (e.g. typical vs atypical major depression, dysthymia, melancholia), and factors that contribute to the interindividual behavioral variability frequently evident in stressor-related behavioral paradigms. These include the stressor type (processive vs systemic stressors), and characteristics of the stressor (controllability, predictability, ambiguity, chronicity, intermittence), as well as organismic variables (genetic, age, sex), experiential variables (stressor history, early life events) and psychosocial and personality factors that moderate stressor reactivity. Finally, a model of depression is reviewed that evaluates the effects of stressors on hedonic processes, reflected by responding for rewarding brain stimulation. Anhedonia is a fundamental feature of depression, and assessment of stressor-related reductions in the rewarding value of brain stimulation, especially when coupled with other potential symptoms of depression, provides considerable face, construct and predictive validity. Stressful events markedly impact rewarding brain stimulation, and this effect varies across strains of mice differentially reactive to stressors, is modifiable by antidepressant treatments, and allows for analyses of the contribution of different brain regions to anhedonic processes. The paradigm is sensitive to several factors known to acts as moderators of stress responses, but analyses remain to be conducted with regard to several such variables.

Cognitive aspects of pain and pain control

The cognitive and cognitive-behavioral approaches have been shown to be very effective in controlling pain and its sequelae both in the laboratory and in the clinical setting. As used in most research and treatment, cognitive approaches are concerned with the way the person perceives, interprets, and relates to his or her pain rather than with the elimination of the pain per se. This article reviews some of the origins of cognitive theory and pain theory, as well as examples of the techniques used and the research support for the approach. Special emphasis is given to self-efficacy, perceived control, and stress inoculation therapy. There is also discussion of some of the limitations of the cognitive approach. The overall conclusion is that the cognitive approach is a powerful and effective one for pain control despite its limitations.

The influence of warning signal timing and cognitive preparation on the aversiveness of cold-pressor pain

This study examined the role of prior warning time, cognitive preparation and self-efficacy in the reaction to cold-pressor pain that has a substantial stimulus duration and leaves a residual effect. Forty-eight, paid, male subjects were randomly assigned to one of 3 cognitive preparation groups: (1) Training group, provided with a self-instructional booklet of pain control techniques, (2) Citizenship group, to control for reading a booklet, and (3) Control group with no advanced preparation. Warning times used on a within-subjects basis were 0, 30, and 180 sec prior to immersion of their arms in cold water. Results indicated that overall, the 180 sec warning time yielded the lowest pain ratings. Warning time had no effect on duration in water for subjects who underwent training, but the 30 sec and 180 sec warning time yielded longer duration in water, for subjects in the other groups. The Training group preparation was effective in raising perceived self-efficacy for coping with pain which, in turn, was found to be correlated with pain tolerance. Perceived self-efficacy was also found to have an effect on heart rate with high scorers yielding a lower reaction upon immersion into the cold water compared to the low scorers. The results point to the need to consider the effect of the stimulus characteristics and the centrality of perceived self-efficacy when preparing a subject prior to pain stimulation.

Sensory and temporal information about impending pain: the influence of predictability on pain

Theories disagree about whether a verbal warning for pain has a detrimental or beneficial effect on the impact of an actual pain stimulus. Scheme-based theories predict a detrimental effect, whereas more representation-based, stimulus-comparator theories propose a beneficial effect. In this study, the influence of sensory predictability and temporal predictability is investigated. To control for attentional processes and to obtain a behavioral measure of the intrusive character of pain, an auditory discrimination task was introduced. This study firmly demonstrates that information about the painful nature of a heat stimulus does not a priori have detrimental effects on the impact of the stimulus. In fact, conditions in which a pain warning was given displayed a diminished impact in the SCR amplitude as well as in the subjectively reported intensity of the heat stimulus. Informing Ss about the exact time of administration did not add to the impact modulation, but instead resulted in a less-anxious state between signals. Although an overall behavioral disruption, particularly at onset, was observed, the behavioral data did not parallel the results of the two other response systems. Results are discussed in terms of scheme-based models, stimulus-comparator theories and the safety-signal hypothesis.

The influence of warning signal timing and cognitive preparation on the aversiveness of electric shock

Many medical and dental procedures are noxious. Finding an optimal way of warning patients concerning the aversive procedures could help them to cope better. A model for the effective use of a warning signal in coping with pain posited that a person needs enough time to be able to react and should possess the skills necessary to utilize the time effectively. It was felt that a very short warning period, e.g., 5 sec, could not be long enough, while a 180 sec warning period would in and of itself become aversive. Reactions to electric shock were obtained from 36 paid, volunteer subjects who were each tested on a within-subject, counterbalanced order at 4 different warning periods: 5, 30, 60, and 180 sec. The subjects were divided into 3 groups: (1) the experimental group was provided with a pretested self-instructional booklet to learn a variety of pain control techniques; (2) the placebo group was provided with a self-instructional booklet on citizenship; (3) the control group waited quietly for 13 min. No significant results were obtained for the different pain-coping conditions. Significant differences, however, were obtained for the various warning periods. Maximum skin resistance changes, higher ratings of pain and of anxiety were obtained for the 60 and 180 compared to the 5 and 30 sec warning periods. Maximum heart rate was obtained for the 30 sec warning. Results were discussed in terms of the psychological meaning of the various measures as well as their clinical implications.

Sense of control: potentials for intervention

A substantial amount of research has demonstrated that the sense of control is associated with numerous positive outcomes, including good health. Many aspects of the personal and social conditions of old age influence the control-health relationship. Environmental events associated with old age often place limits on the range of outcomes that are attainable by older people. Moreover, the association between control and indicators of health status may be altered by old age. Finally, old age may influence the relationship between control and various health maintenance behaviors. Aspects of the sense of control can be altered with small interventions that can enhance health specifically and the quality of aging in general. Given the relationship between control and health in old age, several possible factors may help explain or mediate this relationship including mechanisms of behavioral and cognitive change, and physiological adaptations. Despite the largely positive outcomes associated with increased sense of control, negative outcomes are also possible, especially when control is not desired or entails too much responsibility or other demands.

Aging and health: effects of the sense of control

The relation between health and a sense of control may grow stronger in old age. This could occur through three types of processes: experiences particularly relevant to control may increase markedly in old age; the association between control and some aspect of health may be altered by age; and age may influence the association between control and health-related behaviors or the seeking of medical care. Studies show that there are detrimental effects on the health of older people when their control of their activities is restricted; in contrast, interventions that enhance options for control by nursing home patients promote health. With increasing age, however, variability in preferred amounts of control also increases, and sometimes greater control over activities, circumstances, or health has negative consequences including stress, worry, and self-blame. Mechanisms mediating the control-health relation include feelings of stress, symptom labeling, changes in the neuroendocrine and immune systems, and behavior relevant to health maintenance.