Heart rate and somatic concomitants of mental imagery

A Visual Interactive Narrative Intervention (VINI) for aphasia education: Can digital applications administer augmented input to educate stroke survivors with aphasia?

OBJECTIVE

Persons with aphasia (PWA) face additional barriers to proper healthcare due to inadequate patient education by health professionals unequipped to use augmentative and alternative communication (AAC). The current study examines a digital application that evokes and sustains health information processing through AAC specifically aimed at increasing comprehension with augmented input (AI).

METHODS

A digital application designed to educate PWA about their health condition was compared to a video-recorded doctor providing oral-only education. Sixteen PWA received both education interventions in a crossover manner. Health information processing was assessed through heart rate (HR) and skin conductance levels (SCL), which were collected continually during each administration of education interventions.

RESULTS

PWA demonstrated greater cognitive processing of health information via HR and SCL indices during the digital application compared to the typical oral-only education intervention. The oral-only intervention led PWA to disengage with health information.

CONCLUSION

By combining visuographic materials and adapted language into a customizable narrative structure, digital applications can utilize AI to educate PWA about basic health information (i.e., diagnosis and prognosis).

PRACTICE IMPLICATIONS

The current study's AAC requires minimal training and can be used as an aided support in conjunction with other techniques that increase PWA's access to health information.

Toward brain-heart computer interfaces: a study on the classification of upper limb movements using multisystem directional estimates

OBJECTIVE

Brain-computer interfaces (BCI) exploit computational features from brain signals to perform a given task. Despite recent neurophysiology and clinical findings indicating the crucial role of functional interplay between brain and cardiovascular dynamics in locomotion, heartbeat information remains to be included in common BCI systems. In this study, we exploit the multidimensional features of directional and functional interplay between electroencephalographic and heartbeat spectra to classify upper limb movements into three classes.

APPROACH

We gathered data from 26 healthy volunteers that performed 90 movements; the data were processed using a recently proposed framework for brain-heart interplay (BHI) assessment based on synthetic physiological data generation. Extracted BHI features were employed to classify, through sequential forward selection scheme and k-nearest neighbors algorithm, among resting state and three classes of movements according to the kind of interaction with objects.

MAIN RESULTS

The results demonstrated that the proposed brain-heart computer interface (BHCI) system could distinguish between rest and movement classes automatically with an average 90% of accuracy.

SIGNIFICANCE

Further, this study provides neurophysiology insights indicating the crucial role of functional interplay originating at the cortical level onto the heart in the upper limb neural control. The inclusion of functional BHI insights might substantially improve the neuroscientific knowledge about motor control, and this may lead to advanced BHCI systems performances.

Individual Differences in Physiological Responses to Fearful, Racially Noxious, and Neutral Imagery

Mental imagery has recently emerged as an alternative to traditional laboratory stressors in psychophysiological studies. The present study assessed physiological responsivity to fearful, neutral, and racially noxious image scenes in sixty-two black women. In addition, the utility of several personality variables for predicting physiological changes in response to the scenes was assessed. Thirty-one vivid and thirty-one non-vivid imagers participated in a preliminary session during which they were given progressive relaxation training and were instructed to image an event on cue. On a separate occasion physiological responses to the scenes were assessed. Findings indicated that the fearful and racially noxious scenes elicited comparable increases in corrugator and heart rate activity. The neutral scene had a less pronounced effect on heart rate and corrugator activity than the other scenes. Results of multiple regression analyses in which personality variables served as predictors of physiological activity revealed that certain dimensions of the Type A coronary prone behavior pattern and trait anxiety were significant predictors of physiological reactivity. These predictors were most effective where a conceptual link between the content of the scenes and the specific dimensions was identifiable. The results suggest that the imagery paradigm is useful for studying the effects of complex social stressful situations akin to those growing out of racism. They also underscore the potentially facilitory role personality assessment may have in pinpointing sources of variability in response to this form of laboratory stress.

Does the more vivid imagery of high hypnotizables depend on greater cognitive effort? A test of dissociation and social-cognitive theories of hypnosis

In an investigation of the role of cognitive effort in hypnotic responding, high and low hypnotizable participants produced emotionally neutral imagery in response to effortful versus effortless hypnotic suggestions. Heart-rate increase served as an objective index of cognitive effort, and subjective ratings of imagery vividness, absorption, effort, and control were collected. Compared to lows, high hypnotizable participants experienced their imagery as more vivid and absorbing, yet their heart rates indicated no higher level of cognitive effort than lows. Compared to effortless wording, effortful wording of suggestions increased cognitive effort in lows, as indexed by heart-rate increase, but had no effect on the effort expended by highs. Ratings of subjective control were strongly correlated with subjective effort for lows but unrelated for highs. These results support the dissociated-control theory of hypnosis rather than the dissociated-experience or social-cognitive theories.

Autonomic Nervous System Activity During Actual and Mentally Simulated Preparation for Movement

The aim of this study was to compare actual versus mentally simulated preparation for a complex motor skill. Two behavioral periods are observed during weightlifting: (i) an initial phase in which the subject standing behind the bar is thought to focus his attention on forthcoming execution and (ii) a second phase between hands/bar contact and execution during which the subject is thought to increase activation. Such mental processes accompanying behavioral sequences are correlated with autonomic nervous system activity, phasic responses corresponding to allocation of attentional resources, and tonic variations related to increasing general activation. To study mental processes during preparation for action, 12 subjects performed actual and imagined preparation phases of execution. Six autonomic variables were measured continuously. Skin potential (chi2 = 0.16), skin temperature amplitude (Z = -0.66) and duration (Z = -1.78), skin blood flow amplitude (Z = -0.56) and duration (Z = -1.51), respiratory frequency amplitude (Z = -0.14) and duration (Z = -0.13), and duration of heart rate response (Z = -1.25) were shown to be comparable (p > .05), whatever the modality of preparation. However, during mentally simulated preparation, skin resistance response was shorter than in actual preparation (Z = -2.12, p < .05), thus attesting to a weaker load, whereas lower decrease in heart rate was elicited (Z = -1.96, p < .05). This may be explained by this particular experimental condition because mental preparation would not lead to actual action. Such autonomic variables could be used as feedback to improve performance.

Imagery quality estimated by autonomic response is correlated to sporting performance enhancement

It is now well established that mental imagery practice improves motor skills, but performance efficiency depends on many factors: the main one being individual differences. The aim of this study is to evaluate performance improvement with imagery quality estimated during ANS recording. Volleyball training ("receiving serve") afforded us the experimental paradigm. Subjects were required to pass an opponent's serve to a given team mate. The receiver's performance was evaluated from the accuracy of his pass to the targeted team mate. From these first test results, subjects were divided into two equivalent groups: imagers and controls. After mental practice the two groups were submitted to a posttest similar to the first one. During the pretest, posttest actual practice as well as the last session of corresponding mental rehearsal, six autonomic parameters were continuously recorded. Furthermore, and for the first time, a grade obtained from four different aspects of this response permits qualitative evaluation of each subject's mental imagery. This estimation, based on the well-established link between performance and autonomic response, is validated by the fact that good correlation was obtained between this grade and the performance improvement of each of the "imager" group subjects.

Amplification of the amoA gene from diverse species of ammonium-oxidizing bacteria and from an indigenous bacterial population from seawater

Because the chemolithotrophic ammonium-oxidizing bacteria are an integral component of nitrogen biogeochemistry, a sensitive and accurate method to detect this ecologically important group of microorganisms is needed. The amoA gene of these organisms encodes the active site of ammonia monooxygenase, an enzyme unique to this group of nitrifying bacteria. We report here the use of the PCR technique to detect the amoA gene from pure cultures of chemolithotrophic ammonium-oxidizing bacteria, ammonium oxidizers introduced into filtered seawater, and the natural bacterial population of an unfiltered seawater sample. Oligonucleotide primers, based on the published amoA sequence from Nitrosomonas europaea, were used to amplify DNA from pure cultures of Nitrosomonas europaea, Nitrosomonas cryotolerans, and Nitrosococcus oceanus and from bacteria in seawater collected offshore near the Florida Keys. Partial sequencing of the amplification products verified that they were amoA. These primers, used in conjunction with a radiolabeled amoA gene probe from Nitrosomonas europaea, could detect Nitrosococcus oceanus inoculated into filter-sterilized seawater at 10(4) cells liter-1. Native marine bacteria containing amoA could also be detected at their naturally occurring titer in oligotrophic seawater. Amplification of the gene for ammonia monooxygenase may provide a method to estimate the distribution and relative abundance of chemolithotrophic ammonium-oxidizing bacteria in the environment.

Menstrual-cycle lengthening and reduction in premenstrual distress through guided imagery

This study investigated the effects of a program of relaxation and specific guided imagery on menstrual-cycle length and premenstrual distress. Thirty healthy college women with regular menstrual cycles were studied for 6 months. The subjects completed the Menstrual Distress Questionnaire (MDQ) at the beginning and end of the study and recorded their menstrual cycles for 3 months on an investigator-developed calendar recording sheet. Subjects were then given an audiotape with a progressive muscle relaxation exercise followed by guided imagery with a suggestive message focusing on lengthening the menstrual cycle and delaying the onset of menstrual bleeding. The 15 subjects who completed the entire study had significant increases in cycle lengths during the 3 months of imagery. The total premenstrual distress scores also declined significantly, as did the subscales measuring behavior and negative affect. This study provides preliminary evidence that menstrual-cycle rhythmicity and premenstrual distress are amenable to the mind-body intervention of guided imagery and suggests that further investigation of this phenomena with larger sample size and careful controls for confounding variables be conducted.

The psychophysiology of disgust: differentiating negative emotional contexts with facial EMG

The goals of this study were (a) to examine differing views on the relationship between self-report of emotion and physiological expression of emotion, (b) to differentiate between negative emotional contexts during imagery using facial electromyogram (EMG), and (c) to describe the facial muscle patterning and autonomic physiology of situations that involve expelling or avoiding disgusting sensory stimulation. Fifty subjects imagined situations eliciting disgust, anger, pleasure, and joy in 8-s trials using a tone-cued imagery procedure. Heart rate, skin conductance level, and facial EMG at the corrugator, zygomatic, and levator labii superioris/alesque muscle regions were recorded during imagery, and self-reports of emotion were collected after imagery trials. Self-reports of emotion produced results consistent with the affective categorization of the images. Activity at the levator labii region was higher during disgust than during anger imagery. Corrugator region increase characterized the negative as compared with the positive emotional contents, and activity at the zygomatic region was higher during joy imagery than during the other three emotions. Heart rate acceleration was greater during disgust, anger, and joy imagery than during pleasant imagery. Disgust imagery could be discriminated from anger imagery using facial EMG, and the expressive physiology of disgust was occasioned by the action set of active avoidance or rejection of sensory stimulation.

The effect of experimental muscle pain on the background electrical brain activity

The purpose of this project was to investigate whether specific effects in the background activity of the brain associated with the experience of pain can be depicted by means of quantitative electroencephalography (EEG). Lasting pain was induced by intramuscular infusion of hypertonic saline. The infusion was titrated to maintain pain for a sufficient time to obtain enough data for meaningful analysis. In a first study on 12 subjects, using a single, blind, repeated measures design with randomization of the administration of isotonic (0.9%) and hypertonic (5%) saline, and with subjects unaware of the fact that one substance was isotonic saline, a statistically significant pain response could be attributed to the administration of hypertonic saline. In a second study on 19 subjects, again using a randomized repeated measures design, topographic EEG measures were examined with respect to experimentally induced pain and pain from memory. Prior to each of these experimental stages, baseline recordings were obtained to satisfy the requirement of the crossover design. In addition to the common frequency bands used in EEG, we also obtained data in the frequency range of 35-100 Hz. The short-term variability of the selected EEG measures and their suitability as a sample estimate were assessed by computing the coefficient of variation from all selected epochs of a given subject at baseline. When compared to baseline, spectral analyzed EEG measures during experimental pain demonstrated statistically significant increases in the beta and 35-100 Hz frequency ranges, most notably at the temporal recording sites. There was no statistically significant difference between the EEG measures for (1) experimental pain vs. pain from memory, and (2) the 2 baseline recordings. The great variability in the topographical aspect of the between-subject response was interpreted as being strongly suggestive of the contamination of EEG measures by phenomena attributed to the jaw, facial and scalp musculature. In fact, Pearson correlation coefficients, as high as 0.92, were found between measures in the frequency band of 35-100 Hz and the beta frequency range. The unexplained variance in the heightened beta cortical power density can be attributed to the vigilance scanning of pain processes. Due to the fact that the statistically significant effect of pain on the topographic EEG measures were not different from imagined pain, we concluded that these effects are non-specific for pain.

Autonomic nervous system response patterns correlate with mental imagery

New findings related to autonomic nervous system (ANS) functions may reveal some brain functions, since they can be observed by real time analysis. ANS parameters (skin potential and resistance, skin temperature and blood flow, instantaneous heart rate) and instantaneous respiratory frequency are quantified by original techniques and indices. Results show that ANS responses correlate with mental imagery. Imagery contents influence autonomic responses, thus making it comparable to real activity. Therefore, by using two shooting events as models, the almost identical nature of the ANS response is evidenced during real shooting and in mental concentration before shooting. Next, shooting activity imagery can be distinguished from neutral imagery but is comparable to the activity itself as far as ANS responses are concerned.

Visual decodification of some facial expressions through microimitation

We examined the level of muscular tension of mentalis muscle of 36 students in graphic design at rest and during the presentation of three slides reproducing facial expressions. Analysis showed an increase in the myographic level of mentalis muscle from the third second of measurement onwards after the presentation of the slide in which contraction of the chin was involved. We interpret this result by hypothesizing that the decodification of some facial expressions is realized through a microreproduction of the stimulus from the decodifying subject.