An Evaluation of Finger Pulse Volume as a Psychophysiological Measure of Anxiety

The present experiment explored the utility of finger pulse volume (FPV) as a measure of anxiety. Subjects were exposed to either a threatening or nonthreatening situation, and indices of physiological arousal (pulse rate (PR) and FPV) and self-report of anxiety (Affect Adjective Checklist (AACL)) were collected. Results indicated that FPV was responsive to changes in experimentally induced anxiety and significantly correlated with PR and AACL, although the strength of these relationships was not substantial. Relevance for psychophysiological theory and the clinical observation of anxiety is discussed.     

Comparison of Frontal EMG Biofeedback and Several Types of Relaxation Instructions in Reducing Multiple Indices of Arousal

During the training phase, 96 subjects were given one of four types of relaxation instructions (single instructions, repeated instructions, relaxation training, no instructions) and in addition either did or did not receive frontal EMG biofeedback training. Results indicated that each of the instructions and biofeedback procedures were equally effective in reducing frontal EMG, but that none of these procedures had any effect on subjective anxiety or autonomic indices of arousal (pulse rate, skin temperature, and finger pulse volume). During the generalization/stress phase, subjects were threatened with electric shock and were told to apply the relaxation techniques they learned during the training phase even though no additional instructions and/ or biofeedback training would be provided. To assess the effectiveness of the shock manipulation, a no-threat control group was included. Results indicated that: a) the shock manipulation was effective in increasing arousal, b) previous instructions and/or biofeedback were equally effective in reducing frontal EMG levels, but that c) only relaxation training was consistently effective in reducing subjective and autonomic indices of arousal. These findings: a) suggest that in stressful situations, relaxation training may be more effective than either EMG biofeedback or simple relaxation instructions in producing a general relaxation effect as opposed to a specific EMG effect; and b) indicate the importance of assessing the effectiveness of relaxation procedures during stressful situations during which subjects’ levels of arousal are elevated above resting baseline levels.     

Widespread spatial integration in primary somatosensory cortex

Tactile discrimination depends on integration of information from the discrete receptive fields (RFs) of peripheral sensory afferents. Because this information is processed over a hierarchy of subcortical nuclei and cortical areas, the integration likely occurs at multiple levels. The current study presents results indicating that neurons across most of the extent of the hand representation in monkey primary somatosensory cortex (area 3b) interact, even when these neurons have separate RFs. We obtained simultaneous recordings by using a 100-electrode array implanted in the hand representation of primary somatosensory cortex of two anesthetized owl monkeys. During a series of 0.5-s skin indentations with single or dual probes, the distance between electrodes from which neurons with synchronized spike times were recorded exceeded 2 mm. The results provide evidence that stimuli on different parts of the hand influence the degree of synchronous firing among a large population of neurons. Because spike synchrony potentiates the activation of commonly targeted neurons, synchronous neural activity in primary somatosensory cortex can contribute to discrimination of complex tactile stimuli.     

Chondroitinase ABC promotes selective reactivation of somatosensory cortex in squirrel monkeys after a cervical dorsal column lesion

After large but incomplete lesions of ascending dorsal column afferents in the cervical spinal cord, the hand representation in the contralateral primary somatosensory cortex (area 3b) of monkeys is largely or completely unresponsive to touch on the hand. However, after weeks of spontaneous recovery, considerable reactivation of the hand territory in area 3b can occur. Because the reactivation process likely depends on the sprouting of remaining axons from the hand in the cuneate nucleus of the lower brainstem, we sought to influence cortical reactivation by treating the cuneate nucleus with an enzyme, chondroitinase ABC, that digests perineuronal nets, promoting axon sprouting. Dorsal column lesions were placed at a spinal cord level (C5/C6) that allowed a portion of ascending afferents from digit 1 to survive in squirrel monkeys. After 11-12 wk of recovery, the contralateral forelimb cortex was reactivated by stimulating digit 1 more extensively in treated monkeys than in control monkeys. The results are consistent with the proposal that the treatment enhances the sprouting of digit 1 afferents in the cuneate nucleus and that this sprouting allowed these preserved inputs to activate cortex more effectively.     

Quality of life following bone marrow transplantation: findings from a multicentre study.

Questionnaires assessing a range of quality of life (QOL) outcomes were completed by 200 adult bone marrow transplant (BMT) recipients from five BMT treatment centres. Respondents had undergone allogeneic (46%) or autologous BMT (54%) for a haematological malignancy and were disease free and at least 12 months post BMT (mean 43 months). Variability in post-BMT QOL was reported with deficits in physical, sexual and occupational functioning particularly likely. Allogeneic recipients reported poorer QOL than autologous recipients. Greater age at BMT, lower level of education and more advanced disease at BMT were consistent risk factors for poorer QOL. Contrary to previous research, evidence for improved functional status with the passage of time post BMT was obtained. Factors generally not associated with post-BMT QOL included disease diagnosis, dose of total body irradiation, presence of chronic graft-versus-host disease (GVHD), type of GVHD prophylaxis and extent of marrow graft match. In conclusion, while many BMT recipients reported normal QOL, the majority indicated that their QOL was compromised relative to premorbid status. Prospective, longitudinal research will be necessary to further identify risk factors for poor post-BMT QOL and identify the temporal trajectory of post-BMT QOL.     

Delta-9-tetrahydrocannabinol in cancer chemotherapy: research problems and issues

A critical review of the literature assessing the antiemetic efficacy of delta-9-tetrahydrocannabinol (THC) in patients receiving cancer chemotherapy showed considerable inconsistency in results. The equivocal nature of these results partly reflects the difficulty of doing research on antiemetic therapies, but also can be attributed to differences in the adequacy and nature of the research designs, procedures, and assessment instruments that have been used. Several factors were also identified that are seldom studied but may be important in determining whether THC will be effective: patient variables, such as chemotherapy regimen and age; pharmacologic variables, such as drug tolerance, dose, schedule, toxicity, route of administration, and drug interactions; and environmental variables associated with administration setting. The need to differentiate pharmacologically induced from conditioned nausea and vomiting was also pointed out. We believe that THC does have antiemetic efficacy, but the lack of controlled research does not allow precise knowledge of its true effectiveness and toxicity. Well-controlled trials are needed to help answer some of these questions.     

Cortical and subcortical plasticity in the brains of humans, primates, and rats after damage to sensory afferents in the dorsal columns of the spinal cord

The failure of injured axons to regenerate following spinal cord injury deprives brain neurons of their normal sources of activation. These injuries also result in the reorganization of affected areas of the central nervous system that is thought to drive both the ensuing recovery of function and the formation of maladaptive neuronal circuitry. Better understanding of the physiological consequences of novel synaptic connections produced by injury and the mechanisms that control their formation are important to the development of new successful strategies for the treatment of patients with spinal cord injuries. Here we discuss the anatomical, physiological and behavioral changes that take place in response to injury-induced plasticity after damage to the dorsal column pathway in rats and monkeys. Complete section of the dorsal columns of the spinal cord at a high cervical level in monkeys and rats interrupts the ascending axon branches of low threshold mechanoreceptor afferents subserving the forelimb and the rest of the lower body. Such lesions render the corresponding part of the somatotopic representation of primary somatosensory cortex totally unresponsive to tactile stimuli. There are also behavioral consequences of the sensory loss, including an impaired use of the hand/forelimb in manipulating small objects. In monkeys, if some of the afferents from the hand remain intact after dorsal column lesions, these remaining afferents extensively reactivate portions of somatosensory cortex formerly representing the hand. This functional reorganization develops over a postoperative period of 1 month, during which hand use rapidly improves. These recoveries appear to be mediated, at least in part, by the sprouting of preserved afferents within the cuneate nucleus of the dorsal column-trigeminal complex. In rats, such functional collateral sprouting has been promoted by the post-lesion digestion of the perineuronal net in the cuneate nucleus. Thus, this and other therapeutic strategies have the potential of enhancing sensorimotor recoveries after spinal cord injuries in humans.     

Psychological techniques for controlling the adverse side effects of cancer chemotherapy: findings from a decade of research.

Cancer patients receiving chemotherapeutic treatments often experience unpleasant side effects that compromise the quality of their life and may be so severe that they lead to suboptimal drug dosages, missed treatments, or even discontinuation of treatment. In recent years it has been discovered that some of these side effects result from maladaptive learning. This article reviews over 10 years of research conducted at Vanderbilt University on the prevention and treatment of these psychological side effects. This research includes the assessment of the efficacy of a behavioral relaxation technique, the exploration of procedures that make this intervention clinically practical for widespread application, research aimed at predicting which patients will and will not benefit from the intervention, and the comparison of this intervention to alternative treatment approaches. The review of this research generates four major conclusions and points to several important areas for future inquiry.     

Effectiveness of relaxation training in reducing adverse reactions to cancer chemotherapy

Cancer patients who had developed negative conditioned responses to their chemotherapy either did (relaxation training) or did not (no relaxation training) receive progressive muscle relaxation training and guided relaxation imagery instructions immediately before and during their chemotherapy treatments. Physiological (blood pressure and pulse rate) measures of arousal, frequency of vomiting, and patient-reported and nurse-reported indices of negative affect and nausea were collected during pretraining, training, and posttraining chemotherapy sessions. Results indicated that during both the training and the posttraining sessions, patients in the relaxation training condition reported feeling less emotionally distressed and nauseated, and showed less physiological arousal following the chemotherapy infusion, than patients in the no relaxation training condition. The attending nurses' observations confirmed the patients' self-reports. No differences were found in frequency of vomiting between conditions. These data clearly suggest that the use of relaxation procedures may be an effective means of reducing several of the adverse side effects of cancer chemotherapy.     

Effectiveness of biofeedback for treating migraine and tension headaches: A review of the evidence

A review of the research reveals no evidence that finger temperature biofeedback training or temporal artery pulse biofeedback training is effective for treating migraine headaches. On the other hand, there is evidence that EMG biofeedback training is effective for treating tension headaches, but the EMG biofeedback training is not more effective than less complex and less expensive relaxation training. Reasons for the ineffectiveness of biofeedback training are discussed. The results of the controlled investigations are in sharp contrast to the prevailing beliefs and the results have a variety of implications.