Makoto Iwanaga

Heart rate variability with repetitive exposure to music.

Previous studies of physiological responses to music showed inconsistent results, which might be attributable to methodological differences. Heart rate variability has been used to assess activation of the sympathetic and the parasympathetic nervous systems. The present study aimed to examine heart rate variability with repetitive exposure to sedative or excitative music. The participants were 13 undergraduate or graduate students who were each exposed to three conditions sedative music (SM), excitative music (EM), and no music (NM) on different days. Each participant underwent four sessions of one condition in a day. Sedative music and no music each induced both high relaxation and low tension subjectively. However, excitative music decreased perceived tension and increased perceived relaxation as the number of sessions increased. The low-frequency (LF) component of heart rate variability (HRV) and the LF/HF (high-frequency) ratio increased during SM and EM sessions but decreased during NM sessions. The HF component of HRV during SM was higher than that during EM but the same as that during NM. These findings suggest that excitative music decreased the activation of the parasympathetic nervous system.

Test Anxiety and Working Memory System

The purpose was to examine the effect of test anxiety on deficits in the articulatory loop in the working memory system. We used a verbal memory task to occupy the articulatory loop and a spatial memory task to occupy the visuospatial scratch pad. 17 highly test-anxious and 19 low-anxiety subjects performed both tasks under an anxiety-inducing situation during which they were observed by a monitor camera. Percentage of correct responses and reaction times were measured as indices of task performance. Highly anxious subjects reported feeling worry and cognitive self-concern more than the low-anxiety group. Highly anxious subjects showed a longer mean reaction time on the verbal memory task than the low-anxiety group. On the spatial memory task there was no difference in quality of performance. This finding might suggest that anxiety such as worry and cognitive self-concern interferes with information processing in the articulatory loop of the working memory system.

Coping availability and stress reduction for optimistic and pessimistic individuals

It has been noted that optimists adopt active coping strategies and pessimists employ passive coping strategies. Although active coping strategies are known as adaptive, these strategies under an uncontrollable situation are considered as maladaptive according to the goodness of fit hypothesis. The present study aimed to examine the effect of coping strategies adopted by both optimists and pessimists under a controllable and an uncontrollable situation. Participants were 32 optimists and 32 pessimists selected by the Life Orientation Test. Controllability of aversive situations was operated by ratios of answerable anagram tasks. Main findings were as follows. Optimists tended to adopt active coping strategies and showed lower subjective stress than pessimists. Under a controllable situation, coping strategies adopted by optimists were correlated with subjective stress significantly, while pessimists showed no relationship between coping strategies and stress. These results indicated that high stress shown by pessimists was due to the low efficacy of adopted coping strategies.

The effect of UCS inflation and deflation procedures on ‘fear’ conditioning

Davey (1992: Classical conditioning and the acquisition of human fears and phobias: a review and synthesis of the literature. Advances in Behaviour Research and Therapy, 14, 29-66) hypothesized that subjective revaluation of an unconditioned stimulus (UCS) would determine the strength of the autonomic conditioned response (CR) in the fear conditioning paradigm. The purpose of the present study was to examine the effect of UCS aversiveness on the CR strength in the fear conditioning paradigm. The UCS aversiveness was controlled by the UCS intensity; that is, the UCS intensity was increased for the inflation group or decreased for the deflation group. Thirty subjects were randomly assigned to the inflation or the deflation group, and they participated under both experimental and control conditions. All subjects went through the pretest, the acquisition of classical conditioning, the UCS intensity operation, and the test sessions. The indices of the CR were skin conductance responses (SCRs) and a subjective aversion to the conditioned stimulus (CS). The main results were as follows. (1) The CR strength measured by SCR was increased by the UCS inflation and decreased by the UCS deflation. (2) The subjective aversiveness of the CS was not sensitive to both manipulations of UCS intensity. These results suggested that the autonomic CR strength might be influenced by the subjective revaluation of UCS, as Davey (1992) described. The result from the test of the subjective aversiveness of the CS, however, could not support Daveys model. The difference between expressions of the SCR and the subjective aversiveness of the CS might be caused by different learning systems.

EFFECTS OF EXCITATIVE AND SEDATIVE MUSIC ON SUBJECTIVE AND PHYSIOLOGICAL RELAXATION

Previous investigations using heart rate as a measure have not clarified the excitative-sedative effects of music. One of the sources of this failure was considered to be use of the index of heart rate. The present purpose was to examine the excitative-sedative effect of music on indices of the sympathetic and the parasympathetic nervous activities through spectral analysis of heart rate. The presented stimuli were three excitative musical pieces and three sedative ones. Subjective feelings about music were measured by an adjective checklist concerning musical activity. Heart-rate variabilities divided into two components of Low Frequency, mainly affected by the sympathetic nervous system and of High Frequency, mainly affected by the parasympathetic nervous system. Six types of heart-rate indices were employed: (1) mean increments from posttrial base, (2) coefficient of variances of heart rate, (3) mean powers of Low Frequency, (4) coefficient of component variances of Low Frequency, (5) mean powers of High Frequency, and (6) coefficient of component variances of High Frequency. From the factor analysis based on responses to an adjective checklist, there was a single major activity factor. Activity scores showed some were high during excitative pieces and others low during sedative ones. For heart rate, excitative-sedative effects of music were observed only in indices related to High Frequency. This result suggests that musical effect was observed in measures of the parasympathetic nervous system but not in the sympathetic nervous system.

Harmonic Relationship between Preferred Tempi and Heart Rate

Since people tend to prefer musical tempi ranging from 70 to 100 beats per minute, cyclic physiological response like heart rate is considered one of the factors affected by tempo preference. The present study aimed to examine the relationship between preferred tempi and heart rate. Subjects were instructed to find their favorite tempi while their heart rates were being measured. The presented tone stimulus was 440 Hz, 60 dB pressure of pure tone, and the presented tempo varied from 10 to 300 cycles per minute. The relationship between heart rate and preferred tempo was examined to calculate the density function of ratios of preferred tempi to heart rate. This density function indicated that preferred tempi were distributed mostly one, one and a half, and two times as fast as heart rate. This finding indicated preferred tempi had a simple harmonic relationship to heart rate.

DISTURBANCE EFFECT OF MUSIC ON PROCESSING OF VERBAL AND SPATIAL MEMORIES

The purpose of the present study was to examine the disturbance effect of music on performances of memory tasks. Subjects performed a verbal memory task and a spatial memory task in 4 sound conditions, including the presence of vocal music, instrumental music, a natural sound (murmurings of a stream), and no music. 47 undergraduate volunteers were randomly assigned to perform tasks under each condition. Perceived disturbance was highest under the vocal music condition regardless of the type of task. A disturbance in performance by music was observed only with the verbal memory task under the vocal and the instrumental music conditions. These findings were discussed from the perspectives of the working memory hypothesis and the changing state model.

Resting physiological arousal is associated with the experience of music-induced chills.

In the study of emotion and autonomic nervous system functioning, resting physiological arousal is usually considered a negative characteristic. The present study examined the relationship between resting physiological arousal and positive emotional experience linked to psychophysiological arousal. We assessed resting physiological arousal using markers as high skin conductance level and low respiratory sinus arrhythmia, measured just before participants listened to their favorite music. Participants reported the sensation of chills (goose bumps, shivers) by pressing a mouse button while listening. The results indicated that individuals with resting physiological arousal frequently experience music-induced chills, which evoked unambiguous pleasurable feelings and an increase in skin conductance response. The current results, and the previously demonstrated relationship between resting physiological arousal and negative emotionality linked to psychophysiological arousal (e.g., anxiety, panic), suggest that resting physiological arousal may reflect sensitivity to psychophysiological arousal with both intense positive and negative emotions.

Effects of Personal Responsibility and Latitude for Type A and B Individuals on Psychological and Physiological Stress Responses

Latitude has been considered a dominant factor in stress reduction. Jobs that involve high latitude, however, generally are accompanied by high responsibility, which might induce high levels of stress. Therefore, latitude in a job situation is necessary to examine the effects of responsibility and latitude together. In this study we examined the effects of personal responsibility and latitude for Type A and B individuals on psychological and physiological responses. Thirty-one Type A participants and 31 Type B participants were divided into high- and low-responsibility conditions. Personal responsibility was operated by disclosures about results of the task performed by groups of 3 participants. Participants received both latitude conditions (self-paced and externally paced task). High responsibility elicited psychological responses and increased heart rate; Type A individuals especially showed a remarkable increase of heart rate. On the other hand, latitude did not reduce strain. We concluded that personal responsibility might be one of the dominant factors of stress elicitation.

Synchronous changes of psychophysiological responses and tone pressure: effect of musical training

This study was designed to examine the relationship between psychophysiological responses and tone pressure during music. The main findings were as follows: (1) Mean increments of heart rate (HR) and respiration rate (RR) did not correlate with mean increments of tone pressure. (2) Musical individuals showed consistent changes between HR and tone pressure. (3) Non-musical person showed a high correlation between changes of HR and tone pressure in only a rhythmic and dynamic musical piece. These results showed that trained musicians respond differently from individuals having no musical training.