Soichiro Nomura

Psychological Distress in Workers at the Fukushima Nuclear Power Plants

Rita F. Redberg, MD Mitchell H. Katz, MD Author Affiliations: Division of Cardiology, University of California, San Francisco (Dr Redberg; redberg@medicine.ucsf.edu); and Department of Health Services, County of Los Angeles, Los Angeles, California (Dr Katz). Dr Redberg is the Editor and Dr Katz is the Deputy Editor of the Archives of Internal Medicine. Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest none were reported.

Stress and β-adrenergic receptor binding in the rat's brain

Abstract The effect of acute and chronic electric shocks on β-adrenergic receptor binding in the rats brain was investigated. β-adrenergic receptor subsensitivity in the corter was induced by chronic shocks, but not by acute shocks. This reduction appears to be due to a decreased number of receptors. It seems that stress, by increasing intrasynaptic norepinephrine levels resulting from an accelerated turnover rate, causes β-adrenergic receptor subsensitivity.

Telepsychiatry: assessment of televideo psychiatric interview reliability with present‐ and next‐generation internet infrastructures

Objective: We assessed the reliability of remote video psychiatric interviews conducted via the internet using narrow and broad bandwidths.

Autonomic arousal in cognitive conflict resolution

Although cognitive efforts were reported to elicit global autonomic arousal, which cognitive processes associate with autonomic arousal has not been clear. We investigated autonomic arousal using event-related skin conductance responses (SCRs) during the Stroop color-word task. After baseline SCR deflections were determined in each trial block, SCRs were compared between cognitive conflict conditions (incongruent vs. congruent stimuli), between tasks assigned (word reading vs. color naming), and between erroneous and correct responses. Baseline SCRs were significantly greater at the beginning of each trial block. SCRs were significantly greater with incongruent than congruent stimuli while SCRs differed little between word reading and color naming. SCRs were greater when responses were incorrect. The results suggested that autonomic arousal occurs during cognitive conflict resolution in addition to mental set adoption for a task and in error awareness.

Interhemispheric difference in emotional response without awareness

To investigate interhemispheric differences concerning unconscious human emotional responses processed, we measured human skin conductance responses (SCRs) to masked (unseen) emotional stimuli presented to left or right visual fields. Backward masking was used to preclude conscious processing of emotional stimuli. Masked negative or neutral emotional pictures from the International Affective Picture System (IAPS) were presented to 11 right-handed male volunteers. Mean SCR for negative emotional stimuli presented to the left visual field was significantly greater than mean SCRs for negative emotional stimuli to the right visual field and for neutral stimuli to the left or right visual fields. Thus, the right rather than the left hemisphere appears to respond to preattentive negative emotional stimuli.

Mental health issues of peacekeeping workers

The end of the Cold War has brought a dramatic change to the international political situation and the role of the United Nations peacekeeping operations (PKO) has drawn increased attention. While many reports on PKO have focused on political or sociologic considerations, the mental health of the peacekeepers themselves has received little attention and psychiatric problems that can have a negative impact on mission success have been largely ignored. Participation in PKO creates a number of stressors and serious psychiatric and/or physical disorders may result. Yet, there is little research on this topic, either domestically or globally, and the methodology for clinical intervention remains in an early stage of development. We have reviewed previous reports to determine how various stressors before, during and after deployment affect the participants. Research in associated fields (e.g. crisis workers and military personnel) are also reviewed and their application to peacekeeping psychiatry is discussed. It must be admitted that the significance of PKO is arguable and each PKO is unique in terms of the nature of its mission and the local situation. Yet, the relationship between the psychiatric status of the personnel and the characteristics of an individual mission has never been studied. At present, no clear consensus regarding a framework for psychiatric intervention exists. Studies that enhance the recognition and significance of peacekeeping psychiatry are likely to improve the efficacy of PKO.

The reversal effect of antidepressants on the escape deficit induced by inescapable shock in rats

This experiment investigated the effect of antidepressants on the escape deficit induced by inescapable shock. Following exposure te escapable shock, rats received a single injection of either tricyclic antidepressants (imipramine, desipramine), and atypical antidepressant (nomifensine), or saline. In a subsequent two-way shuttle test, treatments with these antidepressants reversed the escape deficit of the “inescapable-shock” groups without affecting performance of the “escapable-shock” groups. It is suggested that catecholamine re-uptake inhibition of the acute actions of antidepressants contributed to this reversal effect. The findings are discussed in relation to the neurochemical hypothesis of the escape deficit induced by inescapable shock and to an animal model of depression.

Effects of slow repetitive transcranial magnetic stimulation on heart rate variability according to power spectrum analysis

We examined whether repetitive transcranial magnetic stimulation (rTMS) at a low rate could influence autonomic function, specially heart rate variability (HRV) by power spectrum analysis. We studied 16 healthy male volunteers as a stimulation group and 16 others as a sham group. The stimulation group received magnetic stimulations from a circular coil over Cz at a frequency of 0.2 Hz and an intensity presenting 90% of the motor threshold. Experiments in both groups included four daily sessions; at each, a train of 70 stimuli was delivered over 350 s. HRV of low-frequency power (LF) in a standing position and high-frequency power (HF) in a supine position were measured before and after each session. After stimulation, HF and LF powers were significantly increased. After sham stimulation, the power of HF but not that of LF significantly increased. Neither actual nor sham stimulation produced a long-term effect detectable on day 5. The finding of transiently increased LF power following actual but not sham stimulation suggests that rTMS may activate the sympathetic nervous system.

Relationships between temperament dimensions in personality and unconscious emotional responses

BACKGROUND In addition to character dimensions, personality includes temperament dimensions, defined as individual differences in implicit associative learning responses to environmental stimuli processed by unconscious memories. We examined whether temperament dimensions were associated with patterns of unconscious emotional responses of an autonomic nature. METHODS From 70 healthy men, high and low novelty-seeking (NS) groups and high and low harm-avoidance (HA) groups were selected using scores on the Tridimensional Personality Questionnaire measuring temperament dimensions. Emotionally negative, neutral, and positive visual stimuli were presented subliminally using backward masking, and skin conductance responses (SCRs) were measured as an autonomic index of emotional responses. Skin conductance responses to the three emotional stimulus conditions were compared between groups. RESULTS Skin conductance responses in the high NS group were significantly greater than in the low NS group when positive or negative emotional stimuli were presented but not neutral stimuli. Skin conductance responses in the high HA group were significantly greater than in the low HA group for stimuli of all three valences. CONCLUSIONS Autonomic response patterns to unconscious emotional perception differed between NS and HA, suggesting that different dimensions of temperament may be associated with different patterns of unconscious emotional responses. Novelty seeking and HA may be associated with specificity and susceptibility of preattentive emotional perception, respectively.

Accelerated binocular rivalry with anxious personality.

When dissimilar figures are presented to the two eyes individually, perception alternates spontaneously between each monocular view. This phenomenon, designated binocular rivalry, has been used by many scientists as a tool for investigating visual awareness. Some recent studies have suggested involvement of serotonergic neural systems in this phenomenon. We explored the relationship between binocular rivalry and anxiety, a state thought to be associated with serotonergic neural activity. Perceptual alternation rate in dominance of binocular rivalry were compared between normal volunteers with high and low general anxiety as measured using the harm avoidance (HA) scale of the Tridimensional Personality Questionnaire. Perceptual alternation rate and rhythmicity in the high-HA group was significantly greater than that in the low-HA group. The perceptual alternation rate in binocular rivalry was accelerated in anxious subjects, suggesting that binocular rivalry and anxiety may share some common serotonergic neural substrates.