Physiological Effects of Visual Stimulation by a Japanese Low Wooden Table: A Crossover Field Experiment.

The purpose of this study was to evaluate the physiological effects of visual stimulation by a unique Japanese low wooden table on the prefrontal cortex and autonomic nervous activities. A within-participants experiment with 26 male university students was conducted in a Japanese-style room. The visual stimuli were a low wooden table (WT) made of Japanese cypress and a low cloth-covered table (control) for an exposure time of 90 s. Near-infrared spectroscopy was used to measure the prefrontal cortex activity in the left and right prefrontal cortices as an indicator of oxyhemoglobin (oxy-Hb) concentration. Autonomic nervous activity was measured as an indicator of sympathetic (low-frequency/high-frequency component ratio, LF/HF), and parasympathetic (high-frequency components, HF) nervous activities were assessed by heart rate variability. Furthermore, the modified semantic differential method and the Profile of Mood States 2nd edition were used to measure psychological responses. Physiologically, the oxy-Hb concentration in the left prefrontal cortex and ln (LF/HF) were significantly lower during visual exposure to the WT than to the control. Psychologically, more comfortable, relaxed, and natural impressions, as well as improved mood states, were reported during visual stimulation to the WT than to the control. This study demonstrated that viewing a WT led to physiological relaxation and had a positive psychological effect on the participants.

Hemodynamic alterations response to Chinese acupuncture therapy monitored by a custom near-infrared spectroscopy probe with an open hole.

Traditional acupuncture, a popular traditional Chinese medicine (TCM) technique, has demonstrated potential in relieving various ailments' symptoms. However, its black-box feedback loop model has limited proper evaluation and use by unskilled practitioners. This study aimed to analyze hemodynamic signals around acupoints during acupuncture to identify significant parameter changes. We designed hollow near-infrared spectroscopy (NIRS) probes for real-time measurements during acupuncture at acupoints, monitoring oxy-hemoglobin (HbO), deoxy-hemoglobin (Hb), and blood volume (HbT) changes. Acupuncture was performed on the "Xuehai" acupoint in 17 healthy subjects, with NIRS measuring hemodynamic alterations. Results showed significant and consistent increases in Hb and HbT around the acupoint, returning to baseline values after needle removal. One case of fainting revealed a significant Hb increase and HbO decrease. Acupuncture may induce tissue vasodilation and enhance oxygen consumption. This research provides a potential explanation for acupuncture's mechanism and emphasizes NIRS's potential in TCM.

The Mood-Improving Effect of Viewing Images of Nature and Its Neural Substrate.

It has been recently suggested that contact with nature improves mood via reducing the activity of the prefrontal cortex. However, the specific regions within the prefrontal cortex that underlie this effect remain unclear. In this study, we aimed to identify the specific regions involved in the mood-improving effect of viewing images of nature using a 52-channel functional near-infrared spectroscopy (fNIRS). Specifically, we focused on the orbitofrontal cortex (OFC) and dorsolateral prefrontal cortex (dlPFC), two regions associated with affective processing and control. In a randomized controlled crossover experiment, we assigned thirty young adults to view images of nature and built environments for three minutes each in a counterbalanced order. During image viewing, participants wore a fNIRS probe cap and had their oxyhemoglobin (oxy-Hb) measured. Immediately following each image viewing, participants indicated their mood in terms of comfortableness, relaxation, and vigor. Results showed that viewing images of nature significantly increased comfortableness and relaxation but not vigor compared to viewing images of built environments, with a large effect size. Meanwhile, the concentration of oxy-Hb in only the right OFC and none of the other regions significantly decreased while viewing the images of nature compared to built environments, with a medium effect size. We speculate that viewing images of nature improves mood by reducing the activity of or calming the OFC. Since the OFC is hyperactive in patients with depression and anxiety at rest, contact with nature might have therapeutic effects for them.

Online Assessment of Hemodynamics in the Suctioned Volume of Biological Tissue by an Embedded Near-Infrared Spectroscopy Sensor.

Cupping therapy is a promising method to cure or reduce symptoms of some diseases including muscle pain/tenderness/fatigue. Although the applications of cupping therapy have a thousand-year history in traditional Chinese medicine and have been spread to other countries in recent years, cupping therapy is something like a black box, and the unskilled user can hardly control it due to the absence of physiological observations. In this study, we developed a NIRS instrument with three probes to detect the blood-oxygen level of the skin tissue where the cupping therapy is being carried out. Each probe includes two detection channels. One of the probes is embedded in the cup to monitor the hemodynamic parameters in the cupping site, and the other two probes are placed outside, surrounding the cupping site. Using this monitor, we can observe the changes in oxy-hemoglobin ([HbO2]), deoxy-hemoglobin ([Hb]), and total hemoglobin ([tHb]), as well as the heart rate, calculated from the change curves of [HbO2] during cupping therapy in real time. Therefore, the doctor or other users can see the impact of cupping on the tissues to which it is applied which should facilitate the development and understanding of the application of cupping.

Brief Relaxation Practice Induces Significantly More Prefrontal Cortex Activation during Arithmetic Tasks Comparing to Viewing Greenery Images as Revealed by Functional Near-Infrared Spectroscopy (fNIRS).

BACKGROUND: There is little understanding on how brief relaxation practice and viewing greenery images would affect brain responses during cognitive tasks. In the present study, we examined the variation in brain activation of the prefrontal cortex during arithmetic tasks before and after viewing greenery images, brief relaxation practice, and control task using functional near-infrared spectroscopy (fNIRS). METHOD: This randomized controlled study examined the activation patterns of the prefrontal cortex (PFC) in three groups of research participants who were exposed to viewing greenery images (n = 10), brief relaxation practice (n = 10), and control task (n = 11). The activation pattern of the PFC was measured pre- and post-intervention using a portable fNIRS device and reported as mean total oxygenated hemoglobin (HbO µm). Primary outcome of the study is the difference in HbO µm between post- and pre-intervention readings during a cognitive task that required the research participants to perform arithmetic calculation. RESULTS: In terms of intervention-related differences, there was significant difference in average HbO µm when performing arithmetic tasks before and after brief relaxation practice (p < 0.05). There were significant increases in average HbO µm in the right frontopolar cortex (p = 0.029), the left frontopolar cortex (p = 0.01), and the left orbitofrontal cortex (p = 0.033) during arithmetic tasks after brief relaxation practice. In contrast, there were no significant differences in average HbO µm when performing arithmetic tasks before and after viewing greenery images (p > 0.05) and the control task (p > 0.05). CONCLUSION: Our preliminary findings show that brief relaxation practice but not viewing greenery images led to significant frontal lobe activation during arithmetic tasks. The present study demonstrated, for the first time, that there was an increase in activation in neuroanatomical areas including the combined effort of allocation of attentional resources, exploration, and memory performance after the brief relaxation practice. Our findings suggest the possibility that the right frontopolar cortex, the left frontopolar cortex, and the left orbitofrontal cortex may be specifically associated with the benefits of brief relaxation on the brain.

Prosodic influence in face emotion perception: evidence from functional near-infrared spectroscopy.

Emotion is communicated via the integration of concurrently presented information from multiple information channels, such as voice, face, gesture and touch. This study investigated the neural and perceptual correlates of emotion perception as influenced by facial and vocal information by measuring changes in oxygenated hemoglobin (HbO) using functional near-infrared spectroscopy (fNIRS) and acquiring psychometrics. HbO activity was recorded from 103 channels while participants ([Formula: see text], [Formula: see text]) were presented with vocalizations produced in either a happy, angry or neutral prosody. Voices were presented alone or paired with an emotional face and compared with a face-only condition. Behavioral results indicated that when voices were paired with faces, a bias in the direction of the emotion of the voice was present. Subjects' responses also showed greater variance and longer reaction times when responding to the bimodal conditions when compared to the face-only condition. While both the happy and angry prosody conditions exhibited right lateralized increases in HbO compared to the neutral condition, these activations were segregated into posterior-anterior subdivisions by emotion. Specific emotional prosodies may therefore differentially influence emotion perception, with happy voices exhibiting posterior activity in receptive emotion areas and angry voices displaying activity in anterior expressive emotion areas.

Increased oxygenation in the non-contracting forearm muscle during contralateral skilful hand movement.

NEW FINDINGS: What is the central question of this study? When performing skilful hand movement, motor command descends especially towards distal arm muscles. Does central command evoke a vascular response selectively in the distal arm muscles during skilful hand movement? What is the main finding and its importance? We found, using near-infrared spectroscopy, that unilateral skilful hand movement evoked a greater increase in oxygenation of the contralateral forearm muscle compared with that of the upper arm muscles. Mental imagery of the hand movement also increased oxygenation of the forearm muscle. These findings suggest that central command might contribute to the vasodilator response in the non-contracting forearm muscle during contralateral skilful hand movement. ABSTRACT: The human hand is a special organ to perform skilful movement in daily life. To meet metabolic demands of the working distal arm muscles, central command might evoke neurogenic vasodilatation in the muscles. Based on our previous demonstration that a centrally generated vasodilator signal is transmitted bilaterally to skeletal muscles during exercise, centrally induced vasodilatation might occur in the non-contracting distal arm muscles during contralateral skilful hand movement. To examine this possibility, we used near-infrared spectroscopy to measure the relative concentrations of oxygenated haemoglobin (Oxy-Hb; as an index of regional blood flow) in the non-contracting arm muscles during skilful hand movement (two-ball rotation) in 22 subjects. Two-ball rotation increased Oxy-Hb of both forearm and upper arm muscles, with little changes in perfusion pressure and cardiac output. The increased Oxy-Hb was greater in the forearm muscle than in the upper arm muscles. The increased Oxy-Hb of the forearm muscle during two-ball rotation was greater than that during one-armed cranking performed with no load. Mental imagery of two-ball rotation increased Oxy-Hb of the forearm and biceps muscles. The increases in Oxy-Hb of both forearm and upper arm muscles during two-ball rotation were reduced by decreasing the level of task difficulty. Intravenous administration of atropine attenuated the increases in Oxy-Hb of the arm muscles during two-ball rotation. It is likely that contralateral skilful hand movement evokes a selective increase in Oxy-Hb of the non-contracting forearm muscle via a sympathetic cholinergic mechanism and that the increase in oxygenation might be mediated, at least in part, by central command.

Learning Hemodynamic Effect of Transcranial Infrared Laser Stimulation Using Longitudinal Data Analysis.

Transcranial infrared laser stimulation (TILS) is a promising noninvasive intervention for neurological diseases. Though some experimental work has been done to understand the mechanism of TILS, the reported statistical analysis of data is quite simple and could not provide a comprehensive picture on the effect of TILS. This study learns the effect of TILS on hemodynamics of the human brain from experimental data using longitudinal data analysis methods. Specifically, repeated measures analysis of variance (ANOVA) is first applied to confirm the significance of the TILS effect and its characteristics. Based on that, two parametric mixed-effect models and non-parametric functional mixed-effect model are proposed to model the population-level performance and individual variation of this effect. Interpretations on the fitted models are provided, and comparison of the three proposed models in terms of fitting and prediction performance is made to select the best model. According to the selected model, TILS increases the concentration of oxygenated hemoglobin in the brain and this effect sustains even after the treatment stops. Also, there is considerable variation among individual responses to TILS.

Physiological and Psychological Effects of Forest and Urban Sounds Using High-Resolution Sound Sources.

Exposure to natural sounds is known to induce feelings of relaxation; however, only few studies have provided scientific evidence on its physiological effects. This study examined prefrontal cortex and autonomic nervous activities in response to forest sound. A total of 29 female university students (mean age 22.3 ± 2.1 years) were exposed to high-resolution sounds of a forest or city for 60 s, using headphones. Oxyhemoglobin (oxy-Hb) concentrations in the prefrontal cortex were determined by near-infrared spectroscopy. Heart rate, the high-frequency component of heart rate variability (which reflects parasympathetic nervous activity), and the ratio of low-frequency to high-frequency (LF/HF) components (which reflects sympathetic nervous activity) were measured. Subjective evaluation was performed using the modified semantic differential method and profiles of mood states. Exposure to the forest sound resulted in the following significant differences compared with exposure to city sound: decreased oxy-Hb concentrations in the right prefrontal cortex; decreased ln(LF/HF); decreased heart rate; improved feelings described as "comfortable,'' "relaxed," and "natural"; and improved mood states. The findings of this study demonstrated that forest-derived auditory stimulation induced physiological and psychological relaxation effects.

Physiological Effects of Viewing Bonsai in Elderly Patients Undergoing Rehabilitation.

The benefits of various nature-derived stimuli that can be used for stress relief and relaxation has recently gained immense attention; however, there are very few studies about their influence on elderly patients. The present study aims to present the effects of viewing bonsai on autonomic nervous activity, prefrontal cortex activity, and subjective assessment findings of psychological relaxation in elderly patients undergoing rehabilitation. Fourteen participants aged 64⁻91 years (mean age ± standard deviation, 78.6 ± 9.6 years) participated in this study. Miniature potted 10-year-old Japanese cypress bonsai trees were used as visual stimuli. Participants viewed the bonsai for 1 min, and the control comprised of no experimental stimulus. Physiological effects on autonomic nervous activity were assessed by measuring the heart rate variability (HRV) and pulse rate. The effects on prefrontal cortex activity were determined using near-infrared spectroscopy, which involved assessment of oxyhemoglobin concentrations in the left and right prefrontal cortices. Subjective evaluations were achieved by the modified semantic differential method. Viewing bonsai resulted in a significant increase in parasympathetic nervous activity, a significant decrease in sympathetic nervous activity, and a significant increase in the perceptions of feeling "comfortable" and "relaxed." In conclusion, our findings indicated that viewing bonsai induces physiological and psychological relaxation.

Beetroot Increases Muscle Performance and Oxygenation During Sustained Isometric Exercise, but Does Not Alter Muscle Oxidative Efficiency and Microvascular Reactivity at Rest.

OBJECTIVE: To examine the effects of beetroot juice (BRJ) on (i) in vivo skeletal muscle O2 consumption (mVO2) and microvascular reactivity at rest and (ii) muscle performance, muscle oxygenation, and mVO2 during sustained isometric handgrip exercise (IHG). METHODS: Sixteen young males consumed, randomly, a nitrate-rich (8.1 mmol BRJnitrate) or nitrate-depleted (BRJplacebo) BRJ. After 2.5 hours, they performed an occlusion-reperfusion maneuver at rest, a 3-minute sustained IHG, and a sustained IHG to exhaustion with arterial occlusion. Changes in muscle oxygenated hemoglobin (O2Hb), deoxygenated hemoglobin (HHb), microvascular red blood cell content (tHb), and mVO2 were measured using near-infrared spectroscopy. Force output was recorded. RESULTS: During occlusion, the O2Hb decline did not differ between BRJnitrate and BRJplacebo (magnitude: -30.3 ± 1.6 vs. -31.1 ± 1.5 ΔµΜ; slope: -0.107 ± 0.007 vs. -0.111 ± 0.007 µΜ second-1). During reperfusion, all microvascular reactivity indices were not altered after BRJnitrate (e.g., O2Hbslope: 1.584 ± 0.093 vs. 1.556 ± 0.072 µΜ second-1). During the second and third minute of IHG, O2Hb and tHb were higher in BRJnitrate versus BRJplacebo (p < 0.05), and force output was higher during the third minute (10.8 ± 0.7 vs. 9.5 ± 1.2 kg; p < 0.05); HHb did not differ between trials. In IHG with arterial occlusion, BRJnitrate prolonged the time to fatigue (94.1 ± 5.8 vs. 80.1 ± 3.3 seconds; p < 0.01), with no effects on O2Hb decline (O2Hbslope: -0.226 ± 0.015 vs. -0.230 ± 0.026 µΜ s-1) and mVO2 (14.1 ± 1.0 vs. 14.3 ± 1.6 µmol l-1 minute-1). CONCLUSION: Acute BRJ ingestion in moderately trained individuals (i) did not alter in vivo skeletal muscle microvascular reactivity (index of microvascular function at rest) and basal oxidative efficiency, (ii) increased muscle oxygenation during IHG (possibly via enhanced O2 delivery), and (iii) provided ergogenic benefits during sustained IHG with no effects on muscle oxidative efficiency. The ergogenic effects of BRJ appeared independent of its tissue perfusion benefits.

Physiological Effects of Touching Coated Wood.

This study examined the physiological effects of touching wood with various coating with the palm of the hand on brain activity and autonomic nervous activity. Participants were 18 female university students (mean age, 21.7 ± 1.6 years). As an indicator of brain activity, oxyhemoglobin concentrations were measured in the left and right prefrontal cortices using near-infrared time-resolved spectroscopy. Heart rate variability (HRV) and heart rate were used as indicators of autonomic nervous activity. The high-frequency (HF) component of HRV, which reflects parasympathetic nervous activity, and the low-frequency (LF)/HF ratio, which reflects sympathetic nervous activity, were measured. Plates of uncoated, oil-finished, vitreous-finished, urethane-finished, and mirror-finished white oak wood were used as tactile stimuli. After sitting at rest with their eyes closed for 60 s, participants touched the stimuli with their palm for 90 s each. The results indicated that tactile stimulation with uncoated wood calmed prefrontal cortex activity (vs. urethane finish and mirror finish), increased parasympathetic nervous activity (vs. vitreous finish, urethane finish, and mirror finish), and decreased heart rate (vs. mirror finish), demonstrating a physiological relaxation effect. Further, tactile stimulation with oil- and vitreous-finished wood calmed left prefrontal cortex activity and decreased heart rate relative to mirror-finished wood.

Physiological Effects of Touching Wood.

This study aimed to clarify the physiological effects of touching wood with the palm, in comparison with touching other materials on brain activity and autonomic nervous activity. Eighteen female university students (mean age, 21.7 ± 1.6 years) participated in the study. As an indicator of brain activity, oxyhemoglobin (oxy-Hb) concentrations were measured in the left/right prefrontal cortex using near-infrared time-resolved spectroscopy. Heart rate variability (HRV) was used as an indicator of autonomic nervous activity. The high-frequency (HF) component of HRV, which reflected parasympathetic nervous activity, and the low-frequency (LF)/HF ratio, which reflected sympathetic nervous activity, were measured. Plates of uncoated white oak, marble, tile, and stainless steel were used as tactile stimuli. After sitting at rest with their eyes closed, participants touched the materials for 90 s. As a result, tactile stimulation with white oak significantly (1) decreased the oxy-Hb concentration in the left/right prefrontal cortex relative to marble, tile, and stainless steel and (2) increased ln(HF)-reflected parasympathetic nervous activity relative to marble and stainless steel. In conclusion, our study revealed that touching wood with the palm calms prefrontal cortex activity and induces parasympathetic nervous activity more than other materials, thereby inducing physiological relaxation.

Effect of Ocular Movements during Eye Movement Desensitization and Reprocessing (EMDR) Therapy: A Near-Infrared Spectroscopy Study.

INTRODUCTION: Eye Movement Desensitization and Reprocessing (EMDR) is a psychotherapeutic treatment resolving emotional distress caused by traumatic events. With EMDR, information processing is facilitated by eye movements (EM) during the recall of a traumatic memory (RECALL). The aim of this study is to investigate the effects of ocular movements of EMDR on the hemodynamics of the prefrontal cortex (PFC). MATERIAL AND METHODS: Two groups were recruited: a trial group (wEM) received a complete EMDR treatment, whereas a control group (woEM) received a therapy without EM. PFC hemodynamics was monitored by near-infrared spectroscopy during RECALL and during focusing on the worst image of the trauma (pre-RECALL). The parameters of oxy- (oxy-Hb), and deoxy-hemoglobin (deoxy-Hb) were acquired and analyzed in time domain, by calculating the slope within pre-RECALL and RECALL periods, and in the frequency domain, by calculating the mean power of oxy-Hb and deoxy-Hb in the very-low frequency (VLF, 20-40 mHz) and low frequency (LF, 40-140 mHz) bandwidths. We compared pre-RECALL with RECALL periods within subjects, and pre-RECALL and RECALL parameters of wEM with the corresponding of woEM. RESULTS: An effect of group on mean slope of oxy-Hb and deoxy-Hb in pre-RECALL and oxy-Hb in RECALL periods was observed. wEM showed a lower percentage of positive angular coefficients during pre-RECALL with respect to RECALL, on the opposite of woEM. In the frequency domain, wEM had significant difference in oxy-Hb and deoxy-Hb LF of left hemisphere, whereas woEM showed no difference. DISCUSSION AND CONCLUSION: We observed the effect of EM on PFC oxygenation during EMDR, since wEM subjects showed a mean increase of oxy-Hb during RECALL and a decrease during pre-RECALL, as opposed to woEM. Frequency analysis evidenced a reduction of activity of sympathetic nervous system in wEM group during pre-RECALL. Our outcomes revealed a different hemodynamics induced by eye movements in wEM with respect to woEM group.

Benefits of Craniosacral Therapy in Patients with Chronic Low Back Pain: A Randomized Controlled Trial.

OBJECTIVES: To evaluate the effects of craniosacral therapy on disability, pain intensity, quality of life, and mobility in patients with low back pain. DESIGN: A single-blinded randomized controlled trial. PATIENTS: Sixty-four patients with chronic nonspecific low back pain (mean age ± SD, 50 ± 12 years; 66% female) who were referred for physical therapy at a clinical unit of the Health Science School of the University of Almeria (Spain). INTERVENTIONS: Participants were randomly assigned to an experimental group (10 sessions of craniosacral therapy) or a control group (10 sessions of classic massage). OUTCOME MEASURES: Disability (Roland Morris Disability Questionnaire [RMQ, primary outcome] and Oswestry Disability Index), pain intensity (10-point numeric pain rating scale), kinesiophobia (Tampa Scale of Kinesiophobia), isometric endurance of trunk flexor muscles (McQuade test), lumbar mobility in flexion, hemoglobin oxygen saturation, systolic blood pressure, diastolic blood pressure, hemodynamic measures (cardiac index), and biochemical estimation of interstitial fluid. These outcomes were registered at baseline, after treatment, and 1-month follow-up. RESULTS: No statistically significant differences were seen between groups for the main outcome of the study, the RMQ (p = 0.060). However, patients receiving craniosacral therapy experienced greater improvement in pain intensity (p ≤ 0.008), hemoglobin oxygen saturation (p ≤ 0.028), and systolic blood pressure (p ≤ 0.029) at immediate- and medium-term and serum potassium (p = 0.023) level and magnesium (p = 0.012) at short-term than those receiving classic massage. CONCLUSIONS: Ten sessions of craniosacral therapy resulted in a statistically greater improvement in pain intensity, hemoglobin oxygen saturation, systolic blood pressure, serum potassium, and magnesium level than did 10 sessions of classic massage in patients with low back pain.

2,3-Diphosphoglycerate Concentrations in Autologous Salvaged Versus Stored Red Blood Cells and in Surgical Patients After Transfusion.

BACKGROUND: Stored red blood cells (RBCs) are deficient in 2,3-diphosphoglycerate (2,3-DPG), but it is unclear how autologous salvaged blood (ASB) compares with stored blood and how rapidly 2,3-DPG levels return to normal after transfusion. Therefore, we compared levels of 2,3-DPG in stored versus ASB RBCs and in patients' blood after transfusion. METHODS: Twenty-four patients undergoing multilevel spine fusion surgery were enrolled. We measured 2,3-DPG and the oxyhemoglobin dissociation curve (P50) in samples taken from the ASB and stored blood bags before transfusion and in blood samples drawn from patients before and after transfusion. RESULTS: The mean storage duration for stored RBCs was 24 ± 8 days. Compared with fresh RBCs, stored RBCs had decreased 2,3-DPG levels (by approximately 90%; P < 0.0001) and a decreased P50 (by approximately 30%; P < 0.0001). However, ASB RBCs did not exhibit these changes. The mean 2,3-DPG concentration decreased by approximately 20% (P < 0.05) in postoperative blood sampled from patients who received 1 to 3 stored RBC units and by approximately 30% (P < 0.01) in those who received ≥4 stored RBC units. 2,3-DPG was unchanged in patients who received no stored blood or ASB alone. After surgery, 2,3-DPG levels recovered gradually over 3 postoperative days in patients who received stored RBCs. CONCLUSIONS: Stored RBCs, but not ASB RBCs, have decreased levels of 2,3-DPG and a left-shift in the oxyhemoglobin dissociation curve. Postoperatively, 2,3-DPG levels remain below preoperative baseline levels for up to 3 postoperative days in patients who receive stored RBCs but are unchanged in those who receive only ASB RBCs.

Physiological effect of olfactory stimulation by Hinoki cypress (Chamaecyparis obtusa) leaf oil.

BACKGROUND: In recent years, increasing attention has been paid to the physiological effects of nature-derived stimulation. The physiological relaxation effects caused by forest-derived olfactory stimuli have been demonstrated. However, there are no studies on the physiological effects of olfactory stimuli by Hinoki cypress (Chamaecyparis obtusa) leaves. We investigated the effects of olfactory stimulation by Hinoki cypress leaf oil on the left/right prefrontal cortex activity, assessed using near-infrared time-resolved spectroscopy (TRS), and on the autonomic nervous activity, assessed by measuring heart rate variability (HRV). METHOD: Thirteen female university students (mean age, 21.5 ± 1.0 years) participated in the study. Physiological measurements were performed in an artificial climate maintained at 25 °C, 50% relative humidity, and 230-lx illumination. Hinoki cypress leaf oil was used as an olfactory stimulation with air as the control. The odor was administered for 90 s, while the subjects sat with their eyes closed. Oxyhemoglobin (oxy-Hb) concentrations were measured in the prefrontal cortex using TRS. The high-frequency (HF) component of HRV, which is an estimate of parasympathetic nervous activity, and the low-frequency (LF)/(LF + HF) ratio, which is an estimate of sympathetic nervous activity, were measured by electrocardiography. A modified semantic differential method was used to perform subjective evaluations. RESULTS: Olfactory stimulation by Hinoki cypress leaf oil induced a significant reduction in oxy-Hb concentration in the right prefrontal cortex and increased parasympathetic nervous activity. The subjects reported feeling more comfortable. CONCLUSION: These findings indicate that olfactory stimulation by Hinoki cypress leaf oil induces physiological relaxation.

Effects of krill oil containing n-3 polyunsaturated fatty acids in phospholipid form on human brain function: a randomized controlled trial in healthy elderly volunteers.

BACKGROUND: Krill oil, rich in n-3 (omega-3) polyunsaturated fatty acids (PUFAs) incorporated in phosphatidylcholine, has been reported to have many effects on physiological function. However, there are few studies using psychophysiological methods published that describe the effects of krill oil on brain function. We investigated the influence of ingestion of krill oil on cognitive function in elderly subjects by using near-infrared spectroscopy and electroencephalography. METHODS: A randomized, double-blind, parallel-group comparative study design was adopted. Forty-five healthy elderly males aged 61-72 years were assigned to receive 12 weeks of treatment with: medium-chain triglycerides as placebo; krill oil, which is rich in n-3 PUFAs incorporated in phosphatidylcholine; or sardine oil, which is abundant in n-3 PUFAs incorporated in triglycerides. Changes in oxyhemoglobin concentrations in the cerebral cortex during memory and calculation tasks were measured. The P300 component of event-related potentials was also measured during a working memory task. RESULTS: During the working memory task, changes in oxyhemoglobin concentrations in the krill oil and sardine oil groups were significantly greater than those in the medium-chain triglyceride group at week 12. The differential value for P300 latency in the krill oil group was significantly lower than that in the medium-chain triglyceride group at week 12. With regard to the calculation task, changes in oxyhemoglobin concentrations in the krill oil group were significantly greater than those in the medium-chain triglyceride group at week 12. CONCLUSION: This study provides evidence that n-3 PUFAs activate cognitive function in the elderly. This is especially the case with krill oil, in which the majority of n-3 PUFAs are incorporated into phosphatidylcholine, causing it to be more effective than sardine oil, in which n-3 PUFAs are present as triglycerides.

Effects of essence of chicken on cognitive brain function: a near-infrared spectroscopy study.

The aim of this study was to investigate the effects of the essence of chicken on brain function by near-infrared spectroscopy. Twelve healthy elderly subjects took the essence of chicken or a placebo for 7 d in a double-blind cross-over design study. Changes in oxy-hemoglobin concentrations in the bilateral prefrontal areas of the brain were measured while the subjects performed the simple reaction task, the Groton Maze Learning Test, and the working memory task. In the latter case, there were significant interactions in the changes in oxy-hemoglobin concentrations between treatment and period of intake according to two-way repeated ANOVA. The changes in oxy-hemoglobin concentrations significantly increased in several regions of the prefrontal areas of the brain in those taking essence of chicken for 7 d. These results suggest that essence of chicken is useful as a nutritional supplement to enhance or maintain brain function in the elderly.

Changes in hemodynamics and tissue oxygenation saturation in the brain and skeletal muscle induced by speech therapy - a near-infrared spectroscopy study.

Arts speech therapy (AST) is a therapeutic method within complementary medicine and has been practiced for decades for various medical conditions. It comprises listening and the recitation of different forms of speech exercises under the guidance of a licensed speech therapist. The aim of our study was to noninvasively investigate whether different types of recitation influence hemodynamics and oxygenation in the brain and skeletal leg muscle using near-infrared spectroscopy (NIRS). Seventeen healthy volunteers (eight men and nine women, mean age ± standard deviation 35.6 ± 12.7 years) were enrolled in the study. Each subject was measured three times on different days with the different types of recitation: hexameter, alliteration, and prose verse. Before, during, and after recitation, relative concentration changes of oxyhemoglobin (Δ[O2Hb]), deoxyhemoglobin (Δ[HHb]), total hemoglobin (Δ[tHb]), and tissue oxygenation saturation (StO2) were measured in the brain and skeletal leg muscle using a NIRS device. The study was performed with a randomized crossover design. Significant concentration changes were found during recitation of all verses, with mainly a decrease in Δ[O2Hb] and ΔStO2 in the brain, and an increase in Δ[O2Hb] and Δ[tHb] in the leg muscle during recitation. After the recitations, significant changes were mainly increases of Δ[HHb] and Δ[tHb] in the calf muscle. The Mayer wave spectral power (MWP) was also significantly affected, i.e., mainly the MWP of the Δ[O2Hb] and Δ[tHb] increased in the brain during recitation of hexameter and prose verse. The changes in MWP were also significantly different between hexameter and alliteration, and hexameter and prose. Possible physiological explanations for these changes are discussed. A probable reason is a different effect of recitations on the sympathetic nervous system. In conclusion, these changes show that AST has relevant effects on the hemodynamics and oxygenation of the brain and muscle.