ABSTRACT
BACKGROUND: Recent studies reported that vascular cognitive impairment in the elderly caused by arteriosclerosis plays an important role in cognitive disorders in both vascular dementia and Alzheimer's disease. In addition, systemic metabolic disorders such as oxygen metabolism dysfunction could be risk of dementia. Based on these findings, we have developed a deep neural network-based screening test (DNN-based test) of cognitive function using basic blood test data, which allowed prediction of cognitive function expressed by Mini Mental State Examination (MMSE) scores. AIM: Here, we investigated whether the DNN-based test could be applicable to assessment of the effects of exercise-diet on cognitive function. METHODS: We studied the following two groups: (1) seven subjects of the local fitness gym (68.6 ± 3.2 years old). We evaluated cognitive function by the DNN-based test using blood data before and after the intervention (for 3 months). These results were compared with the measured MMSE score. (2) we studied a total of 230 subjects (67.9 ± 7.4 years old) who were members of the Tsuminory health class (Apple classroom). We assessed cognitive function by the DNN-based test before and after the intervention (for 2 months). We compared the predicted MMSE scores by the DNN-based test before and after the 2-month intervention. RESULTS: In the first group, the MMSE score predicted by the DNN-based test increased from 27.1 ± 0.8 to 27.6 ± 0.7 after the intervention period (p = 0.024). The measured MMSE score also increased after exercise, but not significant (P = 0.28). In the second group, the exercise-diet therapy increased the predicted MMSE scores in 189 cases (p < 0.001). In contrast, the therapy significantly reduced the mean MMSE score (p < 0.001). DISCUSSION: The MMSE score predicted by the DNN-based test were increased by exercise-diet therapy in most subjects. The DNN-based test may be useful to monitor the effect of exercise-diet therapy on cognitive function aged people.
Subject(s)
Cognitive Dysfunction , Deep Learning , Dementia , Aged , Humans , Middle Aged , Dementia/diagnosis , Cognition , Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/complications , Exercise , Diet , Hematologic Tests/adverse effects , Neuropsychological TestsABSTRACT
Vascular cognitive impairment (VCI) plays an important role in dementia in elderly people, and refers to the contribution of vascular pathology to the entire spectrum of cognitive disorders, ranging from mild cognitive impairment to severe dementia, as well as the pathological spectrum, from 'pure' Alzheimer disease through degrees of vascular comorbidity to 'pure' vascular dementia. In the present study, we investigated the relationship between cognitive dysfunction and systemic metabolic disorders, by employing deep learning (DL). We studied 202 patients (73.4 ± 13.0 years), 94.6% of whom were undergoing treatment for lifestyle diseases, and 68.8% of whom had a history of cerebrovascular disorder. We evaluated cognitive dysfunction by performing a Mini Mental State Examination (MMSE). We performed general blood examination, including Complete Blood Count and Basic Metabolic Panel, and measured cerebral blood oxygenation in the prefrontal cortex (PFC) using time-resolved near infrared spectroscopy (TNIRS). We then used deep neural networks to assess the MMSE scores of the subjects based on the TNIRS parameters and the blood examination data, independently. Next, we compared predicted MMSE scores based on the TNIRS and the blood examination. There was a significant positive correlation between the TNIRS parameters and the blood examination data (r = 0.6, p < 0.01). These observations suggest that cognitive dysfunction in patients with VCI may be caused by combinations of systemic metabolic disorders such as energy and oxygen metabolisms and cerebral circulatory disturbance due to arteriosclerosis resulting from lifestyle-related diseases.
Subject(s)
Cognitive Dysfunction , Dementia , Metabolic Diseases , Aged , Aged, 80 and over , Cognitive Dysfunction/complications , Dementia/complications , Dementia/physiopathology , Female , Humans , Male , Metabolic Diseases/complications , Middle AgedABSTRACT
The incidence of stress-induced psychological and somatic diseases has been increasing rapidly, and it is important to clarify the neurophysiological mechanisms of stress response in order to establish effective stress management methods. We previously reported that the prefrontal cortex (PFC) plays an important role in stress response. In the present study, we employed near-infrared spectroscopy (NIRS) and electroencephalography (EEG) to investigate the characteristics of PFC activity during mental arithmetic tasks. A two-channel NIRS device was used to measure hemoglobin (Hb) concentration changes in the bilateral PFC during a mental arithmetic task (2 min) in normal adults. Simultaneously, EEG was used to also measure bilateral PFC activity during the same task. We evaluated concentration changes of oxy-Hb induced by the task while analyzing α wave changes using power spectrum analysis. It was observed that oxy-Hb in the bilateral PFC increased significantly during the task (p < 0.05), while α wave power in the PFC decreased significantly (p < 0.01). The present results indicate that mental stress tasks caused the activation of the bilateral PFC. Simultaneous measurements of NIRS and EEG are useful for evaluating the neurophysiological mechanism of stress responses in the brain.
Subject(s)
Electroencephalography , Electromagnetic Phenomena , Oxygen , Spectroscopy, Near-Infrared , Stress, Psychological , Adult , Hemoglobins/analysis , Humans , Oxygen/blood , Oxyhemoglobins/analysis , Prefrontal Cortex/physiopathology , Stress, Psychological/physiopathologyABSTRACT
The prefrontal cortex (PFC) is sensitive to the stress exposure and involved in stress coping. And the effects of gum chewing on the stress have been studied using NIRS. However, when measuring NIRS on PFC during gum chewing, blood flows in shallow tissues (scalp, skin, muscle) might be affected. A NIRS used in the present study first, which has a short distance (1 cm) and the usual (3 cm) source-detector (S-D) regression, can allow eliminating shallow tissues effect of gum chewing. The aim of this study was to investigate the hypothesis that gum chewing activates the right prefrontal cortex (PFC) in stress coping against negative sounds (NS) from the International Affective Digitized Sounds-2 (IADS) as a mental stress task. NS showed activation in the right PFC. There was a significant difference between NS, and NS with Gum, where NS with Gum showed an increased PFC activity, increased alpha wave appearance rate, a higher value in heart rate level, and a higher VAS score indicating 'pleasant'. Gum chewing activated right PFC activity while exposed to negative sounds from IADS as a mental stress task.
Subject(s)
Chewing Gum , Mastication , Sound , Stress, Psychological , Adaptation, Psychological , Adult , Female , Humans , Male , Prefrontal Cortex/physiology , Prefrontal Cortex/radiation effects , Sound/adverse effects , Stress, Psychological/therapy , Young AdultABSTRACT
We present an IoT-based monitoring system for healthcare that allows for long-term measurements of blood pressure (BP), heart rate (HR), and body weight (BW), as well as near-infrared spectroscopy (NIRS) for measurement of prefrontal cortex (PFC) activity. To verify the applicability of the system, it was set up in a local fitness gym for a preliminary study. A total of 39 subjects, selected from members of the gym, participated in the study. We analyzed the BP, HR, and BW data, collected from the subjects over one half-year. In addition, to assess the degree of mental stress of the subjects, we analysed left-right asymmetry of the PFC activity using the laterality index at rest (LIR) of the NIRS parameter. Results show that the subjects were able to measure their physiological data by themselves when they visited the gym, after being instructed how to perform the measurements. Furthermore, the results also indicate that ordinary people can continuously monitor physiological functions such as brain function in a non-medical facility, such as a fitness gym.
Subject(s)
Monitoring, Physiologic , Prefrontal Cortex , Spectroscopy, Near-Infrared , Aged , Female , Functional Laterality , Heart Rate , Humans , Male , Middle Aged , Monitoring, Physiologic/instrumentation , Monitoring, Physiologic/methods , Monitoring, Physiologic/standards , Self-Examination/standards , Stress, PsychologicalABSTRACT
We present an unobtrusive cuff-less sphygmomanometer based on contact-type and optical pulse sensors for continuous and minimally invasive monitoring of blood pressure (BP). We developed a cuff-less sphygmomanometer that utilizes the pulse arrival time (PAT) to estimate continuous BP. To assess its accuracy, we recruited 10 healthy subjects in whom we carried out BP studies using the cuff-less sphygmomanometer compared with a standard cuff-type device in a stationary sitting patient. Preliminary results showed that the mean difference (MD) of estimated systolic blood pressure and diastolic blood pressure were 0.96 ± 9.6 (mean ± SD) mmHg and 1.14 ± 7.5 mmHg, respectively, compared to the control. The corresponding correlation between the estimated BP values and controls were 0.78 for systolic blood pressure (p < 0.01) and 0.69 for diastolic blood pressure (p < 0.01); thus, there were significant correlations. These results suggest that the developed cuff-less sphygmomanometer has the potential for continuous BP monitoring. Finally, we conducted a preliminary study of simultaneous monitoring of cuff-less BP and near-infrared spectroscopy to evaluate the potential for assessment of autonomic nervous system functions during mental stress tasks.
Subject(s)
Blood Pressure Determination , Sphygmomanometers , Adult , Autonomic Nervous System/physiology , Blood Pressure , Blood Pressure Determination/instrumentation , Electrocardiography , Heart Rate , Humans , Male , Monitoring, Physiologic/instrumentation , Monitoring, Physiologic/standards , Sphygmomanometers/standards , Young AdultABSTRACT
Early mobilization and rehabilitation of stroke patients can improve functional recovery. However, effects of mobilization on the responses of the autonomic nervous system (ANS) and emotions in post-stroke patients are not yet clear, particularly in patients with disorders of consciousness. We evaluated the effects of standing load on the ANS and emotions of post-stroke patients (n = 8, 70.8 ± 11.8 years) with a disorder of consciousness by measuring the prefrontal cortex (PFC) activity, which plays important roles in regulation of the ANS and emotions. Employing near infrared spectroscopy (NIRS), we measured concentration changes of oxygenated haemoglobin (oxy-Hb) in the PFC for 10 min at rest. Then, subjects were placed in supine position on a tilt table, and standing loads were given by 30°, 45° and 60° every 5 min. We assessed left-right asymmetry of the PFC activity at rest by calculating the Laterality Index at Rest (LIR; LIR>0 indicates right dominant activity while LIR<0 indicates left dominant activity). We observed fluctuations of oxy-Hb in the PFC at rest, indicating activation of the PFC. Interestingly, 75% (six patients) of the patients exhibited right dominant PFC activation at rest. These patients exhibited an increase of oxy-Hb during standing load; four patients suffered from orthostatic hypotension. Finally, there was a significant positive correlation between LIR before the standing test and oxy-Hb changes during the standing test (r = 0.78, p = 0.02). These results suggest that the standing load might act on post-stroke patients as a stressor, which caused an increase of PFC activity (i.e., rCBF). NIRS may be useful to assess feasibility to start rehabilitation of post-stroke patients with a disorder of consciousness.
Subject(s)
Autonomic Nervous System/physiopathology , Prefrontal Cortex/physiopathology , Stroke Rehabilitation/methods , Stroke/complications , Aged , Aged, 80 and over , Brain Mapping/methods , Early Ambulation/adverse effects , Female , Humans , Male , Middle Aged , Prefrontal Cortex/blood supply , Prefrontal Cortex/diagnostic imaging , Spectroscopy, Near-Infrared/methods , Stroke/physiopathologyABSTRACT
Near infrared spectroscopy (NIRS) has been applied to measurements of cerebral blood oxygenation (CBO) in normal subjects and patients with various brain disorders including cerebrovascular diseases. However, it is not known whether NIRS allow us to measure CBO correctly in patients with abnormal cortices where optical characteristics such as optical pathlength (OP) may differ from those in normal cortex. In the present study, employing a time-resolved NIRS (TNIRS), we compared baseline hemoglobin (Hb) concentrations and OPs between normal and abnormal cortices in chronic stroke patients. We studied five patients with chronic cerebral infarction (two males, three females, age 59.0 ± 24.2 years) who were admitted to the University Hospital of Fukushima Prefectural Medical University. Employing TNIRS (TRS-20, Hamamatsu Photonics), we measured baseline Hb concentrations and OPs (760, 800, 830 nm) at various positions on the head. We observed that deoxy-Hb concentrations were significantly lower on the affected side (p < 0.01), and the tissue oxygen saturation was significantly higher than that on the affected side (p < 0.01), suggesting that oxygen consumption was reduced on the affected side. In addition, the OPs (760, 800 nm) were significantly longer on the affected side (p < 0.05); these changes might be caused by a possible increase of cerebrospinal fluid layer associated with brain tissue degeneration by ischemia. The present results suggest that NIRS should be performed on patients with abnormal cerebral cortices, giving special consideration to the possible difference in optical characteristics between normal and abnormal brain tissues.
Subject(s)
Hemoglobins/analysis , Oxygen Consumption/physiology , Spectroscopy, Near-Infrared/methods , Stroke/diagnostic imaging , Stroke/metabolism , Adolescent , Aged, 80 and over , Female , Humans , Male , Middle AgedABSTRACT
Multi-channel NIRS, so-called optical topography (OT), allows functional mapping of the cortex; however, it takes a long time to set optodes on the head and is relatively expensive. Thus, OT is not suitable as a screening test of brain disorders evaluating many subjects. Recently, a wearable two-channel continuous wave NIRS (CW-NIRS) device has been developed. Such a simple NIRS device may be applicable as a screening test of brain disorders; however, its reliability in measurements of brain function is not yet clear. Here, we tested a two-channel CW-NIRS, which employs single LED (800 nm) for measurement of total hemoglobin (t-Hb) changes. We measured t-Hb changes in the bilateral prefrontal cortex (PFC) during mental arithmetic tasks, employing the CW-NIRS and time-resolve NIRS (TNIRS). The left-right asymmetry of the PFC activity was evaluated by calculating the laterality index (LI; (R-L)/(R + L) of t-Hb), which reflects mental stress. The interval between CW-NIRS and TNIRS measurements was 1-13 days. A significant positive correlation was observed between LI measured by CW-NIRS and TNIRS. These results suggest the reliability of the simple CW-NIRS, and it may be applicable to prevent stress-induced various diseases. Finally, it should be emphasized that the left-right asymmetry of PFC activity is relatively stable.
Subject(s)
Brain Mapping/instrumentation , Hemoglobins/analysis , Prefrontal Cortex/physiology , Spectroscopy, Near-Infrared/instrumentation , Wearable Electronic Devices , Female , Humans , Male , Prefrontal Cortex/blood supply , Young AdultABSTRACT
Stress responses are mediated by complex patterns of cortical and autonomic activity. Earlier studies showed increased recruitment of the right prefrontal cortex (PFC) and parasympathetic withdrawal during a stress task; however, it remains unclear whether these responses change in relation to different levels of psychopathological symptoms, such as trait anxiety. The present study examines the effect of a mathematical task (with a control condition and a stressful/experimental condition) on the PFC and autonomic activity, using a two-channel near infrared spectroscopy (NIRS) and an ECG monitoring system. After a preliminary screening of 65 subjects, a sample of 12 individuals (6 with the highest and 6 with the lowest scores on an anxiety questionnaire, i.e. the STAI trait) was selected. The two groups were similar regarding demographic variables (age, sex, body mass index) and baseline STAI-state scores. Repeated measures ANOVAs were used to compare changes from baseline in oxyhemoglobin (oxy-Hb), heart rate (HR) and root mean square of successive differences (RMSSD) between the two groups. Individuals affected by high levels of trait anxiety showed a reduced bilateral PFC activity during the entire experimental procedure compared to those with low anxiety. No differences in NIRS channels were found between the two groups. During both conditions, RMSSD was lower among individuals affected by high levels of anxious symptoms. Finally, throughout the procedure, changes in HR were higher in the anxious group. Overall, these findings suggest a reduced PFC activity and a larger parasympathetic withdrawal during a stress task in individuals with high levels of trait anxiety compared to those with low anxiety. These results could represent a starting point for future NIRS and ECG studies on the relationship between mental disorders and acute stress responses.
Subject(s)
Anxiety/physiopathology , Autonomic Nervous System/physiology , Prefrontal Cortex/physiology , Stress, Physiological/physiology , Stress, Psychological/physiopathology , Adult , Electrocardiography , Female , Heart Rate/physiology , Humans , Male , Personality/physiology , Pilot Projects , Spectroscopy, Near-Infrared , Young AdultABSTRACT
Aging is associated with changes in biological functions, such as reduced cardiovascular responses to stressful tasks. However, less is known about the influence of age on the reactivity of the prefrontal cortex (PFC) to acute stressors. Therefore, this study aimed to investigate the effects of a computerized-controlled stress task on the PFC and autonomic system activity in a sample of older and younger adults. We recruited a total of 55 healthy, right-handed persons (26 older adults with mean age 69.5, SD 5.8 years; and 29 younger adults with mean age 23.8, SD 3.3 years); groups were balanced for sex. Tasks included a control and an experimental condition: during both tasks individuals had to solve simple mental arithmetic problems. For the experimental condition, all participants were faced with a time limit that induced significant stress. Physiological indexes were collected continuously during the entire procedure using a 2-channel near infrared spectroscopy (NIRS) and an ECG monitoring system. Repeated measures ANOVA were used to assess changes in hemoglobin concentrations, and changes in both heart rate and performance outcomes. NIRS, ECG and performance data showed a significant interaction between the group and condition. Post-hoc analyses evidenced a significant increase in heart rate and Oxy-Hb concentration in the bilateral PFC between the control and experimental condition only in the younger group. Post-hoc analyses of behavioral data showed lower percentages of correct responses and higher response times in the older group. In summary, these results suggested that cardiovascular and cortical reactivity to stress tasks are a function of age. Older individuals seem to be characterized by blunted physiological reactivity, suggestive of impaired adaptive responses to acute stressors. Therefore, future studies should investigate the underlying physiological mechanisms of prefrontal and cardiovascular changes related to aging.
Subject(s)
Aging/psychology , Heart Rate/physiology , Reaction Time/physiology , Stress, Psychological/physiopathology , Stress, Psychological/psychology , Adult , Aged , Aging/physiology , Female , Humans , Male , Middle Aged , Prefrontal Cortex/physiology , Random Allocation , Spectroscopy, Near-Infrared/methods , Young AdultABSTRACT
In order to examine whether near-infrared spectroscopy (NIRS) would be a useful neuromarketing tool, we employed NIRS to evaluate the difference of pleasure-displeasure in women, induced by the use of different types of lipsticks. The subjects used lipsticks A and B; A is softer than B. Concentration changes of oxy-Hb were measured in the bilateral prefrontal cortex (PFC) during use of lipsticks A and B. We evaluated the right and left dominancy of PFC activity by calculating the Laterality Index (LI) (LI = leftΔoxy-Hb - rightΔoxy-Hb); positive LI indicates left-dominant activity while negative LI indicate right-dominant activity. We found a significant interaction between the use of lipsticks A and B, using a two-way factorial analysis of variance [F(1,13) = 9.63, p < 0.01]; Δoxy-Hb in the left PFC was larger than that in the right PFC during the use of lipstick A, while Δoxy-Hb in the right PFC tended to be larger than that in the left PFC during the use of lipstick B (p < 0.1). The LI of lipstick A was larger than that of lipstick B (paired T-test, p = 0.0083). We suggest that lipstick A caused a more positive emotional response than lipstick B, since greater left than right frontal cortical activity is associated with positive affect. These results suggest that 2-channel NIRS may be a useful neuromarketing tool, since it allows objective assessment of pleasure-unpleasure.
Subject(s)
Brain Mapping/methods , Consumer Behavior , Cosmetics , Lip , Marketing/methods , Pleasure/physiology , Spectroscopy, Near-Infrared/methods , Adult , Brain Mapping/instrumentation , Female , Functional Laterality/physiology , Functional Neuroimaging/methods , Humans , Prefrontal Cortex/physiology , Spectroscopy, Near-Infrared/instrumentation , Young AdultABSTRACT
Cognitive function tends to decrease with aging, therefore maintenance of this function in an aging society is an important issue. The role of chewing in nutrition is important. Although several studies indicate that gum chewing is thought to improve cognitive function, it remains debatable whether gum-chewing does in fact improve cognitive function. The Stroop test is a psychological tool used to measure cognition. A shorter reaction time indicates a mean higher behavioral performance and higher levels of oxy-Hb concentration. fNIRS is a powerful, non-invasive imaging technique offering many advantages, including compact size, no need for specially equipped facilities, and the potential for real-time measurement. The left dorsolateral prefrontal cortex (DLPFC) seems to be mainly involved in the Stroop task.The aim of the present study was to investigate the hypothesis that gum-chewing changes cerebral blood flow in the left DLPFC during the Stroop test, and also changes the reaction time. Fourteen healthy volunteers (mean age 26.9 years) participated in this study after providing written informed consent. A piece of tasteless gum weighing 1.0 g was used. Each session was designed in a block manner, i.e. 4 rests (30 s) and 3 blocks of task (30 s). A computerized Stroop test was used (including both congruent and incongruent Stroop tasks) which calculates a response time automatically. The Binominal test was used for comparisons (p < 0.05). The results show activation of the left DLPFC during the Stroop task and that gum chewing significantly increases responses/oxy-Hb concentration and significantly shortens the reaction time.
Subject(s)
Chewing Gum , Mastication/physiology , Stroop Test , Adult , Aging/psychology , Attention/physiology , Cognition/physiology , Female , Functional Laterality/physiology , Humans , Male , Pilot Projects , Prefrontal Cortex/physiology , Reaction Time/physiology , Spectroscopy, Near-Infrared , Young AdultABSTRACT
Recent near-infrared spectroscopy (NIRS) studies demonstrated that physical exercise enhances working memory (WM) performance and prefrontal cortex (PFC) activity during WM tasks in normal adults. Interestingly, the effects of rehabilitation (i.e. physiotherapy) on post-stroke patients could be enhanced by motor imagery (MI), an active process during which the specified action is reproduced within WM without any actual physical movement. However, it is not known whether MI can enhance cognitive function and associated brain activity. To clarify these issues, we evaluated the effect of MI on WM performance and PFC activity during WM tasks in normal adults, employing NIRS. We studied 10 healthy adults. The present study was a crossover comparison test; the MI training and control condition (rest) were applied to the subjects at random. The Time Up and Go method was used for MI training: the subject sat on a chair and conducted MI for 3 min, three times. Neuronal activity (oxyhemoglobin concentration) in the bilateral PFC was measured using 2-CH NIRS during WM tasks. We found that MI improved the behavioral performance of WM compared with the control (p < 0.01). NIRS revealed that MI enhanced PFC activity induced by the WM task compared with the control task (p < 0.01). These results suggest that MI can improve cognitive function and increase associated PFC activity in normal adults.
Subject(s)
Memory, Short-Term/physiology , Motor Activity/physiology , Photic Stimulation , Prefrontal Cortex/physiology , Spectroscopy, Near-Infrared , Adult , Brain Mapping/methods , Cognition/physiology , Cross-Over Studies , Female , Humans , Male , Neuropsychological Tests , Photic Stimulation/methods , Random Allocation , Young AdultABSTRACT
The neurophysiological mechanism of positive versus negative emotions is insufficiently understood. In the present study, we examined the effect of event recall tasks on the prefrontal cortex (PFC) activity using near infrared spectroscopy (NIRS). Nine healthy adults were instructed to recall episodes of their life associated with positive (happiness) and negative (anger) emotion, both silently and verbally. Heart rate (HR) changes were simultaneously measured. NIRS showed an increased oxyhemoglobin (oxy-Hb) in the bilateral PFC during silent and verbal recall of both positive and negative episodes. The changes of oxy-Hb in the bilateral PFC during silent recall of negative episodes were significantly larger than those during silent recall of positive episodes (p < 0.01). There was no difference in average changes of oxy-Hb between silent and verbal recall of negative episodes (p > 0.95), while changes of oxy-Hb during verbal recall of positive episodes were larger than those during silent recall of positive episodes (p < 0.05). Both verbal and silent recall of positive and negative episodes increased HR; however, verbal recall caused larger increases of HR than silent recall (p < 0.01). The present results suggest that recall of negative episodes affect the PFC activity, which plays a key role in cognitive control of emotions, more than positive episodes.
Subject(s)
Affect , Brain Mapping/methods , Oximetry/methods , Oxygen/blood , Prefrontal Cortex/metabolism , Spectroscopy, Near-Infrared , Adult , Anger , Female , Happiness , Humans , Male , Mental Recall , Oxyhemoglobins/metabolism , Time Factors , Verbal Behavior , Young AdultABSTRACT
Physical exercise enhances prefrontal cortex activity and improves working memory performance in healthy older adults, but it is not clear whether this remains the case in post-stroke patients. Therefore, the aim of this study was to examine the acute effect of physical exercise on prefrontal cortex activity in post-stroke patients using near-infrared spectroscopy (NIRS). We studied 11 post-stroke patients. The patients performed Sternberg-type working memory tasks before and after moderate intensity aerobic exercise (40 % of maximal oxygen uptake) with a cycling ergometer for 15 min. We measured the NIRS response at the prefrontal cortex during the working memory task. We evaluated behavioral performance (response time and accuracy) of the working memory task. It was found that physical exercise improved behavioral performance of the working memory task compared with the control condition (p < 0.01). In addition, NIRS analysis indicated that physical exercise enhanced prefrontal cortex activation, particularly in the right prefrontal cortex (p < 0.05), during the working memory task compared with the control condition. These findings suggest that the moderate-intensity aerobic exercise enhances prefrontal cortex activity and improves working memory performance in post-stroke patients.
Subject(s)
Exercise , Memory, Short-Term , Prefrontal Cortex/physiopathology , Stroke/physiopathology , Stroke/psychology , Aged , Aged, 80 and over , Bicycling , Biomarkers/blood , Brain Mapping/methods , Exercise Test , Female , Hemoglobins/metabolism , Humans , Male , Middle Aged , Neuropsychological Tests , Oximetry/methods , Oxygen/blood , Oxygen Consumption , Oxyhemoglobins/metabolism , Prefrontal Cortex/metabolism , Recovery of Function , Spectroscopy, Near-Infrared , Stroke/diagnosis , Stroke/metabolism , Time Factors , Treatment OutcomeABSTRACT
According to the valence asymmetry hypothesis, the left/right asymmetry of PFC activity is correlated with specific emotional responses to mental stress and personality traits. In a previous study we measured spontaneous oscillation of oxy-Hb concentrations in the bilateral PFC at rest in normal adults employing two-channel portable NIRS and computed the laterality index at rest (LIR). We investigated the Pearson correlation coefficient between the LIR and anxiety levels evaluated by the State-Trait Anxiety Inventory (STAI) test. We found that subjects with right-dominant activity at rest showed higher STAI scores, while those with left dominant oxy-Hb changes at rest showed lower STAI scores such that the Pearson correlation coefficient between LIR and STAI was positive. This study performed Bootstrap analysis on the data and showed the following statistics of the target correlation coefficient: mean=0.4925 and lower confidence limit=0.177 with confidence level 0.05. Using the KS-test, we demonstrated that the correlation did not depend on age, whereas it did depend on gender.
Subject(s)
Anxiety/metabolism , Spectroscopy, Near-Infrared , Age Factors , Algorithms , Female , Functional Laterality , Humans , Male , Sex FactorsABSTRACT
With the rapid increase in dementia in developed countries, it is important to establish methods for maintaining or improving cognitive function in elderly people. To resolve such problems, we have been developing a cosmetic therapy (CT) program for elderly women. However, the mechanism and limitations of CT are not yet clear. In order to clarify these issues, we employed time-resolved spectroscopy (TRS) to evaluate the effect of CT on prefrontal cortex (PFC) activity in elderly females with various levels of cognitive impairment. Based on the Mini-Mental State Examination (MMSE) score, the subjects were classified into mild (mean MMSE score: 24.1±3.8) and moderate (mean MMSE score: 10.3±5.8) cognitive impairment (CI) groups (p<0.0001). The mild CI group exhibited significantly larger baseline concentrations of oxy-Hb and t-Hb than the moderate CI group. CT significantly increased the baseline concentrations of oxy-Hb (p<0.002) and t-Hb (p<0.0013) in the left PFC in the mild CI group. In contrast, CT did not change the concentrations of oxy-Hb and t-Hb in the moderate CI group (p>0.05). These results suggest that CT affects cognitive function by altering PFC activity in elderly women with mild CI, but not moderate CI.
Subject(s)
Cognition , Cosmetics , Aged , Female , Humans , Prefrontal Cortex/physiology , Spectrum AnalysisABSTRACT
There is increasing evidence that acupuncture is useful in treating somatic and psychological disorders caused by stress; however, the physiological basis of the effect remains unclear. In the present study, we evaluated the effect of acupuncture on psychological conditions (i.e., anxiety) and prefrontal cortex (PFC) activity. We studied 10 patients with anxiety disorders and measured anxiety levels by means of the State-Trait Anxiety Inventory (STAI), including state anxiety (STAI-1) and trait anxiety (STAI-2). Employing a two-channel NIRS device, we measured oxy-Hb concentration in the bilateral PFC at rest, and evaluated asymmetry of the PFC activity by calculating the Laterality Index at Rest (LIR). The patients were treated by acupuncture at Yui Clinic in Osaka. The treatment significantly decreased the STAI-1 score (p<0.001), but not the STAI-2 score (p>0.05). The NIRS measurements indicated the presence of spontaneous oscillations of oxy-Hb in the bilateral PFC at rest before and after the treatment. Notably LIR decreased significantly in 7 out of the 10 subjects (p<0.01), while 3 subjects showed an increasing tendency. The present pilot study indicates that acupuncture is effective in decreasing anxiety levels in patients with anxiety disorders. Our NIRS data suggest that acupuncture may alter the balance of PFC activity at rest, resulting in relaxation effects. Our NIRS data suggest that acupuncture changes the balance of PFC activity toward left-dominant, resulting in relaxation effects on the patients.
Subject(s)
Acupuncture Therapy , Anxiety/therapy , Prefrontal Cortex/physiology , Spectroscopy, Near-Infrared/methods , Adult , Female , Humans , Male , Middle Aged , Pilot ProjectsABSTRACT
BACKGROUND: Superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis has been used to prevent stroke in patients with moyamoya disease (MD) and non-moyamoya ischaemic disease (non-MD). However, little is yet known regarding the difference between these groups of patients in the extent to which the bypass contributes to maintaining adequate cerebral blood oxygenation (CBO), or the temporal changes after surgery. In the present study, we evaluated the CBO changes induced by bypass blood flow in patients with MD and non-MD during the peri-operative periods employing optical spectroscopy. METHODS: We investigated 13 patients who underwent STA-MCA anastomosis, including 5 MD and 8 non-MD patients. We evaluated the effects of STA blood flow on the CBO in the MCA territory on the anastomosis side, employing visual light spectroscopy during surgery and near infrared spectroscopy (NIRS) at one week after surgery. FINDINGS: In 4 MD patients and one non-MD patient, the STA blood flow increased the oxyhaemoglobin and cortical oxygen saturation (CoSO2), indicating that the bypass supplied blood flow to the ischaemic brain; the CBO changes were observed more frequently in MD than in non-MD patients (p<0.02). The pre-anastomosis CoSO2 (65.4+/-5.4%) in MD was significantly lower than that (72.8+/-7.6%) in non-MD (p<0.05). Postoperative NIRS demonstrated that the bypass began to supply blood flow to the brain in 5 non-MD patients whose bypass did not supply blood flow during surgery. CONCLUSIONS: Although MD has vessels of small diameter as compared to non-MD, the bypass begins to supply blood flow to the ischaemic brain earlier in MD than in non-MD after anastomosis. The fact that the CoSO2 in MD was lower than that in non-MD suggested that the perfusion pressure in MD was lower than that in non-MD, and this might account for the difference in the bypass blood supply after anastomosis between MD and non-MD. Our data suggest that, even if the bypass does not supply blood to the brain during surgery in non-MD, the bypass blood flow gradually increases after surgery.