Odor descriptive ratings can predict some odor-color associations in different color features of hue or lightness.

Background: Olfactory information can be associated with color information. Researchers have investigated the role of descriptive ratings of odors on odor-color associations. Research into these associations should also focus on the differences in odor types. We aimed to identify the odor descriptive ratings that can predict odor-color corresponding formation, and predict features of the associated colors from the ratings taking into consideration the differences in the odor types. Methods: We assessed 13 types of odors and their associated colors in participants with a Japanese cultural background. The associated colors from odors in the CIE L*a*b* space were subjectively evaluated to prevent the priming effect from selecting color patches. We analyzed the data using Bayesian multilevel modeling, which included the random effects of each odor, for investigating the effect of descriptive ratings on associated colors. We investigated the effects of five descriptive ratings, namely Edibility, Arousal, Familiarity, Pleasantness, and Strength on the associated colors. Results: The Bayesian multilevel model indicated that the odor description of Edibility was related to the reddish hues of associated colors in three odors. Edibility was related to the yellow hues of colors in the remaining five odors. The Arousal description was related to the yellowish hues in two odors. The Strength of the tested odors was generally related to the color lightness. The present analysis could contribute in investigating the influence of the olfactory descriptive rating that anticipates the associated color for each odor.

Silence of resident microglia in GPI anchorless prion disease and activation of microglia in Gerstmann-Sträussler-Scheinker disease and sporadic Creutzfeldt-Jakob disease.

GPI anchorless prion diseases (GPIALPs) show numerous coarse prion protein (PrP) deposits in the CNS but neuropil spongiform changes are mild and the incidence of dementia is low. Here, we examined differences in resident microglial phenotypes between GPIALP (D178fs25) and the other prion diseases Gerstmann-Sträussler-Scheinker (GSS) disease and sporadic Creutzfeldt-Jakob disease (sCJD) with respect to homeostasis and activation. Immunohistochemistry was performed on 2 GPIALP (D178fs25), 4 GSS (P102L), and 4 sCJD cases. Homeostatic microglia expressing TMEM119 and P2RY12 were preserved in GPIALP compared to GSS and sCJD. Microglia/macrophage activation in GSS and sCJD was associated with the extent of spongiform change. Immunoelectron microscopy revealed TMEM119 and P2RY12 in PrP plaque cores. Activated microglia/macrophages expressing HLA-DR and CD68 were predominant in GSS and sCJD whereas in GPIALP, homeostatic microglia were retained and activated microglia/macrophages were rarely observed. These data suggest that PrP deposition in GPIALP is less toxic and that microglia may be immune-tolerant to PrP deposition. This may be associated with milder tissue damage and a low incidence of dementia. Whereas microglia/macrophage activation is considered to be a reaction to tissue injury, this study shows that the degree of microglia/macrophage activity might influence the extent of tissue damage.

Physiological comfort evaluation under different airflow directions in a heating environment.

BACKGROUND: Indoor airflow and thermal comfort are difficult to assess through subjective evaluations because airflow sensations can differ based on various factors, such as personal characteristics, interests, preferences, and the current state of mind. Thus, subjective evaluations should be combined with objective assessments, such as physiological measurements. This study evaluated airflow and thermal comfort through physiological measurements, including skin temperature, electroencephalography, respiration, and electrocardiography, in addition to subjective evaluations. METHODS: Twenty participants entered a test room at 30 °C after staying in an acclimation room at 18 °C for 20 min. They were exposed to indirect and direct airflow toward their faces and performed four tasks under each condition: resting, counting to 10 s following time alerts, counting to 10 s in the mind, and mental calculation. The mean speed of the air directed to the participants' faces was 0.123 m/s and 0.225 m/s in the indirect and direct conditions, respectively. RESULTS: The gamma and beta bands of electroencephalograms taken at the left-temporal (T3) and left-parietal (P7) sites showed significantly lower amplitudes under the indirect condition (gamma, T3: p = 0.034, P7: p = 0.030; beta, T3: p = 0.051, P7: p = 0.028). Similarly, the variability of respiration was lower under the indirect condition (p < 0.010). The amplitudes of gamma and beta waves showed significant correlations with anxiousness levels (gamma, T3: r = 0.41; beta, T3: r = 0.35). CONCLUSIONS: Our results suggest that indirect heating airflow causes lower mental stress and fatigue than those induced by direct flow, which is equivalent to more comfort. The results of this study suggest that physiological measurements can be used for the evaluation of unconscious indoor comfort, which cannot be detected by subjective evaluations alone.

Neurofeedback training improves episodic and semantic long-term memory performance.

Understanding and improving memory are vital to enhance human life. Theta rhythm is associated with memory consolidation and coding, but the trainability and effects on long-term memory of theta rhythm are unknown. This study investigated the ability to improve long-term memory using a neurofeedback (NFB) technique reflecting the theta/low-beta power ratio on an electroencephalogram (EEG). Our study consisted of three stages. First, the long-term memory of participants was measured. In the second stage, the participants in the NFB group received 3 days of theta/low-beta NFB training. In the third stage, the long-term memory was measured again. The NFB group had better episodic and semantic long-term memory than the control group and significant differences in brain activity between episodic and semantic memory during the recall tests were revealed. These findings suggest that it is possible to improve episodic and semantic long-term memory abilities through theta/low-beta NFB training.

Data-point-wise spatiotemporal mapping of human ventral visual areas: Use of spatial frequency/luminance-modulated chromatic faces.

Visual information involving facial identity and expression is crucial for social communication. Although the influence of facial features such as spatial frequency (SF) and luminance on face processing in visual areas has been studied extensively using grayscale stimuli, the combined effects of other features in this process have not been characterized. To determine the combined effects of different SFs and color, we created chromatic stimuli with low, high or no SF components, which bring distinct SF and color information into the ventral stream simultaneously. To obtain neural activity data with high spatiotemporal resolution we recorded face-selective responses (M170) using magnetoencephalography. We used a permutation test procedure with threshold-free cluster enhancement to assess statistical significance while resolving problems related to multiple comparisons and arbitrariness found in traditional statistical methods. We found that time windows with statistically significant threshold levels were distributed differently among the stimulus conditions. Face stimuli containing any SF components evoked M170 in the fusiform gyrus (FG), whereas a significant emotional effect on M170 was only observed with the original images. Low SF faces elicited larger activation of the FG and the inferior occipital gyrus than the original images, suggesting an interaction between low and high SF information processing. Interestingly, chromatic face stimuli without SF first activated color-selective regions and then the FG, indicating that facial color was processed according to a hierarchy in the ventral stream. These findings suggest complex effects of SFs in the presence of color information, reflected in M170, and unveil the detailed spatiotemporal dynamics of face processing in the human brain.

Physiological and subjective comfort evaluation under different airflow directions in a cooling environment.

Indoor comfort is influenced by airflow direction, but subjective evaluations can differ. This study evaluates the airflow comfort with subjective assessments and physiological measurements, including skin temperature, electroencephalograms, and electrocardiograms. Nineteen participants entered a test room at 20°C after staying in a room at 32°C for acclimation. They were exposed to indirect and direct airflow conditions to their faces and performed four tasks under each condition: resting, counting to 10 s following time alerts, counting to 10 s in mind, and mental calculation. Subjective assessments showed relatively higher thermal sensation and pleasantness under indirect airflow. The psychological time calculated from counting behaviors was longer under indirect airflow, indicating suppression of negative emotions. The face temperatures significantly declined during experiments under direct airflow. The beta and gamma bands of electroencephalograms were inhibited under the indirect condition, and these amplitudes were negatively correlated with pleasant feelings. Electrocardiogram parameters indicated that sympathetic nervous activity was predominant during counting, following alerts and mental calculation in indirect airflow. This study supports the comfort of indirect airflow based on reliable evidence.

Orientation Preference Maps in Microcebus murinus Reveal Size-Invariant Design Principles in Primate Visual Cortex.

Orientation preference maps (OPMs) are a prominent feature of primary visual cortex (V1) organization in many primates and carnivores. In rodents, neurons are not organized in OPMs but are instead interspersed in a "salt and pepper" fashion, although clusters of orientation-selective neurons have been reported. Does this fundamental difference reflect the existence of a lower size limit for orientation columns (OCs) below which they cannot be scaled down with decreasing V1 size? To address this question, we examined V1 of one of the smallest living primates, the 60-g prosimian mouse lemur (Microcebus murinus). Using chronic intrinsic signal imaging, we found that mouse lemur V1 contains robust OCs, which are arranged in a pinwheel-like fashion. OC size in mouse lemurs was found to be only marginally smaller compared to the macaque, suggesting that these circuit elements are nearly incompressible. The spatial arrangement of pinwheels is well described by a common mathematical design of primate V1 circuit organization. In order to accommodate OPMs, we found that the mouse lemur V1 covers one-fifth of the cortical surface, which is one of the largest V1-to-cortex ratios found in primates. These results indicate that the primate-type visual cortical circuit organization is constrained by a size limitation and raises the possibility that its emergence might have evolved by disruptive innovation rather than gradual change.

The effects of chronic subthalamic stimulation on nonmotor symptoms in advanced Parkinson's disease, revealed by an online questionnaire program.

BACKGROUND: This study was designed to detect and assess the frequency and severity of nonmotor symptoms (NMSs) in advanced Parkinson's disease (PD) and to investigate the effects of subthalamic nucleus deep brain stimulation (STN-DBS) on NMSs. METHODS: We developed an online PC-based questionnaire program to assess NMSs in PD. Twenty-six PD patients who underwent bilateral STN-DBS were assessed. The NMS questionnaire consisted of 54 NMSs in three categories, based on Witjas et al. (2002). For each NMS, the patients were asked whether or not it was present, whether or not the fluctuating manifestations correlated with the timing of levodopa-induced motor fluctuations, and how severe the NMS was. Patients were assessed by this system before surgery and at the follow-up visit, 3 to 6 months after surgery. At the postoperative assessment, patients were also assessed on preoperative NMSs using recall. RESULTS: The most frequent preoperative NMSs were constipation and visual disorders, while the most frequent postoperative NMSs were difficulty in memorizing and pollakiuria. The ranking of most frequent NMSs changed from before to after surgery. NMSs of drenching sweats, dysphagia, and constipation were significantly ameliorated, while NMSs of dyspnea and slowness of thinking were significantly deteriorated after surgery. The preoperative assessment by postoperative recall gave very different results from that of the preoperative assessment. CONCLUSION: An online questionnaire system to assess NMSs in patients with advanced PD suggested that STN-DBS might influence the frequencies of some kinds of NMSs.

Superior mesenteric artery syndrome in a healthy active adolescent.

This report discusses a case of superior mesenteric artery (SMA) syndrome in a previously healthy 15-year-old boy with no weight loss or other common risk factors. The patient presented to the emergency department with acute bilious vomiting and epigastric pain after acute consumption of a meal and excessive quantities of water. The patient was diagnosed with SMA syndrome based on the findings of contrasted CT of the abdomen. In early puberty, boys have a significant increase in lean body mass and a concomitant loss of adipose tissues. These pubertal changes lead to a narrowing of the aortomesenteric space. The acute consumption of food and water caused a transient obstruction at the already-narrowed space, which resulted in the manifestation of SMA syndrome. This case demonstrates that pubertal growth spurt is a risk factor for SMA syndrome, and acute excessive ingestion can trigger SMA syndrome among those in puberty.

Tauopathy in basal ganglia involvement is exacerbated in a subset of patients with Alzheimer's disease: The Hisayama study.

INTRODUCTION: We have conducted the pathological cohort study of autopsied cases of Hisayama residents to reveal a recent trend of dementia-related pathology. We noticed a trend of putaminal involvement of Alzheimer's disease (AD) with parkinsonism. Then, we investigated the accurate prevalence of neurological diseases with putaminal AD pathology in the general population. METHODS: We examined a series of 291 autopsies in the Hisayama study and performed image analysis of immunohistochemistry for microtubule-associated protein tau (MAPT) and amyloid ß. RESULTS: Approximately 65.6% and 36.1% of cases showed putaminal MAPT and amyloid deposits, respectively. Diffuse deposits of them were mainly found in the AD cases. Putaminal MAPT was highly associated with AD-related pathological criteria. Four of 22 cases with severe putaminal MAPT deposition were documented as having developed parkinsonism. DISCUSSION: Severe MAPT accumulation in the basal ganglia was closely related to the development of AD pathology and could occur most frequently in AD cases without comorbidities.

Predictive Factors of Antiparkinsonian Drug Reduction after Subthalamic Stimulation for Parkinson's Disease.

Subthalamic nucleus deep brain stimulation (STN-DBS) improves motor symptoms in individuals with advanced Parkinson's disease (PD) and enables physicians to reduce doses of antiparkinsonian drugs. We investigated possible predictive factors for the successful reduction of antiparkinsonian drug dosage after STN-DBS. We evaluated 33 PD patients who underwent bilateral STN-DBS. We assessed rates of reduction of the levodopa-equivalent daily dose (LEDD) and levodopa daily dose (LDD) by comparing drug doses before vs. 6-months post-surgery. We used correlation coefficients to measure the strength of the relationships between LEDD and LDD reduction rates and preoperative factors including age, disease duration, preoperative LEDD and LDD, unified Parkinson's Disease Rating Scale part-II and -III, levodopa response rate, Mini-Mental State Examination score, dyskinesia score, Hamilton Rating Scale for depression, and the number of non-motor symptoms. The average LEDD and LDD reduction rates were 61.0% and 70.4%, respectively. Of the variables assessed, only the number of psychiatric/cognitive symptoms was significantly correlated with the LEDD reduction rate. No other preoperative factors were correlated with the LEDD or LDD reduction rate. A wide range of preoperative psychiatric and cognitive symptoms may predict the successful reduction of antiparkinsonian drugs after STN-DBS.

Olfactory modulation of colour working memory: How does citrus-like smell influence the memory of orange colour?

Olfactory modulation of vision is not well understood whereas visual modulation of olfaction has been more fully investigated. This study aimed to reveal in a simple manner whether there is olfactory modulation of colour working memory using an odour that induces a citrus-like smell and is associated with orange colours. We assumed that the odour would have modulatory effects on the colour information stored in working memory. To clarify whether these effects are supportive or disruptive, during the colour working memory task we measured an event-related potential component, P3, which is involved in attentional processes of working memory. The results indicated that odour presentation mediated a decline in the rate of correct guesses for orange colours. Furthermore, the odour suppressed P3 during reddish-colour retrieval, including orange. These results suggest that colour working memory in orange can be disrupted via olfactory modulation with citrus-like odours.

Physiological activity in calm thermal indoor environments.

Indoor environmental comfort has previously been quantified based on the subjective assessment of thermal physical parameters, such as temperature, humidity, and airflow velocity. However, the relationship of these parameters to brain activity remains poorly understood. The objective of this study was to determine the effect of airflow on brain activity using electroencephalograms (EEG) of participants in a living environment under different airflow conditions. Before the recording, the room was set to a standardised air temperature and humidity. During the recording, each participant was required to perform a simple time-perception task that involved pressing buttons after estimating a 10-second interval. Cooling and heating experiments were conducted in summer and winter, respectively. A frequency analysis of the EEGs revealed that gamma and beta activities showed lower amplitudes under conditions without airflow than with airflow, regardless of the season (i.e., cooling or heating). Our results reveal new neurophysiological markers of the response to airflow sensation. Further, based on the literature linking gamma and beta waves to less anxious states in calm environments, we suggest that airflow may alter the feelings of the participants.

Recent Increases in Hippocampal Tau Pathology in the Aging Japanese Population: The Hisayama Study.

BACKGROUND: The Hisayama study is a prospective cohort study of lifestyle-related diseases that commenced in 1961. Through it, a significant increasing trend in the prevalence of Alzheimer's disease has been observed over the past 18 years. OBJECTIVES: We sought to investigate the increases in brain pathology related to Alzheimer's disease using automated MATLAB morphometric analyses for quantifying tau pathology. METHODS: We examined a series of autopsied cases from Hisayama residents obtained between 1998 and 2003 (group A: 203 cases), and between 2009 and 2014 (group B: 232 cases). We developed custom software in MATLAB to analyze abnormal tau deposits quantitatively. Specimens were immunostained with both anti-amyloid-ß-protein and anti-phosphorylated tau antibodies. RESULTS: Both the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) criteria for senile plaques and Braak stage for NFT were higher in group B. Morphometric analyses of the hippocampi also revealed a trend toward increased tau pathology in both men and women over 80 years of age in group B. The increases were also significant when the subjects were examined independently according to high or low CERAD scores and in all levels of AD neuropathologic change according to the National Institute on Aging-Alzheimer's Association guidelines (2012). CONCLUSION: We revealed a recent trend of increased tauopathy in the older people, which is partly independent of amyloid-ß pathology.

Evaluation of Cognitive Function When Hearing One's Own Name in Patients With Brain Injuries in Early Developmental Stages.

PURPOSE: The level of residual cognitive function in patients with early brain injury is a key factor limiting rehabilitation and the quality of life. Although understanding residual function is necessary for appropriate rehabilitation, the extent of its effects on cognitive improvement remains unknown. This study evaluated cognitive function in patients with severe motor and intellectual disabilities after early brain injuries due to cerebral hemorrhage or periventricular leukomalacia. We focused on neural responses to hearing the subject's own name (SON). According to previous studies, differences in response to SON are associated with several types of cognitive dysfunction. METHODS: We examined healthy subjects (aged 21.4 ± 1.10 years; control) and patients with a previous brain injury (aged 13-27 years at the time of our analysis) resulting in periventricular leukomalacia or a cerebral hemorrhage during the perinatal period or childhood. We recorded EEG responses to the SON and to other Japanese words, obtaining EEG-evoked potentials with wavelet transformations. RESULTS: Compared with healthy controls, beta power (not alpha power) revealed differences in response to SON by patients with brain injury, especially those with cerebral hemorrhage. CONCLUSIONS: We suggest that alpha and beta power differences reflect different cognitive functions and that the SON response reveals more than one process. Beta powers may reflect the intellectual disability of cognitive function in response to self-relevant stimuli, especially in patients with cerebral hemorrhage. Meanwhile, alpha powers did not differ from those of the healthy controls, suggesting that the patients perhaps paid attention to their own names.

Abnormal auditory synchronization in stuttering: A magnetoencephalographic study.

In a previous magnetoencephalographic study, we showed both functional and structural reorganization of the right auditory cortex and impaired left auditory cortex function in people who stutter (PWS). In the present work, we reevaluated the same dataset to further investigate how the right and left auditory cortices interact to compensate for stuttering. We evaluated bilateral N100m latencies as well as indices of local and inter-hemispheric phase synchronization of the auditory cortices. The left N100m latency was significantly prolonged relative to the right N100m latency in PWS, while healthy control participants did not show any inter-hemispheric differences in latency. A phase-locking factor (PLF) analysis, which indicates the degree of local phase synchronization, demonstrated enhanced alpha-band synchrony in the right auditory area of PWS. A phase-locking value (PLV) analysis of inter-hemispheric synchronization demonstrated significant elevations in the beta band between the right and left auditory cortices in PWS. In addition, right PLF and PLVs were positively correlated with stuttering frequency in PWS. Taken together, our data suggest that increased right hemispheric local phase synchronization and increased inter-hemispheric phase synchronization are electrophysiological correlates of a compensatory mechanism for impaired left auditory processing in PWS.

Efficiency of a "small-world" brain network depends on consciousness level: a resting-state FMRI study.

It has been revealed that spontaneous coherent brain activity during rest, measured by functional magnetic resonance imaging (fMRI), self-organizes a "small-world" network by which the human brain could sustain higher communication efficiency across global brain regions with lower energy consumption. However, the state-dependent dynamics of the network, especially the dependency on the conscious state, remain poorly understood. In this study, we conducted simultaneous electroencephalographic recording with resting-state fMRI to explore whether functional network organization reflects differences in the conscious state between an awake state and stage 1 sleep. We then evaluated whole-brain functional network properties with fine spatial resolution (3781 regions of interest) using graph theoretical analysis. We found that the efficiency of the functional network evaluated by path length decreased not only at the global level, but also in several specific regions depending on the conscious state. Furthermore, almost two-thirds of nodes that showed a significant decrease in nodal efficiency during stage 1 sleep were categorized as the default-mode network. These results suggest that brain functional network organizations are dynamically optimized for a higher level of information integration in the fully conscious awake state, and that the default-mode network plays a pivotal role in information integration for maintaining conscious awareness.

Age-related changes across the primary and secondary somatosensory areas: an analysis of neuromagnetic oscillatory activities.

OBJECTIVE: Age-related changes are well documented in the primary somatosensory cortex (SI). Based on previous somatosensory evoked potential studies, the amplitude of N20 typically increases with age probably due to cortical disinhibition. However, less is known about age-related change in the secondary somatosensory cortex (SII). The current study quantified age-related changes across SI and SII mainly based on oscillatory activity indices measured with magnetoencephalography. METHODS: We recorded somatosensory evoked magnetic fields (SEFs) to right median nerve stimulation in healthy young and old subjects and assessed major SEF components. Then, we evaluated the phase-locking factor (PLF) for local field synchrony on neural oscillations and the weighted phase-lag index (wPLI) for cortico-cortical synchrony between SI and SII. RESULTS: PLF was significantly increased in SI along with the increased amplitude of N20m in the old subjects. PLF was also increased in SII associated with a shortened peak latency of SEFs. wPLI analysis revealed the increased coherent activity between SI and SII. CONCLUSIONS: Our results suggest that the functional coupling between SI and SII is influenced by the cortical disinhibition due to normal aging. SIGNIFICANCE: We provide the first electrophysiological evidence for age-related changes in oscillatory neural activities across the somatosensory areas.

Volatiles emitted from the roots of Vetiveria zizanioides suppress the decline in attention during a visual display terminal task.

The perennial grass Vetiveria zizanioides (vetiver) is mainly cultivated for its fragrant essential oil. Although the components of the oil and their biological activities have been studied extensively, the effect of the volatiles emitted from the roots of V. zizanioides on humans has so far remained unexplored. We investigated the effects of volatile compounds emitted from the cut roots of V. zizanioides (1.0 g, low-dose conditions; 30 g, high-dose conditions) on individuals during a visual display terminal task. Participants who breathed the volatile compounds emitted under low-dose conditions showed faster reaction times and stimulation of sympathetic nerve activity as measured by electrocardiography. These effects were not observed under high-dose conditions. The total amounnt of volatiles emitted during the experiment was 0.25 µg under low-dose conditions and 1.35 µg under high-dose conditions. These findings indicate that volatile compounds emitted from the roots of V. zizanioides under low-dose conditions may have helped subjects to maintain performance in visual discrimination tasks while maintaining high sympathetic nerve system activity.

Short circuit in deep brain stimulation.

OBJECT: The authors undertook this study to investigate the incidence, cause, and clinical influence of short circuits in patients treated with deep brain stimulation (DBS). METHODS: After the incidental identification of a short circuit during routine follow-up, the authors initiated a policy at their institution of routinely evaluating both therapeutic impedance and system impendence at every outpatient DBS follow-up visit, irrespective of the presence of symptoms suggesting possible system malfunction. This study represents a report of their findings after 1 year of this policy. RESULTS: Implanted DBS leads exhibiting short circuits were identified in 7 patients (8.9% of the patients seen for outpatient follow-up examinations during the 12-month study period). The mean duration from DBS lead implantation to the discovery of the short circuit was 64.7 months. The symptoms revealing short circuits included the wearing off of therapeutic effect, apraxia of eyelid opening, or dysarthria in 6 patients with Parkinson disease (PD), and dystonia deterioration in 1 patient with generalized dystonia. All DBS leads with short circuits had been anchored to the cranium using titanium miniplates. Altering electrode settings resulted in clinical improvement in the 2 PD cases in which patients had specific symptoms of short circuits (2.5%) but not in the other 4 cases. The patient with dystonia underwent repositioning and replacement of a lead because the previous lead was located too anteriorly, but did not experience symptom improvement. CONCLUSIONS: In contrast to the sudden loss of clinical efficacy of DBS caused by an open circuit, short circuits may arise due to a gradual decrease in impedance, causing the insidious development of neurological symptoms via limited or extended potential fields as well as shortened battery longevity. The incidence of short circuits in DBS may be higher than previously thought, especially in cases in which DBS leads are anchored with miniplates. The circuit impedance of DBS should be routinely checked, even after a long history of DBS therapy, especially in cases of miniplate anchoring.