Jun-ichi Uemura

Effects of emotional music on visual processes in inferior temporal area.

To investigate the effects of emotional music on visual processes, we analyzed visual evoked magnetic fields (VEF) on listening to emotional music in 14 healthy subjects. Positive and negative pieces of music were delivered during VEF recording following stimulation by emotionally neutral pictures of faces and landscapes. VEF components at 100 (M100) and 150 (M170)ms after stimulus onset were analyzed, and the estimated current strength for M170 following face stimulation was enhanced with negative compared to positive music in the right hemisphere. The equivalent current dipole for M100 and M170 was estimated in the primary visual cortex (V1) and inferior temporal area (IT), respectively. The present results indicate that background music showed a top-down control of the visual processes in IT, which is a core site responsible for the interpretation of facial expression. The emotional contents of music could alter visual processes, especially those involving the face.

Effect of task-irrelevant high-speed verbal stimulation on a visual/verbal word-discrimination task: An event-related potential study

OBJECTIVES We investigated whether incomprehensible high-speed auditory speech stimulation was processed and interacted with visual-word discrimination processing. We hypothesised that an interaction might indicate the capacity of working memory (WM) to perform the temporal processing of auditory verbal information. METHODS We recorded P300 for a visual-word discrimination Oddball paradigm in 14 healthy subjects. Auditory speech and reversed speech stimulation were presented at various speeds as task-irrelevant stimuli during the P300 tasks. RESULTS The P300 latency was prolonged under forward high-speed speech stimuli (× 2.5 and × 3.5) compared with the standard speed and white noise, but there was no effect of reversed speech stimuli on the P300 latency during the word-discrimination paradigm. CONCLUSIONS We considered that high-speed speech stimulation was processed without conscious comprehension and competed with verbal processing during the visual-word-discrimination task, possibly by interfering with the use of WM. SIGNIFICANCE The present study shows the capacity of the brain to process high-speed verbal stimulation and the interaction with a visual-verbal task.

Functional inter-cortical connectivity among motor-related cortices during motor imagery: A magnetoencephalographic study

Abstract Neural connectivity was measured during motor imagery (MI) and motor execution (ME) using magnetoencephalography in nine healthy subjects, MI, and at rest. Lower coherence values during ME and MI between sensorimotor areas than at rest, and lower values during MI between the left supplementary motor area and inferior frontal gyrus than ME suggested the sensorimotor network of MI functioned with similar connectivity to ME and that the inhibitory activity functioned continuously during MI, respectively.

Variability of P300 in elderly patients with dementia during a single day.

We recorded P300 sequentially during a single day in nine patients with dementia in a health care facility. The variability of the P300 response and the relationship between P300 and the Revised Hasegawa Dementia Scale were investigated. The sequential P300 latency and amplitude measurements varied significantly during the day, but the value changes were not related to the scheduled programs in the facility. Although there was no correlation between the values of latency or amplitude and Revised Hasegawa Dementia Scale (HDS-R), the variability index of the P300 latency correlated with the HDS-R score. Variability in the P300 response was considerable and the reproducibility was poor in elderly patients with dementia during the day, although the P300 latency was consistently prolonged. These results suggested that the variability of P300 was not due to transient changes in the level of consciousness, but was related to the latent pathology of fluctuating cognitive functions in patients with dementia.

Recovery function of somatosensory evoked brain response in patients with carpal tunnel syndrome: A magnetoencephalographic study

OBJECTIVE The recovery function of somatosensory evoked magnetic fields (SEFs) was recorded to investigate excitatory and inhibitory balance in the somatosensory cortex of patients with carpal tunnel syndrome. METHODS SEFs were recorded in patients and controls. Recordings were taken following median nerve stimulation with single and double pulses with interstimulus intervals of 10-200ms. The root mean square for the N20m component following the second stimulation was analyzed. SEFs following stimulation of the first and middle digits were also recorded and the location for the equivalent current dipoles was estimated in three-dimensional planes. RESULTS Distances on the vertical axis between the equivalent current dipoles for the first and third digits were shorter in patients than in control participants. The root mean square for the N20m recovered earlier in patients compared to controls; this was statistically significant at an interstimulus interval of 10ms. There was no relationship between N20m recovery and the equivalent current dipole location in the primary somatosensory cortex. CONCLUSIONS Carpal tunnel syndrome was associated with functional disinhibition and destruction of the somatotopic organization in the primary somatosensory cortex. SIGNIFICANCE Disinhibitory changes might induce a maladaptation of the central nervous system relating to pain.

Selection of Activity Items for Development of the Activity Card Sort–Japan Version

The Activity Card Sort (ACS) can both record the clients’ participation and any changes, which is a useful tool for practitioners to establish tailored occupation-focused goals. However, there is a limitation to apply the ACS to Japanese older adults as it consists of culturally relevant activities in the United States. The aim of this study was to select activity items reflecting Japanese older adults’ lifestyles and opinions to develop the Activity Card Sort–Japan Version (ACS-JPN). In the item selection process, a two-round questionnaire survey was conducted for community-dwelling Japanese older adults (Round 1: n = 177, M age = 69.9 years; Round 2: n = 178, M age = 74.9 years). Seventy-two activity items were finally included in the ACS-JPN and were classified into four domains. The ACS-JPN has some unique features compared with other ACS versions. This study only selected activity items. Further work on psychometric properties is needed.

Association between changes in visual evoked magnetic fields and non-motor features in Parkinson's disease

ABSTRACT Visual dysfunction can be caused by several abnormalities, including dysfunctions in the visual cortex and retina. Our aim was to investigate changes in visual evoked brain responses in the primary visual cortex associated with Parkinson’s disease (PD). Sixteen healthy control subjects and ten patients with PD participated in this study. We assessed the visual evoked magnetic field (VEF) using magnetoencephalography (MEG). Checkerboard pattern reversal (CPR) and monotonous grating pattern (MGP) stimulations were used. Magnetic resonance imaging (MRI) was performed to analyze brain volume and generate a tractogram. Cognitive and olfactory function, and Unified Parkinson’s Disease Rating Scale (UPDRS) scores were evaluated in patients with PD. Four components of the VEF (1M, 2M, 3M, 4M) were observed following stimulation. For both stimuli, results from the 1M and 2M components were significantly greater and the latency of the 1M component was increased markedly in the PD group compared with the healthy control group. In the PD group, 1M latency correlated with the UPDRS score of 1 for both stimuli, and a correlation was observed between olfactory function and the UPDRS score of 3 for the CPR stimulation alone. We suggest that the conduction delay observed following visual stimulation occurs peripherally rather than in the primary visual cortex. Degeneration of selective elements of the visual system in the retina, possibly midget cells, may be involved.

The temporal stability and variability across frequency bands in neural synchrony between primary and secondary somatosensory areas following somatosensory stimulation

Highlights • The theta PLV in SI and contralateral SII showed variability within 2 s after the stimulus onset.• The alpha PLV showed temporal stability within 2 s after the stimulus onset.• The neural synchrony between SI and SII varied depending on the frequency band and the inter-regions.