Bayesian-based decipherment of in-depth information in bacterial chemical sensing beyond pleasant/unpleasant responses.

Chemical sensing is vital to the survival of all organisms. Bacterial chemotaxis is conducted by multiple receptors that sense chemicals to regulate a single signalling system controlling the transition between the direction (clockwise vs. counterclockwise) of flagellar rotation.

Macroscopic neural mass model constructed from a current-based network model of spiking neurons.

Neural mass models (NMMs) are efficient frameworks for describing macroscopic cortical dynamics including electroencephalogram and magnetoencephalogram signals. Originally, these models were formulated on an empirical basis of synaptic dynamics with relatively long time constants. By clarifying the relations between NMMs and the dynamics of microscopic structures such as neurons and synapses, we can better understand cortical and neural mechanisms from a multi-scale perspective.

Facilitated lexical ambiguity processing by transcranial direct current stimulation over the left inferior frontal cortex.

Previous studies suggest that the left inferior frontal cortex is involved in the resolution of lexical ambiguities for language comprehension. In this study, we hypothesized that processing of lexical ambiguities is improved when the excitability of the left inferior frontal cortex is enhanced. To test the hypothesis, we conducted an experiment with transcranial direct current stimulation (tDCS).

Phase shifts in alpha-frequency rhythm detected in electroencephalograms influence reaction time.

Although the phase shifts in ongoing oscillations seen in electroencephalograms (EEGs) and magnetoencephalograms are an important factor in discussions of phase dynamics, such as synchrony and reset, few studies have focused specifically on the phase shift. Here we investigate the relationship between phase shifts in alpha-frequency rhythms and reaction times during a visual simple reaction task by applying our previously described method (Naruse et al., 2013), which enables detection of phase shifts from a single EEG trial.

Accuracy of estimating strengths of dipole moments from a small number of magnetoencephalographic trial data.

The conventional analysis estimates both the locations and strengths of neural source activations from event-related magnetoencephalography data that are averaged across about a hundred trials. In the present report, we propose a new method based on a minimum modified-l 1-norm to obtain the dependence of strengths on the presented stimuli from a limited number of trial data. It estimates the strengths from 10-trial average data and the locations from 100-trial average data.

Supramolecular photocyclodimerization of 2-hydroxyanthracene with a chiral hydrogen-bonding template, cyclodextrin and serum albumin.

2-Hydroxyanthracene (HA) in its neutral form smoothly photocyclodimerized to four stereoisomeric [4 + 4]-cyclodimers, which were isolated and characterized for the first time, whereas the anionic form of HA turned out to be photochemically inert. Enantiodifferentiating photocyclodimerization of HA in the presence of a chiral hydrogen-bonding template (TKS159), γ-cyclodextrin (γ-CDx) and bovine serum albumin (BSA) was examined to afford chiral syn-head-to-tail and anti-head-to-head cyclodimers in modest enantiomeric excesses with TKS159 and γ-CDx, but practically no photocyclodimerization proceeded in the presence of BSA probably due to the ionization of HA in the binding sites.

Statistical method for detecting phase shifts in alpha rhythm from human electroencephalogram data.

We developed a statistical method for detecting discontinuous phase changes (phase shifts) in fluctuating alpha rhythms in the human brain from electroencephalogram (EEG) data obtained in a single trial. This method uses the state space models and the line process technique, which is a Bayesian method for detecting discontinuity in an image. By applying this method to simulated data, we were able to detect the phase and amplitude shifts in a single simulated trial.

Cross- versus homo-photocyclodimerization of anthracene and 2-anthracenecarboxylic acid mediated by a chiral hydrogen-bonding template. Factors controlling the cross-/homo-selectivity and enantioselectivity.

Competitive cross-/homo-photocyclodimerization of anthracene (AN) and 2-anthracenecarboxylic acid (AC) mediated by a chiral hydrogen-bonding template (TKS) was investigated under various conditions. The cross-photocyclodimerization was favored by a factor of 4-5 at all temperatures and wavelengths examined to afford the AC-AN cross-dimer in 80-84% yield even at AN/AC = 1 and in 98% yield at AN/AC = 10. The enantiomeric excesses (ee's) obtained were 27-47% for the homo-dimers and 21-24% for the cross-dimer.

Language comprehension dependent on emotional context: a magnetoencephalography study.

In communication, language can be interpreted differently depending upon the emotional context. To clarify the effect of emotional context on language processing, we performed experiments using a cross-modal priming paradigm with an auditorily presented prime and a visually presented target. The primes were the names of people that were spoken with a happy, sad, or neutral intonation; the targets were interrogative one-word sentences with emotionally neutral content.