8 research outputs found
Cerebral response to emotional working memory based on vocal cues: an fNIRS study
IntroductionHumans mainly utilize visual and auditory information as a cue to infer others’ emotions. Previous neuroimaging studies have shown the neural basis of memory processing based on facial expression, but few studies have examined it based on vocal cues. Thus, we aimed to investigate brain regions associated with emotional judgment based on vocal cues using an N-back task paradigm.MethodsThirty participants performed N-back tasks requiring them to judge emotion or gender from voices that contained both emotion and gender information. During these tasks, cerebral hemodynamic response was measured using functional near-infrared spectroscopy (fNIRS).ResultsThe results revealed that during the Emotion 2-back task there was significant activation in the frontal area, including the right precentral and inferior frontal gyri, possibly reflecting the function of an attentional network with auditory top-down processing. In addition, there was significant activation in the ventrolateral prefrontal cortex, which is known to be a major part of the working memory center.DiscussionThese results suggest that, compared to judging the gender of voice stimuli, when judging emotional information, attention is directed more deeply and demands for higher-order cognition, including working memory, are greater. We have revealed for the first time the specific neural basis for emotional judgments based on vocal cues compared to that for gender judgments based on vocal cues
Neutron Imaging Using a Fine-Grained Nuclear Emulsion
A neutron detector using a fine-grained nuclear emulsion has a sub-micron spatial resolution and thus has potential to be applied as high-resolution neutron imaging. In this paper, we present two approaches to applying the emulsion detectors for neutron imaging. One is using a track analysis to derive the reaction points for high resolution. From an image obtained with a 9 μm pitch Gd grating with cold neutrons, periodic peak with a standard deviation of 1.3 μm was observed. The other is an approach without a track analysis for high-density irradiation. An internal structure of a crystal oscillator chip, with a scale of approximately 30 μm, was able to be observed after an image analysis
A Novel Nuclear Emulsion Detector for Measurement of Quantum States of Ultracold Neutrons in the Earth's Gravitational Field
Hypothetical short-range interactions could be detected by measuring the
wavefunctions of ultracold neutrons (UCNs) on a mirror bounded by the Earth's
gravitational field. The Searches require detectors with higher spatial
resolution. We are developing a UCN detector for the with a high spatial
resolution, which consists of a Si substrate, a thin converter layer including
BC, and a layer of fine-grained nuclear emulsion. Its resolution
was estimated to be less than 100 nm by fitting tracks of either Li
nuclei or -particles, which were created when neutrons interacted with
the BC layer. For actual measurements of the spatial
distributions, the following two improvements were made: The first was to
establish a method to align microscopic images with high accuracy within a wide
region of 65 mm 0.2 mm. We created reference marks of 1 m and 5
m diameter with an interval of 50 m and 500 m, respectively, on
the Si substrate by electron beam lithography and realized a position accuracy
of less than 30 nm. The second was to build a holder that could maintain the
atmospheric pressure around the nuclear emulsion to utilize it under vacuum
during exposure to UCNs. The intrinsic resolution of the improved detector was
estimated by evaluating the blur of a transmission image of a gadolinium
grating taken by cold neutrons as better than 0.56 0.08 m, which
included the grating accuracy. A test exposure to UCNs was conducted to obtain
the spatial distribution of UCNs in the Earth's gravitational field. Although
the test was successful, a blurring of 6.9 m was found in the
measurements, compared with a theoretical curve. We identified the blurring
caused by the refraction of UCNs due to the roughness of the upstream surface
of the substrate. Polishing of the surface makes the resolution less than 100
nm