Audiovisual integration in Mongolian Gerbil Evaluated with Sensory Evoked Potentials

ヒトは複数の感覚入力を統合することによって外界を知覚している。視聴覚統合はラットやマウスのような標準的な実験動物であるげっ歯類において研究されている。しかしながらヒトとは異なり、両種とも夜行性である。彼らは視力が悪く、低周波（<5 kHz）に対する聴覚感度はヒトの聴覚感度に比べ著しく悪い。したがって、彼らは視聴覚統合を研究するには不適切な動物モデルである。スナネズミは比較的良好な視力を有しており、その低周波の感度はヒトに似ている。したがって、本研究において、私たちはスナネズミの視覚野周辺での視聴覚統合に関連のある領域を調べた。私たちは視覚刺激のみ、聴覚刺激のみ、視聴覚同時刺激によって生じる感覚誘発電位を計測した。計測部位はそれぞれ1 mm間隔離して計測した。それぞれの計測部位において、視聴覚同時刺激の誘発電位波形と聴覚、視覚単独での誘発電位を足し合わせた波形の類似度を比較した。その結果、計測部位によって類似性が異っており、二次視覚野（V2L）周辺（ラムダから外側に4 mm、前方に2 mm）で最も類似度が低かった。これらの結果から、V2Lはスナネズミにおいて視聴覚統合に関係があり、スナネズミは視聴覚統合の神経基盤を研究するのに適したモデル動物であることを示唆している。Humans perceive the world by integrating multiple sensory inputs. Audiovisual integration has been studied in standard laboratory rodents, such as rats and mice. However, unlike humans, both species are nocturnal. They have poor visual acuity and their auditory sensitivity to low frequencies (<5 kHz) is significantly worse than that of humans (by at least 20 dB). Therefore, they are unsuitable animal models in which to study audiovisual integration. The Mongolian gerbil, [Meriones unguiculatus], has relatively good eyesight and its low-frequency sensitivity is similar to that of humans. Therefore, in this study, we investigated the brain regions related to audiovisual integration around the visual cortex in the Mongolian gerbil. We recorded the sensory evoked potentials (EPs) generated by a visual stimulus alone, an auditory stimulus alone, and synchronized audiovisual stimuli. Each recording site was separated by 1 mm pitch. The similarity of the EP waveforms was evaluated between the audiovisual EP and the sum of the auditory and visual EPs at each recording site. The results showed that the similarity varied depending on the site, and was the lowest around the lateral secondary visual cortex (4 mm lateral and 2 mm anterior to lambda). These results suggest that V2L is associated with audiovisual integration in the gerbil, and that the species is a suitable animal model in which to study the neural basis of audiovisual integration.内容記述(英語)中の[Meriones unguiculatus]は斜体文

SoundFile

Sound files (number of channels = 1; data length = 10 seconds) of echolocation pulses recorded with microphones mounted directly on bats flying alone or in groups of four individuals. The data were digitized using a high-speed data-acquisition card (National Instruments, Model NI PXI-6358, Tokyo, Japan, 16 bit, fs = 500 kHz). File names are as below. "batID"_"flight condition".bi

Discrimination of object information by bat echolocation deciphered from acoustic simulations

High-precision visual sensing has been achieved by combining cameras with deep learning. However, an unresolved challenge involves identifying information that remains elusive for optical sensors, such as occlusion spots hidden behind objects. Compared to light, sound waves have longer wavelengths and can, therefore, collect information on occlusion spots. In this study, we investigated whether bats could perform advanced sound sensing using echolocation to acquire a target's occlusion information. We conducted a two-alternative forced choice test on Pipistrellus abramus with five different targets, including targets with high visual similarity from the front, but different backend geometries, i.e. occlusion spots or textures. Subsequently, the echo impulse responses produced by these targets, which were difficult to obtain with real measurements, were computed using three-dimensional acoustic simulations to provide a detailed analysis consisting of the acoustic cues that the bats obtained through echolocation. Our findings demonstrated that bats could effectively discern differences in target occlusion spot structure and texture through echolocation. Furthermore, the discrimination performance was related to the differences in the logarithmic spectral distortion of the occlusion-related components in the simulated echo impulse responses. This suggested that the bats obtained occlusion information through echolocation, highlighting the advantages of utilizing broadband ultrasound for sensing

Human striatal volume predicts interindividual differences in music-induced intense emotional responses

音楽聴取は 鳥肌が立つ ほど強烈な情動経験をたびたび引き起こす。これまで 鳥肌が立つ という状態を予期することや体験することが、報酬系回路に関連していると報告されてきた。本研究では、音楽による強烈な情動経験の個人差と脳神経系の関連性について、磁気共鳴画像法(magnetic resonance imaging, MRI)を用いた解剖学的検討を行った。19人の被験者は、音楽を聴いて鳥肌が立つような気持ちの時に手元のボタンを押す課題に取り組んだ。実験刺激には、各被験者の鳥肌が立ったことのある曲を使用した。実験の結果、音楽に対して喚起される情動感度の個人差は、右尾状核、左島皮質、右中心後回の灰白質の容積に相関していることが示された。本研究は、鳥肌が立つような審美的体験に関連した解剖学的構造を示し、音楽知覚における大脳辺縁系の報酬系回路の役割を強調するものである。Music can induce intense emotions and physiological responses, such as goose bumps , shivers , or aesthetic chills . Previous studies have suggested that the reward circuit is related to the anticipation and experience of such chills. In this study, we used structural magnetic resonance imaging to investigate individual differences in the intense emotional responses evoked by music. Nineteen subjects were asked to listen to music and report whether they were feeling chills by pressing a button. Each subject selected the music to which they listened based on its having induced chills previously. Our findings offer evidence that individual differences in sensitivity to music-induced emotion might be associated with the gray matter volume in the right caudate, left insula, and right postcentral gyrus. These findings constitute anatomical evidence related to the timing of the aesthetic chills and underscore the role of mesolimbic reward circuits in music perception

Cortico-striatal activity associated with fidget spinner use: an fMRI study

Abstract Fidget spinners are said to be a very successful toy, and it's said that it has a good impact on attention for children with ADHD and hand motor control. However, there is limited scientific evidence to support these claims, and there is a lack of data on neurobiological responses to rotating fidget spinners. To better understand the mechanism whereby fidget spinners affect motor behavior, we tried to identify the neural correlates of rotating fidget spinners using functional magnetic resonance imaging and non-magnetic fidget spinners with five types of ease of rotation. As a result, we confirmed that the pre/postcentral gyrus, middle temporal gyrus, supplementary motor area (SMA), cerebellum, and striatum are activated when rotating spinners. Furthermore, the SMA was activated more with easier-to-rotate spinners. Additionally, a psychophysiological interaction analysis revealed increased functional connectivity between the SMA and the caudate while rotating fidget spinners compared to just holding them. These results suggest that the fine motor control associate with spinning a fidget spinner is supported by the cortico-striatal circuits involved in planning and reward

Supplementary figure 1 from Discrimination of object information by bat echolocation deciphered from acoustic simulations

The SI contains four figures, each of which makes the paper compelling. Please see the caption of each figure for a detailed explanation