Figure/ground segregation from temporal delay is best at high spatial frequencies

Two experiments investigated the role of spatial frequency in performance of a figure/ground segregation task based on temporal cues. Figure orientation was much easier to judge when figure and ground portions of the target were defined exclusively by random texture composed entirely of high spatial frequencies. When target components were defined by low spatial frequencies only, the task was nearly impossible except with long temporal delay between figure and ground. These results are inconsistent with the hypothesis that M-cell activity is primarily responsible for figure/ground segregation from temporal delay. Instead, these results point to a distinction between temporal integration and temporal differentiation. Additionally, the present results can be related to recent work on the binding of spatial features over time

Perceived duration of chromatic and achromatic light

Luminance and color information are considered to be processed in parallel systems. The integration of information from these two separate systems is crucial for the visual system to produce a coherent percept. To investigate how luminance and color lights are perceived in time, we measured the perceived duration of light stimuli with and without colors in a paradigm involving simultaneous perception with presentation of two successive stimulus frames. Luminance contrast and color contrast of the stimuli were set with a chromatic substitution technique. In Experiment 1, the perceived duration of both chromatic stimuli and achromatic stimuli increased as the luminance contrast decreased. Experiment 2 tested if the duration of the percept was influenced by color contrast which was defined by colorimetric purity of the stimuli, when luminance contrast was set as low as practically possible. The result showed that the duration of the percept decreased with increasing color contrast of the stimuli. Moreover, Experiment 3 demonstrated that the trend of perceived duration was consistent with the four primary colors, provided that the effective color contrast of stimulus was corrected based on the contrast sensitivity to the color. These experiments indicate that, with a high luminance contrast level, perceived duration of a stimulus is predominantly defined by luminance contrast, whereas in low luminance contrast conditions, the duration depends on the color contrast. The perceived duration of color stimuli showed an "inverse color contrast effect", similar to the well-known "inverse intensity effect" for luminance stimuli. The similarities and the differences between the two systems, as well as their priorities in processing temporal information of visual stimuli are further discussed. © 2011 Elsevier Ltd. All rights reserved

Hemodynamic change in occipital lobe during visual search: Visual attention allocation measured with NIRS

金沢大学人間社会研究域人間科学系We examined the changes in regional cerebral blood volume (rCBV) around visual cortex using Near Infrared Spectroscopy (NIRS) when observers attended to visual scenes. The oxygenated and deoxygenated hemoglobin (Oxy-Hb and Deoxy-Hb) concentration changes at occipital lobe were monitored during a dual task. Observers were asked to name a digit superimposed on a scenery picture, while in parallel, they had to detect an on-and-off flickering object in a Change Blindness paradigm. Results showed the typical activation patterns in and around the visual cortex with increases in Oxy-Hb and decreases in Deoxy-Hb. The Oxy-Hb increase doubled when observers could not find the target, as opposed to trials in which they could. The results strongly suggest that active attention to a visual scene enhances Oxy-Hb change much stronger than passive watching, and that attention and Oxy-Hb increases are possibly correlated. © 2009 Elsevier Ltd. All rights reserved

The effects of processing speed and memory span on working memory

This study examined the processing speed and memory span of young adults and older people using tasks based on the Wechsler Adult Intelligence Scale-III (WAIS-III, Wechsler, 1997). By comparing the data obtained from these tasks, we examined the effects of processing speed and memory span on working memory (WM). In addition, this study examined how presentation modality and the subject\u27s age are related to WM. Multiple regression analysis of the effect of memory span for each presentation modality used processing time as a factor to predict the WM span of various age groups. The result was two equations for predicting WM span. According to these equations, WM is negatively correlated with "age group" and "processing time," and positively correlated with "memory span." Memory span and processing speed were found to have similar impacts on WM, regardless of the presentation modality. However, our results suggested that visual WM and auditory WM are different functions, and that auditory WM is more strongly affected by memory span than visual WM

Active versus passive listening to auditory streaming stimuli: a near-infrared spectroscopy study.

金沢大学人間社会研究域人間科学系We use near-infrared spectroscopy (NIRS) to assess listeners\u27 cortical responses to a 10-s series of pure tones separated in frequency. Listeners are instructed to either judge the rhythm of these "streaming" stimuli (active-response listening) or to listen to the stimuli passively. Experiment 1 shows that active-response listening causes increases in oxygenated hemoglobin (oxy-Hb) in response to all stimuli, generally over the (pre)motor cortices. The oxy-Hb increases are significantly larger over the right hemisphere than over the left for the final 5 s of the stimulus. Hemodynamic levels do not vary with changes in the frequency separation between the tones and corresponding changes in perceived rhythm ("gallop," "streaming," or "ambiguous"). Experiment 2 shows that hemodynamic levels are strongly influenced by listening mode. For the majority of time windows, active-response listening causes significantly larger oxy-Hb increases than passive listening, significantly over the left hemisphere during the stimulus and over both hemispheres after the stimulus. This difference cannot be attributed to physical motor activity and preparation related to button pressing after stimulus end, because this is required in both listening modes

異種視覚手がかりによる対象検出特性と視覚処理の階層性に関する研究

金沢大学人間社会研究域歴史言語文化学系本年度は、方位及び空間周波数で定義された対象の検出における学習の効果を調べた。【方法】装置及び刺激 刺激画像はパーソナルコンピュータによって作成・制御され、高解像度モニター上に呈示された。刺激は複数個のガボールパッチから構成された。パッチには4通りの空間周波数(SF)、4通りの方位を用いた。手続きと課題 測定は5日間に亘って実施された。被験者はあご台を用いて右目で刺激を観察した。刺激パッチはブザー音に続いて数秒後、凝視点の周囲に呈示され下記の課題を行った。反応には全測定で常に同じ手の同じ指を用いた。実験1:画面中心の凝視点の左右両側視角約0.5度の位置に2つのガボールパッチが呈示された。単純反応課題:刺激が呈示されたら素早く反応することが求められた。単純弁別課題:二つの刺激が同じか違うかを判断して素早く反応した。実験2:画面中央の4つの凝視用パッチを中心にして半径視角約1.5度の同心円上に12個のガボールパッチが呈示された。単純探索課題:異なる方位又はSFのパッチの有無をできるだけ素早く報告した。結合探索課題:呈示されるパッチは2つの次元(方位及びSF)によって定義されていた。被験者は定義に反するパッチの有無を素早く判断報告した。【結果と考察】全被験者において、ほぼ全課題において学習効果が観察された(セッション、試行日を重ねるにつれて反応時間・探索時間の減少がおこった。反応にかかわる運動のレベル(単純反応課題)での学習効果は少なく、むしろ、対象の弁別と判断にかかわる処理過程(その他の3課題)において、それぞれ反応性が向上することが明らかになった。研究課題/領域番号:15730331, 研究期間(年度):2003 – 2005出典：「異種視覚手がかりによる対象検出特性と視覚処理の階層性に関する研究」研究成果報告書　課題番号15730331（KAKEN：科学研究費助成事業データベース（国立情報学研究所））（https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-15730331/)を加工して作

認知的遂行における身体活動と身体適応の効果：研究の現状と見通し

Background. A growing body of literature has demonstrated that regular physical activity (PA) and high fitness levels have a positive impact on cognition. Electroencephalogram (EEG) studies, particularly those using event-related brain potentials (ERPs), have played a key role in the growth of the PA-cognition research field. This paper focuses on reviewing the relevant neuroelectric and behavioral findings on the beneficial relationship between PA and cognition across the human lifespan. The discussion focuses on whether PA reflects a general cognitive enhancement or benefits some cognitive processes more than others. Method. An electronic literature search was conducted up to July 2018. Studies were included in this review if they provided behavioral and neuroelectric evidence within healthy people across their lifespan. Results. Previous studies provided strong evidence of PA-linked benefits related to selective attention, cognitive control, and cognitive flexibility. Furthermore, cross-sectional studies proposed a potential improvement in working memory. Overall, reviewed studies suggested that having an active lifestyle could be associated with significant improvements in executive functions. Conclusion. There is much evidence to support the notion that physical activity influences the neural activity of the brain and cognition. A theory to explain why an active lifestyle might benefit some cognitive processes more than others is needed. Furthermore, it is necessary to identify a set of elemental cognitive processes to understand the brain mechanisms underlying each of these processes. Optimizing the amount of PA that could maximize its benefits on brain health and function should be considered in future studies as well.背景 日常的な身体活動(PA)と身体適応レベルの高さが認知にポジテイプな効果を持つこと を多くの研究が示している。 脳波(EEG)研究特に事象関連電位(ERP)は， PAと認知の研 究分野の広がりに鍵となる役割を果たしてきた。 本報告は． 人間の生涯にわたるPAと認知の有益な関係を神経電気的・行動的に示す顕著な発見に焦点をあて論評する。議論では， PAが一般 的な認知的向上や恩恵を特定の認知過程に与えるのかに焦点をあてる。方法 電子媒体における文献検索が2018年7月に行われた。本報告に含む研究は．生涯健康な人々 において示された行動的・神経電気的発見とした。結果 先行研究は選択的注意， 認知的制御， そして認知的柔軟性に関連したPA関連効果の有力 な証拠を与えている。 さらに． 横断的研究は作動記憶における潜在的改善効果も示唆した。 全体 として， 検証された研究は活動的な生活型を持つことが実行機能における有意な改善をもたらし 得ることを示した。結論 身体活動が脳の神経活動と認知に有益であることを支持する有力な証拠がある。 活動的生 活がなぜいくつかの認知過程においてのみ有益であるのかを説明する理論の構築が求められる。 さらに． これらの基盤となる脳内メカニズムを理解するためには基本的な認知過程の同定が必要 である。 脳の健康と機能におけるPAの恩恵を最大にするPA最を知るために更なる研究が検討さ れねばならない

Oxygen-glucose deprivation decreases the motility and length of axonal mitochondria in cultured dorsal root ganglion cells of rats

神経細胞に対する低酸素－低グルコース（OGD）は，虚血モデルとして用いられる．本研究は，ラット脊髄神経節初代培養細胞および遺伝子工学技法を用いて，OGDが神経軸索のミトコンドリア（Mt）の動態にどのような影響を与えるのかを検討した．結果，OGD暴露の6時間後に停留Mtの長さが有意に減少し，軸索内の球状Mtの割合が増加した．停留Mtの長さが減少したのは，輸送Mtの停止，Mtの分裂および停留Mt自身の短縮であることを明らかにした．これらの現象は軸索変性および細胞死よりも先行して観察されたことから，Mtが治療の対象となることが考えられた

中国人日本語学習者のコロケー ション処理における母語の影響一漢語名詞＋動詞のコロケー ションの場合 一

We carried out an experiment to examine the influence of native language (LI) when Chinese learners of Japanese process Japanese (L2) collocations. In the present study, Chinese-Japanese congruent collocations (C-J), Japanese-only collocations (J-only), and unrelated items were presented visually by computer. The Chinese learners of Japanese were then asked to judge whether the stimuli exist in Japanese or not. Results showed that for low proficiency learners the reaction time for C-J collocation was shorter than that of J-only collocation, while for high proficiency learners the reaction time for C-J collocation was longer than that of J-only collocation. These findings indicate that in the case of J-only collocation, learners can get rid of the influence of Ll as their proficiency increases, while in the case of the C-J collocation, it is difficult for them to get rid of the influence from their LL These results challenge Jiang (2000)\u27s lexical development model.中国人日本語学習者がL2日本語のコロケーションを処理する際のLlの影響を検証するために，本研究を行った。中国語一日本語で一致するコロケーション（C-J），日本語にしかないコロケーション(J-only), 無関連な項目の 3種類の刺激を呈示し． 日本語に存在しているかどうかを中上級の中国人日本語学習者に判断させた。実験の結果，低習熟度の学習者の場合. C-Jの反応時 間がJ-onlyより短いのに対し， 高習熟度の学習者になると，C-Jの反応時間がJ-onlyより長くなった。これらの結果から， 習熟度が高まるに従い， 学習者がJ-onlyコロケ ー ションを処理する際には，Llの影響を乗り越えるようになるのに対し， 習熟度が高くなっても. C-Jコロケ ー ションを処理する際には， Llの影響を乗り越えにくいということが分かった。これはJiang (2000) の語彙発達モデルに反する結果であった