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The human brain automatically processes information at multiple sites when recognizing various types of information at the same time, such as color, shape, etc. Cognitive conflict may occur when conflicting information is recognized at the same time. Functional near-infrared spectroscopy (fNIRS) is often used to examine the brain activity associated with this phenomenon. To examine activation of the visual system, we measured brain activity in the right / left hemispheres during cognitive conflict in the Stroop test. Consistent with the results reported previously by Ehlis, the brain activity in the near inferior-frontal gyrus of the left hemisphere was increased during the incongruent task. The brain activity also increased in the near inferior-frontal gyrus of the right hemisphere during the incongruent task. These results indicated that fNIRS can be used to detect brain activity in the inferior-frontal gyrus of the right / left hemispheres during the Stroop test.

A new technique is described for measuring the adhesion between a sharply curved metal point (platinum, tungsten, titanium, nickel or gold, with a radius of curvature typically 300 nm) and a flat surface (platinum, tungsten, cobalt, silicon or graphite). Adhesion forces as small as 100nN can be measured with a sensitivity (limited by friction and vibration) of 20 nN, and the electrical resistance of the contact region is measured as a function of positive and negative load. Any plastic deformation of the metal point, as well as its cleanliness, is monitored by current and voltage measurements on electrons drawn by field emission from the point before and after contact.For platinum and tungsten surfaces placed in contact with near-zero loads, high values of adhesion (up to 55 pN) were measured provided that both surfaces were sufficiently clean; there is evidence that one area of 'single-asperity' contact is obtained, Ductile extension was occasionally observed, but the experimental curves of resistance against load were otherwise reversible for both positive and negative loads, and unaffected by the magnitude of any previously applied positive load. Measurements of adhesion, resistance and change in resistance as a function of load may be divided into two categories according to whether separation took place at the interface or within the bulk of one of the samples. Generally the results are not consistent with the elastic theory of Johnson er al or with the model of Gane et al. Differences in the behaviour of contacts between the other materials are described. Further analysis may enable the method to be used for measuring values of work of adhesion (change in surface energy) for interfaces between stiff solids.

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Independent component analysis (ICA) is one of the most preferred methods for removing motion artifacts from functional near-infrared spectroscopy (fNIRS) data. In this method, fNIRS signal is separated into some components by ICA. The component which has high correlation between fNIRS signal and motion artifact is determined. This component is removed and fNIRS signal without motion artifact effect is derived. However, because of the influence of blood flow, fNIRS data are often delayed in time compared with the acceleration sensor data. Therefore, the correlation is reduced, and it is difficult to determine whether the component has been derived from the motion artifact. We here propose a method for removing the motion artifact using ICA, which considers the time delay in the fNIRS data. In this proposed method, ICA is performed multiple times, shifting the start time of the fNIRS data with each repeat. Then, only the best correlated result is adopted for comparison with the acceleration sensor data. To examine the effectiveness of this method, its results were compared with the results obtained without considering the time delay. It was found that the proposed method improved that accuracy of removing the motion artifact.