A line display that utilizes saccade has been proposed. When an observer moves his or her eyes on a one-dimensional fixed line display, two-dimensional information is perceived on the retina. In this paper, a high speed flashing line display was developed using a CPLD and PIC microcontroller. The flashing period was reduced to 20 µs, which was less than half that of our previous system. The relationship between the flashing frequency and the optimum distance that can be perceived with the least distortion was clarified. The results show that the higher the flashing frequency is, the more information can be perceived from a farther position. Calculated values, which were based on the relationship between the flashing period and the width of the light source, were almost identical with measured values at the flashing frequencies from 3.3 kHz to 10 kHz. Due to short flashing period, the developed line display not only was visible at distance of 15 m or more, which is suitable for outdoor use, but also realized 16 gray levels.

We can enjoy various video contents such as movies in several ways. In this report, we show the effects of content differences on physiological parameters such as eye movements and CFF. This time we confirmed the difference in responses that after watching a movie. In addition, a consistent change that can infer that due to a movie was also indicated. Our results showed that content differences affect the parameters. This suggests the possibility that the influence of movie contents on the viewer can be evaluated by physiological parameters.

Over the last 10 years, tablets have spread to the point where we can now read electronic books (e-books) like paper books. There is a long history of studies of eye movement during reading. Remarkable results have been reported for reading experiments in which displayed letters are changed in conjunction with eye movement during reading. However, these studies were conducted in the 1970s, and it is difficult to judge the detailed descriptions of the experimental techniques and whether the display time was correctly controlled when changing letters. Here, we propose an experimental system to control the display information exactly, as well as the display time, and inspect the results of past reading research, with the aim of being at the forefront of reading research in the e-book era.

In this paper, we developed saccade-induced line displays including flashing period controllers. The displays speeded up the flashing period of one line using LED drivers and Arduino Uno equipped with AVR microcomputers. It was shown that saccades were easily induced when the observer alternately looks at the two fast flashing line displays apart. Also, we were able to find the optimum flashing period using a controller that can speed up the flashing period and change its speed. We found that the relationship between the viewing angle of the observer and the optimum flashing period is almost proportional.

This paper describes the background noise estimation technique of the tensor product expansion with absolute error (TPE-AE) to estimate multiple sources. The electroencephalogram (EEG) signal produced by the saccadic eye movement is adopted to analyze relationship between a brain function and a human activity. The electrooculogram (EOG) generated by eye movements yields significant problems for the EEG analysis. The denoising of EOG artifacts is important task to perform an accurate analysis. In this paper, the two types of TPE-AE are proposed to estimates EOG and other components in EEG during eye movement. One technique estimates two outer products using median filter based TPE-AE. The another technique uses a reference signal to separate the two sources. We show that the proposed method is effective to estimate and separate two sources in EEG.

We investigated subjects' gaze movement when reading E-books and compared it with that when reading traditional paper books. By examining the eye motion associated with the reader encountering new lines and new pages during reading, we found that each new line was completed with one saccade in both E-books and paper books, but E-books and paper books differed in saccade patterns when the reader encountered a new page. In E-books, a regular eye movement such as steady gaze to the next page's start position was repeated. In contrast, in paper books, there is no regularity in eye movement during this transition. It was shown that reading behavior is variable and depends on the individual.

In order to investigate reading processes of Japanese language learners, we have conducted an experiment to record eye movements during Japanese text reading using an eye-tracking system. We showed that Japanese native speakers use "forward and backward jumping eye movements" frequently [13] [14]. In this paper, we analyzed further the same eye tracking data. Our goal is to examine whether Japanese learners fix their eye movements at boundaries of linguistic units such as words, phrases or clauses when they start or end "backward jumping". We consider conventional linguistic boundaries as well as boundaries empirically defined based on the entropy of the N-gram model. Another goal is to examine the relation between the entropy of the N-gram model and the depth of syntactic structures of sentences. Our analysis shows that (1) Japanese learners often fix their eyes at linguistic boundaries, (2) the average of the entropy is the greatest at the fifth depth of syntactic structures.

Although the line-of-sight (LoS) is expected to be useful as input methodology for computer systems, the application area of the conventional LoS detection system composed of video camera and image processor is restricted in the specialized area, such as academic research, due to its large size and high cost. There is a rapid eye motion, so called 'saccade' in our eye motion, which is expected to be useful for various applications. Because of the saccade's very high speed, it is impossible to track the saccade without using high speed camera. The authors have been proposing the high speed vision chip for LoS detection including saccade based on the pixel parallel processing architecture, however, its resolution is very low for the large size of its pixel. In this paper, we propose and discuss an architecture of the vision chip for LoS detection including saccade based on column-parallel processing manner for increasing the resolution with keeping high processing speed.

Rapid eye motion, or so called saccade, is a very quick eye motion which always occurs regardless of our intention. Although the line of sight (LOS) with saccade tracking is expected to be used for a new type of computer-human interface, it is impossible to track it using the conventional video camera, because of its speed which is often up to 600 degrees per second. Vision Chip is an intelligent image sensor which has the photo receptor and the image processing circuitry on a single chip, which can process the acquired image information by keeping its spatial parallelism. It has also the ability of implementing the very compact integrated vision system. In this paper, we describe the vision chip architecture which has the capability of detecting the line of sight from infrared eye image, with the processing speed supporting the saccade tracking. The vision chip described here has the pixel parallel processing architecture, with the node automata for each pixel as image processing. The acquired image is digitized to two flags indicating the Purkinje's image and the pupil by comparators at first. The digitized images are then shrunk, followed by several steps of expanding by node automata located at each pixel. The shrinking process is kept executed until all the pixels disappear, and the pixel disappearing at last indicates the center of the Purkinje's image and the pupil. This disappearing step is detected by the projection circuitry in pixel circuit for fast operation, and the coordinates of the center of the Purkinje's image and the pupil are generated by the simple encoders. We describe the whole architecture of this vision chip, as well as the pixel architecture. We also describe the evaluation of proposed algorithm with numerical simulation, as well as processing speed using FPGA, and improvement in resolution using column parallel architecture.

To clarify the stereopsis disturbance in patients with Alzheimer's disease (AD), we analyzed binocular eye movement when subjects shifted their gaze between targets at different depths. Subjects are patients with Alzheimer's disease, Mluti-infarct dementia (MID), or Olivopontocerebellar atrophy (OPCA), and healthy controls. Targets are arranged in two ways: along the median plane and asymmetrically crossing the median plane, at distances from the eyes of 1000 mm and 300 mm. When the targets are switched at the onset of a beep, the subjects shifted their gaze to the lit target. The experiment is conducted in a dimly lit room whose structure is capable of providing good binocular cues for depth. In AD subjects, especially in the subjects whose symptoms are moderate (advanced stage), vergence is limited and the change in the convergence angle is small, unstable, and non-uniform. These results are different from those of other patients (MID) and OPCA) or healthy controls and suggest a disturbance of stereopsis in the parietal lobe where AD patients typically have dysfunctions.