Toshiya Morita

Development and features of a TV navigation system

A TV navigation system has been developed to make it easier for viewers to watch television in a multichannel area. It enables viewers to watch programs recommended by the system as well as to select programs using a personalized electronic program guide (EPG) and retrieve programs with a personal filter. The system combines a mechanism for recommending programs in accordance with the preferences and mood of the viewer with personalized program sorting and retrieving in an easy-to-use format. Subjective evaluation tests were held to evaluate the impressions of general viewers with regard to operating this TV navigation system and benefiting from its use. It was found that program recommendations were helpful and that the types of programs desired by a viewer and their method of selection differed according to time of day.

Decoding humor experiences from brain activity of people viewing comedy movies.

Humans naturally have a sense of humor. Experiencing humor not only encourages social interactions, but also produces positive physiological effects on the human body, such as lowering blood pressure. Recent neuro-imaging studies have shown evidence for distinct mental state changes at work in people experiencing humor. However, the temporal characteristics of these changes remain elusive. In this paper, we objectively measured humor-related mental states from single-trial functional magnetic resonance imaging (fMRI) data obtained while subjects viewed comedy TV programs. Measured fMRI data were labeled on the basis of the lag before or after the viewer’s perception of humor (humor onset) determined by the viewer-reported humor experiences during the fMRI scans. We trained multiple binary classifiers, or decoders, to distinguish between fMRI data obtained at each lag from ones obtained during a neutral state in which subjects were not experiencing humor. As a result, in the right dorsolateral prefrontal cortex and the right temporal area, the decoders showed significant classification accuracies even at two seconds ahead of the humor onsets. Furthermore, given a time series of fMRI data obtained during movie viewing, we found that the decoders with significant performance were also able to predict the upcoming humor events on a volume-by-volume basis. Taking into account the hemodynamic delay, our results suggest that the upcoming humor events are encoded in specific brain areas up to about five seconds before the awareness of experiencing humor. Our results provide evidence that there exists a mental state lasting for a few seconds before actual humor perception, as if a viewer is expecting the future humorous events.

Development and tests of a TV navigation system personalized with viewer's habits

A TV navigation system has been developed that enables a variety of viewers to enjoy TV programs in accordance with occasional mood and preferences. The system provides combined facilities of recommending programs and presenting an EPG (electronic program guide) personalized for their interests. Evaluation tests have been accomplished with actual broadcasting contents.

Undetectable Changes in Image Resolution of Luminance-Contrast Gradients Affect Depth Perception

A great number of studies have suggested a variety of ways to get depth information from two dimensional images such as binocular disparity, shape-from-shading, size gradient/foreshortening, aerial perspective, and so on. Are there any other new factors affecting depth perception? A recent psychophysical study has investigated the correlation between image resolution and depth sensation of Cylinder images (A rectangle contains gradual luminance-contrast changes.). It was reported that higher resolution images facilitate depth perception. However, it is still not clear whether or not the finding generalizes to other kinds of visual stimuli, because there are more appropriate visual stimuli for exploration of depth perception of luminance-contrast changes, such as Gabor patch. Here, we further examined the relationship between image resolution and depth perception by conducting a series of psychophysical experiments with not only Cylinders but also Gabor patches having smoother luminance-contrast gradients. As a result, higher resolution images produced stronger depth sensation with both images. This finding suggests that image resolution affects depth perception of simple luminance-contrast differences (Gabor patch) as well as shape-from-shading (Cylinder). In addition, this phenomenon was found even when the resolution difference was undetectable. This indicates the existence of consciously available and unavailable information in our visual system. These findings further support the view that image resolution is a cue for depth perception that was previously ignored. It partially explains the unparalleled viewing experience of novel high resolution displays.

Visual pattern recognition by restricted visual field.

テレビジョンアイカメラと視野制限装置を用いて, 比較的大きな図形文字に対する視野制限時における知覚・認知判断に要する応答時間 (R.T.) と正答率を求めた.用いたパターンは単純幾何学線図形, 同じく点図形, ランダム配置の点図形, ひらがな文字および, 形状はひらがなに似た無意味パターン (偽文字) の5種類である.その結果, (1) R.T.は線図形より点図形の方が, また正文字より偽文字の方が大きい, (2) いずれの図形, 文字の場合でも視野窓が2.0.-2.5.より小さくなるとRTは急増する, (3) 視野制限時の正答率は図形の判断よりも文字の判断の方が高い, (4) この実験条件 (視角で約12.の大きさのパターンを対象) 下に関する限り, 中心視の大きさは2.0-2.50と推定される, などがわかった.