Workers’ Mental Health Problems and Future Perspectives in Japan

This chapter reviews data on the mental health problems of Japanese workers. Some of the main theories that analyze mental health problems are introduced, including occupational/job stress theory, work motivation, work engagement, and social skills. In light of Japan’s disgraceful record of more than 30,000 suicides every year the past ten years or more—a level that is rare in developed nations—an issue related to work circumstances, represented by the term Karoshi, is suggested. This chapter presents an argument toward a solution to the mental health problem in Japan.

Functional Role of the Left Ventral Occipito-Temporal Cortex in Reading

The sensitivity of the left ventral occipito-temporal (vOT) cortex to visual word processing has triggered a considerable debate about the functional role of this region in reading. The debate rests largely on the issue whether this particular region is specifically dedicated to reading and the extraction of invariant visual word form. A lot of studies have been conducted to provide evidences supporting or against the functional specialization of this region. However, the trend is showing that the different functional properties proposed by the two kinds of view are not in conflict with each other, but instead show different sides of the same fact. Here, the authors focus on two questions: firstly, where do the two views conflict, and secondly, how do they fit with each other on a larger framework of functional organization in object vision pathway? This review evaluates findings from the two sides of the debate for a broader understanding of the functional role of the left vOT cortex.

Neuronal Function in the Cortical Face Perception Network

Face perception is considered the most developed visual perceptual skill in humans. Functional magnetic resonance imaging (fMRI) studies have graphically illustrated that multiple regions exhibit a stronger neural response to faces than to other visual object categories, which were specialized for face processing. These regions are in the lateral side of the fusiform gyrus, the “fusiform face area” or FFA, in the inferior occipital gyri, the “occipital face area” or OFA, and in the superior temporal sulcus (pSTS). These regions are supposed to perform the visual analysis of faces and appear to participate differentially in different types of face perception. An important question is how faces are represented within these areas. In this chapter, the authors review the function, interaction, and topography of these regions relevant to face perception. They also discuss the human neural systems that mediate face perception and attempt to show some research dictions for face perception and neural representations.

Motion Control of an Omni-Directional Walker for Walking Support

With the increase in the percentage of the population defined as elderly, increasing numbers of people suffer from walking disabilities due to illness or accidents. An omni-directional walker (ODW) has been developed that can support people with walking disabilities and allow them to perform indoor walking. The ODW can identify the user’s directional intention based on the user’s forearm pressures and then supports movement in the intended direction. In this chapter, a reference trajectory is generated based on the intended direction in order to support directed movement. The ODW needs to follow the generated path. However, path tracking errors occur because the center of gravity (COG) of the system shifts and the load changes due to user`s pressure. An adaptive control method is proposed to deal with this issue. The results of simulations indicate that the ODW can accurately follow the user’s intended direction by inhibiting the influence of COG shifts and the resulting load change. The proposed scheme is feasible for supporting indoor movement.

Speed-Accuracy Tradeoff Models of Target-Based and Trajectory-Based Movements

A tradeoff between speed and accuracy is a very common phenomenon in many types of human motor tasks. In general, the accuracy of a movement tends to decrease when its speed increases and the speed of a movement tends to decrease with an increase in its accuracy. This phenomenon has been studied for more than a century, during which several alternative performance models that account for the tradeoff between speed and accuracy have been presented. In this chapter, the authors present a critical survey of the scientific literature that discusses speed-accuracy tradeoff models of target-based and trajectory-based movement; these two types of movement are the major popular task paradigms in studies of human-computer interactions. Some of the models emerged from basic research in experimental psychology and motor control theory, whereas others emerged from a specific need to model the interaction between users and physical devices, such as mice, keyboards, and styluses in the field of Human-Computer Interaction (HCI). This chapter summarizes these models from the perspectives of spatial constraints and temporal constraints for both target-based and trajectory-based movements.

Audiovisual Integration of Natural Auditory and Visual Stimuli in the Real-World Situation

Bimodal audiovisual (AV) stimuli are detected or discriminated faster and more accurately than either visual or auditory unimodal stimuli. This effect is called audiovisual integration. Recently, researchers have been increasingly focused on the audiovisual integration of natural, auditory, and visual stimuli in real-world situations. There are some differences between audiovisual integration of naturalistic stimuli and non-naturalistic stimuli, such as the time of occurrence of audiovisual integration, and the neural mechanism. Factors affecting audiovisual integration in real-world situations are summarized here, with particular focus on temporal asynchrony and semantic matching. Stimuli of audiovisual integration in the real-world situation should be controlled strictly, especially emotional factors, familiarity factors, semantic matching, and the match of the naturalistic stimuli and non-naturalistic stimuli. In the future, researchers should study the influence of attention on audiovisual integration and the mechanism of audiovisual integration with naturalistic stimuli in the real-world situation.

Effects of Selective and Divided Attention on Audiovisual Interaction

In everyday life, visual and auditory are the most common forms of sensory information. Therefore, audiovisual interaction in the brain plays an important role in performance and perception. In addition, our attention system allows us to dynamically select and enhance the processing of objects and events that are the most relevant at each moment. Some studies suggest that attention can modulate audiovisual integration. However, different neural activity of multimodal audiovisual integration can be seen in different attention conditions. This review focuses on the question of what affects selective and divided attention in audiovisual interaction. Neural activities of audiovisual under selective and divided attention conditions are also discussed. This review aims to bring together and summarize previous studies on the interactions between attention and audiovisual integration.

Evaluation of Olfactory Impairment in Parkinson’s Disease Using Near-Infrared Spectroscopy

Hyposmia, psychiatric disorders, and cognitive problems are common non-motor manifestations of Parkinson’s disease (PD), but how they are related to the progression of PD remains unclear. Olfactory dysfunction, which is a common non-motor symptom of Parkinson’s disease, is considered to be an early manifestation of this disease. The aim of this study is to investigate the usefulness of near-infrared spectroscopy (NIRS) in measuring olfaction in PD patients and to establish the cortical basis of olfactory function in PD patients. This study was conducted on 9 healthy normosmic volunteers and 24 patients with PD. The authors employed a 22-channel NIRS device with eight light-incident fibers and seven light-detection fibers and placed fibers every 2.5 cm on the forehead of volunteers. Isovaleric acid was used as the odor stimulant. The authors measured the changes in total hemoglobin (tHb) concentration from baseline values and compared the results obtained from healthy normosmic volunteers with those from PD patients. PD patients had higher scores in the subjective olfactory test and smaller changes in tHb concentrations compared with normal volunteers. In particular, no changes in tHb concentration were detected in patients with the awareness of the sense of smell disorder.

Feedback-Related Negativity and its Clinical Implications

Appropriate processing of feedback information is critical for human executive functions that guide goal-oriented behavior. Feedback-related negativity (FRN) measurements are feedback signals that are recorded through the scalp and convey unpredicted bad/negative information. This study attempts to characterize FRN in the context of individual psychological disposition, specifically impulsivity. The results show that non-planning individuals produce smaller FRN signals than planning individuals when performing both monetary (experiment 1) and non-monetary (experiment 2) gambling tasks, suggesting that impulsive individuals are prone to make risky choices and to show less evaluation processing and lower negative feedback. Furthermore, the clinical utility of FRN measurements was examined with regard to assessing frontal lobe functions in patients with brain lesions. Reductions in FRN amplitudes in response to go-nogo tasks were associated with impaired inhibition responses. These findings suggest that FRN measurements are useful for electrophysiological assessments of patients with impaired inhibitory control.

Kanji Perception and Brain Function

The semantic processing involved in the visual perception of Chinese characters (Kanji) was studied using electroencephalograms. Thirty concrete Kanji, 30 absolute Kanji and a closed circle were used in a tachistoscopic presentation, wherein one character or a circle was displayed at random for 35 ms, and visual evoked potentials were recorded. The test subjects were11 native Japanese speakers. The concrete Kanji were familiar objects and highly imaginable characters such as a dog, a cat, a cow, etc. The absolute Kanji were familiar Kanji but represented concepts that are difficult to imagine, such as nothing, what, existing, et cetera. P100, N160, P230, and N320 were noted on the evoked potentials. The bilateral posterior temporal lobes and the bilateral occipital lobes were activated for the concrete Kanji at approximately 320ms after the onset of the visual stimuli (P<0.001 by multiple analysis of variance).