The Perceptual Psychology Laboratory: Studying the Capacities of Human Hearing and Vision to Improve Human Functioning and Well-being.

Department of Human Science,Faculty of Design
Associate Professor　Gerard B.　Remijn

What is the special role of whispered speech in our daily life? What makes a human voice attractive or warm? Can sound help us to memorize visual objects? Can we use our eye gaze instead of our fingers to form passwords and log in to a device? These are just some of the research questions that are being investigated at the Perceptual Psychology Laboratory at Ohashi campus. We typically study the limits - or better capacities - of human hearing and vision to increase our knowledge about human perception in general, and to improve human well-being and functioning in daily life. Focusing on the capacities of human perception implies that we look at “special” cases: auditory and visual illusions, speech modes such as whispering and screaming, the perception of absolute pitch and synesthesia (e.g., perceiving color in music or in letters), and much more. We use so-called psychophysical methods, for example when asking someone to adjust one property of a stimulus (e.g. its duration) to that of another stimulus, and we can also measure the brain’s response to vision or sound stimuli using electroencephalography. Below we will introduce some studies in some more detail.

“The whisper is louder than the shout” is one of many proverbs about whispered speech. Whisper is typically used in one-on-one communication where the talker conveys a message that is meant only for the listener, not for others. Whispered speech seems to immediately raise our attention and is a very strong communication tool. Our research has shown that over a certain part in our brain the response to whisper is far stronger than to normal speech, even in young children. The brain area that responds strongly to whisper is a motor-response area over the left hemisphere that normally would be involved in the production of normal speech. Is it perhaps effective to diagnose children’s speech development by using whisper as well?

Although our PC screen is flat, we can easily see depth. This is because our visual system translates two-dimensional information into a three-dimensional image by using certain cues for depth perception. For example, larger objects are probably closer to use than smaller objects. What happens if we manipulate such cues? The Polka Dance stimulus consists of two identical bars that are positioned next to each other and rotate on an imaginary circle viewed sideways. When the size of the bars is kept constant during the rotation we see four different percepts. That is, a single visual motion pattern can be perceived in four different ways! Our brain creates these percepts and by studying this we get to know more about how the brain creates depth perception. Moreover, when we present a short sound the perception of one percept can become more dominant. This shows that sound thus can influence how we see moving objects.

When a stimulus in one sense modality automatically and involuntarily causes a percept in a different sense modality, we speak of synesthesia. A typical example is grapheme-color synesthesia: seeing color in letters or numbers. Sound-color perception is another example. Absolute pitch is possessed by those who can name the pitch of a sound without any other sound reference. Both synesthesia and absolute pitch are special cases of perception that do not often occur in the general population. In the brains of synesthetes and absolute pitch possessors certain connections seem to exist that most of us don’t have. In the Perceptual Psychology Laboratory we are interested in how such special connections came about and can be utilized in daily life. Eventually such knowledge could contribute to a better understanding of learning processes in both typically developing brains and atypically developing brains, such as in the case of autism spectrum disorder.

We always try to find practical applications of our research. One example is the use of visual passwords. Nowadays we need an ever-increasing number of varied and lengthy passwords with alphanumeric characters for many devices. Using passwords with manual input in public spaces (e.g., ATMs, tablets, or telephones) can be prone to “shoulder-surfing” - the password can get stolen. We are therefore investigating an alternative to manual input, and one such candidate is password input using eye tracking: using your eye gaze to select objects on a screen as a visual password. Many different formats and objects are considered and research is performed on, for example, the ideal grid size and density for password formation, the time it takes to memorize visual objects, the effect of sound presentation on visual object memorization, and so on. The goal is to find an optimal visual password system that can be used by any user, including the elderly and users viewing from different positions, such as from wheelchairs.

Our activities are in collaboration with the Research Center for Applied Perceptual Science.　In the case you are interested in our activities or in studying at the Perceptual Psychology Laboratory, please contact Gerard B. Remijn

■References
Hokajo, M., Nakajima, Y., Ueda, K. Hiramatsu C., Nishikawa, M., Remijn, G.B. (2017). A case study on synesthesia: Is there a connection between Japanese hiraganakatakana articulation categories and color grouping? Presented at Fecher Day 2017, Fukuoka, Japan.
Paulus, Y.T., Hiramatsu, C., Kam-Hwei Syn, Y., Remijn, G.B. (2017). Measurement of viewing distances and angles for eye tracking under different lighting conditions. Proceedings of ICACOMIT 2017, IEEE Explore 54-58.
Remijn, G.B., Yoshizawa, T., Yano, H. (in press). Streaming, bouncing and rotation: the Polka Dance stimulus. i-Perception.
Remijn, G.B., Kikuchi, M., Shitamichi, K., Ueno, S., Yoshimura, Y., Tsubokawa, T., Kojima, H., Higashida, H., Minabe, Y. (2017). A NIRS study on cortical hemodynamic responses to normal and whispered speech in 3- to 7-year-old children. Journal of Speech, Language and Hearing Research, 60, 465-470.

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■Inquiries
Department of Human Science,Faculty of Design, Kyushu University,
Associate Professor　Gerard B.　Remijn