Takeshi Hatta

Recognition of Japanese kanji in the left and right visual fields

Abstract Visual half-field recognition was evaluated for non-phonetic logographic symbols ( Kanji ) in Japanese. Greater left visual half-field superiority for both high- and low-familiarity Kanji was found with fixation controlled using a central digit. This result was not consistent with the results of previous studies obtained in the recognition of the other two types of Japanese letters ( Hirakana and Katakana ). It was suggested that the three types of symbols are differentially processed in relation to laterality differences.

Differential processing of Kanji and Kana stimuli in Japanese people: Some implications from stroop-test results

Abstract RTs of Japanese subjects responding to Kanji and Kana Stroop type colour words presented in the left or the right visual field were measured. When subjects tried to respond to Kanji Stroop stimuli, they showed markedly greater interference effect in the case of left visual field presentation, while they showed no visual field differences when they responded to Kana Stroop stimuli. These results support the notion that Kanji has a different property from Kana and suggest a specialization of the right hemisphere for Kanji processing.

Differences in face touching by Japanese and British people

The face touching behavior of Japanese and British subjects was compared under three different conditions, viz. listening to a lecture, listening to music and without a specially assigned task. The results showed that (1) British people did more frequent face touching than Japanese people and left hand usage was more prominent, while the Japanese did not show a hand difference in either the lecture listening or the no-task condition, (2) the duration of face touching did not differ between Japanese and British and (3) British people touched their chin and mouth frequently while Japanese touched their nose and eyes frequently. From these results the hypothesis of cross-cultural difference of cerebral functioning between the Japanese and the British was examined.

Note on hand preference of Japanese people.

It is commonly accepted that not only the biological but also the environmental factors influence the determination of hand preference. While a variety of results have been reported, it is considered that 5 to 10% of the Anglo-Saxon population are lefthanded. According to the results of Clark (1957), 8.0% of male and 5.9% of female students were left-handed, but Dennis (1958) reported that 5.0% of male and 4.9% of female were left-handed in Lebanon. From such data, we infer that sex differences in hand-preference appear in different cultural societies. Although there is outstanding sex difference in frequency of left-handedness in the Western population, the difference in the Near Eastern is not statistically significant. The present study provides additional data on cultural comparisons of hand-preference in a Far Eastern population. The study was conducted at several colleges and offices in Osaka, Japan, in I974 and 1975. A total of 1,199 people, 488 males and 711 females were evaluated for hand-preference with the H a m and Nakatsuka inventory (1975). This inventory has 10 questions about preference for the use of each hand in daily life, i.e., rubbing out, striking a match (match), cutting with scissors, using a knife (without fork), using a screwdriver, shaving, hammering, pinning down, tooth brushing, throwing. The subject is judged to be fully right-handed if he scores +10 and as fully left-handed when he scores -10. This was designed for use on the basis of the latest psychometric method (Hatta & Nakatsuka, 1975). Results showed that 3.09% of people were left-handed. Among those, there were 4.30% male and 2.25% female lefthanders. The sex difference was statistically significant at the level of 5 % ( xa = 4.08, d f = 1) . However, those results indicate that the frequency of left-handedness is less in Japanese samples than in the Anglo-Saxon ones. It might be considered that the correction in use of the left hand to the right is actively made, especially among females in Japan for the features of Japanese letters are more difficult than the Western letters, when they are written with the left hand. Nevertheless, this tendency toward a sex difference seems similar to the Western one bur not to Near Eastern characteristics. From our results, although there are considerable cultural differences between the Western and the Far Eastern groups, the attitudes, cultural conditioning, social norms and child-rearing practices with respect to handedness in Japan are similar to the Western ones.

LATERAL RECOGNITION OF ABSTRACT AND CONCRETE KANJI IN JAPANESE

Abstract and concrete non-phonetic logographic symbols (Kanji) were unilaterally presented in either the left or right visual field. Subsequent recognition performance of 15 male and 15 female students was superior for both abstract and concrete Kanji in the left visual field. Concrete Kanji were more correctly recognized than abstract Kanji in the left visual field. These results suggest that the right hemisphere possesses some ability to process verbal materials.

Comparison of lateral differences for digit and random form recognition in Japanese and Westerners

In this study, a cross-cultural comparison reveals differences in lateralization of hemisphere functions, Japanese students showed visual field symmetry for random shape recognition, whereas English students showed a highly significant left visual field advantage. Both groups showed better right visual field identification for numbers, and for these stimuli no differences between the groups were found.

Visual field differences in mental transformation task

Abstract Two experiments were conducted identical stimuli. In Experiment I, watch figure stimuli were presented tachistoscopically and subjects were requested to read the time. The results showed a left visual field superiority. In Expirement II, subjects were asked to tell the correct time, by means of a mental transformation from-wrong watch and yielded more correct responses in the right visual field. These results were discussed in terms of the roles of the left hemisphere in higher and the right hemisphere in lower psychological processes.

Asynchrony of lateral onset as a factor in difference in visual field.

An experiment in matching judgments was designed to examine a role of perceptual process in apparent asymmetry. Recognition of Hirakana letters (Japanese letters) was required. The experimental condition in which stimuli were presented to the left visual field first and to the right visual field second produced more errors for all stimulus intervals (0 to 60 msec.) than experimental conditions where stimuli were presented to the right visual field first and to the left one second. Especially, superiority of the latter condition was marked with the longest stimulus interval employed. These results indicate superiority of the left hemisphere function for recognizing Hirakana letters and suggest that not only memory but also perceptual process contributes to this laterality effect.

Left-hand preference in frightened mother monkeys in taking up their babies☆

The hand preference of mother monkeys taking up their babies in an emergency situation was investigated. When a relaxed mother monkey was frightened, the hand used to take up a baby and flee was monitored with eight pairs of Old World Monkeys of three different species. Each mother-child pair was given 17-32 trials, all mothers showed a left-hand preference in this behavior.

Hemispheric asymmetries in a tactile bisection task: effects of hemispace of presentation.

The validity of Bowers and Heilmans hemispace hypothesis (Neuropsychologia 18, 491-498, 1980) that laterality effects depend upon the spatial condition in which a stimulus is presented was examined in two tactile bisection experiments (one with adults and the other with kindergarten children). Three indices: absolute error, constant error and directional error were employed to measure the accuracy of the two hands and hemispaces. The results did not support the hemispace hypothesis, though weak spatial condition effects appeared for female subjects.