Ayako Kawakami

Writing errors in Japanese kanji: A study with Japanese students and foreign learners of Japanese

The present study examined kanji errors in handwriting made by Japanese students and Australian learners of Japanese. First, a cognitive psychological model to explain the production of writing errors was proposed based upon the analysis of 374 writing errors of two-morpheme (kanji) compound words generated by Japanese students in spontaneous sentence writing situations. Despite the common assumption that kanji writing errors may not be related to the sounds of kanji characters (i.e., morphological phonology), the present study found that phonologically-related kanji writing errors were most numerous (60.0%), followed by orthographically-related errors (43.6%) and semantically-related errors (29.7%), including some overlap of these three types. Second, 408 kanji writing errors made by students learning Japanese in an Australian university were analyzed. Unlike the Japanese students, these subjects wrote more non-existing kanji and made orthographically-related mistakes rather than semantically- and phonologically-related errors. This result must be related to the level of kanji writing skills held by learners of Japanese. In light of these results, several suggestions were proposed for the methods of teaching kanji writing.

GABAergic systems in the nucleus tractus solitarius regulate noradrenaline release in the subfornical organ area in the rat

Previous studies have shown that catecholaminergic neurons in the nucleus tractus solitarius (NTS) with ascending projections to the subfornical organ (SFO) are highly sensitive to gamma-aminobutyric acid (GABA). To clarify the role of the GABAergic system in the NTS in the regulation of the activity of noradrenergic NTS projections to the SFO, the present study was carried out to investigate the effects of local administration (50 nl) of GABA, the GABA(A) agonist muscimol, the GABA(B) agonist baclofen, the GABA(A) antagonist bicuculline or the GABA(B) antagonist phaclofen into the NTS on the release of noradrenaline (NA) in the region of the SFO using microdialysis techniques in rats under urethane anesthesia. Microinjections of GABA (10(-4) - 10(-2) M) into the region of the NTS significantly decreased the NA release in the SFO area. Injections of either muscimol (10(-4) - 10(-2) M) or baclofen (10(-5) - 10(-3) M) into the NTS region significantly attenuated the NA release in the SFO area. Injections of bicuculline (10(-5) and 10(-4) M), but not phaclophen (10(-6) - 10(-4) M), into the NTS region significantly enhanced the NA release in the SFO area, suggesting that the GABAergic system in the NTS may tonically inhibit the NA release in the SFO area through a GABA(A) receptor mechanism. Neither injection of these drugs in any of the doses used in this study into the NTS region caused any significant changes in the NA release in the sites away from the SFO. Injections of vehicle (50 nl) into the NTS region had no significant effect on the NA release in either the SFO area or the sites away from the SFO. These results suggest that the GABAergic system in the NTS may serve to decrease the release of NA in the SFO area and the two types of GABA receptors are involved in the modulation of the NA release.

Color of computer display frame in work performance, mood, and physiological response

The effects of the color of a personal computer screen on work performance, psychological mood, and autonomic response were investigated. 24 subjects were asked to perform visual tasks presented on the computer display. Three types of computer monitor, which were colored red, blue, or beige, were employed to present visual cognitive tasks. The mood measure, the Japanese Stress Arousal Check List, and heart rate measurement were administered before and after work on each color of computer monitor. Analysis of a low-demand task (Exp. 1) showed that the red computer monitor reduced visual task performance compared to that with the blue, while the blue monitor decreased visual task performance on a high-demand task (Exp. 2). The color of the monitor did not affect mood or heart rate. Based on these findings, the effect of the color of environmental cues on work was discussed.

The action of the A1 noradrenergic region on the activity of subfornical organ neurons in the rat

Electrical stimulation of the A1 noradrenergic region of the ventrolateral medulla produced synatic excitation (n = 19, 9%), inhibition (n = 5, 2%) or no effect (n = 184, 89%) in the activity of a total of 208 neurons in the subfornical organ (SFO) in male rats under urethane anesthesia. Almost all (n = 18) of the excitatory responses (n = 19) were blocked by microiontophoretically-applied phentolamine, an alpha-adrenergic antagonist, but not by timolol, a beta-adrenergic antagonist. The inhibitory response of all the neurons (n = 5) tested was prevented by iontophoretically applied timolol, but not by phentolamine. Approximately a half (n = 9) of SFO neurons that demonstrated the excitatory response to A1 region stimulation exhibited an increase in neuronal activity in response to hemorrhage (10 ml/kg b.w.t.), while remaining neurons (n = 10) were unresponsive. Hemorrhage did not cause any change in the activity of all the neurons (n = 5) that demonstrated the inhibitory response to A1 region stimulation. These results suggest that the medullary inputs to approximately 10% of SFO neurons tested are mediated by alpha-adrenergic excitatory and beta-adrenergic inhibitory pathways, and imply that a part of the excitatory pathways may transmit the peripheral baroreceptor information.

Involvement of NMDA receptor mechanisms in the modulation of serotonin release in the lateral parabrachial nucleus in the rat

Microdialysis was employed to investigate whether N-methyl-d-asparatate (NMDA) glutamate receptor mechanisms are involved in the modulation of serotonin (5-hydoxytryptamine, 5-HT) release in the region of the lateral parabrachial nucleus (LPBN) in freely moving rats. Perfusion of NMDA (10 and 50 microM) through the microdialysis probe significantly enhanced extracellular concentrations of 5-HT and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the LPBN area. Local perfusion of the NMDA antagonist dizocilpine (MK801, 10 and 50 microM) did not change the basal 5-HT and 5-HIAA levels in the LPBN area. MK801 (10 microM) administered together with NMDA antagonized the stimulant effect of NMDA (10 microM). The intake of 0.3M NaCl and water induced by subcutaneous injections of the diuretic furosemide (FURO, 10 mg/kg) and the angiotensin converting enzyme inhibitor captopril (CAP, 5 mg/kg) produced significant increases in the 5-HT and 5-HIAA concentrations in the LPBN area. The increased levels of 5-HT and 5-HIAA caused by the combined treatment with FURO and CAP were attenuated by perfusion of MK801 (10 microM). These results indicate the participation of NMDA receptors in the control of 5-HT release in the LPBN area.

Characteristics of proper names and temporal memory of social news events

Long-term memory of social news events was investigated by means of a questionnaire methodology with a large sample of participants. In Experiment 1, a total of 501 university students were asked to give proper names (i.e., persons and places) that related to a certain news event, and to estimate the date of the event. The accuracy of proper names (especially person names) was superior to that of estimated date (i.e., year). In addition, telescoping effects were found in the events that occurred more than 3 years ago, but time expansion effects emerged in the events that occurred less than 2 years ago. In Experiment 2, in which 182 students participated, the accuracy of proper names and the date estimates tended to be high on the events that participants judged to be given frequent exposure by the mass media. Based on these results, we discuss long-term memory and temporal schemata regarding social news events.

Differential cognitive processing of Kanji and Kana words: Do orthographic and semantic codes function in parallel in word matching task

Relative engagements of the orthographic and semantic codes in Kanji and Hiragana word recognition were investigated. In Exp. 1, subjects judged whether the pairs of Kanji words (prime and target) presented sequentially were physically identical to each other in the word condition In the sentence condition, subjects decided whether the target word was valid for the prime sentence presented in advance. The results showed that the response times to the target words orthographically similar (to the prime) were significantly slower than to semantically related target words in the word condition, and that this was also the case in the sentence condition. In Exp. 2, subjects judged whether the target word written in Hiragana was physically identical to the prime word in the word condition. In the sentence condition, subjects decided if the target word was valid for the previously presented prime sentence. Analysis indicated that response times to orthographically similar words were slower than to semantically related words in the word condition but not in the sentence condition wherein the response times to the semantically and orthographically similar words were Largely the same. Based on these results, differential contributions of orthographic and semantic codes in cognitive processing of Japanese Kanji and Hiragana words was discussed.

Are nonproper chopstick holders clumsier than proper chopstick holders in their manual movements

To examine the working hypothesis that a lack of childhood training in the fine-detailed finger movements illustrated by learning to use chopsticks properly as a child has later rendered such individuals clumsier in the execution of other more adult-like motor movements, four experiments were conducted. Groups of proper and nonproper users (both males and females) performed a task of picking up rice grains (Exp. 1), a pin-down task (Exp. 2), a task of unfastening nuts from bolts (Exp. 3), and a knot-tying task (Exp. 4). Only on the rice-grain transfer task and the knot-tying task, proper chopstick users showed better performance than nonproper users. On the pin-down task and the nuts-and-bolts task, no difference was found between groups. These results suggest that there is no clear evidence to support the hypothesis that a lack of early training for proper chopstick use makes such individuals more clumsy as adults in at least some motor movements.

Semantic Priming of Kanji Words in the Cerebral Hemispheres

Two experiments were conducted to investigate how the spreading activation arose in hemispheres using single and 2-letter Kanji words. Results suggested that single- and 2-letter Kanji words were processed differentially and the semantic activation mechanisms seemed to be different from that of English words.

Image generation and handedness: is the hemi-imagery method valid for studying the hemisphere imagery generation process?

The validity of the proposal by Shuren et al. (Neuropsychologia, 1996, 34, 491-492) that there is some relation between handedness and hemi-imagers was investigated by means of the hemi-imagery test. Two-hundred and two subjects were asked to image one-half of an object and to report which half (left or right) they saw. The analyses, based on criteria identical to those of Shuren et al., did not replicate their findings that subjects were more likely to image the right half of objects than the left, and that right handers are right hemi-imagers. Rather, our subjects were more inclined to image the left half than the right, and no relation between handedness score and right hemi-imagers was found. It is suggested that the reading habits of the different cultures of the groups of subjects may account for this discrepancy.