This study focused on associative learning for new words in the first language and haptic stimuli. In the first, healthy Japanese participants made nine subjective evaluations of haptic stimuli using five-point semantic differential scales (e.g., regarding stickiness, scored from 1 [not sticky] to 5 [sticky]). In the second and third, the participants carried out two learning tasks for associative pairs of a new word in Japanese and haptic stimulus (H), or new words only (W). In the fourth one, after each learning task, participants performed recognition and free recall tasks. The results of the recognition tasks showed that the accuracy rates of W were better than those of H, whereas the response times of W were faster than those of H. Further, preference of haptic features negatively correlated with free recall scores of H; however, there was no significant difference between the free recall scores of H and W.

This study investigated the effect of gustatory stimuli on the associative learning of new (meaningless) word forms in a first language. Japanese native speakers performed the following tasks: (1) subjective evaluations of gustatory stimuli; (2) learning tasks of associative pairs of a new word form and gustatory stimulus (G) or only new word forms (W); (3) recognition memory tasks associated with the G/W condition; (4) free recall task for the G/W conditions. The accuracy rates of W were highest, whereas there was no significant difference between free recall scores. Subjective evaluations of gustatory stimuli negatively correlated with the free recall performance of word forms associated with the gustatory stimuli, while accuracy rates of the recognition and free recall tasks of G were positively correlated. Accordingly, learning new word forms on their own is more effective than associative learning of new word forms and gustatory stimuli in one day of learning.

The purpose of this study was to identify associative processes for words in a second language and their referents. ThirtyJapanese participants learned associative conditions for novel words in Chinese and pictorial referents (CP), as well asnovel words in Chinese and words in Japanese (CJ), against a condition of only novel words in Chinese (C). After thelearning phase, participants conducted 2 retrieval tasks for word recognition and 3 recognition tasks for source-monitoringof the referents. Correct answers for each recognition task were provided to participants after each trial. Although correctanswers in all the conditions gradually increased in both the recognition and retrieval tasks, there were no significantdifferences among these conditions. In contrast, recognition and retrieval speeds were faster for CP than CJ. These findingssuggest that pictures contribute to recognition and retrieval speeds of associations between words in a second languageand referents.

Vowels in words have been associated with specific meanings in sound symbolism (Hamano, 1998; Newman, 1933;Sapir, 1929). The purpose of this study was to examine whether each vowel individually involves physical and emotionalmeanings. Six-hundred and thirteen participants (482 females; M 16.97) rated 5-point semantic differential scales (size,distance, thickness, extent, weight, height, depth, preference, arousal, and familiarity) to presented Japanese vowels (a, i, u,e, and o). Results showed that the size, extent, and thickness of a, u, and o were significantly higher than i and e, whereasthe preference and familiarity of a was higher than the others. These results were consistent with previous findings towhich vowels in sound-symbolic words were associated with physical (i.e., size, extent, and thickness) and emotional (i.e.,preference) evaluations. Our findings suggest that each vowel itself could individually contribute to specifically physicaland emotional evaluations.