Hemispheric differences for verbal and nonverbal stimuli in Japanese- and English-speaking subjects assessed by Tsunoda's method

This investigation compared the performance of Japanese- and English-speaking subjects on T. Tsunoda's DAF key-tapping task, which he purports assesses cerebral dominance for language (1975, Brain and Language, 2, 152–170). Twenty-three native speakers of Japanese and 23 English-speaking subjects were employed in this study. Each subject was administered the DAF key-tapping task utilizing the vowel /a/ and a 1000-Hz pure tone. The results revealed an effect of intensity, whereby an increase in DAF/SAF ratios resulted in an increase in performance disruption. No differences were observed between the two language groups, ears, or between the 1000-Hz pure tone and the vowel /a/. Only 15.5% of the subjects showed the hypothesized right ear advantage for the tone when subjected to an analysis similar to Tsunoda's. All other subjects revealed variable degrees of advantage to either ear, to the same ear, or to to neither ear. It was concluded that no significant functional auditory asymmetry was observed for either group, suggesting that the DAF key-tapping task may not be a sensitive procedure to determine cerebral dominance for language among normals.     

Developmental verbal control of behavior: Implications for self-instructional training

Kindergarten, first-grade, and second-grade children (5, 6, and 7 years of age, respectively) performed a Luria-type verbal control task in which motor responses are initiated to positive stimuli and inhibited to negative stimuli. The task was performed by motor responding only and verbal self-directed motor responding, with these conditions reversed in sequence for one half of each grade group. Although motor responding and verbal-motor responding by the two younger groups were generally poor, their performance equalled that of the second graders when the verbalizing condition followed the silent, motor-only condition. For these children, verbalizing appeared to constitute a second task which interfered with motor responding. Prior practice on motor-only responding, however, facilitated subsequent, concurrent performance of the two tasks. No interference or practice effects were found for the second graders. The results suggested that self-instructional training programs are likely to be successful when adequate verbal-motor coordination can be assumed or when the motor response is within the child's repertoire.