Biomedical subjects

Hama Watanabe

Publications and source records attributed to Hama Watanabe.

5 recordsLinked to original sources

PubMed2006

General to specific development of movement patterns and memory for contingency between actions and events in young infants.

To understand infants' learning of the contingency between their actions and events, we studied inter-limb movement patterns of 48 infants aged 2-4 months when they attempted moving a mobile using a string attached to their arm. The session was composed of baseline, acquisition, immediate retention test, re-acquisition, interference, and delayed retention test periods. The analysis revealed motor pattern dependence on age--infants exhibited increased movement over base line of all limbs (2-month-olds), both arms (3-month-olds), and the connected arm (4-month-olds). The acquired patterns were produced during immediate and delayed test periods across age groups. The results suggest that 2-month-olds can acquire and retain general body movements that induce contingent changes in a mobile, while 3- and 4-month-olds form memories that serve as a constraint enabling highly specific movement of their arm to effectively activate the mobile.

Age Factors↗

PubMed2006

The right hemisphere of sleeping infant perceives sentential prosody.

Behavioral studies proposed that prosodic information in speech sounds plays important roles for human infants to acquire their native languages. Here, we examined the neural basis of prosodic processing in 3-month-old infants. In order to obtain hemodynamic responses with high signal-to-noise ratio, we used near-infrared optical topography in the infants while they were in quiet sleep. First, we observed bilateral activation under each of the normal and flattened speech conditions. The flattened speech sound was created by eliminating changes in the pitch contours of the original utterance. In a direct comparison between the two conditions, the right temporoparietal region showed more prominent activation to normal speech sounds than to flattened speech sounds. This result demonstrates that the localized region of the right hemisphere in 3-month-old infant is involved in the processing of pitch contours. Our findings suggest that prosodic processing in the right hemisphere may facilitate the acquisition of lexical or syntactic knowledge in the early stages of language development.

Brain↗

PubMed2005

Representation of plans: activation in memory.

The purpose of this study is to examine the temporal representation of plans in memory. Two experiments using a priming paradigm were conducted to investigate which plans would be activated in memory when participants processed a particular plan. The 64 undergraduates who participated in Experiment 1 were asked to memorise a 1-month schedule of plans. Results showed that when participants were presented with a particular plan as a prime, the preceding plan in the schedule was immediately activated. After the activation of the preceding plan, the plan following the prime plan in the schedule was activated. Experiment 2 was conducted to examine whether the sequential effect found in Experiment 1 might be based on day order (e.g., plans for day 1, plans for day 2, etc.) or simple ordering of plans (e.g., plan 1, plan 2, etc.). However, in the results of Experiment 2, with 48 undergraduate participants, the dynamic transition in the activation of plans along the time course, seen in Experiment 1, was not observed.

Adult↗

PubMed2004

Is memory for plans unique? a study using common nouns as stimuli.

The present study explored the question of whether the U-shape effect, which was observed in previous experiments on memory for fictitious plans is unique to the memory for plans or not, i.e., are plans for the morning and for the evening recalled better than those for the afternoon. To investigate we used a "common noun" as the material to be memorized instead of the "action phrase" as used in Watanabe and Kawaguchi's earlier experiments. Free recall tasks were performed in two experiments: in Exp. 1, a sample of 15 undergraduates memorized "hour" and "common noun" pairs, while in Exp. 2 another 15 undergraduates memorized "number" and "common noun" pairs. The results of these experiments indicated no significant effect for time of day. This suggests that the U-shape effect observed in Watanabe and Kawaguchi's experiments, in which participants were asked to memorize a combination of an "hour" and an "action phrase" is unique to memory for plans.

Adolescent↗

PubMed2003

Effects of encoding style, expectation of retrieval mode, and retrieval style on memory for action phrases.

The purpose of this study was to examine the effects of encoding style, expectation of retrieval mode, and retrieval style on memory for action phrases using the recall test and the source-monitoring test. In Exp. 1, the subjects were asked to memorize action phrases with a variety of encoding styles (verbal, performance, imaging), expectation of retrieval mode (to-be-remembered, to-be-performed, to-be-forgotten), and retrieval style (verbal, enacted). Analysis showed that memory for action phrases was affected by processes of encoding, i.e., type of encoding and expectation of retrieval at encoding, rather than retrieval. Also, action phrases, which were either acted out, or in which performance was imaged, or where enacting was expected later at the encoding phase, were recalled better. These results were replicated in Exp. 2, in which subjects were asked to identify the source of memories at the time of the recall test. However, results of the source-monitoring test in Exp. 1 which required, following the recall test, that participants recall as many of the test-expectation condition of action phrases as possible, showed that source memory for phrases enacted at encoding was weaker than for those in which performance was imaged or expected later but not enacted at encoding. Since, in Exp. 2, source memory for enacted items at encoding was maintained at a relatively high level, it is suggested that source memory for enacted action phrases at encoding might decay rapidly. In addition, a robust directed forgetting effect was observed in verbal and imaging encoding but not in performance encoding.

Cognition↗