A sensitive period for the acquisition of a nonnative phonological system

Immigrants who had learned English at various ages and who had been in the United States for various amounts of time were judged for degree of accent in English. It was found that age at arrival was a strong predictor of degree of accent, while length of stay had very little effect. Other practice and motivational factors were related to accent only by virtue of their correlation with age at arrival. It was suggested that a sensitive period exists for the acquisition of a nonnative phonological system.This article was adapted from a doctoral dissertation for the Department of Psychology and Social Relations, Harvard University, 1973 (unpublished), which was supported by NSF Grant No. GS-36263 and the Radcliffe Institute.     

Kinetics of photoinduced changes in Ag nanoparticles deposited on an indium tin oxide surface

An enhancement of the UV-visible optical absorption spectra of Ag nanoparticles (NPs) deposited on indium tin oxide (ITO) surfaces of different resistance by a seed-mediated growth technique is presented. A bicolour coherent beam, obtained from a pulsed Nd:YAG laser providing a 1060-nm fundamental wavelength and a double-frequency one at 530?nm, was used. A significant change in the optical density is observed for Ag NPs on low-resistance ITO surfaces (≈4?Ω/square), while almost nothing occurs with high-resistance (≈50?Ω/square surfaces). The spectral position of the maximal absorption at 440?nm is almost preserved in both cases. This result is explained in terms of a local photoinduced static field and surface-plasmon polaritons interacting with photoexcited phonons. A grating effect, arising from the coherent bicolour light forming a superstructure as for quantum crystals, could be another contribution.     

Perceived size and perceived distance in stereoscopic vision and an analysis of their causal relations

Effects of visual angle and convergence upon the perceived sizes and perceived distances of a familiar object (playing card) and a nonrepresentational object (blank white card) were investigated by means of a projector stereoscope with polarizing filters. The results obtained with six Ss indicated that size estimates increased nearly proportionally as the visual angle increased and decreased nearly linearly as the convergence increased. Distance estimates decreased nearly linearly as either the visual angle or the convergence increased. The ratio of the size estimate to the distance estimate for a given visual angle was almost constant irrespective of convergence. In this sense, the size-distance invariance hypothesis held. No clear effect of familiarity was found. Partial correlations were used to discriminate direct and indirect causal relationships between the stimulus variables and perceptual estimates. Both perceived size and perceived distance were found to be determined directly by the two stimulus variables, but to be mutually related only indirectly.     

Shaping of scientific psychology in Japan

Japanese scientific psychology began with Y. Motora's lecture on pyschophysics at the University of Tokyo in 1888. He had just received his PhD under G.S. Hall at Johns Hopkins University, in the USA. He became the first professor of psychology in 1890 and founded the first psychological laboratory at the University of Tokyo in 1903. He studied many psychological problems, including attention, experimentally and theoretically. One of his first students, Matataro Matsumoto, founded the second psychological laboratory at Kyoto University and then succeeded to Motora's position in Tokyo. Matsumoto was interested in experimental studies of human performance and their applications. He trained many able psychologists and organized the Japanese Psychological Association in 1927. Some of his students founded more psychological laboratories in major universities of Japan. They introduced psychological tests, Gestalt psychology, and behaviourism in the 1920s and 1930s. Psychoanalysis was introduced through mainly nonacademic roots and became familiar to Japanese psychologists in the 1930s. After World War II, a strong influence of American psychology came to Japanese psychologists who had already trained in scientific methodology. The areas of research and applications have been greatly widened and the number of psychologists has increased rapidly up to the present day. Promotion of international interactions and indigenous traditions are both expected.     

Role of convergence and binocular disparity in size constancy

Summary The effect of convergence on the perceived size of a light disk presented against a dark background was investigated by means of a projector stereoscope with polarizing filters. The results obtained with four subjects indicate that the logarithm of matched size decreases linearly as the convergence angle increases. The effect of binocular disparity was also examined by presenting a vertical bar beside the disk, but this did not add to the convergence effect. The results of a previous study on binocular disparity were reinterpreted as an effect of convergence difference between two objects. Implications of the present findings to the phenomenon of size constancy were discussed.

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Zusammenfassung Der Effekt der Konvergenz auf die wahrgenommene Größe einer gegen einen dunklen Hintergrund dargebotenen Lichtscheibe ist durch ein Projektorstereoskop anhand Polarisationsfiltern untersucht worden. Die Ergebnisse, die mit vier Versuchspersonen erworben wurden, zeigen, daß der Logarithmus der subjektiv gleichgestellten Größe sich linear mit zunehmendem Konvergenzwinkel verkleinert. Außerdem wurde der Effekt der Querdisparation durch das Darbieten eines vertikalen Lichtbalkens neben der Lichtscheibe untersucht; aber dieser war ohne Effekt. Die Ergebnisse einer vorhergehenden Untersuchung über die Querdisparation wurde neu interpretiert als ein Effekt der Konvergenzdifferenz zwischen zwei Objekten. Die Bedeutung des Versuches für das Phänomen der Größenkonstanz wurde erläutert.

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This study was performed at Chiba University in 1967 during the sabbatical year of the second author.     

Span of attention,backward masking,and reaction time

A test pattern consisting of 0 to 15 dots and a following random dot masking pattern were presented for 5 msec each with SOAs varying between 30 and 200 msec. The subject was asked to report the perceived number of dots in the test pattern as soon as possible and to assign a confidence rating to each report. The span of attention (upper limit for 50% correct numerosity judgments) increased from 2.4 to 9.5 as the SOA increased. Backward masking reduced the reported number of dots from the actual number in the test pattern, especially with small SOAs. Reaction time increased linearly at a low rate (approximately 40 msec/dot) up to 4 dots in the test pattern and then increased linearly at a high rate (approximately 370 msec/dot) as thereported, orperceived, number of dots increased. The two different branches of the reaction time curve were considered to represent two separate processes,subitizing andcounting, as suggested by Klahr (1973), who found similar dual increase rates as a function of the actual number of dots. These findings, as well as causal inference based on partial correlations and path analysis, indicated that the reported (perceived) number of dots and confidence rating were both determined by the number of stimulus dots and the SOA and that the reaction time was determined by the so-determined perceived number of dots and level of confidence. A multistage model is proposed.     

Effects of test-mask similarity on forward and backward masking of patterns by patterns

Summary Effects of test-mask similarity on the masking function were examined in two experiments. In Experiment 1, random bar patterns were used as test and mask stimuli. Bars were oriented in 135° oblique direction in test stimuli, and in 135° or 45° oblique direction in mask stimuli. The SOA was varied from 0 to 100 ms (backward masking). In Experiment 2, red and blue random dot patterns were used as both test and mask stimuli, with SOAs of –100 to 100 ms (forward and backward masking). The subject was asked to report the number of bars or dots as quickly as possible. The results of four subjects in one experiment and five in the other indicated that masking effects were generally greater when the test and mask stimuli were the same in orientation or color than when they were different. Slightly asymmetrical U-shaped functions were obtained both in the same and in different (orientation or color) conditions. A two-factor model with a similarity-related symmetrical integration process and a similarity-unrelated asymmetrical interuption process was considered.Experiment 1 was conducted by the first and third authors at Chiba University, and Experiment 2 was performed by the first and second authors at the University of Tokyo