Theories of early language acquisition

What features of brain processing and neural development support linguistic development in young children? To what extent is the profile and timing of linguistic development in young children determined by a pre-ordained genetic programme? Does the environment play a crucial role in determining the patterns of change observed in children growing up? Recent experimental, neuroimaging and computational studies of developmental change in children promise to contribute to a deeper understanding of how the brain becomes wired up for language. In this review, the muttidisciplinary perspectives of cognitive neuroscience, experimental psycholinguistics and neural network modelling are brought to bear on four distinct areas in the study of language acquisition: early speech perception, word recognition, word learning and the acquisition of grammatical inflections. It is suggested that each area demonstrates how linguistic development can be driven by the interaction of general learning mechanisms, highly sensitive to particular statistical regularities in the input, with a richly structured environment which provides the necessary ingredients for the emergence of linguistic representations that support mature language processing. Similar epigenetic principles, guiding the emergence of linguistic structure, apply to all these domains, offering insights into phenomena ranging from the precocity of young infant's sensitivity to speech contrasts to the complexities of the problem facing the young child learning the arabic plural.     

Asymmetries and errors in perception of depth from disparity suggest a multicomponent model of disparity processing

In three experiments, asymmetries between the processing of crossed and uncrossed disparities were investigated. The target was a luminance-defined circle concentric to a fixation mark, viewed stereoscopically on a computer monitor for 105 msec. Fifteen disparities were presented according to the method of constant stimuli. Observers indicated the apparent direction of target depth relative to fixation. All experiments measured both the accuracy and latency of this response. Experiment 1 showed fewer errors and shorter reaction times for identifying crossed disparities. Experiments 2 and 3 replicated Experiment 1 and also showed that observers may often perceive a target in the direction opposite that prescribed by the disparity information. We propose that the asymmetries and reversals result from differences in computation of sign, not of magnitude. This notion is consistent with a scheme of continuous disparity tuning and accounts for such asymmetries and errors without positing disparity pooling mechanisms.     

Catching With Both Hands: An Evaluation of Neural Cross-Talk and Coordinative Structure Models of Bimanual Coordination

Kelso, Southard, and Goodman (1979) and Marteniuk and MacKenzie (1980) have each proposed a different theoretical model for bimanual coordination. In the model of Kelso et al., a close temporal relationship between the hands in a bimanual task is predicted, even when each hand is required to move different distances. In Marteniuk and MacKenzie's model, separate motor commands are issued so that each limb will arrive simultaneously at the specified movement endpoint, leading to low temporal associations between limbs. In most previous work on bimanual coordination, manual aiming tasks with differing constraints have been used by subjects in individual studies. In this study, the usefulness of existing models for predicting performance in a real-world catching task in which the required movement pattern was constrained by ball flight characteristics was examined. E1even university students caught tennis balls with both hands in the following 3 conditions: Condition 1. Ball projected to the right shoulder area (left hand moved a greater distance than the right); Condition 2. Ball projected to center of the chest area, (both hands moved same distance); and Condition 3. Ball projected to left shoulder area (right hand moved a greater distance). Kinematic data (time to peak velocity, movement initiation time) indicating significant cross-correlations between the left and right limbs in all 3 conditions concurred with the data of Kelso et al. (1979) on manual aiming. Timing appeared to be an essential variable coordinating bimanual interceptive actions. Although the limbs moved at different speeds when each was required to move different distances, times to peak velocity showed strong associations, suggesting the presence of a coordinative structure.     

Evidence Supporting the Importance of Peripheral Visual Information for the Directional Control of Aiming Movement

The focus of the present study was on determining whether the high level of directional accuracy found in aiming studies in which the subjects can see their hand in the visual periphery supports the existence of a kinetic visual channel or, rather, the advantage of binocular over monocular vision for movement directional control. The limits of this kinetic visual channel were also explored. The results of the 1st experiment indicated that seeing one's hand in the visual periphery is sufficient to ensure optimal directional aiming accuracy. Further, no differences in aiming accuracy were noted between monocular and binocular vision. These results supported the existence of a visual kinetic channel. In the 2nd experiment, whether this kinetic visual channel would operate with movements slower (55 degrees /s) than those usually used in studies that had proved its existence (over 110 degrees /s) was delineated. The results indicated that this visual kinetic channel was operative even at relatively slow movement velocities. Central vision of the hand seemed to be used for on-line directional control of relatively slow movements.     

Late Adolescents' Experiences With and Attitudes Toward Videogames1

A total of 229 late adolescents (a large majority 15 to 19 years of age) completed a questionnaire that assesses a broad range of videogame-relevant experiences, preferences, and attitudes. Videogame playing was found to be a more popular, and a more highly regarded, activity among males than females. Gender differences were also found in participants' ratings of their motivations for playing videogames, their evaluations of particular characteristics of videogames, and their selection of their “most favorite” videogame. The differences between frequent and infrequent videogame players appeared to be limited to differences in the extent to which videogame playing is pursued and evaluated as a positive leisure activity, rather than reflecting broad differences in interest or personality. Some relations were found between participants' self-reported personality characteristics (i.e., self-esteem, empathy, conscientiousness, and introversion) and their attitudes toward videogames.     

Perceptions of Brainstorming in Groups: The Quality Over Quantity Hypothesis

Our research focused on the implicit beliefs of potential brainstormers about the possible outcomes of brainstorming. We conducted four studies to assess the relative importance of quality and quantity as goals of brainstorming. In Study 1, we found evidence for a quality over quantity hypothesis: participants indicated that it was more important to produce creative, original, and high quality ideas than to generate a large number of ideas. In Studies 2 and 3, participants displayed support for the quality over quantity hypothesis by showing in group favoritism for a quality dimension but not a quantity dimension. Study 4 showed that participants believed brain-storming would enhance the quality of others' ideas more than one's own ideas, but they did not display a similar bias about idea quantity.     

Racial Attitudes and the Death Penalty1

This study investigated the relationship between overt and subtle forms of racism with Whites' recommendations for capital sentencing of Black and White offenders convicted of murder. White participants (n= 104) viewed 5 other “jurors” (all Whites or 4 Whites and 1 Black) on videotape individually presenting their decisions to vote for the death penalty in the case. It was hypothesized that the bias of high prejudice-scoring participants would be overt, but that the pattern for low prejudice-scoring participants would be more complex. As predicted, among high prejudice-scoring participants, Black defendants received stronger recommendations for the death penalty than did White defendants. Among low prejudice-scoring White participants, Black offenders received stronger recommendations for the death penalty only when a Black juror advocated the death penalty.     

Religious Coping and Heart Transplantation: From Threat to Health

Previous research has established the existence of homogeneous religious coping profiles in cardiac-transplantation candidates labeled as the deferring/collaborators, self-directors, and the eclectic religious copers. However, their prospective impact on outcome has not yet been established. This paper examines potential differences between pre-cardiac transplantation religious coping cluster groups on post-cardiac transplantation quality of life (physical functioning, mental health, and general health). Results indicated that the religious coping profiles of deferring/collaborators and self-directors had significantly better scores on mental health and general health than did the eclectics. Implications for religious-coping research and clinical practice are discussed.