Cerebral asymmetry for American Sign Language: The effects of moving stimuli

Previous studies of cerebral asymmetry for the perception of American Sign Language (ASL) have used only static representations of signs; in this study we present moving signs. Congenitally deaf, native ASL signers identified moving signs, static representations of signs, and English words. The stimuli were presented rapidly by motion picture to each visual hemifield. Normally hearing English speakers also identified the English words. Consistent with previous findings, both the deaf and the hearing subjects showed a left-hemisphere advantage to the English words; likewise, the deaf subjects showed a right hemisphere advantage to the statically presented signs. With the moving signs, the deaf showed no lateral asymmetry. The shift from right dominance to a more balanced hemispheric involvement with the change from static to moving signs is consistent with Kimura's position that the left hemisphere predominates in the analysis of skilled motor sequencing (Kimura 1976). The results also indicate that ASL may be more bilaterally represented than is English and that the spatial component of language stimuli can greatly influence lateral asymmetries.     

A typology of mid-life career changers

This study examines the motivations for and the outcomes of mid-life career change among a sample of 73 men who had left professional and managerial careers between the ages of 34 and 54. Measures of personal desire for change and external pressure to leave were dichotomized to produce a typology of career changers: Drift-outs, Opt-outs, Force-outs, and Bow-outs. The four types of changers were found to differ on a number of variables, including: amount of education completed, additional schooling undertaken to change careers, time taken to make the change, radicalness of change, and the importance of personal values in deciding to leave their former careers. Overall, respondents were found to be highly satisfied with their career redirection.     

From Experience to Relation: Laszlo and Inayatullah,Two Futurists Compared

Humans have two futures: either liberty or uncertainty. In liberty, humans can forecast a vision of the future. However, in uncertainty, humans must forecast multiple futures. This article compares Ervin Laszlo's theory of the liberty future with Sohail Inayatullah's theory of the uncertainty future. Additionally, this article analyzes these two futurists through the lens of Martin Buber, and I argue that the future represents reality not to the “I” of the combination I–It but to the “I” of Buber's preferred combination of I–Thou.     

A Conversation between Theory,Methods, and Data

The 10 year anniversary of the COGITO Study provides an opportunity to revisit the ideas behind the Cattell data box. Three dimensions of the persons × variables × time data box are discussed in the context of three categories of researchers each wanting to answer their own categorically different question. The example of the well-known speed-accuracy tradeoff is used to illustrate why these are three different categories of statistical question. The 200 persons by 100 variables by 100 occasions of measurement COGITO data cube presents a challenge to integrate theories and methods across the dimensions of the data box. A conceptual model is presented for the speed-accuracy tradeoff example that could account for cross-sectional between persons effects, short-term dynamics, and long-term learning effects. Thus, two fundamental differences between the time axis and the other two axes of the data box include ordering and time scaling. In addition, nonstationarity in human systems is a pervasive problem along the time dimension of the data box. To illustrate, the difference in nonstationarity between dancing and conversation is discussed in the context of the interaction between theory, methods, and data. An information theoretic argument is presented that the theory-methods-data interaction is better understood when viewed as a conversation than as a dance. Entropy changes in the development of a theory-methods-data conversation provide one metric for evaluating scientific progress.     

Computing with connections in visual recognition of origami objects

This paper summarizes our initial foray in tackling Artificial Intelligence problems using a connectionist approach. The particular task chosen was the visual recognition of objects in the Origami world as defined by. The two major questions answered were how to construct a connectionist network to represent and recognize projected line drawings of Origami objects and what advantages such an approach would have. The structure of the resulting connectionist network can be described as a hierarchy of parameter or feature spaces with each node in each of the feature spaces representing a hypothesis about the possible existence of a specific geometric feature of an Origami object. The dynamic behavior of the network is a form of iterative refinement or relaxation whose major characteristic is to prefer more globally interesting interpretations of the input over locally pleasing ones. Examples from the implementation illustrate the system's ability to deal with forms of noise, occlusion and missing information. Other benefits are an inherently parallel approach to vision, limitation of explicit ordering of the search involved in matching model to instance and the elimination of backtracking due to the sharing of partial results as the search progresses. Extensions and problems are also discussed.     

Cerebral asymmetry in the perception of American sign language.

American Sign Language (ASL) offers a valuable opportunity for the study of cerebral asymmetries, since it incorporates both language structure and complex spatial relations: processing the former has generally been considered a left-hemisphere function, the latter, a right-hemisphere one. To study such asymmetries, congenitally deaf, native ASL users and normally-hearing English speakers unfamiliar with ASL were asked to identify four kinds of stimuli: signs from ASL, handshapes never used in ASL, Arabic digits, and random geometric forms. Stimuli were presented tachistoscopically to a visual hemifield and subjects manually responded as rapidly as possible to specified targets. Both deaf and hearing subjects showed left-visual-field (hence, presumably right-hemisphere) advantages to the signs and to the non-ASL hands. The hearing subjects, further, showed a left-hemisphere advantage to the Arabic numbers, while the deaf subjects showed no reliable visual-field differences to this material. We infer that the spatial processing required of the signs predominated over their language processing in determining the cerebral asymmetry of the deaf for these stimuli.     

Self- and other regulation during the infancy period

The “other regulation” views of Lev Vygotsky and of Jerome Bruner are contrasted with Jean Piaget's self-regulatory model of infant development. Examples of adult behavior in Piaget's writings and in mother-infant interactions suggest that adults perform behaviors which are analogous to Piaget's type a and b self-regulation. Data from infant games are provided to illustrate the processes by which mothers regulate the environments for their infants and the consequences of such maternal regulation for infant development.