Seeing textons in context

Texton theory holds that visual texture segregation occurs through the preattentive detection of local differences in primitive visual units called “textons.” Three textons have been proposed for shape: lines, line terminators, and line intersections. The experiments reported here show that line closure also behaves like a texton under some conditions. In addition, the experiments show that texture segregation is not determined by texton differences per se, but by the extent to which the unique textons in a region are salient in the context of the textons common to regions. This suggests that preattentive vision is not as simple minded as texton theory claims it to be.     

The electronic chalkboard

The present paper describes “the electronic chalkboard” (TEC), a teaching innovation made possible by the recent development, under a FIPSE grant to CONDUIT, of specialized instructional software. The instructional power of TEC casts the computer in the role of catalyst in the student-teacher dyad and leads to the emergence of the more powerful student-computer-teacher triad. Relevant educational principles and CAI techniques that should ensure the intelligent use of TEC are discussed.     

Reciprocal Effects Between Locus of Control and Job Attributes

The purpose of this study was to examine the reciprocal relationships between locus of control and job attributes of a representative sample of 1383 employees in a large Australian city. It was predicted that employees with an internal locus of control would attain jobs higher on skill-utilization, influence and income than those attained by employees with an external locus of control. It was also predicted that jobs involving high skill-utlization, influence and income would induce greater internal control beliefs than those low on skill-utilization, influence and income. Locus of control was measured using Rotter's scale (Rotter, 1966). Reciprocal causation was assessed using two-stage least squares analysis. For the total sample, it was found that locus of control and job attributes were reciprocally determined. However, locus of control was not related to influence when skill-utilization and income were controlled. When the sample was split on the basis of gender and marital status, the predicted relationships between locus of control, skill-utilization and income were found for married men only. For married women, locus of control was neither a determinant of job attributes nor an outcome of job experience. These sub-group differences were interpreted in terms of differences in job tenure, work values and occupational opportunity.     

Factors influencing readability of rapidly presented text segments

Experiment 1 compared paragraph comprehension for texts shown either as normal pages on a computer terminal screen or as rapid serial visual presentations (RSVPs) of small text segments to a common location. Over several days of practice, reading comprehension was equivalent in the normal presentation mode and the RSVP format. When successive RSVP segments contained some information in common, to mimic the experience of successive parafoveal and foveal views of words in normal reading, comprehension was somewhat worse than when successive segments contained no overlapping information. Experiment 2 used a variety of segment size and segment duration combinations to investigate the optimal means of presenting text in the RSVP format. Across a variety of presentation rates and text difficulties, comprehension was maximal for segments averaging about 12 character spaces in length. In Experiment 3, texts were divided into short idea units or into random segments of equal average length. Comprehension was shown to be greater in the structured condition than in the random condition. An optimal means of presenting text in the RSVP format could be superior to normal presentation methods for reading and other text-processing tasks.     

A word’s meaning affects the decision in lexical decision

The influence of an isolated word’s meaning on lexical decision reaction time (RT) was demonstrated through four experiments. Subjects in two experiments made lexical decision judgments, those in a third experiment pronounced the words used in the lexical decision task, and those in a fourth experiment quickly pronounced their first associative response to the words. Differences in lexical access time for the words were measured with the pronunciation task, and differences in meaning were assessed with the association task. Multiple regression analyses of lexical decision RT were conducted using associative RT, pronunciation RT, and other target word properties (printed frequency, length, instance dominance, and number of dictionary meanings) as predictor variables. These analyses revealed a relationship between lexical decision RT and associative RT after the effects of other variables had been partialed out. In addition, word frequency continued to have a significant relationship to lexical decision RT beyond that shared with pronunciation RT and the other variables. The results of these experiments indicate that at least some of the effect of word meaning and word frequency in lexical decision is attributable to a decision stage following lexical access.     

Childhood aggression and social adjustment as antecedents of delinquency

A sample of 2,453 grade school children were followed into young adulthood through record sources. Teacher interviews provided information about low-peer-status children that was assessed in relation to subsequent delinquency for both sexes and young adult criminality for males. A multivariate design evaluated the joint effects of social class, a measure of family disturbance, and childhood problem behavior factors as antecedents of delinquency. Childhood aggression emerged as the most prominent antecedent factor for males but not for females. Social class and family disturbance were associated with aggression but did not have significant direct effects on delinquency. Aggression was related to severity of delinquency. Dispositional status, reflecting severity, was the best indicator of which delinquent males would have adult criminal records. A causal model is presented.The study was supported by a grant from the Scottish Rite Schizophrenia Research Program, N.M.J., U.S.A. Portions of the study were presented at the Life History Research conference in Monterey, California, 1981. The authors wish to thank June White, Cindy Hanson, and Ned Worell for their help in conducting this research. Data for this research was originally gathered by Merrill Roff. Follow-up data were contributed by Ronald Peek, Donald Bamber, Charles Watson, Shiela Makie, William S. Ward, Edward S. Posey, Chris Hemlabs, and Harriet Barnes.     

Performance of disturbed hyperactive and nonhyperactive children on an objective measure of hyperactivity

Twenty hyperactive emotionally disturbed children (6–11 years) and a matched sample of nonhyperactive emotionally disturbed children were selected from the population of a therapeutic day treatment facility on the basis of teacher ratings. They were administered the Matching Familiar Figures Test-20 and were rated on several scales of impulsivity and/or hyperactivity. Each subject was required to perform on the Delay Task of the Gordon Diagnostic System, which required them to inhibit behavioral responding on a temporally based schedule (DRL-6) in order to win points. Children classified as hyperactive, whether by one or more criteria, were relatively unable to refrain from emitting a high number of nonreinforced responses. Moreover, these performance differences persisted regardless of age or IQ and were stable over the 8 minutes required to complete the test.The authors gratefully acknowledge the efforts of the following members of the Institute of Clinical Psychology, University of Virginia: Richard Abidin, Ann Loper, Ronald Reeve, and Sherry Kraft. Data analyses were conducted using STATMANAGER, Hayden Software Company, copyright 1983.