The Fraser illusion: complex figures

The cause of the Fraser illusion, which occurs when a line made up of tilted segments itself appears tilted, is examined further. In this series of experiments, we used figures that resembled the original Fraser illusion; they were more complex than those reported on in our previous paper (Stuart & Day, 1988). The figures were used to explore two theories of the Fraser illusion further: that it is the result of interactions between orientation selective units, and that it is a consequence of the local, distributed processing of orientation. The presence of background elements like those used in the original illusion led to an increase in the strength of the illusion, but the shape of these elements had no differential effect on illusion strength. There was a differential effect of the background on the assimilative and contrast illusions, owing respectively to small and large tilts of the inducing elements. The illusion was markedly reduced at small visual angles when the background was absent, but it was only slightly affected when the background was present. All these findings are difficult to explain in terms of interactions between single units, either at the same or at different scales in the image. The effects of luminance contrast and isoluminance on the illusion were not consistent with either theory, but they indicated that researchers need to consider the role of figure-ground organization in this illusion.     

Effects of background anger,provocation, and methylphenidate on emotional arousal and aggressive responding in attention-deficit hyperactivity disordered boys with and without concurrent aggressiveness

We investigated the effects of background anger, provocation, and methylphenidate on emotional, physiological, and behavioral responding in children with attentiondeficit hyperactivity disorder (ADHD) with and without concurrent aggression. Our study revealed that ADHD boys showed more emotional and physiological distress when exposed to an interaction in which an administrator chastised each boy's favorite counselor, compared to a friendly interaction between the two adults. The background anger manipulation did not affect the aggressive behavior of the boys against an opponent in an aggressive game. High-aggressive (HA) ADHD boys were more likely to respond to provocation with aggression than low-aggressive (LA) ADHD boys, but only LA boys showed increased physiological reactivity with increasing provocation. Methylphenidate resulted in increased heart rates under all conditions and did not interact with any of the other findings.This project was conducted while the first author had the support of National Institute of Alcohol Abuse and Alcoholism grant AA 06267.The authors wish to thank the staff members of the 1987 Summer Day Treatment Program who assisted in conducting this project. The authors also express their appreciation to Karen Guthrie for coordinating the medication assessment and to Hart Blanton for computer programming.     

Assessment of delusional beliefs during the modification of delusional verbalizations

This study examined the strength of delusional beliefs during the modification of delusional verbalizations of a 51 year-old chronically mentally ill inpatient. The changing-criterion design was used to document the effectiveness of a behavioral treatment package to alter the rate of delusional responses to personal background questions. The results revealed a stepwise decline in the frequency of delusional responses. Generalization effects to novel interviewers were obtained. No changes were obtained on the subject's ratings of delusional beliefs, with the subject assigning ratings of absolute conviction to his beliefs throughout the duration of the study.     

A study of language functioning in Alzheimer patients

Language functioning in Alzheimer's disease is reviewed and the performance of 25 Alzheimer patients on a standard battery is reported. All these hospitalized patients were aphasic to some degree. As a group, they differed from normals on all language variables, and from stroke patients in terms of higher fluency and lower comprehension. Spontaneous speech showed high incidence of circumlocutions and semantic jargon, but no phonemic paraphasias or target approximations. Syllabic perseverations, shouting, inappropriate laughter, and mutism were late-appearing features. Transcortical Sensory, and Wernicke's aphasias were frequent, but Broca's and Transcortical Motor aphasias notably absent. Extent of language impairment correlated with current length of hospitalization but not age. Reading, writing, and performance scores except praxis, were lower than oral language scores. Findings were discussed in relation to previous results, methodology, and language organization in the brain.     

Deep agraphia

A case of agraphia is documented which resembles in every respect the pattern of results obtained in deep dyslexia. Pronounceable pseudowords could not be written to dictation while concrete nouns were more accurately transcribed than abstract nouns. Verbs and functions words were written very poorly and oral spelling was impaired. In addition, semantic paragraphias were present. In contrast to the deficit observed in writing, no such impairment was found for reading. It is concluded that writing can occur without phoneme-grapheme conversion and that codes generated for reading are functionally distinct from codes generated for writing.     

The predictive efficiency of Holland's SDS summary codes in terms of career choice: A four-year follow-up

This study was designed to investigate the predictive efficiency of the primary and secondary summary codes of Holland's Self-Directed Search for Educational and Vocational Planning (SDS) in terms of expressed career choice 4 years later. In 1974, 126 voiationally undecided high school seniors were given the SDS, followed by a revision of Trow's Vocational Choice Inventory (VCI) in which they were asked to express a career choice or a state of indecision. In 1978, this same group was mailed a posttest VCI; the responses of 84 subjects were then analyzed. The subjects' expressed career choices on both the 1974 and 1978 VCI were compared to the primary and secondary summary codes on the SDS which they had taken in 1974. Inspection of the responses indicated that 21.4% of the subjects had made career choices predicted by their primary summary codes and 51.2% had made vocational choices found among their secondary summary codes. Only 27.4% chose a career area not predicted by their 1974 SDS results. The results of this study appear to lend support to the validity of using the SDS summary codes to predict eventual career decisions.     

Acknowledgement

Four experiments examined the effects of noise on semantic memory. The first was a replication of a study by Eysenck, in which subjects had to retrieve words beginning with particular letters which were also instances of specified categories (e.g. Fruit-A). Whereas Eysenck had found that both noise and activation level of the individual interacted with the dominance of the category instance possible, the present study failed to repeat the findings.The remaining experiments used a paper-and-pencil modification of Eysenck's technique; the second and third were successful in showing interactions of dominance and noise, but in opposite directions. The two experiments differed only in the previous experience of the subjects. In a fourth experiment, the same materials were presented in a different sequence, mixing dominant and non-dominant instances. The interaction then disappeared again.These experiments therefore suggest that the effect of noise on memory is not a uniform and mechanical exaggeration of dominance, but depends on the retrieval strategies being employed by the particular subject.