Functional recovery following brain damage: conceptual frameworks and biological mechanisms

Mammals are well known to manifest recovery over time of many functional impairments induced by brain lesions. A brief reveiw is provided of the different conceptual frameworks within which functional recovery has been examined in the literature, and of different neurobiological mechanisms that have been proposed to account for the phenomenon. We observe that these two levels of analysis have frequently been only loosely related. Finally, a newly identified biological mechanism—compensatory collateral sprouting—is described which appears to be closely related to functional recovery in animals with hippocampal lesions, and this is proposed as a powerful new model within which to investigate further the relationship between the phenomenon of functional recovery and its underlying mechanisms.     

Assessing social competencies in lower income preschool children

This study examined social competencies in 4-year-old, lower income, nonwhite preschool children in a replication of work by Shure, Spivack, and Jaeger. Age differential interpersonal cognitive problem-solving skills were investigated, i.e., ability to generate alternative solutions to interpersonal problems, consequential thinking, and school achievement as they relate to behavioral adjustment ratings by teachers and independent observers. A teacher's rating of a child as aberrant or adjusted predicted an independent observer's rating of that child in a naturalistic setting. Children who were rated as adjusted by their teachers had significantly higher scores on an achievement inventory than those children who were rated aberrant, but the study did not find the predicted relationship between problem-solving thinking and adjustment. A version of this paper was presented at the annual meeting of the American Psychological Association, New York, September 1979. The study was supported by grants from the McGregor Fund, the Eloise and Richard Webber Foundation, the David M. Whitney Fund and by the Detroit Public Schools Region 7, for which the authors express grateful appreciation. The authors also wish to thank Myrna B. Shure for her help in carrying out this replication.     

Duration estimates of two information processing components

Adult humans attempted to make quick responses to the first of two sequentially presented visual stimuli. At short interstimulus intervals (less than about 100 msec) accuracy was impaired by a different second stimulus and this was hypothesized to reflect the activity of an information processing component concerned with stimulus registration. At longer interstimulus intervals (up to approximately 350 msec) reaction time was inhibited by a different second stimulus and this was assumed to reflect the activity of a second component concerned with decision. The stimulus registration component was insensitive to variations in the complexity of the task, while the decision component was found to be greater for a task requiring recognition (is the current stimulus the same as an earlier one?) than for one merely requiring choice (what is the current stimulus?). This functional independence and the sizeable difference in the temporal range of susceptibility led to the conclusion that two distinct information processing components were involved.     

Perceived control in continuous loud noise

The effects of two types of perceived control were assessed for performance during and following exposure to continuous loud noise at 90 dBC. Subjects performed a tracking task during exposure and the Stroop test in the period following exposure. Control could be effected either (1) by attenuating the intensity of the noise or (2) by reducing the difficulty of the tracking task. In both cases subjects were encouraged not to exercise control. Performance in treatments involving loud (90 dBC) and soft (55 dBC) noise served as baseline conditions. Perceived control of task difficulty accentuated the tendency for root-mean-square error to rise during the tracking task. There were no significant effects of noise intensi ty on tracking performance. Loud noise reduced the incidence of errors in the Stroop test but perceived control failed to influence this effect. The results are discussed in terms of the generality of perceived control phenomena.     

Verbal ability and mental processing speed

The notion that verbal ability is related to mental processing speed was examined using tasks that systematically varied in semantic content. Subjects' reaction times were measured in five tasks involving arrow matching, physical identity word matching, or taxonomic identity word matching. The findings indicated that matching tasks using different decision rules and different stimuli were all related to verbal ability. In fact, reaction time for subjects required to judge whether two arrows pointed in the same direction was the best predictor of verbal ability. One explanation of the results is that speed of information processing (a general factor) may be the important component of verbal ability which is measured by seemingly different matching tasks.     

Some problems of Wilson's disease

The Leipzig Center for Wilson's Disease in the GDR is charged with the registration and diagnosis of all homozygous Wilson gene carriers, the clarification of all suspected cases, including the heterozygote test, and the co-ordination of long-term treatment. At present, there are 78 recorded Wilson gene carriers living. On the basis of our own comprehensive observations and investigations over prolonged periods of time, questions concerning pathogenesis, genetics, diagnosis and therapeutic measures, including their side-effects, are dealt with.     

Experimentally induced phonological paraphasias.

A motor aphasic patient had to repeat word lists that contained, among other things, words with the sequences r - r - l and l - l - r. These sequences were often repeated as l - r - l (anticipatory distant assimilation) and r - l - r (same type, but less frequently), respectively. These assimilations violate the cross-over constraint (or relevancy condition or adjacency principle) and thus represent another instance of a flagrant contradiction between pathological and normal (natural) phonological processes.     

Aortic isthmus stenosis from a neurological viewpoint

The etiology, pathogenesis, and clinical treatment of stenoses of the isthmus aortae are outlined. Following this, the particular case of a 41-year-old patient with typical stenosis of the isthmus of the aorta is reported. The course of disease required the need for a surgical operation, which had not initially been taken into consideration, to be reexamined. The patient, after performance on him of vascular restoration, is now on a part-time job. Using age as the sole circumstance indicating the inadvisability of performing a surgical operation in the case of stenosis of the isthmus aortae cannot any longer be considered justifiable.