PubMed Health⌕ Search

Biomedical subjects

J Kolodny

Publications and source records attributed to J Kolodny.

5 recordsLinked to original sources
PubMed2000

A neural basis for general intelligence.

Universal positive correlations between different cognitive tests motivate the concept of "general intelligence" or Spearman's g. Here the neural basis for g is investigated by means of positron emission tomography. Spatial, verbal, and perceptuo-motor tasks with high-g involvement are compared with matched low-g control tasks. In contrast to the common view that g reflects a broad sample of major cognitive functions, high-g tasks do not show diffuse recruitment of multiple brain regions. Instead they are associated with selective recruitment of lateral frontal cortex in one or both hemispheres. Despite very different task content in the three high-g-low-g contrasts, lateral frontal recruitment is markedly similar in each case. Many previous experiments have shown these same frontal regions to be recruited by a broad range of different cognitive demands. The results suggest that "general intelligence" derives from a specific frontal system important in the control of diverse forms of behavior.

Adult↗
PubMed1998

Random generation and the executive control of working memory.

A series of experiments explores the capacity for generating sequences of random responses, relating it to the central executive component of working memory. Experiment 1 shows a broadly similar pattern of redundancy increasing with speed of generation for both the verbal generation of digits and the manual pressing of keys. In both cases deviations from randomness are shown to reflect the increasing use of a limited number of stereotyped response sets. The remaining experiments use keyboard generation. Experiment 2 demonstrates that concurrent immediate serial recall decreases randomness, and that longer recall sequences produce less random output. Experiments 3 and 4 show that whereas simple counting has no effect on randomness, serial recall, semantic category generation, and concurrent digit generation have substantial effects, and a concurrent fluid intelligence test has the greatest influence on the randomness of key pressing. It is suggested that the task of random generation resembles that of category fluency because it requires the subject to switch retrieval plans and inhibit repetition. On this basis it is predicted that a task involving repeated switching of categories will interfere with generation, despite being predictable and having a low memory load. Experiments 5 and 6 confirm this prediction. Strengths and limitations of the switching hypothesis are discussed, as are the implications of our results for the analysis of executive processes.

Adult↗
PubMed1985

Recurrent prolactinoma and meningioma following irradiation and bromocriptine treatment.

This case report describes a 45-year-old man with a massive extrasellar prolactinoma, treated initially with surgery and radiotherapy, who experienced a dramatic reduction of the bulk of his tumor but persistence and subsequent progression of an extrasellar portion while receiving long-term bromocriptine therapy, despite stable, suppressed prolactin levels. Although the residual tumor was thought to be adenomatous tissue unresponsive to bromocriptine, a meningioma was ultimately diagnosed. Because the meningioma may have been radiation-induced, clinicians are reminded to consider a second neoplasm in cases of apparent bromocriptine treatment failures, especially when prolactin levels are stable.

Adult↗