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R Paterson

Publications and source records attributed to R Paterson.

11 recordsLinked to original sources
PubMed1984

Emergent features, attention, and object perception.

The perceptual processing of arrows and triangles and of their component angles and lines was explored in a number of different tasks. The results suggest that some analysis of shapes into simpler parts occurs preattentively, because these parts can recombine to form illusory conjunctions when attention is divided. The presence of "emergent features," such as closure or arrow junctions, was inferred from predicted correlations in the pattern of performance across tasks and across individual subjects. Thus triangles (for most subjects) and arrows (for some subjects) behave as if they had a perceptual feature that is absent from their parts and that mediates parallel detection in search and easy texture segregation. For some subjects, circles could apparently supply the additional feature (presumably closure) required to form illusory triangles from their component lines, whereas for other subjects circles had no effect. The fact that triangle lines can form illusory conjunctions with another shape makes it unlikely that triangles are perceived holistically and strengthens the interpretation that relies on emergent features.

Adolescent↗
PubMed1980

Adrenocorticotropic hormone may be transported directly from the pituitary to the brain.

Experiments were designed to test the hypothesis that pituitary hormones may be delivered directly to the brain. Concentrations of adrenocorticotropic hormone (ACTH) in the plasma were determined in blood samles obtained simultaneously from the carotid artery, the sagittal sinus, and the jugular vein of three awake sheep. Seizures were induced electrically to stimulate ACTH secretion, and at precise intervals thereafter several simultaneous comparisons were made in each animal. In many of the post-seizure comparisons, the ACTH plasma concentrations within the sagital sinus exceeded those within the carotid artery as well as those within the jugular vein, indicating that this hormone was released from the pituitary and carried directly through capillary beds of brain to the venous blood within the sagittal sinus. The experiment was repeated in one hypophysectomized sheep and, in this animal, ACTH concentration in the plasma was reduced, but that in the sagittal sinus still was elevated after the seizure, an indication that some ACTH (or ACTH-like material) was released from the brain itself.

Adrenocorticotropic Hormone↗