Stratification in perception and action

Summary This paper discusses the concept of stratification, in the sense of levels of analysis and levels of control, in relation to human perception and performance. It is contended that functional analysis is the proper level of analysis for the domain of perception and action. This is illustrated by means of models of cognitive energetics and motor control. The functional level of analysis can be situated in between the level of symbolic representations and the level of neurophysiological mechanisms. It is also argued that the concept of levels of control provides a way of integrating or relating ecological and information-processing approaches to psychology, in the sense that ecological psychology is concerned with lower and more peripheral levels of control (coordinative structures). Finally, some remarks are made on the relation between cognition and perception and action, drawing on Piaget, and it is proposed that the concept of schema is more appropriate for the domain of perception and action than is the notion of symbolic representations.     

Metamemory in older adults: the role of monitoring in serial recall

Older and younger adults were asked to think aloud while studying sets of pictures matched in difficulty for immediate serial recall. When instructed only to remember, young adults tended to study longer, rehearse more, and recall better than did older adults on the most difficult lists. Young adults were also much more likely to spontaneously test themselves during study in the most difficult condition. Older adult groups instructed either to study longer or to self-test, both showed improved recall. Only the older adults who had been instructed to self-monitor, however, recalled better on tests of short-term maintenance and generalization; overt rehearsal data showed that these older adults continued to test themselves. Metamemory deficits may be present with older adults when a strategy, like self-testing, is needed to generate metamemorial knowledge. Strategies such as self-testing can be easily taught, however, and they hold promise of being useful across situations.     

Focal changes in cerebral blood flow produced by monetary incentive during a mental mathematics task in normal and depressed subjects

The purpose of this experiment was to determine the effect of incentive-induced arousal on the diffuse and regional cerebral blood flow (rCBF) response during cognitive activation for normal and depressed groups. Two normal rest CBF measurements were followed by two mental mathematics activation CBF measurements. For the first activation measurement, half the subjects in each group were offered monetary incentive for correct performance and half the subjects received no monetary incentive. All subjects were offered monetary incentive on the final activation run. The effect of monetary incentive on the first activation run was to increase CBF activation at four detectors in the left hemisphere. Incentive did not affect the CBF activation response when introduced following practice on the activation task (on the final run). Depressed groups had lower resting blood flow than normals, but the distribution of flow and the CBF response to incentive were almost identical in the two groups.     

Response input interface

A circuit for interfacing experimental response signals with logic apparatus that controls experimental events is described. The unit shapes and holds the signal until its presence has been detected by the controlling program.     

Typicality and familiarity of faces

We examined context-free familiarity information as a source of the effects of face typicality upon face recognition. Experiment 1 tested memory for typical and unusual faces by (1) subjects who received an input list followed immediately by a recognition test (standard condition), (2) subjects who viewed all test faces (targets and lures) prior to the input list (prefamiliarization condition), and (3) subjects who viewed all test faces after the input list but prior to recognition (postfamiliarization condition). Although false-alarm errors in the standard condition were lower for unusual than for typical faces, this effect was reduced by postfamiliarization and was eliminated entirely by prefamiliarization. The prefamiliarization and typicality effects were replicated in Experiment 2, which showed that patterns of old judgments were compatible with the hypothesis that, although familiarity of new faces is greater if these faces are typical, the increment in familiarity that results from presentation is greater if these faces are unusual.