No abstract

A framework for the conceptualization of a broad range of memory phenomena is proposed in this article. The framework integrates research on memory performance in young children, the elderly, and individuals under stress with research on memory performance in normal college students. One basic assumption of this viewpoint is that encoding operations vary in their attentional requirements. Operations that drain minimal energy from our limited-capacity attentional mechanism are called automatic; their occurrence does not interfere with other ongoing cognitive activity. Automatic operations function at a constant level under all circumstances. They occur without intention and do not benefit from practice. Certain automatic processes, we propose, are ones for which humans are genetically "prepared." These processes encode the fundamental aspects of the flow of information, namely, spatial, temporal, and frequency-of-occurrence information. These automatic processes are expected to show limited developmental trends. Other automatic processes develop through practice and function to prevent the subcomponents of complex skills from overloading our limited-capacity system. Contrasted with these processes are effortful operations such as rehearsal and elaborative mnemonic activities. They require considerable capacity and so interfere with other cognitive activities also requiring capacity. They are initiated intentionally and show benefits from practice.A second assumption of the present framework is that attentional capacity varies both within and among individuals. Depression, high arousal levels, and old age are among the variables thought to reduce attentional capacity. The conjunction of the two basic assumptions of the proposed framework yields the important prediction that the aged and individuals under stress will show a decrease in performance only on specific memory tasks, namely, on tasks requiring effortful processing.Evidence from the literature on development, aging, depression, arousal, and normal memory is presented in evaluation of the framework, and four experiments are described. The bulk of the available data is supportive of the framework. For instance, evidence indicates that frequency processing is not influenced by intention, practice, depression, or age. The article also includes discussion of the origins of this viewpoint in other attention and memory theories.

This article proposes a prototypical schema theory of memory. Such a theory assumes the operation of four central encoding-processes: selection-a process that chooses only some of all incoming stimuli for representation; abstractiona process that stores the meaning of a message without reference to the original syntactic and lexical content; interpretation-a process by which relevant prior knowledge is generated to aid comprehension; and integration-a process by which a single, holistic memory representation is formed from the products of the previous three operations. The article evaluates the supportive and critical evidence for these processes in light of the need for any theory of memory to account for three fundamental observations: accuracy, incompleteness, and distortion. The central retrieval process of schema theory, reconstruction, is also discussed in this context. Evidence seems to indicate that the memory representation is far richer and detailed than schema theory would suggest.

Two experiments assess adult age differences in the extent of inhibition or negative priming generated in a selective-attention task. Younger adults consistently demonstrated negative priming effects; they were slower to name a letter on a current trial that had served as a distractor on the previous trial relative to one that had not occurred on the previous trial. Whether or not inhibition dissipated when the response to stimulus interval was lengthened from 500 ms in Experiment 1 to 1,200 ms in Experiment 2 depended upon whether young subjects were aware of the patterns across trial types. Older adults did not show inhibition at either interval. The age effects are interpreted within the Hasher-Zacks (1988) framework, which proposes inhibition as a central mechanism determining the contents of working memory and consequently influencing a wide array of cognitive functions.

This chapter focuses on a set of attentional or executive control processes, all inhibitory, that operate in the service of an individual's goals to narrow and constrain the contents of consciousness to be goal relevant. An uncluttered or narrowly focused “working memory,” rather than a large one, is the ideal processing system. The narrow focus maximizes the speed and accuracy of on-line processing because it reduces the likelihood of switching attention to goal-irrelevant representations. The work is similar to that of other investigations in its focus on executive processes as a critical source of working memory variation as well as variation in many cognitive domains. The emphasis on inhibitory processes may be the characteristic that most differentiates their work from others.