[ CogSci Summaries home | UP | email ]

Haberlandt, K. (1999) Chapter 5: Memory for skills. In Human Memory: Exploration and Applications, Allyn & Bacon. Needham Heights, MA.

Author of the summary: Debajyoti Pati, 2000, gte811q@prism.gatech.edu

Skills are different from fact because one may know how to execute a skill/, but it is altogether a different task to describe how. Memories for skill are implicit, and could be observed only in terms of improved performance after prior exposure. Priming, where a subject is exposed to a stimuli prior to doing a task, or prior exposure to the same task bears an impact on performance, and is called the priming effect. In some cases, having an excellent memory is also considered a skill. Implicit memory is in essence unconscious, unlike explicit memory which involves conscious and deliberate recollection of knowledge. Various studies have demonstrated a dissociation between implicit and explicit memory, and most of those studies have focused on priming, and perception & performance enhancement resulting from prior experience with a task.

Warrington and Weiskrantz (1968) provided the impetus for research on priming, in their research work on the memory of amnesic patients. Their work suggested that priming improves performance as a result of automatic facilitatory effect in the neural structures. Subsequently, priming effects have also been shown on nonimpaired people. Jacoby (1983) propounded the view that priming could be an expression of memory owing to its lasting effects. He compared priming and explicit memory as a function of various encoding conditions, which included the no-context, context, and the generate condition. The test phase included the perceptual identification phase and recognition memory test. He found a dissociation between implicit and explicit memory measures. Priming effects have also been reported in word completion, lexical decision, picture identification, comprehension, problem solving, and judgment & attitude formation tasks. In word completion tasks, words presented during the inspection phase are found to be more likely to be completed as compared to control words. In lexical decision tasks, a speed up in decision is observed in relation to repeated items, more in the cases of rare words. In picture priming studies, repeatition leads to increased speed of response as well as accuracy. Priming in problem solving tasks could be observed in unconscious plagiarism. Priming also has an effect when people make judgment regarding objects and individuals. R.B.Zajonc"s (1980) study revealed that the frequency of exposure has considerable impact on the appeal of initially unfamiliar stimuli. Such an effect is also noticed in attitude towards racial and gender stereotypes, and is used frequently by advertisers. Another effect of priming is the false-fame effect, where prior exposure could lead to familiarity and false judgment regarding a person or an object.

Priming is similar to explicit memory but for a few crucial differences. Priming is sensitive to change in modality of the stimulus, where as explicit memory is not. Priming is not subject to retroactive interference, where as the interference effects in explicit memory has been widely documented. Amnesic patients exhibit priming in a variety of priming paradigms, although some issues like the duration of priming effect is under debate.

Neuroscience has made important contributions to cognitive sciences. Early studies in the field gained knowledge on the relation of brain structure and memory from case studies of accident victims and other patients. Introduction of brain-imaging methods intensified this line of inquiry. PET research is one of the important ones where the pattern of cerebral blood flow is studied to identify patterns related to various tasks. Behavioral methods is yet another method where studies use the divided visual-field paradigm, where it has been found that priming depends on an interaction between the physical form of the test stimuli, including the type font and the hemisphere processing the information. Electrophysiological measures is yet another research field in this domain.

Implicit learning is an important study area in memory studies. Learning rules (artificial grammar) has led to studies on learning, discrimination, recognition and transfer. Learners acquire grammatical strings more quickly than ungrammatical ones, readily discriminate between string types, respond more quickly to grammatical ones, and also show evidence of transfer of knowledge to new situations. Amnesic patients perform relatively well in this task. On the question of what people learn in these exercises, three differnet hypotheses has been propounded. The rule-learning hypothesis suggests an implicit learning of rules, where as the exemplar hypothesis suggests that subjects remember individual exemplars. A third hypothesis suggests the acquisition of chunks or letter combinations by the subjects. People"s ability to form abstractions is another area of study, where they learn to abstract the prototype underlying similar stimuli. Similarly, people, including amnesic patients, demonstrate good intuition about the co-occurrence of events, and are equally good in learning event sequences. Problem solving is an important area where memory is vital. Some of the examples include arithmetic, algebra and geometry problems. Programming computers and solving puzzle are a second type of problem solving. Language comprehension, and musical performance are some other examples. Practice plays an important role in skill acquisition and performance. Skill acquisition has been characterized in three stages; the cognitive stage, the associative stage and the autonomous stage. Practice plays an important role in all stages, it has been suggested that for best result practice should be continued even after mastery f the skill, it should be distributed over time, and people should try to generate solutions on their own. It has also been suggested that memory improves with practice, which has been demonstrated in several domains including digit span, chess, etc..


Back to the Cognitive Science Summaries homepage
Cognitive Science Summaries Webmaster:
JimDavies (jim@jimdavies.org)
Last modified: Wed Apr 26 09:42:52 EDT 2000