Chapter 6: Learning and memory
IMPLICIT LEARNING
Ask Yourself
- Do you always know what you know?
- Are the same brain areas and processes involved in learning to ride a bike and learning the theory of how to ride a bike?
- If you lost your memory, would you still be able to tie your shoe-laces?
What You Need To Know
| 1. IMPLICIT LEARNING (E&K p. 210) |
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IMPLICIT LEARNING
- Seger (1994) defined implicit learning as "learned complex information without complete verbalisable knowledge of what is learned".
- There are clear similarities between implicit learning and implicit memory.
- Reber (1993) proposed five characteristics of implicit memory and learning that differ from explicit memory and learning:
- Robustness
- Age independence
- Low variability
- IQ independence
- Commonality of process.
- There are three main types of research on implicit learning:
- Looking at whether healthy participants can learn fairly complex material in the absence of conscious awareness.
- Looking at brain-damaged patients with amnesia to decide whether their implicit learning is intact.
- Using brain imaging to see if different areas are associated with implicit and explicit learning.
- Anderson (e.g., 1983, 1996) developed his Adaptive Control of Thought (ACT) model.
- During the development of automatic skills, conscious representations are gradually transformed into unconscious ones.
- Some research has shed doubt on the ACT model.
- Failure of participants to indicate conscious awareness does not prove that learning was implicit.
- Shanks and St. John (1994) propose two criteria to show implicit learning (note these were not really possible on many early studies):
- Information criterion—the information provided on the awareness test must be the information that is responsible for the improved performance.
- Sensitivity criterion—the test of awareness must be sensitive to all relevant knowledge.
Evidence
- Howard and Howard's (1992) study showed evidence of implicit learning of a pattern with no explicit learning seen.
- Shea et al. (2001; see E&K p. 211) found that task performance was significantly worse where participants were told there was a pattern than on a repeated segment when participants were unaware.
- Shea et al. concluded that information that is not readily accessible may have learning benefits over information which is readily available to consciousness.
ACTIVE REFERENCE LINK: Shea, C.H., Wulf, G., Whitacre, C.A., & Park, J.-H. (2001). Surfing the implicit wave. Quarterly Journal of Experimental Psychology, 54A, 841–862. [Link to http://journalsonline.tandf.co.uk/openurl.asp?genre=article&eissn=1464-0740&volume=54&issue=3&spage=841]
- Perruchet et al. (2003) argued that provision of explicit instructions led participants to attend to information that was not relevant for good task performance.
ACTIVE REFERENCE LINK: Perruchet, P., Chambaron, S., & Ferrel-Chapus, C. (2003). Learning from implicit learning literature: Comment on Shea, Wulf, Whitacre, and Park (2001). Quarterly Journal of Experimental Psychology, 56A, 769–778. [Link to http://journalsonline.tandf.co.uk/openurl.asp?genre=article&eissn=1464-0740&volume=56&issue=5&spage=769]
- Wilkinson and Shanks (2004; see E&K p. 212) conducted an interesting pattern-learning study and their findings supported the view that sequence learning is explicit.
- Findings with brain-damaged patients are inconsistent.
- Much of the research has used artificial grammar learning tasks where participants must decide whether a string of letters conforms to an artificial grammar rule.
- Typically, healthy participants do well even though they cannot verbalise the rules of the grammar.
- Knowlton et al. (1992) found that amnesics' performance was similar, suggesting that they had intact implicit learning.
- However, when these patients were instructed to recall specific strings used, they performed worse than healthy participants, presumably as this needed explicit learning.
- Channon et al.'s (2002) study cast doubt on the assumption that grammar learning is normal in amnesia when materials of sufficient sensitivity are used.
RESEARCH ACTIVITY: Artificial grammar learning
- Grafton et al. (1995) looked at brain regions involved in implicit learning (with PET) and found motor and supplementary motor area activation.
- Explicit learning has been shown to be associated with activation of the right premotor cortex, dorsolateral cingulate, parietal cortex and anterior cingulate (Gazzaniga et al., 1998).
- Aizenstein et al. (2004) used fMRI and reported prefrontal, anterior cingulate and early visual area activation during both implicit and explicit learning. However the prefrontal activation was greater with explicit learning tasks.
- Differences have been less clear in other studies.
- Assuming separate systems for implicit and explicit learning Anderson (1983, 1996) has considered how they interact.
- His theory is that performance is initially supported by explicit processes and, after practice, implicit processes become strong enough to support performance alone.
- Willingham and Goedert-Eschmann (1999; see E&K p. 213) found evidence to support this.
- More evidence is needed to clarify the relationship.
Evaluation
- Much experimental evidence suggests an important distinction between implicit and explicit learning.
- Amnesic patients generally show evidence of intact implicit learning despite their impaired explicit learning.
- We can predict that brain areas associated with working memory and attentional control should be more active during explicit, than implicit, learning.
- However, there are grounds for being sceptical about the existence of implicit learning.
- It is hard to devise tests of awareness that can detect all the task-relevant knowledge of which participants have conscious awareness.
- Amnesic patients do not always have intact implicit learning.
- Overall, implicit learning probably does exist.
- Most tasks probably use a mixture of implicit and explicit learning.
- See evidence from Kelly, 2003 (below).
ACTIVE REFERENCE LINK: Kelly, S.W. (2003). A consensus in implicit learning? Quarterly Journal of Experimental Psychology, 56A, 1389–1391. [Link to http://taylorandfrancis.metapress.com/openurl.asp?genre=article&eissn=1464-0740&olume=56&issue=8&spage=1389]
So What Does This Mean?
It has been claimed that implicit learning differs from explicit learning in terms of the presence or absence of consciously accessible knowledge. Much evidence supports the distinction between implicit and explicit learning, and amnesic patients often show intact implicit learning but impaired explicit learning. In addition, brain areas involved in working memory and attention are often more active during explicit than implicit learning.
However, it has proved difficult to show that claimed demonstrations of implicit learning satisfy the information and sensitivity criteria, and some brain-imaging studies and studies on amnesic patients shed doubt on the notion of implicit learning.
It is likely that the distinction between implicit and explicit learning is too simple, and that more complex theoretical formulations are required.
