Chapter 6: Learning and memory
THE ARCHITECTURE OF MEMORY
Ask Yourself
- What happens to a phone number when you stop trying to remember it and start to just know it?
- Why is it that some people with amnesia can remember their childhood but not what they had for breakfast?
- Why do I forget so much of this information as soon as I have read it, and how can I stop things going in one ear and out the other?
What You Need To Know
| 1. MEMORY STORES (E&K p. 189) |
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| 2. SHORT-TERM MEMORY: STANDARD MODEL (E&K p. 193) |
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MEMORY STORES
The multi-store model (see E&K pp. 189–190) is based on common features of different theories.
- Information is initially received, and briefly held, by the sensory store.
- Some information is attended to and processed by the short-term store.
- Some information is transferred from short- to long-term store.
- Long-term storage often depends on rehearsal.
Theories of attention and memory often overlap (see E&K chapter 5).
Sensory stores
- Most information in the environment is not attended to.
- The iconic store (or visual store) has limited capacity and duration.
- Evidence—Sperling's (1960) study (see E&K p. 190) found that information decayed in about 0.5 seconds.
- The echoic store is a transient auditory store holding relatively unprocessed input.
- Evidence—Treisman's (1964) study (see E&K p. 191) found that unattended auditory information lasted about 2 seconds in echoic storage.
Short- and long-term stores
- The difference between these stores is similar to William James's (1890) distinction between primary and secondary memory.
WEBLINK: An interesting biography of William James http://www.emory.edu/EDUCATION/mfp/jphotos.html
- Short-term store has:
- very limited capacity
- fragility of storage.
- Short-term memory capacity can be assessed by using digit span and by looking at the recency effect.
- The recency effect in free recall means that the last few items in a list are usually much better remembered in immediate recall than are the items in the middle of the list.
- Bjork and Whitten (1974) showed that the recency effect still exists if participants count backwards for 12 seconds after each item on the list is presented, which was not predicted by Atkinson and Shiffrin (1968).
INTERACTIVE EXERCISE: Capacity in short-term memory
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- Double dissociation indicates that two tasks probably involve different processing mechanisms and provides strong evidence for the distinction between short-term and long-term memory store. See the evidence from Shallice and Warrington, 1970.
- Forgetting from long-term and short-term stores involves different mechanisms.
- Long-term store forgetting is mainly cue-dependent (see later) where memories still exist but are inaccessible.
Evaluation
- To justify the existence of three qualitatively different types of memory store (sensory, short-, and long-term), we must show major differences between them.
- Temporal duration
- Storage capacity
- Forgetting mechanism(s)
- Effects of brain damage.
- The multi-store model is oversimplified.
- Warrington and Shallice (1972) showed that short-term memory is not unitary.
- Shallice and Warrington (1974) showed that patient KF had variable problems with short-term memory of different types of information.
- Logie (1999) discussed that short-term memory often involves accessing the long-term store.
- The multi-store model has often been used as a starting point for other theories.
- e.g., Atkinson and Shiffrin's (1968, 1971) model of the long-term store.
- The multi-store model can be criticised for focussing too much on structural aspects of memory rather than on memory processes.
SHORT-TERM MEMORY: STANDARD MODEL
- Several theorists (e.g., Shiffrin, 1999) have proposed a revised theoretical account of the short-term store, which can be called the standard model (Nairne, 2002).
- Main assumptions:
- Information in a state of activation.
- Activated information accessed immediately and effortlessly.
- Activation is fragile.
- Essentially:
- Activated information from long-term memory is in the short-term store.
- Decay of activation causes information to leave the short-term store.
- Decay can be prevented by rehearsal.
WEBLINK: Richard M. Shiffrin's homepage http://www.indiana.edu/~alldrp/members/shiffrin.html
Evidence
- The theory predicts that short-term memory should be better for words that can be rehearsed more rapidly.
- There is contradictory evidence about this—Baddeley et al. (1975) vs. Lovatt et al. (2000; see E&K p. 194).
ACTIVE REFERENCE LINK: Lovatt, P., Avons, S.E., & Masterson, J. (2000). The word-length effect and disyllabic words. Quarterly Journal of Experimental Psychology, 53A, 1–22. [Link to http://journalsonline.tandf.co.uk/openurl.asp?genre=article&eissn=1464-0740&volume=53&issue=1&spage=1]
- The theory states that forgetting is due to decay, however proactive interference also has a role (Keppel & Underwood, 1962).
- If forgetting is due to decay, forgetting should be rapid in the absence of rehearsal.
- This was observed by Peterson and Peterson (1959) but contradicted by Nairne et al. (1999; see E&K p. 194).
ACTIVE REFERENCE LINK: Nairne, J.S., Whiteman, H.L., & Kelley, M.R. (1999). Short-term forgetting of order under conditions of reduced interference. Quarterly Journal of Experimental Psychology, 52A, 241–251. [Link to http://journalsonline.tandf.co.uk/openurl.asp?genre=article&eissn=1464-0740&volume=52&issue=1&spage=241]
WEBLINK: James S. Nairne's homepage http://www.psych.purdue.edu/~nairne/home.html
- Tehan and Humphreys (1996) present evidence against the assumption that information in short-term memory is directly accessible and depends on the nature of the retrieval cue (see E&K p. 194).
Evaluation
- Most assumptions in the standard model are either incorrect or only partially correct.
So What Does This Mean?
According to the multi-store theory, there are separate sensory, short-term, and long-term stores. There is strong evidence to support the notion of various qualitatively different memory stores, but this approach provides a very oversimplified view. For example, multi-store theorists assumed there are unitary short-term and long-term stores, but the reality is more complex.
According to the standard model, activated information from long-term memory is in short-term memory, decay of that activation causes that information to leave short-term memory, and decay can be prevented by rehearsal.
This account de-emphasises the roles of proactive interference and of retrieval cues in short-term memory and forgetting.
WEBLINK: An article on techniques for memory retention http://coe.sdsu.edu/eet/Admin/TOC/index.htm
