Mem & Cog Ch.5 Studies

Sperling: Iconic Memory

Sensory Memory

Procedure: Receive 12 Letters → cue → whole or partial report

Conclusions:

1/2. Whole vs Partial Report: Sensory Memory fades too quickly in WR

3. Delay reduces partial report advantage; you can hold Icon for >1 Second

4. Partial report based on category has no advantage

5. There is a partial report advantage to physical characteristics

6. Info in the Icon can be masked or erased by other visual stimuli.

Echoic Memory

Sensory Memory

3- or 4-man procedure, 3-4 sources of 9 letters simultaneously → Cue→Recall

Conclusions:

1. Whole report ( no cue), 4.2/9 Letters reported

2. Partial Report (visual cue), 4.9/9 Letters reported

3. Stimulus→Delay->Whole or Partial report; partial report not better; cannot hold info in echo for >4 Seconds

4. Partial report: Stimulus→Auditory cue→Report, Backward masking, no advantage

Sensory Memory

Capacity: large

Coding: modality-specific memory, relatively unprocessed

Duration: short ~1 sec, Icon: ~.5 sec, Echo ~2-3 sec

Suggests: We should be able to process a lot of info, but we need more time to analyze it

Positive; what you see is what you remember, except in cases of over exposure.

Short term memory capacity

Memory Span

Miller: Capacity

Short - Term Memory

Conclusion: People can remember 7+- 2 items in a new sequence, but can raise that number by chunking info.

Conrad: encoding

Short-Term Memory: Encoded acoustically for ~30 sec

Procedure: Stimulus(letter auditory)→Recall

Conclusion: Participants got confused after 7 letters.

Letters with similar sounds (P&T) are harder to recall than letters that look similar yet sound different (P&F).

Brown and Peterson: 18 Seconds

Short-Term Memory

Procedure: Shown a trigram(CHJ) → Count backwards from 3 → Recall

Conclusion: After 18 seconds of counting trigram forgotten.

Glanzer and Cunitz: 30 Seconds

Short-Term Memory

Studied recency effect in free recall using the serial position curve

Procedure: Study 15 words → Free recall

Conclusion: After 30 seconds recency effect disapears and words forgotten.

Waugh and Norma: Probe-Digit Task

Short-Term Memory

Procedure: Shown up to 16 digits→Tone→Recall digit following the probe

Confounds: Interference vs. Decay. ( 2 rates of presentation used: slow and fast)

Hypothesis:

1. Decay Hypothesis: The rate of recall will be lower with slow presentation and higher with fast presentation.

2. Interference Hypothesis: The rate of recall will remain the same regardless of how fast or slow the presentation is.

Conclusion: Memory performance decreased as a function of interference items regardless of time.

Sternberg: Retreival

Short-Term Memory

Procedure: Study up to 6 items →probe→recall if the probe was in the list

Hypothesis:

1. Parallel Search: Simultaneous comparison of stimuli means that response time should be the same regardless of size

2. Serial Self-Terminating Search: Check the test probe against only those items needed to make a response. (V-shaped graph)

3. Serial Exhaustive Search: Check test probe against all items regardless of if a match is found. (Positive linear graph)

Conclusion: Supported the serial exhaustive search process.

Short Term Memory

Capacity: Memory Span; 7+-2

Coding: Acoustic

Duration: 18-30 seconds

Forgetting: Interference

Retrieval: Serial exhaustive

STM can be inaccurate(negative), i.e., we forget ALOT.

Baddeley and Hitch

Working Memory

• Immediate memory used for current info

• Limited capacity WORK space (similar to attention) that can be divided between storage and control processing

• A breakdown of STM into separate components

1. Phonological Loop: Subvocal rehearsal to maintain auditory material

2. Visuospatial Sketchpad: Mental image for visual and spatial info

3. Central Executive: Directs the flow of info, chooses what will be operated on, operates as an attention system.

4. Episodic Buffer: Limited-capacity temporary storage system, integrates a variety of stimuli sources.