Chapter 5 PSYC 362 Notes PDF

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These are chapter 5 notes from a lecture by Professor Whitney Hawkins...

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Chapter 5 Lecture Notes:  Types of Memory  Sensory Memory - unattended information that is presented quickly and stored briefly  Short-term Memory (STM)- attended information for up to 20-30 seconds  Long-term Memory (LTM)- holds information for long periods of time  Primacy effect -people recall more words at the beginning and end of the list  Serial position effect - recalling more words at the beginning of the list  Recency effect - recalling more words at the end of the list  Why does this happen? 

Participants typically repeat the list to themselves when the list starts (rehearsal) but then stop after the first few words

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The recency effect occurs because the last few words are still in sensory or shortterm memory

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We were asked to wait to clear the memory (avoid recency effect)

 Sensory Memory  Sensory memory is a record of what we perceive 

E.g. if we quickly look up at a billboard while driving

 Many cognitive researchers hypothesize there are separate sensory memories for each sensory modality 

Sensory memory for taste, sensory memory for smell, etc.

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Most research focuses on iconic memory (visual) and echoic memory (auditory)

 Iconic Memory  Sperling (1960) presented participants with a display for 0.5 seconds and had them recall the letters 

Ps only reported ~ 4 of the 12 letters

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Whole-report condition

 In another experiment, played a tone AFTER the display 

Partial-report condition

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Low-pitched tone = recall bottom row

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Medium-pitched tone = recall middle row

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High-pitched tone = recall top row

 Sperling (1960)  Regardless of the tone, Ps were almost always completely accurate! 

This means they must have remembered the whole display because they didn’t know what tone they would hear.

 Why did they have better memory in the second experiment? 

Sperling believed it was because in the whole-report condition, Ps lost the information in their memory by the time they wrote the first few letters.

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Implies information only lasts briefly in the memory system being used.

 If tone was delayed 1 second, recall, decreased.  Neisser (1967) called this memory the icon 

Sensory memory storage system for visual information

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Lasts about 1 second

 Can be erased by masking

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Presenting stimuli after the icon

 Echoic Memory  Sensory memory for auditory stimuli 

Often called echo (as opposed to icon for visual stimuli

 Moray Bates, and Barnett (1965) gave Ps a “four-eared” listening task  Like the dichotic listening task but with four channels 

Ps asked to report all letters they heard in the whole-report condition or letters from a certain channel in the partial-report condition

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Ps reported more accurately in the partial-report condition

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Like icon, information is stored briefly

 Suffix effect – a sound presented after the auditory stimuli acts as a mask.  Final notes about sensory memory: 1. Modality specific (visual sensory memory holds visual information, etc.) 2. Capacities are larger but storage duration is very short 3. Stored information is mostly unprocessed (stored on physical aspects, not meaningful aspects) 4. Some researchers think that this would not happen in the real world  Short-term memory  If I tell you to call a number and you need to walk across the room to the phone, how would you remember the number? 

Most people would repeat the number until they got to the phone ~ Rehearsal!

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Once the number is dialed, most people forget it – STM

 Note: most cognitive psychologists hypothesized STM lasts 2 minutes but some neuropsychologists hypothesize STM lasts about a day. This class will assume 2 minutes.  Many factors distinguish STM from LTM 

Length of storage

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Capacity - how much information can be stored

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Coding - the form in which the information is stored

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The way information is forgotten

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The way information is retrieved

 There has been much debate over STM so we will discuss traditional descriptions then newer proposals (including working memory)  George Miller (1956) found that the number of items we can keep in our short-term memory is 7+ or -2. 

This is called the capacity.

 Later research revealed memory span is not __consistent____ 

Number of bits of information a persona can recall depends on: o Age of participant o Attention o Type of stimuli (numbers, letters, words, etc.) o Practice (e.g. Chase and Ericsson [1982] found with practice Ps could remember about 80 random digits)

 One way to remember more information is by chunking 

Grouping together information in a more meaningful way

 Retention duration – the amount of time a memory trace remains available for retrieval

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~ 20 seconds for STM

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This means you have ~ 20 seconds before you forget a piece of information (if you don’t rehearse it)

 How did researchers determine this retention duration? 

Brown (1958) and Peterson (1959) utilized the Brown-Peterson task o Ps presented with three letters (e.g. BKG) o Ps also presented with a number (e.g. 347) o Ps told to remember the letters while counting backward out loud by 2s o They counted to avoid rehearsal

 Researchers found the information decays within about 20 seconds. 

Decay – break apart

 Other researchers challenged this decay explanation and proposed an interference mechanism  Inference explains that instead of decaying, newer information can bury older information.  How could interference explain the Brown-Peterson task? 

Computing and announcing the number could bury the three digits

 We do not know which theory is correct.  Working Memory  Baddeley and Hitch’s studies cast doubt on the traditional concept of STM. 

They asked participants to hold a series of digits in STM while also verifying the truth of sentences seen on a computer screen.

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Even a full load of six digits in memory slowed down processing of sentences, particularly difficult ones, but participants were still able to complete the task.

 Because of these results, Baddeley and Hitch argued for the existence of working memory, a limited capacity temporary storage system that underpins complex human thought.  Working memory is conceived as being made up of multiple components. 

The central executive directs the flow of information, choosing what to operate on and how.

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The phonological loop carries out rehearsal of verbal material.

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The visuospatial sketch pad maintains visual material through visualization.

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The episodic buffer is a temporary system that integrates information from _____________________.

 Working memory doesn’t just store information; it is a process that makes information available to other cognitive processes such as reasoning.  An interesting application of the working memory concept is the idea of stimulusindependent thoughts (SITs), such as daydreams. 

Both auditory and visuospatial tasks can disrupt the production of SITs tasks can disrupt the production of SITs.

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However, practiced tasks produce less interference with SITs than novel or challenging tasks.

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People’s minds tend to wander naturally; it requires control from the central executive to maintain focus on a goal.

 Research shows that higher WMC (working memory capacity) indicates more control over cognitive focus. 

People with higher WMC have shown higher ability to: o reason o make consistent decisions o overcome effects of misleading information in an eyewitness task o solve problems

 In summary, there are several key differences between the conceptualizations of shortterm memory and working memory. 

STM can be thought of as information that is actively being processed

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WM includes these active memory traces as well as attentional processes used to maintain them

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WM has several components and is involved in a variety of forms of cognitive processing.

 Memories are not “stored” in one particular place in the brain. 

The case study of H.M., who lost his ability to transfer new ______________ memories into _________________ memory after surgery, indicated the importance of the rhinal cortex in forming memories.

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Findings from other brain-damaged people have implicated areas in the ___________________ as being important for working memory.

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PET scan studies show different patterns of activation for verbal working memory (primarily in the left frontal and left parietal lobes) versus spatial working memory (right parietal, temporal, and frontal lobes)...