What is memory?

The mental process of registering, storing and retrieving information.

There are different types of memory.

Who can remember what they were wearing on the first day of this term?

Do you remember what you ate last Friday for lunch?

three types of memory

• Sensory memory• Short-term memory• Long-term memory

Both STM & LTM are studied in terms of:

Encoding – Making sense of information

Capacity – How much information

Duration – How long information can be stored for

Sensory Memory

Duration: Seconds

Capacity: Small instant

Encoding: not applicable

Short Term Memory

• Duration: 18-30 seconds

• Capacity: 7+/- 2 items

• Encoding: Acoustic

Short Term MemoryDuration 18 – 30 seconds

• Peterson & Peterson suggested that where information is continually rehearsed it can be stored in the short-term memory indefinitely but is lost as soon as interference blocks rehearsal.

Short Term MemoryDuration 18 – 30 seconds

• Ever been given a telephone number and had to keep repeating it avoiding all distractions until you wrote it

down to prevent forgetting it then you were experiencing Maintenance Rehearsal?

• Reitman (1974) Short duration is due to displacement; as new information is coming into the short-term memory it is kicking out the previous information due to its limited capacity (7 +/- 2 chunks).

• Information decays (fades away) rapidly in short term memory unless rehearsed.

Short Term MemoryCapacity7+/- 2

Miller’s Magic 7 +/-2

Miller (1956) The magical 7 +/-2. The STM can hold on average between 5 & 9 items of information.

Chunking: Grouping the items together into chunks. Telephone number: when you remember it you often recite a group of the numbers as together e.g. 01253 720 742, rather than 01255364289.

Meaningful chunks are even easier to remember: CBC, FBI, NBC

Long Term Memory

• Duration: Lifetime

• Capacity: Limitless

• Encoding: Semantically

Long Term MemoryDuration

Bahrick (1975) Investigation of the duration of very-long-term memory (VLTM). Tested the duration by testing recall of real-life information.Participants included 392 American ex-high school students aged

17-74.

Recall was tested in four ways:1. Free recall of the names of as many of their

former classmates as possible.2. A photo recognition test where they were

asked to identify former classmates in a set of 50 photos, only some of which were their classmates.

3. A name recognition test.4. A name and photo matching test.

• 90% accuracy in FACE AND NAME RECOGNITION after 34 YEARS

• 80% accuracy for NAME RECOGNITION after 48 YEARS• 40% accuracy for FACE RECOGNITION after 48 YEARS

• 60% accuracy for FREE RECALL after 15 YEARS• 30% accuracy for FREE RECALL after 30 YEARS

Classmates are rarely forgotten, but cues are sometimes needed.

Recognition was better then recall.

Procedural memories that are concerned with how to do things

*Declarative memory, which is how we remember what

things mean, and can make links between a stimulus and previous experience.

SEMANTIC processing: The LTM encodes according to meaning.

Long Term MemoryEncoding