psy3051-week4-lecture-pt1

INTRODUCTORY LECTURE

• definition of memory — “the retention of experience-dependent internal representations over time”

  • processes involved in retaining, retrieving, and using information about; stimuli, images, event, ideas, and skills after the original information is no longer present

Introduction to Memory

• Focus on sensory memory and short-term memory as components of memory.

• Historical reference to William James (late 19th century) on different types of memory.

EARLY THEORIES—William James' Memory Types

• primary memory: short term memory, current contents of consciousness (what we're aware of now)

  • being aware of surroundings, feelings (clothes on the body)

• secondary memory: long term memory, mental representations that are not currently in our consciousness—information that can be retrieved

  • remembering the name of a past teacher, retrieving long-term memories into consciousness

  • retrieval process: the mechanism of bringing information into conscious awareness from memory stores

Types of Memory

• primary memory—accessible to consciousness

  • sensory memory; short-term memory; working memory

• secondary memory—represents memories not in consciousness

  • long-term memory

  • distinction within long-term memory: main one is whether your ability to recall memory is automatic or effortful

    • declarative/explicit memory—effortful recall; historical facts

    • non-declarative/implicit memory—automatic recall; how to ride a bike

      • motor skills are typically here

Modal/MULTI-STORE Model of Memory

• [insert model]

• information process flow

  1. sensory memory (input from the senses); brief

  2. short-term memory (focused attention); stays briefly—though rehearsal pushes the chances of it staying and being encoded

  3. long-term memory (encoding and rehearsal); permanent store, knowledge and previous experiences are stored

     • long-term memory allows for retrieval back to short-term memory

Sensory Memory

• acts as a buffer for incoming sensory information

• characteristics:

  • high capacity: holds large amounts of information

  • short duration: information held for a very brief time

    • less than a second for visual stimuli, about 10 seconds for auditory stimuli

• types of sensory memory:

  • iconic memory: visual sensory memory

  • echoic memory: auditory sensory memory

  • new information is constantly overwriting old information in sensory memory

    • iconic — with 1 sec

    • echoic — within 10 sec

Iconic Memory

• demonstrated through persistence of vision—an optical illusion where the human eye and brain continue to perceive an image for a brief period after it has disappeared from view

  • when moving a sparkler OR those art flip books (that’s so raven)

• thaumatrope: an example that illustrates how two images can merge visually when spun rapidly.

Echoic Memory

• holds auditory information, essential for language processing and conversation; speech perception

  • asking a distracted person for the time—processing the echoic memory storage

Experimental Evidence for Sensory Memory Duration (ADVISED FOR REVISION DURING EXAM @ 20:00 LECT 1)

• sperling’s experiment, 1960

  • whole report vs. partial report tasks to measure iconic memory.

    • whole report: recall all letters shown in a brief display (average 37% correct)

    • partial report: tone cue to recall specific row (approx. 83% correct)

  • results indicated iconic memory lasts less than one second

Short Term Memory (STM)

• holds a limited amount of information for a limited duration (about 15-20 seconds)

  • unlike sensory memory, short term memory can be actively rehearsed to extend duration

    • remembering and repeating a validation code

  • rehearsal is an effortful process

Measuring Duration of Short Term Memory—PETERSON & PETERSON, 1959

• [insert image]

• preventing rehearsal demonstrated STM limits

  • typical performance indicates that after increasing delays without rehearsal, memory performance decreases

Capacity of Short Term Memory—GILKER, 1992

• digit span task: typically allows recall of 5-9 items

  • miller’s law: 7 ± 2 items (average capacity)

    • relies on what the item is the context behind it

• chunking: grouping information to extend short-term memory capacity

  • grouping random numbers into a meaningful date reduces cognitive load—remembering as “1946” instead of “1-9-4-6”