Chapter 8 : MEMORY:
From her Lectures (I only have lecture 23 here)
- We cant really identify memory physically
- To uiunderstand how memory works we need to see how information is entered in the brain
- How information is maintained (storage)\
- How information is translated into action (retrieval)
- How does the mind interpret short term information?
- What techniques do we use to remember information?
- What initianted the act of remembering and forgetting?
- Remembering short term:
o Atkinson and Shifferin: multi-store model of memory
o People rely on two memory systems
o 1. Sensory memory: sensory stimuli in a relatively pure unanalyzed form are stored in a
very brief period of time like snap shots of the world, the external message is like an
image is represented in detail that lasts for a few moments.
o 2. Sort term memory: limited capacity working memory, we use to hold information after
it has been analysed onto a meaningful form 1s to less than 1 minute. Rapidly forgotten
but can be maintained in the process of rehearsal.
o Multistore memory can be translated to long term memory to be encapsulated to neural
connection and retrieved at a later time.
- Sensory memory: the ability to extract information that is critical at a glance. How much
information can the human extract at a single glance?\
- Apparatus Apikistoscop? Presents visual display for a certain duration. The researchers mmight
flash a matrix of letter s for a second and ask the person to identify the letters.
- Participants insist that they have seen all the letters but they perform very poorly
- Researchers: George Sperling: on each trial he would present the matrix of letters (4 or 3 only),
and after the matrix was removed Sperling presented a tone, if the tone was high, low or medium
pitch the person had to report top bottom or medium. ) partial---
- The result: this showed that they didnt lie when they saw the matrix, but by the time they
produced the answer they had forgotten it, which resulted in bad performance - Visual memory (iconic memory): visual input that is being retained for less than a second.
Asking the participants to retain only parts of the display made them perform faster.
- In further experiments swirling measured the duration of sensory memory. Buy using this
technique he was able to know how long it is for people to remember before the image fades
away which is less than a second.
- After the matrix he presented them with a blank screen, assuming that the human brain acts like a
camera, and the participants will remember the information for a bit on the blank screen
- Echoic memory (sound): works like iconic memory. Auditory information that is stored for a
short operiod of time (2-3 seconds) mistake in textbook.
- Other types of sensory memories that refer to other senses
- Meaningful chuinks of iinofrmation.
- Short term memory: if you never rehearse what you think now you will never remember it.
- Sensory memory maintains a relatively exact representaioon of the physical stimuli received
- Introspection: bill---
- what kinds
- the way people used the inner voice to store information .
- repetition process:
Overview of memory:
- Learning is the change in behavior based on experience.
So, learning is evidence for brain plasticity
- Memory: is the cognitive process of encoding, storing, and retrieving information.
- Encoding: is the active process of putting stimulus information into a form that can be used by our
- Storage: is the process of maintaining information in memory
- Retrieval: is the active process of locating and using information stored in memory
- We are highly aware of these cognitive processes as they happen, but most of the time the storage of
information is not available or at least deactivated, the retrieval of information is a mix between the to
because retrieval requires a reactivation process.
i.e. what is the last line of Silent Night? You started thinking about the beginning of the song
first didnt you?
- Donald Hebb used this active/latent distinction to show that the brain remembered information in two
ways: dual trace theory: he said that information that was active was in that state because neurons were firing
Hebb thought that this activity was due to feedback circuits of neuron.
Repeated firing in turn, would strengthen synaptic efficiency of the circuit, leading to
structural changes in the neurons involved.
This structural change would persist after the activity has ceased.
The brain therefore retained traces of an experience either in a latent or active structural state.
Hebbs theory was later supported by long term potentiaion
- Richard Atkinson and Richard Shiffrin: memory has three forms: sensory memory, short-term
memory, and long term memory
- Sensory memory: is memory in which representations of the physical features of a stimulus are
stored for a very brief time a second or less. It is accurate while it lasts
- Short term memory: is an immediate memory for stimuli that have just been perceived.
Information soon leaves short-term memory, and unless it is stored in long-term memory it will
be lost forever.
- You can rehearse information until it was part of long-term memory.