human memory
TRANSCRIPT
Human
MEMORY
Let’s define memory…
•is an ability to store, retain, and recall information and experiences.
•is our ability to encode, store, retainand subsequently recall information and past experiences in the human brain.
TYPES OF MEMORY
• Memory actually takes many
• different forms. We know that
• when we store a memory,
• we are storing information. But,
• what that information is and
• how long we retain it determines
• what type of memory it is.
• The biggest categories of memory
• are short-term memory (or working memory) and long-term memory, based on the amount of time the memory is stored.
Storage: Retaining Information
Storage is at the heart of memory. Three stores of memory are shown below:
SensoryMemory
WorkingMemory
Long-termMemory
Encoding
RetrievalEncoding
Events
Retrieval
*Sensory Memory
-is the shortest-term element of memory.
-The ability to look at an item for a second and
then remember what it looked like.
-It is processed approximately 200-500
milliseconds after an item is perceived.
Sensory Memories
Iconic0.5 sec. long
Echoic3-4 sec. long
Hepatic< 1 sec. long
The duration of sensory memory varies for the different senses.
Sensory Memory
SensoryMemory
WorkingMemory
Long-termMemory
Encoding
RetrievalEncoding
Events
Retrieval
*Short-term Memory (Working
Memory)
• Short-term or working memory is the brief time of keeping something in mind before dismissing it or pushing it into long-term memory. The hippocampus and subiculum store short-term memories.
Chunking
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The capacity of the working memory may be increased by “chunking.”
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4 chunks
Duration
Peterson and Peterson (1959) measured the duration of working memory by manipulating
rehearsal.
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The duration of the working memory is about 20 sec.
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Working Memory
SensoryMemory
WorkingMemory
Long-termMemory
Encoding
RetrievalEncoding
Events
Retrieval
*Long-Term Memory
-Is the ability to store more information for long periods of time (life times) like phone numbers, names and address’ from when we were kids.
-long-term memory can store much larger quantities of information for potentially unlimited duration (sometimes a whole life span). Its capacity is
immeasurably large.
- Long-term memory is often divided into two further main types: explicit (or declarative) memory and
implicit (or procedural) memory.
Explicit (declarative) memory (facts): factual knowledge
& personal experiences
Types:
> episodic memory
>semantic memory
Implicit (procedural) Memory (skills): Long-term
memories of conditioned responses and learned skills, e.g.,
driving
Types of Long-Term Memory
1. Declarative/explicit memory (“knowing what”)
refers to those memories that can be consciously
recalled.
>It is sometimes called explicit memory, since it
consists of information that is explicitly stored and
retrieved, although it is more properly a subset of
explicit memory.
>Declarative memory can be further sub-divided into
episodic memory and semantic memory.
1.1 Episodic Memory
> represents our memory of experiences and
specific events in time in a serial form, from which
we can reconstruct the actual events.
Personal experiences linked with specific times
and places
serial memory of events
1.2 Semantic Memory
>on the other hand, is a more structured record
of facts, meanings, concepts and knowledge about
the external world that can be described and
applied..
Impersonal facts and everyday knowledge
– structured memory of facts, concepts, skills
2. Procedural memory (“knowing how”)
>is the unconscious memory of skills and how to do
things, particularly the use of objects or movements
of the body, such as playing a guitar or riding a bike.
Procedural memory is sometimes referred to as
implicit memory, because previous experiences and
conscious awareness of these previous experiences,
Long-Term Memory
SensoryMemory
WorkingMemory
Long-termMemory
Encoding
RetrievalEncoding
Events
Retrieval
Memory Retrieval
Once information has been encoded and stored in
memory, it must be retrieved in order to be used.
There are four basic ways in which information can
be pulled from long-term memory
• Recall• Recollection• Recognition• Relearning
Memory Recall/Retrieval
*Retrieval, recall or recollection (calling back
the stored information in response to some cue
for use in a process or activity)
previously encoded and stored in the brain.
*During recall, the brain "replays" a pattern of
neural activity that was originally generated in
response to a particular event,
Why Do We Forget? Five Key Theories
• Decay
• Interference
• Motivated Forgetting
• Encoding Failure
• Retrieval Failure
Five Theories of Forgetting (Continued)
1. Decay Theory:
memory degrades with time
2. Interference Theory: one memory
competes (interferes) with another
–Retroactive Interference (new information interferes with old)
–Proactive Interference (old information interferes with new)
3. Motivated Forgetting: motivation to forget unpleasant, painful, threatening, or embarrassing memories
4. Encoding Failure: information in STM is not encoded in LTM
5. Retrieval Failure: memories stored in LTM are momentarily inaccessible (tip-of-the-tongue phenomenon)
Five Theories of Forgetting (Continued)
Forgetting: Memory Failure
• prospective memory– remembering to do something in the future
content – remembering what to do
timing – remembering when to do it
– absentmindedness
• amnesia– anterograde amnesia
inability to store new information and events
– retrograde amnesiainability to retrieve past information and events
>age factor
>brain injury etc…
THE END