HCI Slides By Naeem Gill....

1. Human
MEMORY

2. Let’s define memory…
•is an ability to store, retain, and recall
information and experiences.
•is our ability to encode, store, retain
and subsequently recall information
and past experiences in the human
brain.

3. 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.

5. Storage: Retaining Information
Storage is at the heart of memory. Three
stores of memory are shown below:
Sensory
Memory
Working
Memory
Long-term
Memory
Encoding
RetrievalEncoding
Events
Retrieval

6. *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.

7. Sensory Memories
Iconic
0.5 sec. long
Echoic
3-4 sec. long
Hepatic
< 1 sec. long
The duration of sensory memory varies for the
different senses.

8. Sensory Memory
Sensory
Memory
Working
Memory
Long-term
Memory
Encoding
RetrievalEncoding
Events
Retrieval

9. *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.

10. Chunking
F-B-I-T-W-A-C-I-A-I-B-M
The capacity of the working memory may be
increased by “chunking.”
FBI TWA CIA IBM
4 chunks

11. Duration
Peterson and Peterson (1959) measured the
duration of working memory by manipulating
rehearsal.
CH??
The duration of the working memory is about
20 sec.
CHJ
MKT
HIJ
547
547
544
541
…

12. Working Memory
Sensory
Memory
Working
Memory
Long-term
Memory
Encoding
RetrievalEncoding
Events
Retrieval

13. *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.

14.  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

15. 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.

16. 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

17. 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

18. 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,

19. Long-Term Memory
Sensory
Memory
Working
Memory
Long-term
Memory
Encoding
RetrievalEncoding
Events
Retrieval

20. 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

21. 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,

22. Why Do We Forget? Five Key Theories
• Decay
• Interference
• Motivated Forgetting
• Encoding Failure
• Retrieval Failure

23. 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)

24. 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)

25. 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 amnesia
inability to retrieve past information and events
>age factor
>brain injury etc…

26. THE END 