Transcript classical conditioning

Chapter 35 Learning and Memory
Learning
The acquisition of knowledge or skill
 Types of learning

• Non-associative
– Habituation, sensitization
• Associative
– Classical conditioning
– Operant Conditioning
Nonassociative
No
paired stimulus/response
– habituation
•
•
repeated exposure to a stimulus results in
reduced responding to that stimulus
generally neutral, non-noxious stimuli
– sensitization
Associative
Paired
stimulus/response
– classical conditioning (two stimuli are paired;
when the light shines ----- get food)
– operant conditioning (stimuli and response
are paired; push lever = food
Classical Conditioning

Conditioned stimuli (no overt response) and
unconditioned stimuli (gives an overt response)
– not simply timing of events relative to each
other
– we can detect a positive correlation between
two stimuli (efficiency of pairing)
– Extinction can occur over time (unpaired)
Operant conditioning
 trial-and-error learning
– A predictive relationship between response and a
stimulus
– behaviors that are rewarded tend to be repeated
– those that cause aversive consequences are not
repeated
– timing is important
– must have predictive element
Learning involves forming
memories
II Memory
 storage
and retrieval of information
1. Stages of Memory

Short-term memory and long-term memory
– Short-term memory (STM, or working memory) – a
fleeting memory of the events that continually happen
– lasts seconds to hours
– limited to 7 or 8 (not more than 12 items) pieces of
information

Long-term memory (LTM)
– has limitless capacity
– can be blocked by blocking protein synthesis
Transfer from STM to LTM

Factors that affect transfer of memory from
STM to LTM include:
– Emotional state – we learn best when we are alert,
motivated, and aroused
– Rehearsal – repeating or rehearsing material
enhances memory
– Association – associating new information with
old memories in LTM enhances memory
– Automatic memory – subconscious information
stored in LTM
2. Declarative (Explicit) or Nondeclarative
(Implicit) Memory
Declarative（explicit）memory
• Knowledge
we have conscious access to
•
Episodic （情景式）
• Personal experiences / events etc.
 Canoeing on Lake Winnipeg, surfing in San Diego
• Often referred to as autobiographical memory
•
Semantic （语义式）
• Conceptual knowledge
 “Where is Lake Winnipeg, where is San Diego?”
 “How do you canoe, how do you surf?”
Declarative (Fact) memory:
–Entails learning explicit information
–Is related to our conscious thoughts （有意
识的思维） and our language ability
–Is stored with the context in which it was
learned
Nondeclarative or Implicit

Procedural
learned skills or habitual responses
Skill memory


–
–
–
less conscious than fact memory and involves
motor activity
acquired through practice
do not retain the context in which they were
learned
Structures Involved in Fact Memory

Fact memory involves the following brain areas:
– Hippocampus and the amygdala （杏仁核）
– Specific areas of
the thalamus and
hypothalamus
– Ventromedial
prefrontal cortex
and the basal
forebrain
Figure 15.8a
Major Structures Involved with Skill Memory

Skills memory involves:
– Corpus striatum – mediates the automatic
connections between a stimulus and a motor
response
– Portion of the
brain receiving
the stimulus
(visual in this
figure)
– Premotor and
motor cortex
Figure 15.8b
3. Mechanisms of Memory
 Changes
that take place during memory
include:
– Neuronal RNA content is altered
– Dendritic spines change shape
– Unique extracellular proteins are deposited at
synapses involved in LTM
– Presynaptic terminals increase in number and
size, and release more neurotransmitter
4. Forgetting
•
Decay theory
•memory fades away with time, unless there
is rehearsal
•
Interference theory
•memory for other material interferes with
information we are trying to remember
Decay Theory of Forgetting
• Memory fades away with time
• unless there is rehearsal
Rehearsal
Amount of information
100%
Day 1 Day 2
Day 7
Day 30
• Example: reviewing notes after class
Forgetting as a result of
interference


Retroactive （逆行性）
Interference
Proactive （顺行性）Interference
Retroactive Interference
Current learning interferes with recall of
previously learned material
Learn
A
Time
Learn
B
Memory
Loss
for A
Proactive Interference
Prior learning interferes with retention of
new information
Learn
A
Time
Learn
B
Memory
Loss
for B
5. Retrograde and
Anterograde Amnesia (失忆症）
Time
Retrograde
Anterograde
Head Trauma
《Random Harvest》(1942）
《鸳梦重温》
导演：Mervyn LeRoy
编剧：James Hilton
主演：Greer Garson
Ronald Colman