PSY2043 Ch07 Lecture Notes

PSY2043 Introduction to Psychology

Ch07 Learning and Conditioning

Intended Learning Outcomes

• Understand the history of the study of animal and human learning.
• Know the different types of conditioning and the way in which they are studied.
• Understand the brain physiology underlying learning processes.
• Know the topics of cognition and motivation, as they interact with learning.
• Identify different types of learning such as: classical versus instrumental conditioning, and observational learning.
• Explain the empirical paradigms used to study learning processes.
• Identify situations in which cognitions and/or motivations affect learning.

PERSPECTIVES on LEARNING 学习的各种观点

• Learning
  • is a relatively permanent change in behavior that is the result of experience 因经验而造成行为相对持久性的改变
  • Four basic kinds of learning
    • (1) habituation and sensitization
    • (2) classical conditioning
    • (3) instrumental conditioning
    • (4) complex learning
• 行为主义观点、认知观点、生物观点

Classical Conditioning 经典性条件反射

Pavlov’s experiments

• (1) US to UR
• (2) CS&US to UR
• (3) CS to UR
• Drug tolerance 耐药性
  • classical conditioning contributes to drug tolerance
  • situational specificity of drug tolerance 药物耐受的情境特异性
• Acquisition 习得
  • define (CS, US) as reinforced trial
  • repeated (CS, US), and CR increase
  • the left panel of the figure(learning curve), called acquistion stage of the experiment
  • 食物同时摇铃，流口水越来越多
• Extincition 消退
  • US omitted, CR diminish
  • Extinction: learning that CS no longer predicts the US
  • 不给食物，只摇铃，慢慢就不流口水了
• Spontaneous recovery 自然恢复
  • if participant allowed to rest and then presents only CS again, CR reappears
  • effect of REST
  • 休息一会后，只摇铃，又会流口水
  • 说明在消退以后，即使不流口水了，习得的东西也没有被忘记
• Stimulus generalization 刺激泛化
  • 对相似的刺激产生类似的反应
  • e.g. 巴甫洛夫的狗听到摇铃铛会流口水，用类似的但不一样的声音刺激，也会流口水
• Stimulus discrimination 刺激辨别
  • 如果持续强化刺激，狗最后可能只会对铃铛声音流口水，也就是说能分辨不同刺激
• Second-order conditioning 二阶条件反射
  • e.g. light, meat -> tone, light, meat
• Conditioning and fear
  • e.g. light, electrical shock, pain -> light, pain

Cognitive factors 认知因素

• Pavlov & others believed conditioning occurs if CS & US were temporally contiguous
• a predictive (or reliable) relationship between CS & US more important than temporal contiguity or frequency of pairings (Rescorla, 1972).

Biological constraints 生物性限制

• animals are “pre-programmed” to learn particular things in particular ways (evolution & gene)
• 在 classcal conditioning 中，刺激能否被联结受限于生物
• Learned taste aversion 习得性味觉厌恶
  • 对某种食物的不良体验会让人对该食物产生厌恶，这不符合经典条件反射
  • 因为有一次体验就会产生厌恶，并没有重复配对而且 CS-US 间隔通常很长

INSTRUMENTAL CONDITIONING / OPERATIONAL CONDITIONING

• Thorndike’s experiment : law of effect
  • 如果能立即获得奖励的话，行为会被强化

Skinner’s experiments

• Baseline: the inital rate of pressing
• Acquisition & extinction: depends on food

• 	Bad	Good
  Giving	Positive Punishment (behavior -)	Positive Reinforcement (behavior +)
  Taking Away	Negative Reinforcement (behavior +)	Negative Punishment (behavior -)

• Shaping：全新的行为
• Conditioned/secondary reinforcer：几乎都是二阶反射
• Generalization and discrimination
• Schedules of reinforcement
  • Ratio schedules
    • Fixed ratio schedules (FR)
    • Variable ratio schedules (VR)
  • Interval schedules
• Aversive conditioning厌恶性条件反射：反应后立即受到负面事件，导致反应减弱
  • Escape Learning 逃离学习：a response terminates aversive event
    • leave toilet
  • Avoidance Learning 回避学习：a response is learned to prevent aversive event
    • close the door of the toilet

Cognitive factors

• Temporal contiguity is an important factor for it to occur
• Control: instrumental response is conditioned only when an organism interprets reinforcement as being controlled by its response
• Contingency

Biological constraints

LEARNING AND COGNITION

Observational learning 观察学习

• Human often learn without behavior being reinforced immediately through imitation & observational learning – copying behavior of others you deem successful

Prior beliefs

LEARNING AND THE BRAIN

Habituation and sensitization

Classical conditioning

Cellular basis of learning

LEARNING AND MOTIVATION

Arousal

From incentives to goals

Intrinsic motivation and learning