Classical conditioning Study Guide

📖 Core Concepts Classical conditioning – learning when a neutral stimulus (CS) becomes predictive of a biologically potent stimulus (US). Conditioned stimulus (CS) – formerly neutral cue that now predicts the US. Unconditioned stimulus (US) – stimulus that naturally elicits an unconditioned response (UR). Conditioned response (CR) – learned response to the CS. Unconditioned response (UR) – innate reflex to the US. Contingency & prediction – learning occurs only when the CS reliably predicts the US; random pairings fail. Evaluative conditioning – a subtype that changes the liking of a stimulus (positive US → more positive CS, negative US → more negative CS). 📌 Must Remember Forward conditioning (CS precedes US) is the most effective. Delay: CS overlaps with US onset. Trace: CS ends, then a trace interval before US. Second‑order conditioning – CS2 paired with already‑conditioned CS1; CS2 can later elicit the CR. Extinction reduces CR strength but does not erase the original CS‑US association → spontaneous recovery, renewal, reinstatement possible. Rescorla–Wagner equation: $$\Delta V = \alpha \beta (\lambda - \Sigma V)$$ $\alpha$: CS salience, $\beta$: US learning rate, $\lambda$: max associative strength (1 if US present, 0 if absent), $\Sigma V$: total associative strength of all present cues. Blocking: Prior learning about CS1 (full prediction of US) prevents learning about a new CS2 added on the same trials (ΔV for CS2 = 0). Latent inhibition – pre‑exposure to a neutral stimulus without US makes later conditioning to that stimulus slower. Conditioned inhibition confirmed by summation test (CS‑ + CS+ reduces response) and retardation test (CS‑ learns slower). 🔄 Key Processes Acquisition Repeated CS‑US pairings → increase associative strength (ΔV positive). Extinction Present CS alone → set $\lambda = 0$, producing negative ΔV → associative strength declines toward 0. Recovery from Extinction Reacquisition: CS‑US re‑pairing → faster ΔV because V is not zero. Spontaneous recovery: after a rest, CR re‑appears (weak). Disinhibition: novel intense stimulus after extinction temporarily restores CR. Reinstatement: US alone after extinction revives CR when CS tested. Renewal: test in original conditioning context → CR returns. Generalization vs. Discrimination Generalization gradient: similarity → response strength. Discrimination training introduces a CS‑ (non‑reinforced) to sharpen response to CS+. 🔍 Key Comparisons Delay vs. Trace conditioning Delay: CS and US overlap → stronger acquisition, less reliance on hippocampus. Trace: CS ends before US → requires a trace interval, engages hippocampal/antero‑cingulate circuits. Blocking vs. Latent Inhibition Blocking: CS2 added after CS1 already predicts US → no learning about CS2. Latent inhibition: CS pre‑exposed without US → reduced attention to CS, slower later learning. Rescorla–Wagner vs. Attention‑based models (Mackintosh; Pearce & Hall) RW: learning driven solely by prediction error (λ‑ΣV). Attention models: learning rate (α) itself changes based on predictability. ⚠️ Common Misunderstandings Extinction = erasure – false; original CS‑US memory persists, leading to recovery phenomena. CR = UR – often similar but can differ qualitatively; stimulus‑substitution theory is insufficient. Higher‑order conditioning = direct CS‑US pairing – wrong; CS2 never directly contacts US. Blocking proves no learning about CS2 – actually, learning may occur but is not expressed (Comparator theory). 🧠 Mental Models / Intuition Prediction error as “surprise” – the brain updates associations only when the outcome is different from what the CS predicts. Associative strength as a “budget” – each trial allocates part of a limited budget (λ) to the cues present; once the budget is full, new cues get nothing (blocking). Context as a background cue – treat the experimental room as a low‑salience CS that can modulate renewal and extinction. 🚩 Exceptions & Edge Cases Latent inhibition cannot be explained by plain RW (ΔV = 0 despite CS‑US pairing). Spontaneous recovery and renewal occur even after extensive extinction, contradicting the assumption that V returns to zero. Trace conditioning fails with lesions to hippocampus, unlike delay conditioning. Comparator theory predicts performance effects without requiring a lack of learning about the blocked cue. 📍 When to Use Which Predictive learning questions → apply Rescorla–Wagner (compute ΔV). Explaining why a novel cue fails to acquire conditioning after pre‑exposure → invoke latent inhibition or attention‑based models. Context‑dependent recovery → consider context as an additional CS (renewal). Assessing whether a cue is inhibitory → run summation and retardation tests. Designing behavioral therapies → use extinction‑based protocols (systematic desensitization, exposure) or counter‑conditioning (replace fear CS with pleasant CS). 👀 Patterns to Recognize “CS‑US → CR” pattern → acquisition. “CS alone → ↓CR” pattern → extinction. “CS‑ + CS+ → ↓CR” → conditioned inhibition (summation). “CS‑ after extensive CS+ training → slower acquisition” → retardation test. “Change in response after context switch” → renewal. 🗂️ Exam Traps Choosing “extinction erases memory” – the correct answer notes that original learning persists and can re‑emerge. Confusing latent inhibition with blocking – latent inhibition involves pre‑exposure without US; blocking involves already‑learned CS predicting US. Assuming CR always matches UR – many exam items test knowledge that CR can be qualitatively different (e.g., fear CR vs. salivation UR). Applying the Rescorla–Wagner formula to latent inhibition – it will give ΔV ≈ 0, but the model does not explain the underlying attentional change. For trace conditioning, selecting “hippocampus not needed” – incorrect; trace conditioning critically depends on hippocampal/antero‑cingulate pathways. --- Study this guide a few minutes before the exam: focus on the bolded keywords, the core equation, and the characteristic patterns of each phenomenon.