A person who was bitten by a dog at age 7 now avoids all dogs. Decades pass without another bite, yet the fear has not diminished. What best explains why the phobia persists?
AThe original fear memory is continuously refreshed by repeated conditioning events
BAvoidance prevents the disconfirmatory experience needed for extinction, preserving the fear memory
CFear memories stored in the amygdala spontaneously strengthen over time without reinforcement
DThe person lacks sufficient insight into the irrational nature of the fear
Avoidance is the maintaining mechanism of specific phobias. Each time the person avoids a dog, anxiety decreases (negative reinforcement), strengthening the avoidance behavior. Crucially, the person never encounters a dog without being harmed, so the original CS→fear association is never challenged. The fear is preserved not because it is re-strengthened, but because it is never tested. Insight (option D) does not extinguish conditioned fear — behavior change requires actual exposure.
Question 2 Multiple Choice
Exposure therapy requires 'response prevention' — the person must not escape or avoid the feared stimulus. Why is this requirement central to the treatment's mechanism?
AEscape would provide additional aversive experiences that re-condition the fear
BEscape would prevent the habituation of physiological arousal necessary for treatment to work
CWithout response prevention, the person cannot form the new CS→safety associations that inhibit fear
DResponse prevention directly erases the amygdala's original fear memory
The mechanism of exposure is extinction learning: forming a new memory that the CS (feared stimulus) predicts safety, not threat. If the person escapes, this new safety association cannot be built — the person only learns that escape reduces anxiety, reinforcing avoidance. Response prevention keeps the person in contact with the CS long enough for a competing CS→safety memory to form. Option D is wrong because LTP-based fear memories are highly stable; exposure creates a competing memory, it does not erase the original one.
Question 3 True / False
Avoidance maintains specific phobias through negative reinforcement: escaping a feared situation removes an aversive state, making avoidance more likely in the future.
TTrue
FFalse
Answer: True
This is the core maintaining mechanism. Negative reinforcement strengthens behavior by removing something aversive — in this case, anxiety. Because avoidance reliably and immediately reduces anxiety, the behavior is strongly reinforced. The tragic irony is that the very behavior that reduces short-term distress preserves the long-term disorder by preventing extinction.
Question 4 True / False
Exposure therapy eliminates specific phobias by erasing the original fear memory stored in the amygdala.
TTrue
FFalse
Answer: False
Fear memories formed through conditioning involve LTP-like strengthening of amygdala circuits and are remarkably stable — they are not erased. Exposure therapy works through extinction learning: creating a new, competing memory that the feared stimulus is safe. This new CS→safety association (mediated by prefrontal-amygdala pathways) inhibits the original CS→fear response. The original memory remains but is overridden. This also explains why phobias can return after a gap or in new contexts — the original memory is still there.
Question 5 Short Answer
Why does avoidance maintain a specific phobia rather than allowing it to fade naturally over time?
Think about your answer, then reveal below.
Model answer: Avoidance prevents the person from ever encountering the feared stimulus without harm, so the conditioned CS→fear association is never disconfirmed. Without exposure, there is no opportunity for extinction learning — no new CS→safety memory can form. Each successful avoidance also provides negative reinforcement, further strengthening the avoidance behavior. Fear memories are highly stable and do not simply weaken through the passage of time; they require active disconfirmation through non-reinforced exposure to change.
This question targets the counterintuitive truth that time alone does not extinguish fear. The fear memory encoded in amygdala circuits is durable and does not decay from disuse. Only contact with the feared stimulus in the absence of harm can create the competing safety memory needed to suppress fear responding.