This week, we’re back for some more Psych/Soc section as we’re wrapping up full length 10. Once again, we’re joined by Clara from Next Step Test Prep.
[03:00] Passage 8
Acute stress is associated with altered cognitive functioning, in particular with respect to decision making, Under stress, individuals exhibit less flexible cognitive processing together with altered risk and feedback processing. Collectively, these effects suggest that stress taxes executive functions, and thus they point to the potential impact of stress on the regulation and monitoring of the decision process. Indeed, the decision is not only about selecting the right option; it is also about assessing its appropriateness relative to the circumstances, that is, whether one can be confident or not about one’s action. Researchers conducted a study on the impact of stress on the sensitivity of confidence judgments, also termed metacognitive accuracy.
The stress response consists in a cascade of mechanisms governed by the hypothalamic-pituitary-adrenocortical (HPA) axis, leading notably to the release of cortisol and catecholamines. Within the brain, these hormones are known to target specifically the prefrontal cortex (PFC), thereby altering higher cognitive functions. Of considerable interest regarding metacognition, it has been proposed that one of the early effects of acute stress is to dampen activity in regions subserving endogenous attention in favor of orienting resources to vigilance and action, that is, to exogenous attention.
In the experiment, high, medium, and low responders to stress were first identified according to the concentration of the cortisol in saliva at the peak of hormonal response to interpersonal stress. Twelve months later, participants performed a perceptual decision task with confidence judgments. Researchers operationalized metacognitive sensitivity as the extent to which confidence judgments discriminated correct and incorrect responses. They predicted that high responders should have lower scores on this measure. However, mean confidence did not differ across stress groups (p>.91), meaning first that participants were well calibrated in view of their average performance of 83%, and second that stress reactivity did not translate into underconfidence or overconfidence.
[05:45] Some Tips
The terms above can seem so confusing. When you’re listing out those groups, even the terms can be opposite, just highlight those. They’re great examples to tell us about experimental groups in the study. Additionally, if they talk about correlation or causation, especially in Bio passages, these are the only times she recommends taking notes. This is especially helpful if you easily get confused and overwhelmed by such language.
[07:25] Question 40
Cortisol inhibits the release of hormones that act earlier in the HPA axis. This type of regulation is known as:
(A) positive feedback
(B) negative feedback
(C) allosteric regulation
(D) paracrine regulation
The correct answer here is B. The vast majority of feedback processes you’re going to see on the MCAT are negative feedback. The passage is a classic example here where cortisol is the product of this pathway. Whenever a product is relatively downstream in a pathway, it feeds back on earlier in compounds that acted in this pathway. It acts to decrease its own production. This is what keeps cortisol from completely going out of control because it inhibits its own release.
Don’t get caught up in words that aren’t familiar. It’s very common for the MCAT to use some classic examples. These are usually something that you should already know about. They’re just throwing in a couple of words that are relevant to the passage.
[10:40] Question 41
When exposing subjects to a stressful stimulus, researchers observed that they recorded a physiological response in the subjects before the subjects reacted in any other way. This is consistent with which theory or theories of emotion?
(A) I only
(B) II only
(C) I and II only
(D) I and III only
The correct answer here is D. Just knowing a little more about them will get you far. The key with theories of emotion is that the James-Lange theory and the Schachter-Singer are really similar. In James-Lange theory, what happens first is a physiological response. Say, you see a bear in the woods, your heart rate will increase and then you’ll receive some emotional response like fear. And it’s the same with the Schachter-Singer theory. The only difference is that it accounts for the possibility that you can consciously interpret what you’re seeing. So if someone surprises you for your birthday, you might not interpret it the same way as you saw a bear. The key takeaway here is that I and III go together.
[13:55] Question 42
After going through boot camp in the military, Alice reported to her family members that the boot camp was stressful but was a valuable experience because it taught her that she was capable of accomplishing more than she had thought. What concept best describes this type of stress?
(A) Adaptive stress
(B) Cognitive stress
The correct answer here is D. Distress is what we commonly think of as bad stress or it’s damaging all the time. Eustress, on the other hand, is very MCAT-relevant which refers to productive stress. It’s usually chronic and resolves more quickly. It’s sort of a learning experience. Adaptive stress is not a thing. There’s an adaptive coping mechanism but for the purpose of the MCAT, there’s only distress and eustress. Cognitive stress is also just made up. They’re confusing similar areas but it’s not a type of stress either.
[16:20] Question 43
A subsequent study replicated the methodology of the researcher described in the passage, with the following exceptions. They increased the sample size by a factor of four, performed both parts of the experiment on the same day, and used a different perceptual decision-making task. They found small but significant differences (p<.05) in metacognitive accuracy depending on stress response. Which of the following is NOT a reasonable explanation of the discrepancy between these two studies?
(A) The sample size of the first study was too small to detect a small but significant difference in performance.
(B) Hormonal response profiles to stress are short-lived and changeable, meaning that by waiting for 12 months to perform the second half of the study, the groups of high-, medium-, and low-responders in the first study were no longer valid.
(C) The sample size of the first study was too small to eliminate the effect of chance.
(D) The perceptual decision-making task was more stress-inducing in the second study than in the first study.
The correct answer here is C. The key here is the word “eliminate.” The idea of chance is something random. We can never eliminate the effect of chance but we can just minimize it. So C is a false statement. The second study couldn’t eliminate the effect of chance either since it’s just not something you can do. “Eliminate” is also an extreme word, making sense that it’s the only one that’s not reasonable.
Answer choice A talks about the sample size and we all usually have a good idea that a bigger sample size is better. But B is an answer that trips a lot of people up. It’s just a long answer choice so they could think there’s something in it that could make it wrong. But it’s totally true.
[23:10] Next Step Test Prep
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