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Session 13
In today’s Atlantic article, we’re putting Jack Westin’s MCAT CARS techniques to the test to understand the author’s ideas on hallucinating. It’s a fun psychology passage that may just come up in your exam.
Also, please be sure to check all our other podcasts on MedEd Media so you can get as many resources you need to help you on this long journey towards becoming a physician!
Link to article:
There’s a good chance you’ve hallucinated before.
If you’ve ever felt the buzz of your phone against your thigh only to realize the sensation was entirely in your head, you’ve had a sensory perception of something that isn’t real. And that, according to the psychologist Philip Corlett, is what makes a hallucination.
To many, this definition may seem shockingly broad. Hallucinations were long considered the stuff of psychoses or drug trips, not a regular and inconsequential part of life. But Corlett operates on the idea that hallucinations exist within a hierarchy. At the highest level, according to Corlett’s collaborator Albert Powers, they would be something like hearing “whole sentences of clearly spoken speech of a being who seems quite real.” But, moving further down the line, hallucinations can be far more banal: an imagined text message, a phantom raindrop, a new parent’s mistaken sense of her child by her bedside.
This hierarchy perspective represents an ongoing revelation in how widespread and varied hallucinations can be. A survey in the early 1990s found that 10 to 15 percent of the population of the United States experienced vivid sensory hallucinations at some point in their lives. And scientists have begun to take seriously the idea that voice hearing and other forms of auditory hallucination can be benign or “nonclinical.” This newfound ubiquity has come with a host of questions. Why is it so common for people to perceive what isn’t there, and how does the brain allow this to happen in the first place? To find answers, researchers have turned to the mechanics of how we perceive reality itself.
For Corlett and Powers, both from the Yale School of Medicine, hallucinations have everything to do with expectations. In a new paper in Science, they explore how the mysterious experiences fit into a larger, speculative idea about how the brain works—and, in a sense, what the brain is. The pair recounts a 2017 studythey conducted, in which their group tried to induce hallucinations both in people who commonly report hallucinations across the psychotic spectrum and in people who don’t normally hallucinate. The participants were taught to expect to hear a tone after being shown a flashing light, and then were made to press a button when they thought they heard a tone. They were told to hold down the button longer to rate their confidence in what they heard. People who regularly hallucinate held the button—that is, they hallucinated—significantly longer than those who don’t.
Corlett and Powers see this experiment as evidence for their perspective on how people understand the world around them. By their way of thinking, the brain works by “predictive coding”: integrating new information based on the beliefs built on old information. “When we go about the world, we’re not just passively perceiving sensory inputs through our eyes and ears,” Corlett says. “We actually build a model in our minds of what we expect to be present.”
[02:15] Determining Easy vs Hard Passages
Jack enumerates three things to distinguish which is easy or heard. First is your subjective viewpoint on the topic. Most premeds are not philosophy or history majors so they would probably find philosophy and art passages harder since they’re not interested in it.
Second, easy arguments are just easier to read. If they’re not so abstract and they’re more relatable, then they’re easier for students.
Third, is the style of the author – which includes the number of hard vocabulary words they use, the way the author portrays the material, etc.
[04:18] Paragraph 1, Sentence 1-2:
There’s a good chance you’ve hallucinated before. If you’ve ever felt the buzz of your phone against your thigh only to realize the sensation was entirely in your head, you’ve had a sensory perception of something that isn’t real.
Jack says:
The author starts the article with hallucination and that even us could feel this sometimes through the phone buzzing against the thigh.
[04:51] Paragraph 2, Sentence 2:
And that, according to the psychologist Philip Corlett, is what makes a hallucination.
Jack says:
It’s defining hallucination which is a sensory perception that something isn’t real. This is not so hard for students because this may have happened to them. The topic is way more relatable than last week’s invisible hand.
[05:47] Paragraph 3, Sentence 1:
To many, this definition may seem shockingly broad.
Jack says:
Maybe the definition above isn’t real.
[06:08] Paragraph 3, Sentence 2:
Hallucinations were long considered the stuff of psychoses or drug trips, not a regular and inconsequential part of life.
Jack says:
The author compares this definition as the psychosis and drug trips versus the phantom buzzing in your pocket.
[06:35] Paragraph 3, Sentence 3:
But Corlett operates on the idea that hallucinations exist within a hierarchy.
Jack says:
The author suggests there may be some hierarchy of stuff from drug trips to something benign as a phantom buzz.
[07:06] Paragraph 3, Sentence 4:
At the highest level, according to Corlett’s collaborator Albert Powers, they would be something like hearing “whole sentences of clearly spoken speech of a being who seems quite real.”
Jack says:
At the highest level in this hierarchy of hallucination is hearing sentences from someone who seems real but isn’t. That’s our normal way of looking at it.
[07:39] Paragraph 3, Sentence 5:
But, moving further down the line, hallucinations can be far more banal: an imagined text message, a phantom raindrop, a new parent’s mistaken sense of her child by her bedside.
Jack says:
So there’s that spoken speech in one top level and far below the hierarchy is these other examples. It’s trying to support the idea that the definition that Corlett brings up is actually correct because there’s a hierarchy. The author is trying to convince us that this is actually a hallucination, so we hallucinate all the time apparently.
[08:29] Paragraph 4, Sentence 1:
This hierarchy, respective, represents an ongoing revelation in how widespread and varied hallucinations can be.
Jack says:
If we do take this perspective of hierarchy then the author is saying that hallucinations can be very varied.
[08:55] Paragraph 4, Sentence 2:
A survey in the early 1990s found that 10 to 15 percent of the population of the United States experienced vivid sensory hallucinations at some point in their lives.
Jack says:
We don’t know vivid hallucinations mean at this point. But it seems that the percent is pretty big.
[09:29] Paragraph 4, Sentence 3:
And scientists have begun to take seriously the idea that voice hearing and other forms of auditory hallucination can be benign or “nonclinical.”
Jack says:
Scientists begin to think that because of this hierarchy, we can have benign and nonclinical hallucinations and not just the drug trips and psychosis. So maybe they’re not that bad after all. The author is trying to paint a picture that hallucinations are a part of life.
[10:20] Paragraph 4, Sentence 4:
This newfound ubiquity has come with a host of questions.
Jack says:
We don’t know what ubiquity means at this point and we hope that we get a sense of the context as we keep reading.
[10:38] Paragraph 4, Sentence 5:
Why is it so common for people to perceive what isn’t there, and how does the brain allow this to happen in the first place?
Jack says:
Another question is being set up. Why do we hallucinate?
[10:55] Paragraph 4, Sentence 6:
To find answers, researchers have turned to the mechanics of how we perceive reality itself.
Jack says:
It seems like we’re transitioning into a whole new part of the passage. We were talking about hallucination, its definition, how the definition is broad, and everyone hallucinates. Now, we’re talking about why do we even hallucinate to begin with.
[11:34] Paragraph 5, Sentence 1:
For Corlett and Powers, both from the Yale School of Medicine, hallucinations have everything to do with expectations.
Jack says:
They’re saying hallucinations have to do with expectations.
[11:52] Paragraph 5, Sentence 2:
In a new paper in Science, they explore how the mysterious experiences fit into a larger, speculative idea about how the brain works—and, in a sense, what the brain is.
Jack says:
They’re introducing a journal or publication that explains what the brain is.
[12:22] Paragraph 5, Sentence 3:
The pair recounts a 2017 study they conducted, in which their group tried to induce hallucinations both in people who commonly report hallucinations across the psychotic spectrum and in people who don’t normally hallucinate.
Jack says:
The author talks about this study on inducing hallucinations with people who have them and those who don’t.
The MCAT loves to test on experiments. So better make sure you understand what’s happening in the experiment, who the subjects are, what they’re testing for. They’re testing to see why we hallucinate and now we’re given subjects.
[13:09] Paragraph 5, Sentence 4:
The participants were taught to expect to hear a tone after being shown a flashing light, and then were made to press a button when they thought they heard a tone.
Jack says:
They’re setting up an experiment and they’re expected to hear a tone after a flashing light and then hit the button when you hear the tone.
[13:32] Paragraph 54, Sentence 5:
They were told to hold down the button longer to rate their confidence in what they heard.
Jack says:
If you really thought you heard it, hold the button longer.
[13:44] Paragraph 5, Sentence 6:
People who regularly hallucinate held the button—that is, they hallucinated—significantly longer than those who don’t.
Jack says:
So there was no tone ever. All they’re doing is to see whether or not you hallucinate. And the hallucination is based on whether or not you hear the tone. But you never actually hear. YOu just see the flashes.
Questions that can be asked on the MCAT here is when you look at the lights, expect to hear something. And when you hear it, go ahead and click on the button. So if you’re hallucinating you actually hear the sounds. And it seems like the ones holding it down more are the ones categorized as hallucinators, to begin with.
The author is bringing in the experiment since at the beginning of the paragraph, they talked about, everything has to do with expectations. So it’s suggesting that this experiment proves that it’s based on expectations. If you’re expecting to hear a sound, you will press it longer. So it suggests that people who hallucinate expect things more. So hallucinations can be connected to hallucinations in some way.
[16:54] Paragraph 6, Sentence 1:
Corlett and Powers see this experiment as evidence for their perspective on how people understand the world around them.
Jack says:
The researchers are saying this is proof that expectations are what’s driving how people understand the world around them.
[17:16] Paragraph 6, Sentence 2:
By their way of thinking, the brain works by “predictive coding”: integrating new information based on the beliefs built on old information.
Jack says:
Our bain is constantly using old information trying to integration and predict what our experiences may be.
[17:44] Paragraph 6, Sentences 3-4:
“When we go about the world, we’re not just passively perceiving sensory inputs through our eyes and ears,” Corlett says. “We actually build a model in our minds of what we expect to be present.”
Jack says:
Corlett is saying that everything we’re perceiving is built on our expectations.
The big picture of this paragraph is that our expectations are based on hallucinations. We hallucinate because our brain is expecting something to happen. The whole topic is about hallucination.
[18:55] Possible Questions on the MCAT
One of the questions MCAT loves to ask is: what is one of the weaknesses of the study? And if you know the study is about hearing what you expect to hear something, we could suggest that one of the weaknesses is that it’s based only on hearing. Maybe there’s a different type of hallucination when you see things.
So they could test these kinds of ideas when something is weak or strong in the experiment or parts of the experiment are missing. Maybe there should be an extra control group. Understand the ins and outs of the experiment because this will be very helpful.
A lot of students tend to rush through the experiment but you have to know what it’s really saying because they will ask you about those experiments.
One big main idea is that hallucinations are from the brain expecting something to happen. And another one is that hallucinations are on a spectrum, which has a hierarchy.
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