The Situationist

Posts Tagged ‘brain’

Dan Gilbert on Why the Brain Scares Itself

Posted by The Situationist Staff on November 8, 2009

Dan Gilbert1For the Harvard Law Record, Harvard Law Students, Anush Emelianova and Gustavo Ribeiro, wrote a nice summary of Dan Gilbert‘s recent lecture at Harvard Law School.  His lecture, titled “Why Does the Brain Scare Itself?,” drew a  crowd of roughly 150 students and contributed to Gilbert’s reputation as an amazing and captivating speaker.    Here’s Emilianova and Ribeiro’s description.

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Why does the brain scare itself?  On Monday, October 19, Professor Dan Gilbert confronted this question in an event sponsored by first-year Section VI. Professor Gilbert, who wrote  the bestselling book Stumbling on Happiness, is a Professor of Psychology at Harvard University and the Director of Harvard’s Hedonic Psychology Laboratory. He opened his remarks by stating that the power of the mind to automatically make predictions by simulating outcomes is the key feature that distinguishes humans from other animals.

Because the brain is made up of semi-independent systems, it can talk to itself or even “scare itself.”   But Prof. Gilbert believes that the limited mental capacities of humans impose limits on the accuracy of predictions about the emotional impact of future events. He demonstrated this by identifying four limitations of the brain’s ability to simulate the future: unrepresentativeness, essentialization, truncation, and presentism.

According to Prof. Gilbert, humans’ mental simulations are unrepresentatively based on the individual’s best or worst memories, failing to correspond to the average experience.  When the mind produces imaginary scenarios, the images tend to be essentialized, that is, distilled to a simplified image with the details cut out.  Remembered experiences also interfere with accurate prediction because they are truncated and fail to incorporate the ability to adapt to different situations over time.  Furthermore, Prof. Gilbert believes the human mind has a “presentist” bias, accepting in most circumstances the fiction that tomorrow will be exactly like today and that the feelings at the moment of making a decision will persist until the outcome of that decision arises. As an example, Professor Gilbert demonstrated a photograph of a 16-year-old who had tattooed Pac-Man on her head, suggesting that the excitement of the moment would eventually give way to regret.

Professor Gilbert does not believe humans have the capacity to systematically prevent errors in mental simulations.  “As I marinate you in the bloopers and foibles, the mistakes and biases of the human mind, you must be thinking, is there anything we can do about this? I’m happy to tell you the answer is no,” he said.

Despite the failure of predictions to account for dynamic circumstances, humans tend to adapt or rationalize outcomes to make themselves feel better.  Prof. Gilbert illustrated this tendency with the satisfied attitude of Pete Best, the original drummer for the Beatles.

Despite missing out on being part of one of the most successful bands ever, Best said in a 1994 interview that, “I’m happier than I would have been with the Beatles.” Professor Gilbert argued that this was a striking example of rationalization.

Prof. Gilbert also indicated that there may be techniques available to minimize some types of cognitive error.  “Surrogation,” or asking others about their experience of a similar situation, can act as a more reliable guide than one’s own expectations. In fact, according to Prof. Gilbert, any random person’s actual experience of a given situation is likely to be much more predictive of our future enjoyment than our imaginary simulation of that same experience.

“Human beings are all basically the same.”

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The Project on Law and Mind Sciences will make the video of Gilbert’s talk available within the next few weeks.  To review a sample of related Situationist posts, see “Dan Gilbert To Speak at Harvard Law School,” “Dan Gilbert on the Situation of Our Decisions,” Dan Gilbert on the Situation of Psychology,”The Situation of Climate Change,” The Heat is On,”The Situation of Happiness,” and “Conversation with Dan Gilbert.”

Posted in Behavioral Economics, Emotions, Events, Illusions, Life, Social Psychology | Tagged: , , , | Leave a Comment »

Nancy Kanwisher on the Situation of our Brain

Posted by The Situationist Staff on August 25, 2009

BrainFor Observer, publisehd by the Association for Psychological Science, Ann Conkle wrote a nice summary of Nancy Kanwisher‘s fascinating keynote address at this years APS Annual Convention in San Francisco.  Here are some excerpts of Conkle’s article, titled “Sharpening the Focus on Brain Function.”

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Is your brain like a Swiss Army knife? . . . Is it jam-packed with specialized tools that are unfolded only when a specific situation arises? Or is it more all-purpose, with a few parts that tackle many different situations? Convention Keynoter and APS Fellow Nancy Kanwisher (Massachusetts Institute of Technology) is attempting to find out.

Following centuries of debate about specialized brain regions — from the phrenologists to Broca — the development of fMRI technology has ushered in a new era of studying brain regions. By monitoring the blood flow necessary to support neural activity, fMRI has allowed researchers to track which regions of the brain are involved in processing specific stimuli. With this new weapon in her arsenal, Kanwisher performed a now-classic study published in 1997. In it, participants sat in an fMRI scanner while looking a series of faces and objects. She and her colleagues identified an area in the fusiform gyrus on the bottom surface of the temporal lobe that responded more strongly when the participants viewed faces than when they viewed objects. Dubbed the fusiform face area, this region seemed like it could be specialized for processing faces.

But the researchers could not yet be sure. What if the area responded to everything animate, or everything round? A decade of more detailed research confirmed their original hypothesis — the fusiform face area lived up to its name. At the same time, Kanwisher’s lab discovered two other specialized areas: the parahippocampal place area, which specializes in processing places, and the extrastriate body area, which specializes in processing images of the body.

These answers only lead to more questions. These areas are involved in processing certain categories, but do they merely process perceptual input or actually reflect conscious experience? What are the roles of genes and experience in wiring up these areas? And finally, how much of the brain is like this? Is our entire cortex broken up into small pieces, each with their own special domain? Kanwisher and her colleagues are tackling these questions head on.

Do these areas only engage in their respective categorical processing or do they perform other functions as well? For example, take the fusiform face area. It is most active when viewing faces, but it also shows lesser activity when the participant is looking at other visual stimuli, like objects. Something in the pattern of this lower activity could be crucial in processing input other than faces. Evidence against this idea comes from research on patients with neurological trauma, who sometimes lose face perception abilities without losing object perception. But, the low chance of finding subjects with a lesion in just the right spot make this research limited. Other researchers have turned to transcranial magnetic stimulation (TMS), a method that uses magnetic fields to transiently disrupt neural activity. The fusiform face area is too deep in the brain to be affected by TMS, but the extrastriate body area is closer to the scalp and susceptible to the TMS disruption. When the neural activity in this region is disturbed, participants are impaired in the ability to recognize bodies but have no difficulty recognizing faces or other objects. Although these specialized areas may collect information about other types of stimuli, it seems that they are only necessary for processing information of their specific type.

Are the functionally specific regions merely perceptual processers or do they reflect our conscious experience? To illustrate the difference between perception and experience, Kanwisher instructed the audience to pick up the 3-D glasses left on the seats. But, before we could put them on, she showed us two images, a red-tinted image of a face and a green-tinted image of a house. Then she superimposed the house on the face creating a red/green face/house jumble. But, when looking at this jumble through glasses with one red-tinted and one green-tinted lens, so that the house image goes to one eye and the face image to the other, you don’t experience a jumble — you experience a red face that fades to a green house and back and forth as your brain attempts to make sense of this new situation. Even though your experience of what you are seeing is changing, the image beamed to your retina is constant the whole time. Work from Kanwisher’s lab showed that in this situation, activity in the fusiform face area corresponds with one’s experience, not with the actual perceptual input.

Further, not only does the activity in specialized areas correspond with what we consciously see, it also corresponds with what we imagine. Kanwisher has put people in the fMRI machine and asked them to imagine familiar faces and places. The same areas are active when participants are imagining faces and places as when they are actually looking at faces and places. It’s not just what you are physically seeing, but what you are consciously aware of that is processed by this area.

So, where do these specialized areas come from? What role do genes and experience play in their construction?

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For answers to those questions and the rest of Conkle’s summary of Kanwisher’s talk, click here.

To watch a video of Kanwisher’s Keynote presentation, click on the video below.

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For a sample of related Situationist posts, “Smart People Thinking about People Thinking about People Thinking” and ““The Grand Illusion” — Believing We See the Situation.”  To review a collection of Situationist posts on neuroscience, click here.

Posted in Classic Experiments, Neuroscience, Video | Tagged: , , , | 2 Comments »

The Split Brain and the Interior Situation of Theories of the Self

Posted by The Situationist Staff on August 26, 2008

The following (5 minute) video demonstrates the effects of split brain surgery where the corpus collusum is severed. The effects are explained by Dr. Michael Gazzaniga.

From Youtube: “To reduce the severity of his seizures, Joe had the bridge between his left and right cerebral hemisphers (the corpus callosum) severed. As a result, his left and right brains no longer communicate through that pathway. Here’s what happens as a result.”

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To watch a (3.5 minute) clip from Situationist contributor Phil Zimbardo’s program, Discovering Psychology, in whcih Michael Gazzaniga discusses the essential role of the “interpreter” in creating in each of us a unique sense of self.

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Below you can watch an vintage (11 minute) video in which a very young Dr. Gazzaniga goes into detail regarding his early split-brain research on animals and humans (includes a fascinating example of how the right and left hands of a split-brain patient squabble with one another as if hands from two different individuals).

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For a sample of related Situationist posts, see “Our Interior Situations – The Human Brain,” “Learning to Influence Our Interior Situation,” It’s All In Your (Theory of the) Mind,” “Smart People Thinking about People Thinking about People Thinking,” Vilayanur Ramachandran On Your Mind,”Jonathan Haidt on the Situation of Moral Reasoning,” “Unconscious Situation of Choice,” The Situation of Reason,” and Part I, Part II, Part III, and Part IV of “The Unconscious Situation of our Consciousness.”

Posted in Choice Myth, Classic Experiments, Neuroscience, Video | Tagged: , , , , , , , | 3 Comments »

Learning to Influence Our Interior Situation

Posted by The Situationist Staff on July 16, 2008

From TED: Neuroscientist and inventor Christopher deCharms demonstrates a new way to use fMRI to show brain activity — thoughts, emotions, pain — while it is happening. In other words, you can actually see how you feel.

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Posted in Neuroscience, Video | Tagged: , , , , , | Leave a Comment »

 
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