Discover the mechanism of judgment and trust

How do we know what other people are thinking? How do we judge others and what happens in the brain when we do that?

MIT neurologist Rebecca Saxe is addressing these difficult questions and many other questions. Rebecca's goal is nothing more than to find out how the brain forms unique abilities that make people unique - to make moral judgments, develop a system of beliefs and understand language.

'It is a big goal, but each part of it can be explained in different ways.'

Saxe is a lecturer in MIT's brain and cognitive sciences in 2006, majoring in social awareness - the way people interpret the thoughts of others. This is a difficult topic because human thoughts and beliefs cannot be directly observed.

'These are extremely abstract forms of thought, although we use them well and often in everyday life.'

Although it is impossible to observe direct thinking, one can observe indirectly which part of the brain works when people think of certain things. Saxe detects the jaw vessels that only think of humans with a technique called functional magnetic resonance imaging (fMRI), a type of brain scan that measures the flow of blood.

Using fMRI, Saxe is able to identify a region of the brain (temporal apex) that lights up when people think of other people's thoughts , something we often do when trying to figure out why people are Act like this or another.

According to Nancy Kanwisher, Professor of Brain Science and Cognition at MIT and Saxe's doctoral thesis instructor, this finding 'is one of the most surprising discoveries in the field of brain cognitive science. people.'

"We already know that some parts of the brain are involved in specific areas of motor and cognitive manipulation, but many suspect that the cognitive process is as abstract as understanding the thoughts of others can be done in just one piece of the cortex. "

Functional magnetic resonance imaging shows a region of the brain called the crown junction (TPJ) that lights up.MIT neurologist Rebecca Saxe proved that TPJ works when people think about other people's thoughts.(Photo: Rebecca Saxe)

Brain analysis

Because the fMRI method reveals brain activity indirectly by monitoring blood flow rather than neuronal burning, it is considered a rather crude tool in cognitive research. However, according to Saxe, it still provides a valuable approach for neuroscience scientists.

More precise methods, such as recording the activity of individual neurons, cannot be applied to humans because they cause injury. fMRI captures only the general picture of brain activity, helping to see what part of the brain is involved in complex cognitive activities.

Saxe's recent works use fMRI to delve into moral evaluation - specifically what happens in the brain when people judge whether other people are behaving ethically. Assessing the behavior of others in such situations turns out to be a complex process depending on more than just a single phenomenon.

'Two events with completely identical judgments receive extremely different responses based on our inferences about the mental state of others and what they are thinking.'

For example, assessments are often based on whether the reviewer has a conflict with the person who took the action. When a soldier activates a bomb, the observer's perception of whether the soldier intends to kill civilians does not depend on whether the soldier and observer are on the same side in conflict.

In a future project, Saxe and one of his postdoctoral colleagues plan to study how children build trust in their long-lasting racial races (for example, Muslims and Serbs in the former Yugoslavia, or Sunnie and Shiite in many Middle East regions).

They hope to first identify the areas of the brain that work when people think of members of a contradictory group, then observe any changes in brain activity following the example negotiation efforts. like 'peace campaign' that brings together children from two different groups of people.

Great questions

Saxe obtained a Ph.D. from MIT in 2003, and recently her first graduate student, Liane Young, defended her doctoral thesis successfully. This expands the number of female brain and cognitive scientists at MIT, starting with Molly Potter, psychology instructor, and Kanwisher instructor.

Saxe, from Toronto, said she wanted to become a scientist since she was a child, because her cousins ​​were biochemists.

First, 'I want to be a geneticist because I think it's interesting that you can make life out of chemicals. You can start with a molecule and make a person. I think this is very surprising. '

She was eventually attracted to neuroscience because she wanted to explore bigger questions, such as how brains form the brain.

She said this step put her in the position she wanted in the ongoing process of scientific research, including from small systems such as cell signaling paths to the whole of human society. At each level, there is a balance between the size of the question and the specificity of the answer.

'I'm doing this because I want to pursue more abstract questions, perhaps at the price of not finding the answer.'