What is the core issue with reverse inference?

What is the core issue with reverse inference?

• A. All brain regions do only one thing.
• B. Stimulus-response mapping is perfect.
• C. One brain region does not equal one psychological process.
• D. Brain activity directly reveals exact thoughts.

Answer: (C)

Reverse inference is the tendency to infer a specific mental state from the activation of a particular brain region. The problem is that most brain areas participate in many different processes, and the same process can recruit different regions depending on context. So seeing activation in a region does not prove that a particular thought or feeling is occurring. For instance, the amygdala can be activated by fear, but also by novelty, high arousal, or general salience, depending on the situation. Because of this non-specificity, inferring exact thoughts from brain activity is unreliable. In more precise terms, you’d need probabilistic evidence that a given mental state is more likely given the activation, which requires knowledge of base rates and conditional probabilities; without that, reverse inference can be misleading. Thus, one brain region does not equal one psychological process.

Reverse inference is the tendency to infer a specific mental state from the activation of a particular brain region. The problem is that most brain areas participate in many different processes, and the same process can recruit different regions depending on context. So seeing activation in a region does not prove that a particular thought or feeling is occurring. For instance, the amygdala can be activated by fear, but also by novelty, high arousal, or general salience, depending on the situation. Because of this non-specificity, inferring exact thoughts from brain activity is unreliable. In more precise terms, you’d need probabilistic evidence that a given mental state is more likely given the activation, which requires knowledge of base rates and conditional probabilities; without that, reverse inference can be misleading. Thus, one brain region does not equal one psychological process.