Dr. John-Dylan Haynes of the Max Planck Institute for Human Cognitive and Brain Sciences and colleagues have recently shown that using brain scans they can predict with fairly high accuracy which of two choices test subjects will choose when deciding to add or subtract two numbers.
To address the question of whether intention might be reflected in prefrontal cortical activity, the researchers in the new work used functional magnetic resonance imaging (fMRI) to assess brain activity while subjects concentrated on their choice of intended mental action, but prior to execution of the action. Specifically, subjects were free to choose between adding or subtracting two numbers and were asked to hold in mind their intention until numbers were presented on a screen, along with a choice of outcomes (one of which was correct for the addition choice, one correct for the subtraction choice). Subjects then selected the correct answer according to their planned task, revealing their intended action.
The researchers found that during the delay between the subjects' choice of task and execution of the task, it was possible to decode from activities in two regions of the prefrontal cortex which of the two actions (addition or subtraction) individuals had chosen to pursue. Different patterns of activity were seen during actual execution of the task, showing that regionally distinct neural substrates were involved in task preparation and execution. Decoding of intentions was most robust when activity patterns in the medial prefrontal cortex were taken into account, consistent with the idea that this region of the brain participating in the reflection of an individual on his or her own mental state.
Are you ever bothered that this sort of research takes all the mystery out of life? Do you start seeing humans as less lofty and noble intentions as no better than the most criminal and vicious intentions?
Our secret intentions remain concealed until we put them into action -so we believe. Now researchers have been able to decode these secret intentions from patterns of their brain activity. They let subjects freely and covertly choose between two possible tasks - to either add or subtract two numbers. They were then asked to hold in mind their intention for a while until the relevant numbers were presented on a screen. The researchers were able to recognize the subjects intentions with 70% accuracy based alone on their brain activity - even before the participants had seen the numbers and had started to perform the calculation.
Imagine one could develop an algorithm to analyse brain scans that can detect the intention to lie. Such a capability would make a great lie detector. Another use? To operate robotic prostheses.
Intentions exist in a network of neurons.
The study also reveals fundamental principles about the way the brain stores intentions. "The experiments show that intentions are not encoded in single neurons but in a whole spatial pattern of brain activity", says Haynes. They furthermore reveal that different regions of the prefrontal cortex perform different operations. Regions towards the front of the brain store the intention until it is executed, whereas regions further back take over when subjects become active and start doing the calculation. "Intentions for future actions that are encoded in one part of the brain need to be copied to a different region to be executed", says Haynes.
Whenever I think of brain scans done by governments I think of Mick Jagger singing "These days its all secrecy, no privacy".
|Share |||Randall Parker, 2007 February 08 11:05 PM Brain Surveillance|