When it comes to making decisions, it seems that the conscious mind is the last to know.….electrical activity in the supplementary motor area, involved in initiating movement, and in the anterior cingulate cortex, which controls attention and motivation, appeared up to 5 seconds before a volunteer was aware of deciding to press the button. This backed up earlier fMRI studies…that had traced the origins of decisions to the prefrontal cortex a whopping 10 seconds before awareness
“It’s always nice when two lines of research converge and to know that what we see with fMRI is actually there in the neurons,” says Haynes.
Kreiman told the BNA conference that he is now working on predicting decisions in real time, and to see if it is possible to reverse a decision before it hits consciousness – by flashing up the word “stop” on a screen as soon as telltale activity shows up in the brain.
There are no firm results yet, but Kreiman suspects there may be a measureable “point of no return” in the brain. “So far all we have is people saying, ‘that was weird, you read my mind’,” he says.
If this kind of “mind-reading” is possible, a new study…, suggests that it may not be restricted to decisions about moving a finger. Using fMRI, Haynes has found that the very brain areas involved in deciding to move are also active several seconds before a more abstract decision, like whether to add or subtract a series of numbers.
He suggests that the prefrontal and parietal cortex may be general decision-making circuitry, passing activity on to different parts of the brain depending on the task at hand. “Perhaps decisions arise from a similar set of areas, then either flow into motor systems, for pressing buttons, or the parietal cortex for doing calculations,” he says.
[There is research suggesting this model is backwards.]
…As for what it means for one of the longest-running debates in science – the question of whether we do or do not have free will – Haynes is pretty clear. “What we need now is 20 years of serious neuroscience, not more speculation about the handful of studies that have been done so far,” he says.
Kreiman agrees, but says that these early results at least bring the question of free will out of the realms of magic and mystery. “There is no magic. There are neurons, and there are ions that flow through membranes, and that it what is orchestrating our decisions,” he says. “We don’t need to invoke freedom.”