Visualizing Human Intention

Neuroscientists may predict what you will do before you do it.

Scientists have verified that it’s possible to predict a person’s actions (specifically, a range of hand movements) before those actions take place. The researchers from the University of Western Ontario sought to reveal how planning activity in the areas of the brain that are associated with reaching and grasping (the superior parietal cortex, middle intraparietal sulcus, and dorsal premotor cortex) indicated future movement.

Using functional magnetic resonance imaging (fMRI), which reveals blood flow within the brain, the researchers discovered that the brain’s grasping areas do indeed take more blood flow not only when acting, but also when considering whether or not to pick up an object. Interestingly, the blood-flow pattern changes depending on whether the subject intends to grasp the object by the top or bottom and whether she intends to turn it.

“It now seems clear that fMRI pattern analysis in humans can provide a new tool for capturing neural representations only previously detected with invasive electrode recordings in monkeys,” the researchers write.

“Neuroimaging allows us to look at how action planning unfolds within human brain areas without having to insert electrodes directly into the human brain. This is obviously far less intrusive,” says psychology professor Jody Culham, one of the study’s authors.

The finding follows previous studies on the relationship between planning and action in the brain. In a 2009 paper published in the journal Psychological Science, Washington University researcher Nicole Speer and her colleagues used fMRI to examine hemoglobin flow when people read fiction and discovered that the “readers mentally simulate each new situation encountered in a narrative.” Specifically, when people read about a character grasping and holding an object, the area of the reader’s brain associated with those actions draws more blood. The brain regions that are activated “closely mirror those involved when people perform or imagine or observe similar real-world activities.”

These and similar breakthroughs could one day aid in the creation of better prosthetic devices that respond to and return signals to the brain more like actual limbs.

—Patrick Tucker

Source: “Decoding Action Intentions from Preparatory Brain Activity in Human Parieto-Frontal Networks” by Jason P. Gallivan et al. The Journal of Neuroscience (June 29, 2011).