Brain Probe Causing Actions, & Falsely Thinking It Was Free Will

April 18, 2012 11:44 AM

I'm looking for videos of people having their brain probed by a brain surgeon, causing them do or say things, but where they invent "reasons" for why they did or said those things, falsely believing they acted out of free will.

Basically, I'm looking for a video like the KAYAK brain probing commercial http://www.youtube.com/watch?v=Flov7Q6pQNk, except that I want the patient to be awake and think s/he was acting out of free will.

posted by Eiwalker to science & nature (5 answers total)

Well...it doesn't quite work that way in reality with cortical stimulation! Sorry.

But if you want some real fun, I suppose, look up some videos of Wada tests, where they put each half of the brain to "sleep" using intracarotid sodium amytal. People then will say complete nonsense, or deny that there's anything wrong with a clearly paralysed limb (the opposite side of the body will go to "sleep" too), or make up really strange stories to justify the things they can't do with only one "awake" half of the brain. Or, I guess, stroke victims with hemineglect or any kind of confabulation in general.
posted by vetala at 11:58 AM on April 18, 2012 [3 favorites]

Many governments would pay a lot of money if what you described were possible. Fortunately, it's pretty much the stuff of Hollywood fantasy.
posted by IAmBroom at 12:10 PM on April 18, 2012

Patients are almost always aware of the changes caused by cortical stimulation. And the stimulation doesn't cause anything even close to that complex.

One great case (and relatively complex as these things go) out of our lab was a patient undergoing cortical mapping before respective surgery to treat seizures. When the docs stimulated a certain temporal lobe spot, the patient said, "Whoa.. I just had a weird flashback to high school." Sure enough, somehow stimulating that spot reliably made him think of high school. Even cooler, when we presented high-school related words to the patient (names of teachers, friends, etc.), we got reliably different activation at that spot than for other non-high school words (but still relating to things/people/places in his distant past). Now, there's great debate about what exactly stimulation does; current theory suggests that it knocks out the tissue around the stimulation spot. So that spot in the patient's brain was likely a high-school inhibitory spot, and stimulating it disinhibited high school memories. But again, he knows what's going on and what's causing it.

And again, that's much more complex an effect than is usually seen in cortical stimulation. Usually patients will see flashes of color (phosphenes) or their fingers will twitch. Stimulating Broca's area will knock out speech fluency.

As to what you're talking about... The closest thing I can come up with -- patients coming up with amazing stories to adapt to physiological changes -- is the sort of thing vetala talks about. Really amazing confabulation. Anosagnosia is sort of a general term of being pathologically unaware of one's condition. V.S. Ramachandran documents patients who have paralyzed limbs but deny that it's his/her limb (somatoparaphrenia). "Well, whose is it?" asks the doctor. "My brother's."

Or patients who effectively have the functional connection between face processing and emotion severed. (I'm simplifying somewhat.) In other words, they see a family member's face, but have no emotional response. The explanation they come up with? The person is an impostor, or a robot (Capgras delusion).
posted by supercres at 12:37 PM on April 18, 2012 [8 favorites]

Resective surgery, not respective. (Gr, autocorrect.)

Anyway, I think the differences between cortical stimulation and long-term changes caused by, e.g., a stroke are (a) the timescale -- the latter involves some amount of cortical remapping that can't take place in the brief seconds of cortical stimulation, and (b) usually there's something else going on when you see a confabulating patient. Cortical stimulation is a very focal (and very temporary) "lesion", while any natural pathology is likely to be much more diffuse, given that it's often caused by stroke, which knocks out blood flow to a larger section of cortex.
posted by supercres at 1:00 PM on April 18, 2012

I also cannot think of any way of getting the video you're envisioning.

You might be thinking of the split brain experiments (which apparently got a Nobel Prize http://www.nobelprize.org/educational/medicine/split-brain/background.html ). These were a series of experiments on people whose corpus callosum (nerve fibres connecting the two hemispheres of the brain) had been cut. They were important in exploring which ares of the brain are more important for certain functions before we had brain scanners.

I seem to remember reading about experiments where words were shown to the non-language hemisphere and there were ways of showing that the person had access to the meaning of the words without being aware that they could read them. These experiments have to be set up in very carefully controlled ways otherwise they don't work.

By the way, we have a much more sophisticated understanding of hemispheric specialization these days! The whole left brain right brain thing annoys me immensely.
posted by kadia_a at 9:10 AM on April 19, 2012