Practical Neuroscience: “Scientific evidence that you probably don’t have free will”

At some point business and policy makers are going to have to accept these scientific facts.  It may take a generation of old thinkers dying off, however.  The below post is excerpted from the full post here @

Scientific evidence that you probably don’t have free will

Humans have debated the issue of free will for millennia. But over the past several years…experiments reveal that our subjective experience of freedom may be nothing more than an illusion. Here’s why you probably don’t have free will.

….. As the early results of scientific brain experiments are showing, our minds appear to be making decisions before we’re actually aware of them — and at times by a significant degree. It’s a disturbing observation that has led some neuroscientists to conclude that we’re less in control of our choices than we think — at least as far as some basic movements and tasks are concerned.

At the same time, however, not everyone is convinced. It may be a while before we can truly prove that free will is an illusion.

Neuroscientists first became aware that something curious was going on in the brain back in the mid 1960s.  German scientists Hans Helmut Kornhuber and Lüder Deecke discovered a phenomenon they dubbed “bereitschaftspotential” (BP) — a term that translates to “readiness potential.”  Their discovery, that the brain enters into a special state immediately prior to conscious awareness, set off an entirely new subfield.

After asking their subjects to move their fingers (what were self-initiated movements), Kornhuber and Deecke’s electroencephalogram (EEG) scans showed a slow negative potential shift in the activity of the motor cortex just slightly prior to the voluntary movement. They had no choice but to conclude that the unconscious mind was initiating a freely voluntary act — a wholly unexpected and counterintuitive observation.

Needless to say it was a discovery that greatly upset the scientific community who, since the days of Freud, had (mostly) adopted a strictly deterministic view of human decision making. Most scientists casually ignored it.

But subsequent experiments by Benjamin Libet in the 1980s reinforced the pioneering work of Kornhuber and Deecke….His data showed that the readiness potential started about 0.35 seconds earlier than participants’ reported conscious awareness.

He concluded that we have no free will as far as the initiation of our movements are concerned, but that we had a kind of cognitive “veto” to prevent the movement at the last moment; we can’t start it, but we can stop it.

From a neurological perspective, Libet and others attributed the effect to the SMA/pre-SMA and the anterior cingulate motor areas of the brain — an area that allows us to focus on self-initiated actions and execute self-instigated movements.

Modern tools show the same thing
More recently, neuroscientists have used more advanced technologies to study this phenomenon, namely fMRIs and implanted electrodes. But if anything, these new experiments show the BP effect is even more pronounced than previously thought.

The results were shocking. Haynes’s data showed that the BP occurred one entire second prior to conscious awareness — and at other times as much as ten seconds. …

The cognitive delay, he argued, was likely due to the operation of a network of high-level control areas that were preparing for an upcoming decision long before it entered into conscious awareness. Basically, the brain starts to unconsciously churn in preparation of a decision, and once a set of conditions are met, awareness kicks in, and the movement is made.

In another study, neuroscientist Itzhak Fried….showed that the neurons lit up with activity as much as 1.5 seconds before the participant made a conscious decision to press a button. And with about 700 milliseconds to go, Fried and his team could predict the timing of decisions with nearly 80% accuracy. In some scenarios, he had as much as 90% predictive accuracy.

Different experiment, similar result.
Fried surmised that volition arises after a change in internally generated fire rates of neuronal assemblies cross a threshold — and that the medial frontal cortex can signal these decisions before a person is aware of them.  “At some point, things that are predetermined are admitted into consciousness,”  And in yet another study, this one by Stefan Bode, his detailed fMRI experiments showed that it was possible to actually decode the outcome of free decisions for several seconds prior to it reaching conscious awareness.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s