Your Memories’ Chemical Romance

One of the things that all college philosophy students debate is the concept of Free Will. Do we have the ability to chose our own destinies? Are we truly independent sentient creatures? How much of a role do the Fates play in the Human drama?

I tended to come down on the side of Free Will, if for no other reason than the alternative was rather empty and disappointing. It was bleak to consider ourselves as nothing more than self-aware chemical reactions, mere ghosts in a bio-chemical machine.

Over the ensuing decades, the philosopher’s craft has in part given way, first by the Behaviorists, more recently by the Neurologists. I was reminded of this while reading The Forgetting Pill Erases Painful Memories Forever in this month’s Wired.

Regular readers know that a favorite area of study is Behavioral Economics. I often reference the various cognitive foibles we are susceptible to, including selective perception and retention.

As it turns out, there is a lot more to memory than the usual biases we typically think of as impacting our psychological processes. In fact, there are very specific neurological elements at play:

“Every memory begins as a changed set of connections among cells in the brain. If you happen to remember this moment—the content of this sentence—it’s because a network of neurons has been altered, woven more tightly together within a vast electrical fabric. This linkage is literal: For a memory to exist, these scattered cells must become more sensitive to the activity of the others, so that if one cell fires, the rest of the circuit lights up as well.

Scientists refer to this process as long-term potentiation, and it involves an intricate cascade of gene activations and protein synthesis that makes it easier for these neurons to pass along their electrical excitement. Sometimes this requires the addition of new receptors at the dendritic end of a neuron, or an increase in the release of the chemical neurotransmitters that nerve cells use to communicate. Neurons will actually sprout new ion channels along their length, allowing them to generate more voltage. Collectively this creation of long-term potentiation is called the consolidation phase, when the circuit of cells representing a memory is first linked together.

Regardless of the molecular details, it’s clear that even minor memories require major work. The past has to be wired into your hardware. . . .”

In  other words, a re memories are have a physical manifestation of channels, receptors and connections amongst the our neurons. What really caught my attention was the way a memory is “reprocessed” each time we recall it. This leads to a variety of results, the most important of which is how inaccurate our memories actually are.

Because of this process, it is relatively easy to erase memories on a selective basis:

“The secret was the timing: If new proteins couldn’t be created during the act of remembering, then the original memory ceased to exist. The erasure was also exceedingly specific. The rats could still learn new associations, and they remained scared of other sounds associated with a shock but that hadn’t been played during the protein block. They forgot only what they’d been forced to remember while under the influence of the protein inhibitor.”

What this means is every time you rethink about something purely from memory, you essentially recreate it from scratch:

“The disappearance of the fear memory suggested that every time we think about the past we are delicately transforming its cellular representation in the brain, changing its underlying neural circuitry. It was a stunning discovery: Memories are not formed and then pristinely maintained, as neuroscientists thought; they are formed and then rebuilt every time they’re accessed.”

Consider what this means for you each time you put on a new position or consider a new trade based on your own recall. You are setting yourself up for trouble.

“The brain isn’t interested in having a perfect set of memories about the past,” LeDoux says. “Instead, memory comes with a natural updating mechanism, which is how we make sure that the information taking up valuable space inside our head is still useful. That might make our memories less accurate, but it probably also makes them more relevant to the future.”

As to Free Will, we probably have a lot less of it than we imagine. At  least we can be aware of these limitations and endeavor to operate around them.


The Forgetting Pill Erases Painful Memories Forever
Jonah Lehrer
Wired |February 17, 2012

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