Is thinking conscious or unconscious?

January 28, 2020Posted inneurologism

Sherlock Holmes smokes his pipe reclining on cushions and wearing a roomy overcoatThere are two ways to define thinking: each leads to a different answer to the question of whether thinking is conscious or not.

  1. Thinking as a subjective experience. If someone asks you what you are thinking about, you can introspect, and describe your thought process. You can also say that you weren’t really thinking at all.
  2. Thinking as the cause of ideas and thoughts. If you discover a thought, then you can infer that the process that led up to the thought was a form of thinking, even if there was no subjective experience associated with the process.

We can test our preference for definition 1 or definition 2 by considering an example.

Sherlock Holmes was a good chemist. When he found himself stuck while attempting to solve a mystery, he would sometimes distract himself by doing a chemistry experiment. At the end of such an experiment, he often found that a solution simply popped into his head.

If serotonin deficiency isn’t the cause of depression, then why do SSRIs work?

December 2, 2019Posted inneurologism12 Comments

Acetaminophen (a.k.a paracetamol) relieves some types of headache. But this does not mean that these headaches are caused by acetaminophen deficiency. The brain doesn’t even produce acetaminophen.

The point of this analogy is to make clear that a medicine can work even if it is not acting on the cause of the symptom. In many cases a medicine can work even when the cause of the symptom is completely unknown.

Less is more? A strange case of improvement in intelligence & personality after removal of prefrontal cortical tissue!

November 7, 2019Posted inneurologism

While reading a paper on the neuroscience of dreaming I came across a reference to a 1940 paper by Donald Hebb and Wilder Penfield. It’s a neurosurgery case study that is quite stunning. It shows that in some cases, removal of prefrontal brain tissue can actually cause improvements in intelligence and personality. So basically it’s the opposite of the Phineas Gage story.

Here are some excerpts from the paper:

Hebb1.png

Why is the brain so sensitive to early life experiences?

October 25, 2019Posted inneurologism

I was asked this question on Quora:

From an evolutionary standpoint, why would the early years of brain development be paramount in determining life-long neurological patterns, when those patterns can often be detrimental to long-term success in life?

Good question. We can restate it as follows:

Why would natural selection allow animals to be so sensitive to negative early experience?