Perception and cognition lecture notes

This past Tuesday we had a lecture on perception and cognition as part of the Good and Bad Science course I’m taking. My rough notes are below.

Perception and Cognition

Dan Larhammar, Professor of Molecular Cell Biology at the Department of Medical Cell Biology; Dan Larhammar Research Group

Can we trust our senses and experiences?

The aim for the lecture was to describe different types of observations and experiments that show the limitations or errors in our own perception and cognition. Some are quite dramatic. They will all point to the same direction - our brains make mistakes.

We all have these limitations. We all make mistakes, and we do all the time. But by raising awareness we can notice when it happens to ourselves and to others, and look at ways to handle/tackle this.

The quest for consciousness

Understanding human self-consciousness is described as one of the greatest challenges for science. (Consciousness - a hard problem? “Facing up to the problem of consciousness”, Journal of Consciousness Studies: 1995)

Conscious experience is a subjective experience and can never be described with complete accuracy to anybody else.

In “The Conscious Mind”, David Chalmers argues that reductive explanations of the consciousness do not hold.

“An isolated neuroscientist in a black and white room knows everything about how the brain processes colors, but does not know what it is like to see them. By itself empirical knowledge of the brain does not yield complete knowledge of conscious experience.”

David Chalmers, The Conscious Mind

Qualia - subjective qualities of mental experiences (eg the redness of red). We can measure the red wavelengths that hit our eyes, but there are two variants of our red receptor that affect the wavelength that generates the maximum response. Different individuals will have strongest experience shifted from that of others.

Fun fact: .5 and 1% of women have deviating red-green vision, but most are men. Why? Men don’t have another X-chromosome to fall back on if the first is defective.

Others had concrete suggestions for where consciousness resides: Roger Penrose, Stuart Hameroff have suggested that consciousness resides in the microtubules of cells.

Penrose: “Whatever consciousness is, it must be beyond computable physics.”

The microtubules suggestion is a ridiculous, almost preposterous suggestion according to the lecturer, as microtubules exist in every eukaryotic cell. Amoeba, yeast,etc have microtubules.

[L: I asked at this point why smaller organisms having microtubules is what makes the microtubules theory ridiculous. I understood it might be ridiculous for other reasons, but did not grasp why smaller organisms possessing these things rules out the possibility. The comments are below.]

Lecturer pointed out that while the definition of consciousness is not wholly pinned down, in the sense that he talks about it, consciousness is being aware that things are happening and think about these events. Each cell can detect things around it, but this is mere perception. Perception reacting to stimuli.

Single cell eukaryotes are not known to perform things different from bacteria, and bacteria do not have microtubules. The consciousness comes gradually in much more advanced organisms with regard to number of cells and how cells in one organism interact with one another. Neuroscientists are convinced that it takes a nervous system to generate self consciousness to be aware that things happen and think about them.

According to most biological neuroscientists consciousness is a scale.

[L: The above shed some light on it for me, but I think I still don't know enough to understand why the above rules out the microtubules theory. Especially if consciousness is a scale as said above. Need to read more about it!]

The consciousness wager

In 1988, two top thinkers made a bet about whether science can explain the feeling of being. Neuroscientist Christof Koch and philosopher David Chalmers disagreed whether in 25 years from that date we’d know the neural correlates of consciousness.

The following morning Chalmers was interviewed by Per Snaprud. Chalmers told him about the bet. Koch thought in 25 years we will know the neural correlates of consciousness, Chalmers said we won’t. The winner would get a box of fine wine from the loser.

Then they forgot about it, and nothing happened for nearly 25 years until Per Snaprud happened to think of this again. He went in his attic, looked at some old tape recordings, and found the tape of David Chalmers. Snaprud Chalmers and Koch and asked if they were prepared to decide who would win the bet.

A big event was organized in New York on the 25th anniversary of the wager. David Chalmers won - we did not yet know the neural correlates of conscious experience. Then they entered another bet that 25 years from that date they would meet again.

During the years before this there had been quite a few researchers trying to address this. An article criticized Chalmers’ idea that this should be such a big problem. Steven Novella, US neurologist, thinks when we know the mechanisms of consciousness - how the cells communicate with one another - the whole problem fades and disappears and we will look at the processes themselves. Each individual might have a slightly different experience, but at least we’ll know whats going on in the brain.

Two main hypotheses emerged:

Global neuronal workspace theory: Specialised modules send messages into a vast network where they compete for dominance. The winner is broadcast globally, and thus enters consciousness. An interconnected network.
Integrated information theory: Phi, a measure of consciousness, is higher in systems with many interconnected modules, such as a “hot zone” at the back of the brain.

There has been intense debate between the two camps. Results do not match either of the theories, but IIT fits a bit better. However, others have claimed that the experiments proposed to test the hypotheses are close to pseudoscientific circular arguments.

Long neurons

Some neurons are very long. A single neuron can wrap all around the brain, reaching quite far. It is proposed those are the types of neurons that could be involved in consciousness as they connect with very distant parts of the brain.

Limitations to our ability to make objective judgements

Confirmation bias: The tendency to search for, interpret, favor, and recall information in a way that confirms or supports one’s prior beliefs or values.
Motivated reasoning (emotional appeal): To start with a conclusion and then search for supporting data: value-based, identity-protection.
Lazy thinking: Not using critical aspects of our minds. accept statements without questioning them.
Dunning-Kruger effect: Unskilled and unaware of it.
Misplaced trust: Trusting sources that are not reliable. Biased info from media, filter bubbles, echo chambers
Pseudoscientific jargon: Jargon to make something sound scientific when it isnt. which is funny because everyone realizes the best argument one can possibly have is one that is scientific.

Flat Earth Society: Confirmation bias, identity-protection, filter bubble

Since Trump term 1, terms like ‘fake news’, knowledge resistance, and alternative facts have become widespread. But the problems as such are much older than that. Relativism and constructivism try to make science sound less certain. Of course we should always be on our guard against scientific findings, especially if they go against what we think is established fact. But sometimes this is taken into the absurd, where all types of observation are plainly rejected.

Truth: I think therefore I Am
Post-truth: I believe therefore I’m right!

Fun fact: A one-humped camel is called a “dromedary”. WHAT?!!?!??

In natural settings we interpret things as relative and not absolute. even color vision is relative.

Laughter rationalization

A patient suffered from epilepsy with seizures that were resistant to pharmacological treatment. Neurosurgeons decided the only way is to remove carefully the damaged part of the brain that triggers the epileptic seizures. Once under anesthesia, they opened the skull of the patient to expose the brain and then let the patient wake up. Then, ifferent areas of the cerebral cortex was stimulated carefully with an electrode to observe what responses that will elicit.

In this patient, the seizures were in an area at the top of the brain. If one stimulated one spot it would stop her speech. Others would affect movements of arms and legs. Everything fit nicely. What they observed when they stimulated her while awake is that stimulating one region very weakly would induce a smile. If they stimulated more intensely, she would burst into laughter. When they asked her why she was laughing, the patienet would describe a situation or give an example of what she was thinking of that triggered the laughter. She would make up events that seemed reasonable, like “I was thinking of this TV show I was watching.”

The point was that we will make up rationalizations to make our actions make sense.

[L: At this point I asked if the stimulation could have actually triggered her memories of the funny things? As opposed to triggering the physical laughter. I.e., maybe she wasn't lying?=]

The answer was that in theory the memories she gave were so different that it was unlikely she would be thinking of them from stimulation of the same spot.

In 1960s when there were no pharmacological treatments for epilepsy, in a few cases one cut off the bridge between the two hemispheres so they couldn’t communicate. They would then provide different information to the left and right eye, and to the speech center. This resulted in different responses depending on whether it was the right or left hemisphere that responded to a question. Either vocally on the left or with the left hand which is regulated by right hemisphere, patients could give opposing answers or make up different responses. One could be accurate and another totally made up, leading to conclusion that the brain after-rationalizes to explain its own behavior.

Agenticity

When things happen we assume someone triggered them. We think there is an agent behind it - like a god, for example.

Patternicity

We try to find patterns in events. We are in fact obsessed with finding patterns. This has great survival value. If we can discern a pattern, we can better predict what is going to happen next. If things happen randomly we have no use for this, but we try anyway. Numerous experiments have shown that when people gamble they are looking for patterns in random events and always lose.

“Im OK; you’re biased”

We think we are objective, but are aware that others can be biased.

Lazy, not biased

Susceptibility to partisan fake news is better explained by lack of reasoning than by motivated reasoning. We have capacity to think critically, but don’t use it as often as we should.

Conclusion

Our perception can be partial and selective.
Our cognitive processing can be strongly biased.
The strength of science lies in its provisional nature, its open-mindedness, its capacity for doubt and uncertainty. - Chris Quigg 2003

Feb 20, 2026

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