Personal Science Week 230309 : Consciousness

Consciousness and senses

This is your weekly summary, delivered each Thursday, of thoughts and ideas we think will be useful to Personal Scientists. Use science for personal, rather than professional reasons.

This week we discuss consciousness, and how to tell if you have any special senses.

Much of Personal Science is about learning to observe. (In fact, that’s the subtitle of the excellent introduction by Gary Wolf et al). But to observe requires assumptions about the trustworthiness of our senses. How much can we really trust what we see?

Philosophers have grappled with this question for millennia, with the entire discipline of cognitive science devoted to the problem since the 1950s. Neuroscientists, psychologists, and even quantum physicists have weighed in on what it means to observe and the many bizarre and nonintuitive experiments that prove how little we can trust the senses.

Tens of millions of people still argue about the colors in “The Dress”, a 2015 viral internet meme that exposed significant differences in the way that normal people perceive everyday objects.

Is it white and gold, or black and blue? “The Dress” By Cecilia Bleasdale

All of the research points to the startling conclusion that our senses are an illusion. Our brains are not simple computers equipped with sensors that detect signals from real objects “out there”. Instead, our brains generate from scratch a detailed simulation of the world, and our senses merely provide feedback to guide the usefulness of that simulation. Dreams, hallucinations, or psychedelic experiences are what happens when the body’s normal sensory feedback is inhibited.

To learn more, I recommend two excellent books that will change your mind about how much you can trust your senses: The Case Against Reality by Donald Hoffman and Being You by Anil Seth.

Both books are full of examples that explain illusions like The Dress or the McGurk Effect (where you “hear” differently depending on what you see).

What’s more, people appear to have significant differences in the ways we perceive and process “reality”. You may have heard of prosopagnosia or ‘face blindness’, a condition that affects as many as one person in fifty, including Brad Pitt. These otherwise normal and healthy people have difficulty recognizing faces. A good friend of mine tells me she didn’t even know she had it until well into adulthood — she uses other cues, like body shape, voice, hair style and more to tell people apart.

Can you picture a person’s face when they’re not there? A surprising number of people, including the co-founder of Pixar, are unable to conjure mental images like faces, a condition called aphantasia. Similarly, around 15% of people can’t see 3D at a 3D movie.

On the other side of the spectrum is synesthesia, a condition that gives people an additional sense, like associating words or sounds with colors. Chess champion Magnus Carlsen can “see” chess boards without looking. Great musicians have similar abilities with sounds.

Test yourself

To learn more about your own illusions, sign up for the Perception Census, developed by Researchers from the University of Sussex and University of Glasgow.

It took me about 15 minutes to work my way through the first section, answering questions to see how well I can identify objects and faces.

Besides offering links to more details about what is being studied in each question, the site includes a helpful summary of how your answers compare to the other 40,000 participants who have joined so far.

About Personal Science

Personal Science uses science for personal reasons (understand something for yourself) rather than professional ones (it’s your job). Because so many personal issues tend to be health-related, many Personal Science endeavors tend to focus on optimization related to the human body.

But just as medical science is only one aspect of science, we can use the principles of science for much more than the study of personal health. Personal Scientists can ask questions about the world in general, in both what we call “physical” sciences like astronomy or physics and “social” sciences like linguistics or politics.

Email us (info@personalscience.com) or leave a comment if you have other ideas you’d like to discuss.