27: David Eagleman | How Your Brain Makes Sense of the World

Sensory Substitution

David Eagleman introduces the concept of sensory substitution, where artificial means replace or enhance natural senses. He explains how devices like wristbands and vests can translate sound into vibrations on the skin, allowing deaf individuals to 'hear' through touch 1. This intuitive technology enables users to recognize sounds such as a dog barking or a person laughing from day one 1.

You’d be surprised at how intuitive the whole thing is. So we have a series of videos on YouTube that we have with like, okay, here's a dog barking, here's someone knocking on a door, here's a person laughing, here's a person speaking, here's a car passing you, here's a smoke detector -- all these things are unbelievably intuitive, strangely so, when you listen to them with your skin, you think, “Oh yeah, that's a dog barking. That's a person laughing, that's a blah, blah, blah.”

--- David Eagleman

He also discusses the limitations of earlier sensory substitution devices, like the brain port, which used the tongue to transmit visual information but proved impractical for everyday use 2.

   

Human Augmentation

The discussion then shifts to human augmentation, where David Eagleman explores the potential to enhance human senses beyond their natural capabilities. He describes how NeoSensory's devices can extend sensory perception, such as feeling the presence of objects or people through vibrations on the skin 3. This technology could lead to superhuman abilities, like sensing infrared or electrical signals 3.

This is exactly why I've started this company, NeoSensory, to do exactly this. So, you know, we build these devices. This is our wristband here. We've built these vests that are covered in vibratory motors and the vests convert any kind of data stream into patterns of vibration on the torso.

--- David Eagleman

He also touches on the ethical and practical challenges of more invasive augmentation methods, such as implanting electrodes in the brain 4.

   

Illusions of Perception

David Eagleman delves into the illusions of perception, explaining how our senses can deceive us and shape our reality. He highlights that vision is largely constructed by the brain, with less than 5% of visual input coming from the eyes 5. This internal model of the world is constantly updated based on expectations and new data 6.

The amount that's coming in through here is about less than 5% of your eyes through your eyes itself. Exactly. And that's because if you actually look at the number of fibers going to the visual cortex from the eye, you've got a certain number of fibers. Those go to this intermediate realization. And then that goes to the visual cortex that provides 5% of the input to the visual cortex and all the rest of the input is from elsewhere.

--- David Eagleman

This understanding has significant implications for fields like eyewitness testimony, where perceived reality can be highly unreliable 6.