UNSEEN BOOK AUTHOR KEELAN LEYSER KEYNOTE SPEAKER UNSEEN STAGE 2000

The Psychology of Magic

Lewis & Leyser

Dr David Lewis & Keelan Leyser

Lewis & Leyser is the partnership of neuropsychologist Dr David Lewis and digital illusionist Keelan Leyser. For over two decades, they have combined academic psychology with the art of magic to show people how their minds really work, and how easily those minds can be fooled.

David and Keelan first met when Keelan was studying Philosophy and Economics at University College London (UCL). David, already one of the most respected psychologists in the country, spotted something unusual: a performer who could demonstrate cognitive principles live, in real time, in front of an audience. The two began working together and formed Lewis & Leyser in 2001.

Since then, they have delivered lectures, workshops and keynote presentations at conferences around the world for companies including Microsoft, Intel, Google and BP. Their work showed audiences how the techniques behind magic (misdirection, priming, attention manipulation, expectation bias) are the same techniques used in business, marketing and everyday life to influence what we see, what we believe and what we choose.

Unseen: Blind Spots and Why We Miss What Matters Most

Unseen is the culmination of the Lewis & Leyser partnership: three years of writing that distilled two decades of shared lectures into a single book. Published by Bloomsbury Sigma, it turns the tools of the magician's trade into a lens for understanding the mind, and asks a deceptively simple question — how much of what we think we see is really there?

Rather than assume perception is reliable, the book examines the moments it quietly fails us: what slips past our attention, how expectation rewrites what we notice, and why confident experts are often the easiest to deceive. It then shows how those same weaknesses are exploited — in shops, in politics and on our screens — and, more importantly, how to guard against them. Unseen was David Lewis's final published work.

The book is accompanied by more than 30 companion video demonstrations, so readers can experience each effect for themselves rather than simply read about it.

Order Unseen

Out now in hardback, eBook and audiobook · Bloomsbury Sigma · 336 pages.

Order from Bloomsbury

What reviewers said

A riveting and relevant work of pop psychology. Publishers Weekly
Informative and eye-opening. — Booklist

Dr David Lewis

Neuropsychologist

David Lewis helped shape the field he became known for. A neuropsychologist, Chartered Psychologist and Fellow of the Royal Society of Medicine, he was voted one of the '50 Most Influential Psychologists in the World Today' and is often called the 'father of neuromarketing'. He founded Mindlab International, worked as a photojournalist earlier in his career, and wrote or co-wrote more than 30 books. Unseen was his last.

In loving memory of Dr David Lewis (1942–2025), co-author, colleague and dear friend.

Keelan Leyser

Digital Illusionist & Mentalist

Keelan Leyser is one of the world's leading digital illusionists and tech magicians — a former British Magic Grand Prix Champion who has taken his act to more than 60 countries and over 100 television shows. It was his knack for staging cognitive science in real time that first drew David to him, and that instinct runs through everything the two created together.

keelanleyser.com

Impulse

Before Unseen, Lewis & Leyser collaborated on Impulse: Why We Do What We Do Without Knowing Why We Do It, published by Random House in the UK, US and Japan. The book examined the hidden forces behind impulsive behaviour and the unconscious drivers of everyday decision-making.

DR DAVID LEWIS AND KEELAN LEYSER ON THIS MORNING ON ITV 1080
Business Speakers at Google UK
Lewis and Leyser
Keelan Leyser Keynote Speaker - Impulse Book