A potent illustration of how compelling mental illusions can be, even when we know they're illusions. This has important implications for policy change and medical decision making, among others. (Graphics from Wikipedia; presentation is licensed Creative Commons Attribution Share-Alike: use it freely with attribution and same license attached.)

1. Obviously, Square A is darker
than Square B. Right?
Graphics: Wikipedia optical illusions page, April 7, 2012 Creative Commons
Slide: e-Patient Dave, Society for Participatory Medicine (e-patients.net blog) Attribution Share-Alike

2. Obviously, Square A is darker
than Square B. Right?
Graphics: Wikipedia optical illusions page, April 7, 2012 Creative Commons
Slide: e-Patient Dave, Society for Participatory Medicine (e-patients.net blog) Attribution Share-Alike

3. Obviously, the top circle’s darker,
and it’s in a darker square. Right?
Graphics: Wikipedia optical illusions page, April 7, 2012 Creative Commons
Slide: e-Patient Dave, Society for Participatory Medicine (e-patients.net blog) Attribution Share-Alike

4. Obviously, the top circle’s darker,
and it’s in a darker square. Right?
Graphics: Wikipedia optical illusions page, April 7, 2012 Creative Commons
Slide: e-Patient Dave, Society for Participatory Medicine (e-patients.net blog) Attribution Share-Alike

5. Even if you look again, knowing it’s an
illusion, the illusion’s still real to you.
(Kinda makes a mockery of “I know what I saw!”, yes?)
Obviously, Square A is darker Obviously, the top circle’s darker,
than Square B. Right? and it’s in a darker square. Right?
Graphics: Wikipedia optical illusions page, April 7, 2012 Creative Commons
Slide: e-Patient Dave, Society for Participatory Medicine (e-patients.net blog) Attribution Share-Alike

6. Decades of research
have shown that
the same thing happens
with many options we’re shown,
not just optical.
Graphics: Wikipedia optical illusions page, April 7, 2012 Creative Commons
Slide: e-Patient Dave, Society for Participatory Medicine (e-patients.net blog) Attribution Share-Alike

7. It’s a major challenge for social change,
behavior change, and policy change.
Obviously, Square A is darker Obviously, the top circle’s darker,
than Square B. Right? and it’s in a darker square. Right?
Graphics: Wikipedia optical illusions page, April 7, 2012 Creative Commons
Slide: e-Patient Dave, Society for Participatory Medicine (e-patients.net blog) Attribution Share-Alike

8. The books Nudge, Switch,
and Thinking, Fast and Slow
discuss the challenges
of irrational perceptions.
532 pages, 6”x9.1”
320 pages, 5.5”x8.5” 320 pages, 5.2”x8.5”
Graphics: Wikipedia optical illusions page, April 7, 2012 Creative Commons
Slide: e-Patient Dave, Society for Participatory Medicine (e-patients.net blog) Attribution Share-Alike

9. The books Nudge, Switch,
and Thinking, Fast and Slow
discuss the challenges
of irrational perceptions.
I call such perceptions “invisibly irrational,”
because I know what I see – or think I see – 532 pages, 6”x9.1”
and no amount of information
will change an illusion, optical or other.
320 pages, 5.5”x8.5” 320 pages, 5.2”x8.5”
Graphics: Wikipedia optical illusions page, April 7, 2012 Creative Commons
Slide: e-Patient Dave, Society for Participatory Medicine (e-patients.net blog) Attribution Share-Alike

10. The books Nudge, Switch,
and Thinking, Fast and Slow
discuss the challenges
of irrational perceptions.
I call such perceptions “invisibly irrational,”
because I know what I see – or think I see – 532 pages, 6”x9.1”
and no amount of information
will change an illusion, optical or other.
We need to understand this about
ourselves and others, realize that certainty
can still be wrong, and help reach good
choices – despite the illusions.
320 pages, 5.5”x8.5” 320 pages, 5.2”x8.5”
Graphics: Wikipedia optical illusions page, April 7, 2012 Creative Commons
Slide: e-Patient Dave, Society for Participatory Medicine (e-patients.net blog) Attribution Share-Alike

11. Blog of the Society for Participatory Medicine
ParticipatoryMedicine.org
Graphics: Wikipedia optical illusions page, April 7, 2012 Creative Commons
Slide: e-Patient Dave, Society for Participatory Medicine (e-patients.net blog) Attribution Share-Alike