Researcher uses card trick to reveal unconscious knowledge

November 17, 2011 by Bob Yirka in Neuroscience report

(Medical Xpress) -- Spanish neuroscientist Luis Martínez of the Institute of Neurosciences in Alicante, has shown that an exception exists regarding “change blindness” and it can be demonstrated by using a simple card trick known as the Princess Card Trick. In the trick, the “magician” shows the viewer five cards and asks them to mentally pick one. They are instructed to not say which it is. The magician then turns the deck over, shuffles it a little bit, then removes one card from the deck and lays it face down on the table. The remaining cards are then turned back over and shown to the viewer, who finds that the card they mentally picked is now missing.

This video is not supported by your browser at this time.

Princess Card Trick video.

The trick works because the viewer fails to notice that the first deck has been “replaced” by another as it was being turned over; none of the cards in the second deck match the first (the blindness part), thus it appears that the card that was removed was the one chosen. But, this is just the first part of the experiment. Martínez wants to know if the viewer really did see those first cards or not. So, what’s really going on here is a means to force the viewer to focus individually on each card in the first deck. This is because the second part of the experiment involves pulling out two new cards one of which is identical to one of the cards in the first deck and asking the viewer to identify which of the two was in the first deck. Upon being shown, most viewers say they don’t know. But when forced to choose, 80% of viewers pick the right card, and that’s where the subconscious mind has itself played a trick. It’s taken in a lot more of the information than the viewer realized and then showed its hand so to speak, only when pressed.

Martinez presented his findings at this past week’s annual meeting of the Society for Neuroscience where he also explained that the trick can be shown in other ways, such as with faces in photographs. Viewers shown a photograph of a male face were later asked to view a group of several photographs of men’s face and were asked to say whether they original face was among them. Most people found it difficult to say, but when forced to choose, were again very likely to pick the right one from the stack.

Martínez says the whole process can be thwarted however, if viewers are distracted by say, a magician chattering away the whole time he is performing the trick. Such chatter appears to prevent the subconscious mind from seeing all the things it would were the chatter not going on. Or maybe it’s more that it sees it, but cannot file it away in memory.

There’s one more trick here, in the Princess Card Trick, and that is how the decks are switched. In reality, they’re not. What happens is that a trick deck is used with four of the five cards having different suits (diamond, heart, etc.) stamped on their corners which are then displayed by showing just the top, or just the bottom part of the . The fifth one is the only one shown in full.

© 2011 Medical Xpress

5 /5 (2 votes)  

Filter


Move the slider to adjust rank threshold, so that you can hide some of the comments.


Display comments: newest first

Isaacsname
Nov 17, 2011

Rank: 5 / 5 (1)
...I had this trick when I was 10. I would be interested to see what would happen if the faces and colors were mismatched with the suits, ie black heart and Q, for queen , but a Jack's picture instead, so on and so forth.
Rank 5 /5 (2 votes)
Related Stories
Relevant PhysicsForums posts

More news stories

For combat veterans suffering from post-traumatic stress disorder, 'fear circuitry' in the brain never rests

Chronic trauma can inflict lasting damage to brain regions associated with fear and anxiety. Previous imaging studies of people with post-traumatic stress disorder, or PTSD, have shown that these brain regions can over-or ...

Neuroscience created May 18, 2013 | popularity 5 / 5 (1) | comments 0 | with audio podcast

Temporal processing in the olfactory system

The neural machinery underlying our olfactory sense continues to be an enigma for neuroscience. A recent review in Neuron seeks to expand traditional ideas about how neurons in the olfactory bulb might encode information about ...

Neuroscience created May 17, 2013 | popularity 4 / 5 (1) | comments 0 | with audio podcast report

Melon focus headband turns to Kickstarter for rollout plans

(Medical Xpress)—What if the quality of your work depends more on your focus on the piano keys or canvas or laptop than your musical or painting or computing skills? If target users can be convinced, they ...

Neuroscience created May 17, 2013 | popularity 3.7 / 5 (3) | comments 0 | with audio podcast weblog

Deep brain stimulation: A fix when the drugs don't work

Neurological disorders can have a devastating impact on the lives of sufferers and their families.

Neuroscience created May 17, 2013 | popularity 5 / 5 (1) | comments 0 | with audio podcast

Brain makes call on which ear is used for cell phone

If you're a left-brain thinker, chances are you use your right hand to hold your cell phone up to your right ear, according to a newly published study from Henry Ford Hospital in Detroit.

Neuroscience created May 16, 2013 | popularity 2 / 5 (2) | comments 0 | with audio podcast


New theory on genesis of osteoarthritis comes with successful therapy in mice

Scientists at Johns Hopkins have turned their view of osteoarthritis (OA) inside out. Literally. Instead of seeing the painful degenerative disease as a problem primarily of the cartilage that cushions joints, ...

Computational tool translates complex data into simplified 2-dimensional images

In their quest to learn more about the variability of cells between and within tissues, biomedical scientists have devised tools capable of simultaneously measuring dozens of characteristics of individual ...

Researchers identify a potential new risk for sleep apnea: Asthma

Researchers at the University of Wisconsin have identified a potential new risk factor for obstructive sleep apnea: asthma. Using data from the National Institutes of Health (Heart, Lung, and Blood Institute)-funded Wisconsin ...

Study finds that sleep apnea and Alzheimer's are linked

A new study looking at sleep-disordered breathing (SDB) and markers for Alzheimer's disease (AD) risk in cerebrospinal fluid (CSF) and neuroimaging adds to the growing body of research linking the two.

'Gap' for HIV vaccine efforts after latest setback

The hunt for an HIV vaccine has gobbled up $8 billion in the past decade, and the failure of the most recent efficacy trial has delivered yet another setback to 26 years of efforts.

Ginger compounds may be effective in treating asthma symptoms

Gourmands and foodies everywhere have long recognized ginger as a great way to add a little peppery zing to both sweet and savory dishes; now, a study from researchers at Columbia University shows purified components of the ...