ESP Cards ........ the classic examination tool of parapsychology.
The PLF ESP set includes two complete games (2 x 25 cards) with the well-known symbols developed by Dr. KARL ZENER and Prof. JOSEPH BANKS RHINE in the 1920s:
5 cards "Circle" white back 5 cards "Circle" blue back
5 cards "Cross" white back 5 cards "Cross" blue back
5 cards "wavy lines" white back 5 cards "wavy lines" blue back
5 cards "square" white back 5 cards "square" blue back
5 cards "star" white back 5 cards "star" blue back
In addition, the PLS ESP Set includes three different double image cards as well as two double back cards
(white/white and blue/blue).
The cards are back-marked according to a new and innovative system.
A marker should of course always be invisible to the audience, but identifiable with a (first) glance for the knowing performer. Each system will therefore have to move between these two poles. The PLF Marking System makes use of a special feature of the visual sense and information processing in the brain.
In short, you can always see what you are expecting at that point. Our brain always supplements pictorial perceptions to what it expects from its experiences. This is the basis of many optical illusions - and this is exactly what the PLF ESP Cards make use of.
An uninitiated person will not notice the mark because he sees the back image like this,
as he expects it to be. You, on the other hand, once you know the system, won't be able to overlook the change you made to mark it; it will happen right in front of your eyes!
Translated with www.DeepL.com/Translator