A practical example. Colour photographs give a nicely coloured 
stereo-model, but if the operator is concentrating on parallaxes and 
height differences, he will be hardly aware of colour. This can be 
demonstrated by combining a colour print and its black-and-white stereo 
partnere 
[Another limitation becomes obvious when guessing a number of 
irregularly spread pieces in one glance (sheep, or apples, or coins). 
Up to 7 we manage to recall, above this low number, we make mistakes, 
unless there is enough time to count, 
An interesting question is how accurate the flow of information is 
carried outs will signals loose precision if they are transferred to 
  
the brain, will the last decimal be cancelled? Can the visual system D). o 
"work" better than within 10% or is it 1%? (See also Par. 6 - "Computer") 
MEMORY - Short and Long -, this is almost as if 
speaking about computers. Unlike computers, man has 
a memory capacity big enough to store all events 
which passed through the neural system up to the 
brain during lifetime. However, the difficulty is 
that memory does not consist of a fast and a slow 
seotion but of an active and & passive form, an 
  
accessible and an inaccessible part. As a consequence, we do not know 
what we know, nobody can remember and list all the trees he knows, nor 
the names of soils starting with an s. Moreover, there is a SHORT-TERM : 
memory, to store telephone-numbers just for dialling, and a LONG-TERM 6 0 
memory for the home number, or other frequently needed names and codes, 
Obviously, FORGETTING is an essential property of human memory; 
because the restricted capacity of the active memory could not cope 
with the ability to change the contents of the active memory, Le 
forgetting was forbidden. (Ceraso 1967) 
[This is again an essential points human memory is continuously 
changing. Facts in the short-term memory can be transferred to the 
long-term memory by repeated or completely different presentation, 
Being in the long-term memory, they can be recalled easily if 
regularly needed (active memory), but if the impression is not 
emphasized (as could be done by an examination), we forget to 
re-locate the storage place, as if the access, the path way, faded 
away. And again, a moderate emotion can improve the wanted recall.)