Learning
is something that we do all the time. This isn’t the focused effort that we
might put into a course, but rather the everyday problems of the environment
that we’re working in. This often involves us in learning complex systems and
what response we need to make to them. We do this without realizing that we’re
acquiring knowledge. This is termed implicit learning.
In
some instances, this type of learning could be a matter of survival. For
example if we are learning to fly a plane, responding to turbulent air requires a correct prediction of movement. Of course, there are many other examples
that might have less dire consequences of slower learning.
Thoughts
about the learning process bring some questions to mind. One of these is what
affects our learning rate? Dienes et al
set themselves to have a look at this and studied things like mood. Their paper
is in Friday’s edition of the Public Library of Science (1).
Being
psychologists, they went to the computer screen and pressing buttons for the
answers. Basically they had colored squares appearing on the screen and the
human lab rats had to press buttons indicating their prediction of which side
of the screen the image would appear.
They
put in variations and controls in an attempt to isolate the good data. The
basic premise was that if the lab rat thought that they could see a pattern,
they would be using a series of the previous images to make their decision.
This corresponded to a slow learning rate in that the correlation with earlier
occurrences would fade slowly with number of tests.
Now
a fast learning rate meant that there would be some weight on the previous
occurrence but little or none on events prior to that, so the correlation would
fall off rapidly with number of trials. The decrease was taken to be
exponential with a steeper decay (faster learning rate) for those candidates
who only let the previous test affect their choice and not the third and fourth
test back in time.
The
results of the controls compared to an amnesia patient showed that the person
suffering from amnesia had a faster learning rate, that is, he took less notice
of previous result on his choice. Perhaps he couldn't remember?
The
experimenters introduced another twist in that to some participants they
displayed a happy face prior to their choice and to others they displayed a sad
face. This influenced the mood of the participants who were being tested. The
results showed that the happy people had a longer correlation decay, that is,
the learned more slowly.
The
big message that I take away here is that should I go gambling on something
random like a coin toss, I’d better make sure that I’m unhappy or suffering
from amnesia to avoid getting caught up in trying to see patterns in random
events and fall foul of the gambler’s fallacy.
