Game Development Reference
In-Depth Information
P
ROBLEMS WITH
P
ERCEPTION
Often, the way people perceive and process things is the major bottleneck to estab-
lishing a sorting of how we would prefer things. One of these problems is the actual
perception
of a stimulus. While this may seem obvious, it is an important facet of the
process to cover. At the very core, a stimulus must be perceived to be included in
consideration. This is somewhat different than the simple fact of whether or not the
stimulus
exists.
Plenty of stimuli exist and yet are either below a threshold of de-
tectability (e.g., too quiet to hear) or outside the sphere of awareness (e.g., happening
behind or around the corner from the intended observer). In those cases there is a
legitimate argument that, despite the very real occurrence of the trigger event, the
agent was simply not able to be aware of it. If the agent was not aware of it, he
couldn't use it as part of the decision-making process.
The science of
psychophysics
is an area of study that deals with a much more
subtle and even scientifically intriguing area. It deals with the way that we psycho-
logically process differences in stimuli. For example, if someone were to hand you
two objects of similar weight—one in each hand, could you tell if they were differ-
ent weights or the same? Could you tell how much different the weights were. If one
weight was five pounds and the other one was six, would you be able to tell that the
difference was the same as if they weighed four and five pounds respectively? In
both cases, the difference is one pound, yet they may feel significantly different.
How much different would the weights have to be before you were able to accu-
rately determine which of the two was heavier?
If we are modeling the sense of hearing for an agent, we would likely want to
take into account what level of sound would be perceptible to that agent. We also
may want to take into account how loud that sound is compared to other sounds
in the area—that is, the relative sound level. It is entirely possible that a loud sound
could go unnoticed when it is heard in concert (so to speak) with other loud
sounds. Also, could the sound be mistaken for something else? My wife swears that
there is a stairwell door in the hospital at which she works that squeaks in a manner
that sounds remarkably (and eerily) like our cat that died in 2005. It is not a case of
feline reincarnation as a fire door; it is a matter of flawed perception.
Likewise, different people can perceive visual stimuli in dramatically different
ways. My dad is red-green color blind, for example. If he isn't specifically looking
for it, he will not see a red traffic light in a background of a green tree. (Or a green
light in a background of a red tree, I suppose.) If he were to visit a city that flipped
their traffic lights upside down, he would really be in trouble!
