| |
Abstract:
Abstract: In a probability guessing experiment, subjects try
to guess which of two events will occur next. Humans tend to match
the frequency of previous occurrences in their guesses. Animals
other than humans tend to maximize or always choose the option that
has occurred the most frequently in the past. Investigators have
argued that frequency matching results from the attempt of humans
to find patterns in sequences of events even when told the
sequences are random. There is independent evidence that the left
hemisphere of humans houses a cognitive mechanism that tries to
make sense of past occurrences. We carried out a probability
guessing experiment with two split-brain patients and found that
they exhibited frequency matching in their left hemispheres and
maximizing in their right hemispheres. We obtained a conceptual
replication of that finding on patients with unilateral damage to
either the left or right hemisphere. We conclude that the neural
processes responsible for searching for patterns in events are
housed in the left hemisphere. Further, we investigated whether
this interpretative mechanism can be "put to sleep" in normal
subjects using a variety of distractor tasks, and specifically
whether the left hemisphere's performance in split-brain patients
would be affected by this manipulation and not the right.
|
