Tower of London
The planning and problem solving components of executive
function were assessed using the Tower of London Task.
Tower of London software (Sanzen Neuropsychological
Assessment Tests) was used to perform this computer-based
task. This software allowed the researcher to create a Tower
of London Task with multiple patterns and trials. A Tower of
London Task was created to match the patterns and trials of
The Drexell II Tower of London Task. The computer screen
was split into two sections, the “work space” on the left and
the “goal state” on the right. This task required participants to
rearrange the orientation of three colored balls (red, blue,
green) located in the “work space” so it matched that of the
colored balls in the “goal state”. The “goal state” showed the
three balls placed on three “sticks” of differing lengths. The
first (longest) stick was able to hold all three balls, the second
(shorter) was able to hold two balls, and the third (shortest)
was able to hold only one ball. The user interface required the
use of a mouse to control which balls were selected and where
they were moved. Participants were instructed to match the
pattern shown in the “goal state” while making as few moves
as possible. They were also informed that only one ball could
be moved at a time and balls underneath another ball could not
be moved. The participants then completed a practice trial,
which initiated the program. This task consisted of 14 trials
and progressed from easier trials (could be completed with a
minimum of three moves) to more difficult trials (could be
completed with a minimum of seven moves). The participants
continued working on a given trial until they successfully
matched the pattern in the “goal state”. Performance was
measured by summing the total number of moves across all
trials and this provided the measure of planning.