Mental Rotation Experiment Software (MENTROT)
Overview
The program MENTROT runs a version of Cooper & Shepard's mental rotation paradigm. On each trial, a symbol
resembling an upper-case 'F' is presented. The symbol is presented at one of eight orientations, and is either a letter 
'F' or the mirror-image of an 'F'. Examples of both a normal and a reversed symbol are shown in the figure. The
subject's task is to determine whether the symbol is a normal or a reversed 'F', and to respond as quickly as possible
by pushing the "Z" key if the symbol is reversed, or the "/" key if the symbol is not reversed. If the response was
incorrect, or if an invalid key was pressed, a brief tone is presented. Raw data from the experiment are placed in the
file DROT.DAT. An analysis program (ROTANAL) reads the data file and computes means and standard deviations
of the reaction times for correct responses at each orientation. The output of the analysis is placed in the file
AROT.ANL.
Running the experiment
To run the experiment, type MENTROT and hit "Enter". When asked to "Press any key to begin",
pressing the 'P' key will allow the user to change various parameters that determine the design of the experiment and
the timing of trial events. Pressing a key other than 'P' will cause the program to begin the first trial immediately.
The parameters that can be safely changed are listed below, along with their probable default values.
1. Number of trials per block (should be
multiple of 16):
(default=48)
2. Total number of blocks per session:
(default=5)
4. Number of practice blocks:
(default=1)
5. Inter-trial interval (msec):
(default=1500)
6. Duration of error tone (msec):
(default=500)
7. Interval between cue and stimulus (msec):
(default=500)
10. x location of stimuli (0 to 32000):
(default=16000)
11. y location of stimuli (0 to 32000):
(default=12000)
12. Length of vertical segment (video units):
(default=3000)
13. Length of horizontal segment (video units):
(default=2500)
20. Maximum allowed Reaction Time (msec):
(default=5000)
Note. The stimulus is equally likely to be non-reversed or reversed at each of the eight orientations. The various
stimuli are presented in a randomly determined order.
Analyzing the data (You will need analysis program available below)
Simply type ROTANAL and hit "Enter" from the directory in which the experiment was run. When asked "Number
to trim from each end" the user has the option to exclude the desired number of extreme reaction times from the
analysis. Hitting "Enter" will not exclude any data. To view the means from each condition TYPE or PRINT the
file AROT.ANL. Orientations are designated 0 through 7, where 0 = vertical, 1 = 45o clockwise from vertical, 2 =
90o clockwise, etc. If you want to view the raw data, TYPE or PRINT the file DROT.DAT. Each time that
MENTROT is run, the program will destroy all previous DROT.DAT data files. Each time that ROTANAL is run, it
will destroy all old AROT.ANL files. Therefore, be sure to look at the data before the experiment is run again.