The algisimeter is used to map the skin's responsiveness.  By placing the point gently on the surface of the skin, different nerve endings are stimulated.  The subject is asked to rate the sensation for strength -- giving ratings of 0, 1 or 2.

      To maintain accuracy during placement, a grid stamp is available.  You simply ink the stamp with washable ink and press it on the area of skin to be measured.  To locate the grid accurately measure from a standard location such as the middle knuckle or a vein.  I have data sheets in my office which makes recording the data easier.

      Several weights are available for the algisimeter.  Simply unscrew the end weight and add or remove additional weights.

    Color Illusion:

      The color illusion is comprised of a set of circular cards and a motor to rotate them.

      This is a classic demonstration in the sensation of color.   The motor can be adusted to rotate at different speeds to see the effect on the illusion.

    Ear Muffs and Plugs:

      The ear muffs and plugs will not provide absolute silence if there is a great deal of noise in the environment.  They are effective if the room is already quiet.  Students have used them in sensory deprivation studies, attention studies, and modality studies.


      Several pairs of headphones are available for presenting auditory stimuli.  They are all surface headphones.  Do not use earplug headphones in your studies.

      The choice to use headphones or speakers for presenting auditory stimuli will depend on the study.  Headphones often increase the attention to the stimuli and it is possible to separate the channels.  The use of speakers allows the subject to move freely.  If you are using music as a variable in your study, you may prefer to use speakers to provide background stimulation.  You might even wish to contrast the two methods.

    Illusion Cards:

      There is a rich literature regarding illusions and the variables which influence our perceptions.  Some illusions are developmental - children don't see them, but adults do.  Some illusions are based on violations of perspective.  Still other illusions are the result of the way in which our brains process information.

      The illusion set includes the Necker Cube, the Poggendorf illusion, Horizontal-Vertical illusion, the Old Woman - Young Girl illusion, and of course the Mueller-Lyer Illusion.

      If you are interested in doing a study with illusions, we also have computer based illusions and there are several sites on the Internet.

    Mirror Tracer:

      Have you ever tried to read a book in a mirror?  In the mirror tracer task the subject has to trace the pattern of a star as they look at it in a mirror.  Some subjects succeed easily, while other struggle to move their hand.

      This electronic version of the mirror-tracer counts the number of times that the subject goes out of the boundaries.  Other measures which can be taken are a) total time to complete the pattern, b) number of times paused, c) number of reversals, d) miscellaneous verbal behavior.  Further, you might consider dividing the pattern into sectors to see if the behavior differs from one area to the next.

    Mirror Tracer - Paper Version:


      This task is the same as the one above, but the subject traces the pattern on a piece of paper with a pen.  While there is no counter, the paper record can be analyzed later to compare subjects.

      In both tasks, remember to carefully position the hand of each subject in the same way.  If you are going to let them rest their arm against the table, have all subjects take the same position.  Use the same type of pen for all subjects.  A ball-point with low resistance works best.

    Picture and Word Stimuli Sets:

      I have five or six sets of teaching materials designed to teach verbal and reading skills.  Each has an array of large cards with pictures or words on them.  There are hundreds of these cards.  Some of the sets also include dolls and puppets.

      While many of the pictures are a little old-fashioned, most of them are suitable for use in verbal memory, recognition, and association tasks.

      The advantage to using such graphics is that they are all drawn with the same style and complexity.  Thus, subjects are not given additional cues to memory by the change of graphic style, size, and color palette.  The words are also printed in a standard size and font.

      If you are only doing a word list, there are better materials available in the computer programs section.  If you are using the computer to present your materials, graphics can be scanned to make small *.bmp files.  You might also look at collections of clip-art on the Internet, in WordPerfect and at the Media Center.

    Star Tracer:

      The star tracer looks similar to the mirror tracer, but it measures different skills.  The subject grasps the handles and uses the arms to control the pointer from a distance.  People with good eye-hand coordination or people who are able to adjust their large motor responses might excel at this task.  It could be interesting to see if those who describe themselves as good at sports vs. clumsy have accurate self-attributions.

      The task was developed for industrial psychologists to test the ability to operate machines and equipment.  There is a fairly large literature on such measures, although much of it will be found before 1980.

      The star tracer can be attached to the counter which will automatically record the number of times the subject goes out of the lines.  The counter can also beep to tell the subject that they have made an error.

    Steadiness Tester -- Hole Type:

      The steadiness testers might remind you of something from the Farmington Fair, that is probably because the carnival examples were adapted from the psychology equipment.  Or, perhaps the psychologist saw it at a county fair and saw different possibilities.

      Just as the Science Museum in Boston has a popular display centered on the mirror tracer, the steadiness tester has a fascination for many people.  It measures both small-motor coordination and steadiness of the hand.  Many variables effect both, and the steadiness tester can be used as one measure of stress, preparedness, and perhaps fitness.

      The subject is asked to place the stylus in each hole, starting with the largest.  The counter can be attached to the stylus to automatically count the number of touches.  In addition, you can record the total amount of time for the task, the amount of time for each hole, the amount of time between holes, or the smallest hole achieved without error.

      You should give standard instructions concerning the depth of placement, the amount of time the stylus is to be held in the hole, and the placement of the hands and arms.  Some subjects might discover that holding the stylus hand with their other hand greatly increases their skill level!

    Steadiness Tester -- Slot Type:

      The slot type tester tests both small-motor coordination and steadiness, but also looks at the ability to move the arm in a straight line.  As a diagnostic tool for an industrial psychologist, it would apply to tasks requiring motion as well as placement.

      The subject is asked to start moving the stylus from the wider end to the narrower end.  The counter can be attached to the stylus to automatically count the number of touches.  In addition, you can record the total amount of time for the task, the distance at which the first error was made, or improvement across trials.

      You can provide audio feedback for your subjects on both the slot type and the hole type steadiness testers.  This feedback may either improve or detract from performance.

      On this task, it is better if the subject does not rest their arm on the table.  If they keep their arm in the same place, their hand will describe an arc and it will harm their performance.  If they move their arm along the table, this could act as a guide for their hand and their performance would be improved.  Be careful to place the equipment parallel to the subject and at the same distance from their elbow/shoulder.  The distance will vary depending on the height of the subject.


      If you are presenting visual stimuli, the tachistoscope will let you control the amount of time each item is seen by the subject.  There are thousands of applications for this piece of equipment.  It's even useful as a tongue-twister.

      The tachistoscope attaches to a Kodak Ektagraphic slide projector.  You sign out the slide projector from the equipment room at the Media Center.  It might be best to take the tachistoscope with you so that you can be sure of getting the correct lens.  You can then try it out to be sure of the controls.

      I have several sets of slides which can be used as stimulus materials or the Media Center can make custom slides for your experiment.  They have a complete price list at the front desk.

      Pretest your settings before you begin your experiment.  If you are doing verbal memory, you probably don't want to use 1/10th of a second -- the subject might not see it.  If you are doing an experiment where the subject is to be influenced by surrounding stimuli, faster presentations might be in order.

      You might test a group of subjects at the same time.  If the projector is placed at the back of the room with the screen at the front, and subjects are in the middle of the classroom, the differences in angle of view will be minimal.  Place your subjects at the same distance from the screen.

    Window Illusion:

      When I was in seventh grade, I saw a demonstration of the window illusion on television.  I decided then to become a psychologist.  You never know what kids are watching in TV!

      The window illusion demonstrates perspectival illusions.  The window appears to rotate, while in reality it is moving back and forth across a limited arc.  I am not sure if anyone will need it as equipment in an experiment, but you might want to try it out for the fun of it.


©   Marilyn Shea, November 1999
some pictures by Josh Keezer, mouseover graphics by Josh Glavine

Department of Psychology, University of Maine at Farmington