Katie Haubrich
Construct Validity of the Steinman Motion Illusion Task When Paired with a Standardized Read Test
Background Research Question Method
Results Implications Relevant Links

Livingstone, Rosen, Drislane, and Galabura (1991)  found that people with specific reading disorder (SRD) have trouble distinguishing the temporal order of two visual stimuli occuring in rapid succession because these items fuse together and become one.  Livingstone et al. (1991) hypothesized that this problem was coming from a magnocellular pathway deficit because upon investigation of the specimans of people with SRD. The SRD group had smaller magnocellular cells than the control group.

Marigan and Mansell (1993) also found anatomical evedence for a magnocellular pathway deficit.  They studied the anatomical make up of the visual system of primates and found that primates visual systems are identical to our.  Merigan and Mansell (1993) also found that when there were leisons observed in the magnocellular pathways of primates,  these primates exhibited many of the symptoms that are readers with a SRD did.

In 1995, Steinman developed a task that was hypothesized to be sensitive enough to detect the difference between those individual affected by a magnocellular pathway (m-pathway) deficit and those individuals who are not.  This task, in theory, may be better for detecting a magnocellular pathway deficit because the m-pathways control eye movement when reading and the Motion Illusion task would be able to detect abnormal eye movement from through its motion detection component.
Research Question
The purpose of this study was to establish the concurrent validity of the Line Motion illusion task with a standardized reading test.

Participants were recruited from undergraduate psychology majors that attend a small libral arts college in the northeast.  A total of 14 people participated in this study.  Thirteen Partiipsnts were White and one participants was African-American. 

The Reading History Questinnaire, that was used in this study, was developed, by myself, to evealuate wether any of the participants or their siblinds had a history of a reading disorder.  The questionnaire examined possible deficits in reading, attention, and learning for both the subject and their siblings.

The Motion Illusion task used was develop by Steinman in 1995 to evaluate motion detection in eye movement.  For the purposes of this study, the task was run from the University Of Missisippi experiment page (see link at bottom of page).  The task has three different conditions; left motion cue (when the cue appears from the left), right motion cue (when cue appears from the right), and no motion (when the cue appears simutaneously).  The point od subjective simultaneity (PPS) score was obtained from this task and compaire to the reading rate and comprehension score from the Nelson-Denny Reading Test.

The Nelson-Denny Reading Test (NDRT) was developed by Brown, Fishco, and Hanna (1993) to test for specific reading disorders.  The NDRT is composed of two subtests: a vocabulary test and comprehension test.  For the purposes of this study only  the comprehension test was used.  From the comprehension test the reading rate and comprehension score was calculated.  The reading rate score was calculated by having the participant record what line they were on, in the first  reading passage,  at the end of one minute.  Comprehension score was calculated by dividing the number of correct answers with the number of total answers.

Participants were each tested individually in a small, computer lab.   First, each participant filled out the Reading History Questionnaire.  Then, each participant completed the Motion Illusion Task on the University of Missisippi psychology experiments page (see link at the bottom of the page).  After coompleting the Motion Illusion task, participants completed the NDRT (see link at the bottom of the page).


There was no significant correlation between reading rate, comprehension scores, and PPS scores.
No construct validity was found.



There were many confounding variables present within the group of participants that may of hindered the possibility of obtaining significant correlations or construct validity.  First, the group of participants that were tested did not have a history of SRD, attention problems or learning difficulties; nor did their siblings have a history of any of these disorders.  Consequently, this population was not ideal for taking a reading test that focused on readers with SRD, because they had none.  Nor was this group ideal for taking the Motion Illusion task, which is theorized to pick up on a magnocellular pathway deficit, when there was no awareness of any magnocellular pathway deficit in any of the participants.  Second, the test group was very small (N=14).  Finally, the group that was tested was extremely homogeneous.  All participants that were tested came from a middle to upper middle class background.  They had much the same preperation in their schooling to go on to secondary school (i.e. college prep courses in high school).

Relevant Links

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