Running head: CONTENT AND EYE BLINKS
1
Reading Content and Eye Blinks
Elisabeth Sepulveda
St. Olaf College
Author Note:
This lab was conducted on November 2, 2014, at St. Olaf College, as part of Research Methods
in Psychology with help from Professor Charles Huff and Teacher Assistant Jenna Harder. I can be
reached at sepulvee@stolaf.edu
CONTENT AND EYE BLINKS
2
Abstract
Eye movement has long been considered indicative of attention. In the following study, we sought to
assess the impact of both hard and easy reading material upon eye blinks, in order to discern whether
meaningful conclusions regarding attention could be inferred. Our results were only marginally
significant, however the identified confounds lead us to believe that future, controlled, iterations of the
study could lead towards meaningful results in reading, attention, and ultimately, learning.
CONTENT AND EYE BLINKS
3
.
Effect of Attention on Eye-Blink Response
The relationship between eye blinks and attention is a long-investigated phenomenon in the
literature. Scientists have found that assessing eye blinks provides insight into cognitive processes such
as the perceptual span, preview benefit, eye movement control, and models of eye movement (Rayner,
2009). As a result, establishing systematic methods for collecting meaningful data based on eye
movement has become a valuable focus in research efforts. Just and Carpenter’s classic study, which
seeks to find a correlation between reading comprehension and eye movement, sets the foundation for
our study through establishing an eye-blink analysis model for assessing attention (1980). Orchard and
Stern’s usage of EOG eye movement recordings in relation to difficulty of reading material, extends
this research structure into a more detailed model, creating the basis for our methodology (1991).
Additionally, their distinction between classically-conditioned Reflex blinks, consciously-controlled
Voluntary blinks, and environmentally-responsive Endogenous blinks, introduce relevant confounding
variables to consider when assessing blink-response to reading material.
In our study, we sought to assess the influence of reading material—whether easy or difficult—on
patterns of attention, as manifested in number of eye blinks. Data was collected using an
Electrooculogram in order to quantitatively measure response to easy and difficult reading material as
related to baseline blinks. We hypothesized that difficulty of the reading material modulates blinkresponse, with easy material eliciting less blinks, and difficult material eliciting more.
Method
Participants
Participants in this study were all students in the Research Methods in Psychology Lab B
CONTENT AND EYE BLINKS
4
section. Students in the lab include both domestic and international students from both genders, all
within the ages of 18-24 years.
Materials
Materials used in this study were a BioMac MP36 Workstation, Alcohol-acetone Prep Pads,
Non-Latex gloves, Biopac Lesson 10 EOG 1, Biopac Electrode Lead Set (SS2L-2 Sets), Disposable
Electrodes, a computer, and SPSS for data analysis. A reading excerpt from the “Three Little Pigs” and
an excerpt from Kant’s “Critique of Pure Reason” were included for the “Easy” and “Hard” reading
materials.
Procedure
The study was designed to measure the impact of reading material on number of eye blinks,
with number of blinks in easy and difficult reading categories contrasted against a baseline category for
each student in the lab. In order to create this effect, students were first introduced to the experimental
design by Professor Chuck Huff, who described the reading material categorization and process of
measuring blinks to the class. Students then chose a lab partner and dispersed towards different
Electrooulogram stations throughout the lab.
Once students arrived at the station, the BioPac MP36 units were checked to make sure they were
off before electrode leads were plugged into the MP36, with Horizontal as channel 1 and Vertical as
channel 2. The MP36 machine was then turned on, latex gloves were put on, and for each pair, student
A cleaned student B’s face with Alcohol Prep Pads, before placing 6 electrodes on student B’s face—
two directly over each eye, one on the outside corner of each eye, one in the middle of the forehead,
and one under the right eye. The horizontal electrode lead set from channel 1 was attached to electrodes
next to right eye, left eye, and above the left eye. The vertical electrode lead set from channel 2 was
attached to electrodes above and below the right eye as well as in the middle of the forehead. Masking
CONTENT AND EYE BLINKS
5
tape was used to secure wires in place.
Once electrodes and lead sets were attached, student A opened the BIOPAC student lab program,
selected “Lesson 10—Electrooculogram”, and clicked on “Calibrate”. Student B, facing the computer,
then looked from extreme left to extreme right and back to center 4 times, then extreme top to extreme
bottom and back to center 4 times to calibrate the program. Following calibration, student A clicked
“Record” on the program, and held a pen approximately 10 inches in front of student B, while moving
the pen laterally 10 inches and back to the center over the course of 3 seconds, repeating this motion for
up and down eye movements as well.
Once calibration was in place, student A held a piece of blank paper approximately 10 inches in
front of student B, and recorded student B’s eye movement over the course of 60 seconds. Blinks were
counted, and data was recorded under the category of “Baseline”. Next, student A held “The Three
Little Pigs” in front of student B, and recorded eye movements for another 60 seconds, while student B
read. Number of eye-blinks were counted and entered under the “Easy” category. Finally, student A
held Kant’s “Critique of Pure Reason” excerpt in front of student B, and recorded eye movements for a
final 60 seconds. Number of eye-blinks were counted and entered under the “Hard” category. Student
researchers then switched places, to ensure that data was collected for each lab member, and results
were compiled into a chart for statistical analysis through SPSS, based on the total collection of class
data.
Results
On average, the participants blinked -3.1667 times less than their baseline number of blinks
during the easy reading (SD = 10.347), and 2.9167 times more during the hard reading (SD = 14.7923).
Though the adjusted blink rate for the hard reading is larger than the adjusted easy rate, it is not
CONTENT AND EYE BLINKS
6
significantly larger (t (11 ) = -1.703, p = .117).
Discussion
Because participants blinked only slightly less than their baseline during the easy reading, and
only slightly more than their baseline during the hard reading, no strong conclusions regarding
attention can be inferred. While the adjusted blink rate for the hard reading produced stronger results, it
was not by a significant margin, and therefore only slightly supports the hypothesis.
Of note is the fact that data ranged widely based on individual participants—from Baseline to
Easy to Hard—and as such, there is a great degree of variance between individual results. As a result,
the averages used for statistical analysis leave room for additional analysis between participants. For
example, unlike the studies read for context in the introduction, intentional blinks were not measured
against unintentional blinks—all blinks were included in the data. Because participants were also
simultaneously researching, their prior knowledge about the study, along with their awareness of the
ways in which their eye movement was being assessed, could have influenced their blinks in any one of
the categories, ultimately skewing the data. Additionally, some students wore contact lenses during the
study while others didn’t—a factor proven to correlate with blinking, while unrelated to the reading
attentiveness we were measuring for.
While the results of the study were only marginally significant, with consideration given to
potential confounds affecting blinking, meaningful results could, potentially, be discovered in later
iterations of the study. If eye-blinks are, indeed, significantly correlated with reading comprehension,
an understanding of input and comprehension in learning can be furthered, through using eye blinks as
an indicator of attention to material. While the jump to meaningful conclusions appears large, the
potential for insight into learning processes through further study of this phenomenon is a promising
CONTENT AND EYE BLINKS
7
reward.
References
Goldstein, R., Bauer, L. O., & Stern, J. A. (1992). Effect of task difficulty and interstimulus
interval on blink parameters. International Journal of Psychophysiology, 13, 111-117.
Just, M. A., & Carpenter, P. A. (1980). A theory of reading: From eye fixations to
comprehension. Psychological Review, 87(4), 329-354.
Loebech, J, & Thorsheim, H, (2010). Eye Blinks and Eye Movements in Cognition. Unpublished
manuscript, Department of Psychology, St. Olaf College, Northfield, MN. USA.
Orchard, L. N. & Stern, J. A. (1991). Blinks as an index of cognitive activity during reading.
Integrative Physiological and Behavioral Science, 26(2), 108-116.
Rayner, K. (2009). Eye movements and attention in reading, scene perception, and visual search.
Quarterly Journal of Experimental Psychology, 62(8), 1457-1506.