Eye movements reveal temporal expectation deficits in ADHD

September 12, 2017, Association for Psychological Science
Credit: Association for Psychological Science

A technique that measures tiny movements of the eyes may help scientists better understand and perhaps eventually improve assessment of ADHD, according to new research published in Psychological Science.

Emerging evidence shows that small involuntary eye movements (saccades and microsaccades) are a promising new tool for shedding light on the hidden workings of mental processes like attention and anticipation, cognitive processes that are often impaired in individuals with ADHD. The new study suggests that carefully tracking eye movements offers a new method for empirically monitoring temporal expectation in people with ADHD.

"The eye is restless and eye movements occur constantly, even when observers try to avoid them. Our study shows that this continuous stream of eye movements is temporarily paused before an anticipated visual event," says psychologist and neuroscientist Shlomit Yuval-Greenberg (Assistant Professor at Tel Aviv University), senior author on the study. "This attenuation in eye movements can be used as an estimate for whether and when the occurrence of regular events was indeed predicted."

Yuval-Greenberg and colleagues found that neurotypical individuals (those without a diagnosis of ADHD) tended to have different patterns of eye movements compared with individuals who had an ADHD diagnosis.

"We found that individuals with ADHD tended to not attenuate their eye movements before a predictable event, which suggests that they were not able to predict the event and/or to act upon predictions," Yuval-Greenberg explains.

The team's findings indicate that careful analysis of eye movements may offer an objective measure to complement other tools used for diagnosis and assessing treatment efficacy.

For their study, Yuval-Greenberg and colleagues collected data from a group of 20 individuals who had an ADHD diagnosis and a group of 20 neurotypical controls. Those in the ADHD group were asked to refrain from taking any ADHD-related medication for 24 hours prior to the testing sessions.

On two different days, the participants came into the lab where they were shown a series of colored shapes on a screen while their eye movements were monitored. The participants were instructed to press a key whenever they saw a red square (which appeared around 25% of the time). On one day, participants were shown the shapes at predictable intervals: Every two seconds the next shape would appear. On the other day, the time between shapes varied from 1 to 2.5 seconds. Participants were not told that the timing would be different between the two sessions.

When the stimulus appeared at regular, predictable intervals people in the control group responded more quickly than when it appeared at varied intervals. However, the reaction times of those with ADHD did not improve under predictable conditions.

The researchers also found that those in the control group tended to have fewer eye movements immediately before a predicted event. In contrast, those in the ADHD group did not show the same eye slowdown in preparation for an upcoming stimulus.

However, the researchers were surprised to find that an ADHD diagnosis was not the best predictor of an individual's ability to stay focused on the task.

"It is well documented that ADHD is a heterogeneous disorder. It is also documented that only some of the individuals with ADHD experience difficulties in maintaining focused attention throughout a monotonous task," Yuval-Greenberg says. "Yet we were most surprised to reveal that the individual ability to stay focused throughout the task was a better predictor for the attenuation of eye movements than whether or not that individual was diagnosed with ADHD."

This finding is valuable because it demonstrates the importance of assessing the specific neuropsychological functioning of each individual, Yuval-Greenberg explains. And the study highlights the potential use of as an objective measure of temporal expectation.

Explore further: Licensing, motor vehicle crash risk among teens with ADHD

More information: Yarden Dankner et al, Prestimulus Inhibition of Saccades in Adults With and Without Attention-Deficit/Hyperactivity Disorder as an Index of Temporal Expectations, Psychological Science (2017). DOI: 10.1177/0956797617694863

Related Stories

Licensing, motor vehicle crash risk among teens with ADHD

June 12, 2017
Adolescents with attention-deficit/hyperactivity disorder (ADHD) are licensed to drive less often and, when this group is licensed, they have a greater risk of crashing, according to a new study published by JAMA Pediatrics.

Inhibitory motor control problems may be unique identifier in adults with ADHD

November 16, 2016
Young adults diagnosed with ADHD may display subtle physiological signs that could lead to a more precise diagnosis, according to Penn State researchers.

ADHD or just immature?

March 10, 2016
Attention-deficit hyperactivity disorder (ADHD) is typically diagnosed in childhood and manifests as an inability to sustain attention and control activity levels and impulse control. Some reports have indicated a prevalence ...

Involuntary eye movement a foolproof indication for ADHD diagnosis

August 13, 2014
Attention Deficit Hyperactivity Disorder (ADHD) is the most commonly diagnosed – and misdiagnosed – behavioral disorder in children in America, according to the Centers for Disease Control and Prevention. Unfortunately, ...

Gyroscopes can help diagnose ADHD

June 10, 2014
The latest miniaturised movement sensors, incorporating both accelerometers and gyroscopes, can be used to provide an objective diagnosis of attention-deficit/hyperactivity disorder (ADHD), according to new research in the ...

CDC: More than one in 10 kids diagnosed with ADHD

November 26, 2013
(HealthDay)—More than one in 10 children and adolescents are diagnosed with attention-deficit/hyperactivity disorder (ADHD), an increase of 42 percent in less than a decade, according to a study published online Nov. 25 ...

Recommended for you

Global study finds youngest in class more likely to be diagnosed with ADHD

October 15, 2018
A new global study involving the University of Adelaide has found that children who are the youngest in their classroom are more likely to be diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) than their older ...

Much still unclear about relationship between screen media use and ADHD in children

October 5, 2018
There is a statistically small relationship between children's screen media use and ADHD-related behaviours. This is the finding of an extensive literature review on this subject carried out by researchers from the UvA's ...

Brain scans reveal common patterns can predict variations in ADHD

September 24, 2018
Distinct brain patterns can help explain variations in the way children present with attention deficit hyperactivity disorder (ADHD), paving a course towards improved treatment and support for the common neurodevelopmental ...

ADHD may increase risk of Parkinson's disease and similar disorders

September 12, 2018
While about 11 percent of children (4-17 years old) nationwide have been diagnosed with attention-deficit hyperactivity disorder (ADHD), the long-term health effects of having ADHD and of common ADHD medications remains understudied. ...

Over past 20 years, percentage of children with ADHD nearly doubles

September 3, 2018
The number of children diagnosed with attention deficit hyperactivity disorder has reached more than 10 percent, a significant increase during the past 20 years, according to a study released Friday.

ADHD rates rising sharply in US kids

August 31, 2018
(HealthDay)—The number of ADHD diagnoses among children has risen dramatically in the past two decades, going from 6 percent to 10 percent, a new report shows.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.