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Professor Studies How Athletes 'Sandbag' Concussion Tests

CC Psychology Professor Kristi Erdal has identified ways in which some athletes might cheat on a widely used test to assess concussions.

In a study published recently in the Archives of Clinical Neuropsychology, Erdal, a neuropsychologist, gave the well-known ImPACT test to 75 Colorado College men and women athletes and asked them to try to perform poorly. Eight participants, for a total of 11 percent, managed to score lower than they should have, successfully maneuvering past the test's built-in validity indicators.

They "sandbagged" the test. Ordinarily given at the beginning of a season, the test establishes a baseline for comparison if an athlete is injured. Athletes may sandbag the test so that if they are injured, their injuries will not show up because they had already performed poorly on the baseline test.

For example, National Football League quarterback Peyton Manning told an interviewer last year that he intentionally performed poorly on NFL baseline concussion tests "in order to not be benched after being injured," Erdal wrote in her study.

Erdal's study was the first to focus on how someone might try to beat the test. Other studies have estimated the amount of invalid baseline tests to range from 6 to 11 percent of test-takers. Erdal found that successful sandbaggers are those who cheat just enough that their scores dip, but not dramatically.

"Subtlety wins the day," said Erdal, who noted that the students who managed to beat the test did so by performing somewhat poorly on parts of the test, but not enough to raise "red flags," or validity indicators, that are built into the test.

Erdal, who has been at Colorado College for 17 years, began early on to think about the question of how concussion testing affected athletes. In the mid-90s, when she was still a graduate student, she worked on an influential study that found that prolonged symptoms from concussions were likely motivated by the possibility of secondary gain (such as compensation), notably in accidents and insurance cases. "This was one of those papers that got people thinking," she said.

Her study of how someone could successfully do the opposite - lower a baseline score so that a concussion wouldn't show up in a later test - has begun a discussion among neuropsychologists in the field. She is hoping that others will try to replicate the study.

The students who took part in the study were athletes who had completed their sports careers at CC and were not planning to continue professionally. "We didn't want to give them the ability to cheat," Erdal said. "And, we didn't want to interfere, to set up a situation where a person had more practice in this than they should have."

Erdal also found no difference in sandbagging ability between males and females, what sport they played, or whether they had had a concussion in the past. The 33 men and 42 women in the study played a variety of sports, including lacrosse, soccer, football, swimming/diving, tennis, water polo, and volleyball.

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Report an issue - Last updated: 12/16/2020