In an article published in the journal PLOS ONE, the researchers demonstrated that even simple conversation slows down key stages of eye movement, significantly impacting the ability to perceive the environment in a timely manner, especially while driving.
In the experiment involving 30 healthy volunteers, the researchers analyzed eye movements under three different conditions: during conversation, while passively listening to text, and in conditions with no additional load. The results showed that it was indeed conversation, rather than just auditory perception, that increased gaze reaction time, slowed its movement toward the target, and worsened fixation on objects. All these delays occurred at early stages of visual processing.
According to the authors of the study, while each individual delay may seem insignificant, in real-world conditions they can accumulate and lead to late detection of potential hazards, such as pedestrians, obstacles, or traffic signals. This is particularly important as approximately 90% of the information necessary for safe driving is perceived through vision.
The findings confirm that conversations, including hands-free communication, can subtly impair visuomotor mechanisms at the stages of recognition and decision-making. The authors emphasize that the cognitive load arising from conversation may be one of the factors contributing to an increase in errors and accidents in complex situations.
