People blink less frequently when perceiving important information

New research has shown: the more difficult it is for a person to understand speech in noise, the less frequently they blink - and this effect does not depend on lighting.

As reported by TUT.AZ with reference to data from the research group, two experiments were conducted as part of the work, demonstrating that the decrease in blink frequency is directly related to increased mental efforts when perceiving speech in challenging conditions.

Almost 50 adult volunteers participated in this fascinating study. The subjects were in a special soundproof room where they were asked to fix their gaze on a cross located on the screen while simultaneously listening to short sentences through headphones. The researchers artificially created various acoustic conditions - from almost perfect silence to extremely noisy environments that significantly hindered speech comprehension.

Scientists recorded a surprising phenomenon: during the listening of sentences, participants blinked significantly less frequently compared to periods before and after the experiment. A particularly dramatic decrease in blink frequency was observed in the most unfavorable noise conditions, when the subjects' brains were working at the limit of their capabilities, trying to decipher speech signals.

Similar results were obtained when varying the signal-to-noise ratio, as well as in conditions of different illumination - from dim to bright light. Particularly noteworthy is that the blinking pattern remained stable regardless of lighting conditions, which convincingly proves that the observed effect is directly related to cognitive load, not to the physical parameters of light affecting the eyes.