Visual change-related brain potentials elicited by changes in doll hair color in school-aged children.

Change-related brain responses are specifically elicited when the regularity of a continuous sensory stimulus is disrupted and are recorded by electroencephalography or magnetoencephalography. These responses are one of the higher brain functions representing memory-based comparison processes between the current and previous sensory states. The present study aimed to record change-related visual evoked potentials in children aged 6-10 years. Pictures of a doll were presented for 1.5 s, and participants were given the task of quickly pressing a button when glasses appeared on the doll, which occurred in 5% of trials. In the remaining 95% of trials, one third used pictures with no change, while the others used a similar picture but with a hair color change, from rose to yellow or from brown to pink, 1000 ms after the stimulus onset. The results obtained showed that in all 37 children tested, the abrupt change in hair color elicited clear biphasic responses consisting of occipital positivity at approximately 130 ms (P130) followed by negativity at 250 ms. The P130 latency decreased linearly up to 92 months of age and remained stable thereafter, suggesting that this method may serve as an objective tool for assessing brain development in children. In addition, it could potentially be used to evaluate whether and how specific toys influence neural processing at different developmental stages.