Elaborazione della magnitudine nell’illusione di Delboeuf classica e numerica

Understanding the cognitive processes and neural mechanisms involved in perceiving and processing quantities is crucial for uncovering the intricacies of human cognition. The debate over the existence of a single magnitude system, which includes non-symbolic number estimation and other magnitudes like time and space, persists due to limited definitive evidence. Recent research has explored whether biases influencing spatial decisions also impact numerosity judgments using visual illusions such as the Delboeuf illusion. Current findings support the notion of a generalized magnitude system, yet studies that directly compare the perception of the Delboeuf illusion with its numerical counterpart are lacking. This study aims to investigate the potential existence of a generalized magnitude system by examining if the same perceptual bias similarly affects different magnitude processing. Moreover, participants underwent three transcranial alternating current stimulation (tACS) at different frequencies (7 Hz, 18 Hz, and placebo) to determine whether these stimulations influence quantity processing in both the classic Delboeuf illusion and its numerical counterpart. Based on previous research, we hypothesize that theta-frequency tACS will enhance visual integration, thereby strengthening the illusion, while beta-frequency tACS will reduce illusion strength by promoting visual segregation.