Task Evoked EEG reveals neural processing differences in Aphantasia

Aphantasia is characterized by a diminished or absent capacity for visual imagery, affecting an estimated 3–4% of the population. While functional MRI research has linked visual imagery to regions such as the hippocampus and occipital lobes, it reveals little about the temporal dynamics underlying this phenomenon. Electroencephalography (EEG), with its millisecond resolution, is well-suited for capturing such activity but has only been applied to aphantasia in two case studies, leaving a critical gap in our understanding. We conducted the first group EEG study comparing individuals with aphantasia (n = 62) to controls (n = 59) during rest and tasks probing attention and working memory. Aphantasic participants showed reduced P300 signals—an neural response linked to attention and memory updating—during a visual oddball task, suggesting decreased attentional engagement and impaired episodic memory updating. Lower frontal delta power during a high-load n-back task further suggested reduced reliance on internal imagery and a decreased need to suppress external distractions. Despite these neural differences, behavioral performance remained comparable, indicating possible compensatory strategies. Our findings provide the first electrophysiological evidence that individuals with aphantasia exhibit distinct neural signatures during cognitive tasks, contributing to a growing body of work that redefines how the absence of visual imagery shapes cognition and perception.