• Neurophysiological signals (electroencephalogram [EEG] and related brain potentials) became central for linking neural activity with cognition, development, trauma, and disease across species, via recording, interpretation, and clinical EEG assessments [5], [7], [11], [12], [17], [18], [20].

• Cortical mapping and cytoarchitecture informed functional localization through electrical stimulation, cytoarchitectural studies, and cross-species cortex analysis (prefrontal macaque, human cortex, cebus monkey) [3], [4], [6], [8], [19].

• Lesion and brain-removal studies reveal causal roles of specific regions in intelligence and behavior, including frontal and temporal lobes and post-removal outcomes, across case reports and post-traumatic analyses [2], [9], [14], [15], [16].

• Developmental trajectories of brain electrical activity from infancy through childhood underpin cognitive development, with ontogenetic electrical potentials and cross-age comparisons [11], [12], [13], [18].