• Habituation and novelty-driven visual attention emerge in infancy: fixation decreases for familiar patterns while novel ones attract longer looking times, signaling early perceptual learning across months [4], [15], [14], [10], [10], [19], [1].

• Face processing shows differential responses to familiar and distorted faces, with longer looking at regular representations and accompanying affective/physiological responses, indicating early face encoding and evaluation [3], [8].

• Memory and object-concept development are traced through longitudinal observations and infant memory studies, linking retention and anticipation to early cognitive structuring [5], [9].

• State and physiology modulate infant perception: heart-rate patterns, orienting, and neural maturation vary with stimulus properties and the infant's arousal/state, shaping processing strategies [16], [17], [20], [13].

• Social contingency and environmental stimulation drive perceptual-cognitive development: maternal interaction patterns and contingencies influence expectancy formation and information processing [7], [18], [13].