Four-month-old infants can focus attention strongly enough to temporarily miss a subsequent interesting stimulus, a phenomenon called attentional blink that in adults reflects a serial processing bottleneck for conscious access. Infants viewed a central teddy bear followed by a lateralized face at varying delays. They missed the face at the shortest delay (400 ms), detected it at 800 ms only when it appeared in the left visual field, and required 1,200 ms for detection in the right visual field, indicating hemispheric asymmetry. Trial-by-trial measures showed that deeper engagement with the first target predicted missing the second, supporting the presence of a global workspace in early infancy with slower dynamics.
Consciousness in infants during the first year of life is difficult to study because they cannot report their experiences. Recent behavioral and brain imaging studies show that infants engage in complex learning and have more structured brains than previously thought. By applying global workspace theory, which identifies brain signatures of conscious perception in adults, evidence suggests conscious perception exists in the second half of the first year. Evidence before five months is less solid due to few studies. The question of conscious perception before term remains open, with the possibility of short periods that could facilitate early learning.