Cognitive Functions of the Fetus.

The human brain is intricately designed to execute cognitive functions, such as perception, attention, action, memory and learning. The complete nervous system is active during prenatal development and the aim of this review is to present data on fetal cognitive functions. The fetus processes sensory stimuli at a cortical level, including painful stimulus, from about 25 weeks of gestation onwards. At gestational week 34, the fetus is able not only to perceive complex acoustic external sounds but also to discriminate between different sounds. Fetal action planning is established by 22 weeks and investigations using four-dimensional ultrasound reveal that complexity of fetal motor action and behavior increases as pregnancy progresses. The capacity of the fetus to learn and memory are prodigious. At term, subcortical structures of the brain are well developed. There is high activity in primary cortical areas and low activity in association areas. Clinically relevant data on cognitive functions of the fetus could be important for the management of fetal pain and treatment of preterm infants as well as for improved neurodevelopmental outcome of fetuses from high-risk pregnancies. Finally, the brain's developmental journey, including development of cognitive functions, continues with the same intensity in the postnatal period.