Hemodynamic responses to visual stimulation in occipital and frontal cortex of newborn infants: a near-infrared optical topography study.

A near-infrared optical topography (OT) was used to reveal spatio-temporal changes in the cerebral oxygenation of newborn infants in response to brief visual stimulation. Newborn infants were presented 3-s stroboscopic light flashing at 14 Hz during spontaneous sleep. Event-related changes in oxy- and deoxyhemoglobin ([oxy-Hb] and [deoxy-Hb]) were observed over the occipital and frontal cortex. The visual stimulus produced statistically significant increases in oxyhemoglobin not only in the occipital cortex but also in the prefrontal cortex. These results suggest that the cerebrovascular coupling is already functioning in newborn's brain. The prefrontal activation implies that it may contribute to early processing of sensory signals.