July 20, 2009

Memories Inside the Womb

Babies begin learning even before they are born. Scientists in the Netherlands have now demonstrated short-term memory in fetuses at 30 weeks. The study, conducted by researchers at Maastricht University Medical Centre and the University Medical Centre St. Radboud, provides insights into fetal development that may help address and prevent abnormalities.

Using ultrasound technology, researchers studied 100 healthy pregnant Dutch women and their fetuses, measuring changes in how a fetus responded to repeated stimulation. After receiving a stimulus a number of times, the fetus stopped responding to the stimulus, indicating that the stimulus was accepted as "safe." This change in response is called "habituation." In a second session, the fetus "remembered" the stimulus and the number of repetitions needed for the fetus to habituate to other stimuli diminished.

The researchers found fetal short-term memory of 10 minutes at 30 weeks, based on the significantly lower number of stimuli needed to reach habituation in a second session conducted 10 minutes after the first. They also found that 34-week-old fetuses can store information and retrieve it four weeks later. Fetuses were tested at 30, 32, 34, and 36 weeks, and again at 38 weeks. The 34- and 36-week-old fetuses in the study habituated much faster than the 38-week-old fetuses that had not been tested before.

The study's authors were quoted as saying, "A better understanding of the normal development of the fetal central nervous system will lead to more insight into abnormalities, allowing prevention or extra care in the first years of life and, as a consequence, fewer problems in later life."

SOURCE: Child Development, July/August 2009