New research suggests that fetuses have memories. The experimentation involved seeing how long it would take fetuses to reacclimate or rehabituate to startling noise. They found that the time it took decreased if the second round of noise occurred within the then discovered 'memory window'. The window lasted 10 minutes for a 30 week old and at least 4 weeks for a 24 week old.
""Habituation is a form of learning and a form of memory," Nijhuis said. He and his colleagues used the habituation tests to examine memory in fetuses 30 to 38 weeks old. They found that 30-week-old fetuses had a "memory" of 10 minutes — if the fetuses received a second round of sound stimulation 10 minutes after the initial test, it took them a lot less time to become habituated to the noise during their second session, and they stopped responding after only a few stimuli, he said.
The researchers also found that 34-week-old fetuses were able to "store information and retrieve it four weeks later," he said. The team came to this conclusion after performing the habituation tests at 34 weeks and then again at 38 weeks. The scientists compared the response of the 38-week-old fetuses who had been tested before with that of fetuses who had not been tested before."