A comparison with age-matched control groups revealed that after both delays, only infants who had napped after learning remembered the target actions at the test.Additionally, after the 24-h delay, memory performance of infants in the nap condition was significantly higher than that of infants in the no-nap condition.

This is most likely an age-inappropriate schedule for a 4 month old, as I learned the hard way. What is quite likely happening right now is that your child is not awake long enough to get tired enough to make it through the sleep cycle transition.

In turn your child has a short nap and is overtired from not getting the full benefit of a longer nap, so your child exhibits drowsy signs earlier than a child who is well-rested. Since your child sleeps an age-appropriate long stretch at night your child is probably capable of more time awake during the day.

Alger, a postdoctoral research fellow with a doctorate in Cognitive Neuroscience.

She is currently conducting research in the Sleep, Stress, and Memory Lab at the University of Notre Dame. Napping might carry the stigma of laziness, but what many don’t realize is that your brain is hard at work during your siesta. Napping promotes inter-session habituation to emotional stimuli.

The potential benefits of infant sleep for memory processing are largely unexplored.

Here we show evidence that having an extended nap (≥30 min) within 4 h of learning helps 6- and 12-month-old infants to retain their memories for new behaviors across a 4- and 24-h delay.This is the first experimental evidence to our knowledge for an enhancing role of sleep in the consolidation of declarative memories in the first year of life.At a time in life when growth and development occur at an unparalleled rate, human infants spend the majority of their time asleep.My daughter is 4 1/2 months old and she only naps for 30-45 minutes at a time. She is only awake 1.5 hours before she begins showing sleep signs.She wakes up happy, but she is tired again after a little over an hour. But there have been times where she will sleep two hours or longer if I'm holding her (which I have stopped doing altogether for her naps). Your child is waking up after reaching the light sleep portion of a sleep cycle.However, very little is known about the role of sleep in early memory processing.