The Role of Sleep on Object Recognition and Object Categorization in 4.5-Month-Old Infants

Sleep is important for learning, specifically for infant learning. However, there is minimal work examining the effects of sleep on specific areas of infant learning, such as object-category formation. Object-category formation is the ability to form categories of distinct objects. For instance, animals are categorically distinct from cars, as are books from computers. Previous studies have tested categorization by familiarizing infants with an object and then testing infants under one of two conditions: either the infants would view two distinct objects move together (the move-together event) or move apart (the move-apart event) after being initially adjoined. These tests are conducted either immediately following familiarization or 72 hours following familiarization. Results from these studies demonstrate that infants form an object category if tested immediately but not if tested 72 hours following familiarization. However, these studies do not examine the effects of sleep on category formation in 4.5-month-old infants. As a result, the inability to categorize 72 hours following familiarization may result from no sleep following familiarization. Therefore, this study investigates whether infants form object categories when sleep does or does not immediately follow familiarization. If sleep is crucial for object category formation, infants will look longer at the move-together condition, suggesting infants view the display as having two distinct objects. However, if sleep is not crucial for this ability, infants will look for an equal amount of time at the move-together and move-apart test events. This study will indicate the importance of sleep on learning, particularly during early infancy.