Fill in the blanks to complete the passage about infantile amnesia.
Unlike amnesia in adults, infantile amnesia is not a disorder but a normal condition: It is one's inability to recall events that occurred before the age of about ... years. Some researchers explain this phenomenon as a consequence of the toddler brain's immature ..., while others see a connection to the pace of ... development. A third camp holds that young children do not yet ... enough to encode sensory information effectively.