Final answer:
The duration for the brain to build synaptic gaps for memory retention is not definitively established but is understood to occur over periods of hours to weeks. Ebbinghaus's studies indicated significant memory decay within 20 minutes to 24 hours, suggesting that continued reinforcement is necessary for robust memory retention.
Step-by-step explanation:
The question addresses how long it takes for the brain to build synaptic gaps for memory retention, which relates to the biological processes of memory formation and consolidation within the realm of neuroscience. There is no precise 'one size fits all' time duration for memory retention, as this can vary based on several factors including the complexity of information and individual differences. However, we do know from research like the studies conducted by Hermann Ebbinghaus and more recent work in synaptic plasticity that the process of memory consolidation can occur over periods of hours to weeks, with the initial short-term memory storage lasting 15 to 30 seconds and consolidation into long-term memory potentially taking a few hours to weeks.
According to Ebbinghaus's forgetting curve, an average person loses 50% of memorized information after 20 minutes and about 70% after 24 hours due to storage decay, indicating that the brain's ability to retain new information decays quickly initially and then levels out.
Ultimately, while the duration of exposure to new information that is required for the brain to build the necessary synaptic gaps for retention is not definitively established, repeated exposure, practice, and the use of memory reinforcement strategies like spaced repetition are key factors that help in forming and strengthening the synaptic connections vital for long-term memory retention.