Scientists have long known the brain's hippocampus is crucial for long-term memory. Now a new study has found the hippocampus also plays a role in short-term memory and helps guide decision-making. The findings shed light on how the hippocampus contributes to memory and exploration, potentially leading to therapies that restore hippocampal function, which is impacted in memory-related aging and neurodegenerative diseases such as dementia, the study authors said.