What Memories Are Made Of

Evolutionary Role

Michael Yassa, a neurobiologist, explains that memory's primary evolutionary purpose is to promote future survival. He describes the brain as a "giant prediction machine" that uses past experiences to make better decisions, such as avoiding dangers or seeking out beneficial resources 1. This predictive function of memory is crucial for survival, allowing us to simulate future possibilities based on past experiences.

Memory evolved for one reason and one reason only, and that's to promote our future survival.

--- Michael Yassa

Sanjay Gupta and Michael also discuss the basic building blocks of brain function, such as neurons and synapses, to provide a foundation for understanding how memories are formed and recalled 1.

   

Memory Types

The case of Henry Molaison, known as HM, provides significant insights into the types of memory and their mechanisms. After a surgery that removed his hippocampus, Henry could no longer form new declarative memories but retained the ability to learn motor skills and reflexes 2. This case revealed that different types of memory rely on different brain circuits, with the hippocampus being crucial for declarative memory but not for procedural memory 3.

The hippocampus is important for some types of memory, but not others.

--- Michael Yassa

Henry's condition helped scientists understand the complexity of memory systems and the specific roles of different brain regions in memory formation and retrieval 3.