Final answer:
An engram is the physical trace of memory, represented by a group of neurons in the brain. Contrary to mnemonic devices used for aiding in memory, engrams are the biological result of encoding information.
Step-by-step explanation:
An engram is the physical trace of memory. It is not a memory storage unit in the brain per se, but rather a group of neurons that serve as the physical representation of memory. Beginning with pioneering work by Karl Lashley, psychologists have sought to understand how memories are encoded and stored in the brain. Lashley suggested that memories are not stored in a single location but are distributed throughout the entire brain. Modern research has revealed the importance of brain areas like the cerebellum, hippocampus, and amygdala in memory storage and processing.
Mnemonic devices, on the other hand, are tools used to aid memory, often by organizing information into a form that is easier to remember. They are not the same as engrams, which are the result of the brain's biological encoding of information. A mnemonic like HOMES to remember the Great Lakes or 'Please Excuse My Dear Aunt Sally' for the order of mathematical operations are methods used to help encode and recall information, but the actual engrams are the neural connections formed in the brain.