Table 1:

Memory functions across human nervous system, computers, and cells.

Privilege	Nervous System	Computers	Cells
Input	Sensory input	Device input (keyboard, mouse, sensors)	Protein factors, Environmental conditions, Reproduction
Read (access, view)	Short-term memory (hippocampus)	Read-only memory (ROM), Cache, RAM. and Hard Drive	DNA, chromatin, mRNA, Post-translational modifications (PTMs), epigenetic marks
Write (store, modify)	Long-term memory, neuroplasticity, synaptic changes	External Memory (Hard Drive), Cache, RAM, Hard Drive	DNA, mRNA, proteins, PTMs, epigenetic marks
Execute (move, duplicate, move, copy)	Memory consolidation synaptic plasticity, gene expression	Processor, Cache, RAM	Signaling pathways / trafficking, replication, transcription, translation
Erase (delete)	Short term memory loss, forgetting	Deletion from Hard Drive, RAM clearance	Apoptosis, PTMs, epigenetic modifications

The Input function receives information from an external source. Humans receive sensory input by sight, hearing, smell, taste, and touch. Computers receive information from devices like keyboards and sensors. Cells take inputs from external primary messengers or environmental conditions. In all cases, the inputs are transmitted and written to a memory storage location.

The Read function, also called access or view, accesses stored information without modifying it. In the nervous system, this occurs first in sensory nerves, then in the hippocampus (short-term memory), and later from brain regions (long-term memory). In computers, information is read from input devices or storage locations, and written to Cache, RAM, and hard drives. In cells, genetic information is read from DNA and written by transcription and replication. Other forms of cellular memory have specialized reading, moving, executing, and writing collectively called cell processes.

The Write function, also somewhat synonymous with store or modify, reads existing memories as an input, and writes the information to a new location (stores) or overwrites information at an existing location (modify). In humans, sensory or environmental input are transmitted and stored in the hippocampus which is a read-write function, similar to computer RAM. This is considered short-term memory. Long-term storage involves synaptic plasticity and gene expression in other brain regions. Computers write data to RAM before committing it to external storage. In cells, inputs are written in many different biochemical ways. The cell has evolved multiple mechanisms for short-term storage such as chemical concentration gradients, capacitance, protein localization, post-translational modifications to proteins, covalent and structural modifications of chromatin (epigenetic), and gene expression. Longer term storage is in the form of DNA.

The Execute function reads stored information, processes it, and writes the output to a location. In computers, the processor loads instructions from RAM and carries them out. In the nervous system, short term memories stored in the Hippocampus are executed directly, or are processed and consolidated, writing them to other brains regions for long term memory. Cells are much more heterogeneous in how memory is processed. Cells execute many processes such as DNA replication, transcription, translation, or many others.

The Erase function, also called delete, removes information stored at a specific location. In the nervous systems, short-term memory in the hippocampus is purged upon consolidation to select for more persistent, longer-term memories in other brain regions. Likewise, in computer systems, short-term memory in RAM, or Cache in computers are often purged and select data is stored in hard drives, but unlike brains, can be selectively deleted. Cells routinely degrade mRNA, modify chromatin, or degrade proteins. Long-term memory in the form of DNA is generally not erased, similar to the nervous system.