This article answers the question of how many years of memory the human brain can hold. The article will also highlight basic and interesting facts about human memory, as well as answer some frequently asked questions about the human brain and memory in the end.

How Many Years of Memory Can the Brain Hold?

In essence, we can hold about 300 years of memory in our brain. Hence, virtually there is no limit to the amount of information we can store and remember. It does sound strange when considering that we forget a lot of information on a daily basis, however, it is true that our storage capacity for learning is essentially limitless.

The human brain’s capacity for memory is equivalent to trillions of bytes of information. A study at Stanford found that our cerebral cortex alone has the space to hold 125 trillion synapses. Another study found that one synapse in the human brain can hold up to 4.7 bits of information.

Neurons are brain cells that make up the brain. Neurons are responsible for transmitting messages that they carry to the brain from the body and vice versa. Synapses bridge the gap between the neurons in the brain and help them carry the messages to be transmitted.

Hence, if there are 125 trillion synapses in the human brain, and one synapse can carry an average of 4.7 bits of information, then we can say that the human brain’s memory capacity equals 1 trillion bytes or 1 TB.

If we compare our brain to the television, this would be equivalent to holding 3 million hours’ worth of TV shows. Moreover, we’d have to let the TV run continuously for over 300 years to run out of 2.5 petabytes worth of storage.

However, when it comes to short-term memory, we can remember only a few things.

Short-term memory lasts for brief periods of time. It is not as short as sensory memory, but it is not as permanent as long-term memory either. Another name for short-term me, or is primary or active memory.

According to Miller (1956), adults can hold upto 5 to 9 items in their short-term memory. It is usually believed that the short-term capacity of humans is around 7 plus or minus 2 items.

Short-term memory can last from about 20 to 30 seconds or less according to the Information-Processing Model of Memory put forth by Atkinson and Shiffrin (1968). This model is also known as the Multi-Store Memory Model.

These limits on our short-term memory help in explaining why cramming a lot of information just a few days before an exam can result in you forgetting everything you’ve learned. This is because there has been no rehearsal of the information on your part.

Memories from short-term memory can be transformed into long-term memories by rehearsal. This means simply repeating the information to yourself several times.

Another way to move information into the long-term is by elaborating the information and making it personally meaningful by entailing deeper processing of the information in question.

Working memory is considered to be the fourth distinct kind of memory by some experts, while others are of the view that working memory and short-term memory can be used interchangeably.

The majority of our knowledge is stored in long-term memory. Generally, any information that can be recollected after 30 seconds is considered to be a long-term memory.

There is no limit on how much information can be stored in the long-term memory and how long it will remain there. Long-term Memory can be of two types: explicit and implicit long-term memory.

Learning New Information Leads to Physical Changes in Your Brain Structures

An interesting finding suggests that when we learn new skills such as a musical instrument or a new language, it creates physical changes in our brain. This is because these activities are similar to exercising for our brain.

These findings have been suggested through studies that have used Magnetic Resonance Imaging (MRI), where scientists are enabled to visualise these changes by comparing visuals before and after learning takes place.

This means that, when we learn new skills, it does not just lead to increased blood flow in special brain areas, but also structural changes in the white and grey matter, changes considered to be long-lasting!

False Memories

We can sometimes remember events that did not take place. False memory is a concept that was studied by Loftus, who found that participants tended to falsely report events that did not take place in the first place.

Loftus and Palmer (1974) presented participants with videos of traffic accidents of various time ranges in random order. Participants were first asked to give their own account of the incident and were then interrogated with a critical question that enquired about the speed of the vehicles that collided.

Speed of the vehicle had marked variations in the phrasing of the questions, that is, the use of verbs like smashed, bumped, collided and contacted in the questions influenced the report of the event they originally witnessed.

Loftus and Palmer in this study gave two interpretations of these findings suggesting that participants either faced “Responder Bias” – that is they altered their responses to be in line with the question however, their perception was not distorted – or they experienced alteration of memory altogether.

To determine that the participant’s memory demonstration of the events was in fact altered to the degree their perception of the event changed, Loftus and Palmer followed up with another experiment and enquired about a detail – broken glass when the cars collided – that was not visible in the original video.

Participants reported the presence of broken glass on higher than chance levels thus providing evidence that post-event information can not only distort memory but also induce false memories in humans. (Loftus & Palmer, 1974)

Evidence that post-event information can induce high levels of false memory, however, has also been reported in cases where experimental participants were asked to summarise specific details of an event rather than the entire event.

Small details of the event are highly susceptible to misleading post-event information such that the participants were more likely to misattribute such suggested items to originally presented videos. (Lane et al., 2001)

Relationship Between Testing and Memory

One way to improve your memory is by testing it. You can try self-testing, and it will do wonders for your memory, more than re-reading the same content.

Even low-stakes testing can be extremely beneficial for learning, as suggested by research. The reason why testing works best in improving your memory is that it makes you confront if there are any gaps in your knowledge. It forces the brain to work harder in retrieving information and thus strengthens neural connections. These strengthened neural connections are easier to access in the future. Thus, the brain acts as a muscle that becomes stronger with exercising.

The benefits of testing yourself for better learning are that retrieval from scratch strengthens later retention. This is also called “the testing effect”. Testing also helps us identify gaps in our knowledge and helps us transfer our pre-existing knowledge to newer contexts. It helps us in organising our knowledge better. It improves our meta-cognitive abilities and prevents interference of old material into the learning of newer material. It also helps in encouraging us to study further.

Conclusion

This article answered the question of how many years of memory the human brain can hold. The article also highlighted basic and interesting facts about human memory, as well as answered some frequently asked questions about the human brain and memory.

Frequently Asked Questions: How Many Years of Memory Can the Brain Hold?

How much of our life do we end up remembering?

It has been estimated that we only end up remembering less than .001% of our lives. However, research has yet to demonstrate it.

Do we forget what we read?

The forgetting curve shows us that we forget 60% of what we read in about 2 hours of reading it. The curve also shows that information is lost over time when we don’t rehearse it.

Why can’t I remember my childhood at all?

It is common to not remember the first several years of your life. This is known as infantile amnesia. This is because the hippocampus, which is responsible for the formation and storage of memory, is underdeveloped in the early years of life.

At what age is the brain the sharpest?

Your brain is the sharpest at the age of 18.

References

Atkinson, R. C., & Shiffrin, R. M. (1968). Chapter: Human memory: A proposed system and its control processes. In Spence, K. W., & Spence, J. T. The psychology of learning and motivation (Volume 2). New York: Academic Press. pp. 89–195.

Lane, S. M., Mather, M., Villa, D., & Morita, S. K. (2001, November). How events are reviewed matters: Effects of varied focus on eyewitness suggestibility. Memory & Cognition, 29(7), 940-7. doi: 10.3758/BF03195756

Loftus, E. F., & Palmer, J. C. (1974). Reconstruction of Automobile Destruction : An Example of the Interaction Between Language and Memory’. JOURNAL OF VERBAL LEARNING AND VERBAL BEHAVIOR, 13, 585-589.

Miller, G. A. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological review, 63(2), 81.