How Much Memory Does Your Brain Have?

This article will answer the question of what is the Memory Capacity of the brain. It will also discuss the comparison of the brain with a computer. The article further highlights interesting facts about the brain, and some frequently asked questions about the same.

How Much Memory Does Your Brain Have?

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. 

The human brain is a marvellous organ and has many more capabilities apart from memory. More and more studies are highlighting the brilliance of the human brain, and it is only a matter of time till we discover all of its capabilities. 

There are about 1 billion neurons in the human brain and each of these neurons has 1,000 other connections with other neurons accounting for more than trillions of connections. 

Here’s where it gets interesting, if each neuron could only store a single memory, we would run out of space to store memories and might only have a few GBs of storage. Hence, our brain would store just as much memory as an iPod or a USB drive. 

However,  the human brain’s neurons are smarter than that, and they combine so that each one of the billion neurons can hold many complex memories together. This is what helps the human brain has a storage capacity of 2.5 petabytes, or in simpler terms, a million gigabytes. 

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. 

It is difficult to calculate the precise storage capacity of the human brain. This is in part because scientists are unaware of how to exactly measure the size of memory. Secondly, some memories are more complex and detailed and may take up more space as compared to other simpler memories. Moreover, some information is not remembered by the brain because it doesn’t deem it to be important. 

The human brain can hold as much information as available on the entire Internet in its memory, as has been suggested by newer research. 

The Human Brain Is Incredibly Efficient

Newer findings also suggest that the brain stores information while it is fairly active. It is interesting to note that most neurons in the brain do not fire when responding to the signals incoming to the brain, however, the body is efficient in translating the signals received into physical structures. This suggests that the brain works more effectively than a computer. Most of the brain’s parts doing the heavy lifting aren’t doing much most of the time. 

Even if brain cells are inactive around 80% of the time, it is still difficult to explain why and how a computer needs 50 million times more energy than the human brain in doing the same tasks. 

Types of Memory 

When it comes to understanding different kinds of memories, there has been a heated debate on the classification of memories by experts. One agreed-upon consensus seems to be the acceptance of the existence of three types of memory, while the other types of memories fall under these three categories. 

Another way to classify memories is to think about them in terms of stages and processes. Experts who tend to categorise memory into explicit memory and implicit memory assert that sensory memory, short term memory, and long term memory are stages of memory and not categories or types of memory. 

Sensory Memory 

Sensory memory stores information received by the senses after they have received the stimulation. Experts who believe in stages of memory instead of categorization of memory claim that the formation of all memories begins with the information being stored in sensory memory. 

Sensory memory is very brief, holding information only for a few seconds. Recalling the sensation of touch, or a sound you heard while walking is an example of sensory memory. 

When a sensation is continuously recurring, you begin to expand on it by attaching other memories to it. This is when the sensory memory is transformed into your short-term memory. More rehearsal can shift it to your long-term memory. 

The types of sensory memory are:

  • Iconic memory: Iconic memory obtains information through sight. It lasts for just 1 second. 
  • Echoic memory: Echoic memory deals with information that is auditory in nature and lasts for about 1 to 2 seconds.
  • Haptic: Haptic memory deals with memories for touch sensations, and lasts for approximately 2 seconds long.

Short-term Memory 

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.

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.

Long-term Memory

Majority if our knowledge is stored in the 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. 

Explicit Long-term Memory 

The memories that we consciously store and take time to memorise and form are known as explicit memories. This can include remembering your phone number, your friend’s birthday, childhood events, academic information, etc. 

There are two types of explicit memory:

  • Episodic Memory, contains information about your life events, for example, when you received your first A grade in school.
  • Semantic Memory holds information about general knowledge and facts that you have acquired over the years. 

Implicit Long-term Memory 

Explicit memories are not the only memories that we form and use. Implicit memories are formed without any conscious awareness. It also tends to influence how we behave and think. 

Implicit memories involve the learning of motor skills like walking, riding a bike, or writing. Thus, even if you ride a bike after 10 years, you will still remember it with the help of implicit memory.

Conclusion 

The article covered information on how much memory is stored by the human brain. It also covered details about the types of memories that have been classified by experts. 

Frequently Asked Questions: What is the Memory Capacity of a Human Brain?

What is affected by Alzheimer’s disease?

Explicit memories are hugely affected by Alzheimer’s disease. 

What are the three basic functions of memory?

The three basic functions of memory include encoding, storing, and retrieving information. 

Can your brain get full?

No. This is because the human brain is very sophisticated. In order to make space for new information, old information is pushed out of the system instead of just cramming and crowding information in.

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.

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.

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