<p>There is still much that is not completely understood about the process of memory and forgetfulness, and the following is what I have been able to find out.</p>
<p>It is understoood that physiologically, the establishment of long-term memory involves a process of physical changes in the structure of neurons (or nerve cells) and their synapses in the brain, through a process known as long-term potentiation (LTP). (<a href="http://www.human-memory.net/types_long.html" rel="nofollow noreferrer">Mastin, 2018</a>; <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/long-term-potentiation" rel="nofollow noreferrer">Science Direct, 2018a</a>).</p>
<p>Short-term memory can become long-term memory through the process of consolidation, involving rehearsal and meaningful association (strengthening the physical structure of neurons and their synapses). Unlike short-term memory (which relies mostly on an acoustic, and to a lesser extent a visual, code for storing information), long-term memory encodes information for storage semantically (i.e. based on meaning and association).</p>
<p>The opposite to LTP is long-term depression (LTD) (<a href="https://doi.org/10.1016/B978-0-12-800900-0.00003-8" rel="nofollow noreferrer">Dharani, 2015</a>), whereby the neuronal and synaptic structures are weakened, and forgetfulness develops, after a certain triggering activity. (<a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/long-term-depression" rel="nofollow noreferrer">Science Direct, 2018b</a>).</p>
<p>There are several forms of LTP and LTD classified by their mechanisms and their mode of induction (<a href="https://doi.org/10.1016/B978-0-12-397032-9.00018-2" rel="nofollow noreferrer">Hammond, et al. 2015</a>), and LTD can be temporary or permanent.</p>
<blockquote>
<p>LTD synergistically functions with long-term potentiation (LTP) to generate a balanced, stable memory mechanism. Although LTP plays a major role in the associative type of learning that occurs in the hippocampus and neocortex, LTD is a major player in the error-driven learning that occurs in the cerebellar cortex. Recent studies have revealed complex signal transduction processes underlying LTD. In the long run, LTD may lead to a loss of synapses, or to preservation as silent synapses that have recently been found to prevail in the cerebellar cortex (<a href="https://doi.org/10.1016/B978-008045046-9.00807-X" rel="nofollow noreferrer">Ito, 2009</a>).</p>
</blockquote>
<p>To answer your question</p>
<blockquote>
<p>is it possible to purposefully and permanently forget a specific memory</p>
</blockquote>
<p>It seems possible, and <a href="https://doi.org/10.1016/B978-0-12-397032-9.00018-2" rel="nofollow noreferrer">Hammond, et al. (2015)</a> discusses induction of LTD, however induction of LTD to forget a specific memory would be impossible at this present time that I can find.</p>
<h2>References</h2>
<p>Dharani, K. (2015). Chapter 3 - Memory. <em>The Biology of Thought: A Neuronal Mechanism in the Generation of Thought–A New Molecular Model</em> p.53-74. doi: <a href="https://doi.org/10.1016/B978-0-12-800900-0.00003-8" rel="nofollow noreferrer">10.1016/B978-0-12-800900-0.00003-8</a></p>
<p>Hammond, C., Goaillard, J-M., Debanne, D. &amp; Gaiarsa, J-L. (2015). Chapter 18 - Synaptic Plasticity. <em>Cellular and Molecular Neurophysiology (Fourth edition)</em> p361-389. doi: <a href="https://doi.org/10.1016/B978-0-12-397032-9.00018-2" rel="nofollow noreferrer">10.1016/B978-0-12-397032-9.00018-2</a></p>
<p>Ito, M. (2009). Long-Term Depression: Cerebellum. <em>Encyclopedia of Neuroscience</em>, p533-539. doi: <a href="https://doi.org/10.1016/B978-008045046-9.00807-X" rel="nofollow noreferrer">10.1016/B978-008045046-9.00807-X</a></p>
<p>Mastin, L. (2018). <em>Long-Term Memory</em> [Online]<br>Retreived from: <a href="http://www.human-memory.net/types_long.html" rel="nofollow noreferrer">http://www.human-memory.net/types_long.html</a></p>
<p>Science Direct (2018a). <em>Long Term Potentiation</em> [Online]<br>Retreived from: <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/long-term-potentiation" rel="nofollow noreferrer">https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/long-term-potentiation</a></p>
<p>Science Direct (2018b). <em>Long Term Depression</em> [Online]<br>Retreived from: <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/long-term-depression" rel="nofollow noreferrer">https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/long-term-depression</a></p>

CC BY-SA 4.0
2018-12-18T13:31:56.397Z
LTP/D and the ultimate way in which memories are long-term stored are processes that are quite far apart. LTP is mainly studied in the hippocampus (short term memory) whereas the cortex holds the long-term memories. The latter relies on complex retrieval systems
AliceD
CC BY-SA 4.0
2018-12-18T14:03:39.487Z
@AliceD - From what I understand, whilst the hippocampus and cerebellum handle the processes of LTP/D, leading to a *"balanced, stable memory mechanism"* (Ito, 2009) both sort-term memory and long-term memory are held in the cortex. Dharani (2015) referenced in my answer also pointed out through recent research that LTD was found in other areas of cortex involved in memory and learning. Am I confused?
Chris Rogers
CC BY-SA 4.0
2018-12-18T16:42:21.517Z
No you're not confused, I meant to say the LTP/D research has focused on the hippocampus as the process is relatively simple there. In the cortex things are much more complicated.
AliceD
CC BY-SA 4.0
2018-12-18T12:58:07.237Z
2018-12-18T13:28:23.120Z
2020-06-17T09:55:31.633Z
Chris Rogers
<p>If cognitive memory is compared to computer memory, then is it possible to purposefully and permanently forget a specific memory, using known technologies and methodologies?</p>

CC BY-SA 4.0
2018-12-17T18:06:24.117Z
Related: [The computer model of the brain](https://psychology.stackexchange.com/q/19983/7001); possible duplicate of: [Is it possible to erase problematic memories?](https://psychology.stackexchange.com/q/10079/7001)
Arnon Weinberg
<neuroscience><learning><memory>
Is is possible to "delete" a memory permanently?
John Doe
# Is is possible to "delete" a memory permanently?

(Asked by: username_0 on 2018-12-17)

If cognitive memory is compared to computer memory, then is it possible to purposefully and permanently forget a specific memory, using known technologies and methodologies?

**Tags:** neuroscience, learning, memory

> **Comments:**
> **username_1**: Related: [The computer model of the brain](https://psychology.stackexchange.com/q/19983/7001); possible duplicate of: [Is it possible to erase problematic memories?](https://psychology.stackexchange.com/q/10079/7001)  

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## 1 answers

### Answer by username_2 on 2018-12-18. Score: 2 | Accepted answer

There is still much that is not completely understood about the process of memory and forgetfulness, and the following is what I have been able to find out.

It is understoood that physiologically, the establishment of long-term memory involves a process of physical changes in the structure of neurons (or nerve cells) and their synapses in the brain, through a process known as long-term potentiation (LTP). ([Mastin, 2018](http://www.human-memory.net/types_long.html); [Science Direct, 2018a](https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/long-term-potentiation)).

Short-term memory can become long-term memory through the process of consolidation, involving rehearsal and meaningful association (strengthening the physical structure of neurons and their synapses). Unlike short-term memory (which relies mostly on an acoustic, and to a lesser extent a visual, code for storing information), long-term memory encodes information for storage semantically (i.e. based on meaning and association).

The opposite to LTP is long-term depression (LTD) ([Dharani, 2015](https://doi.org/10.1016/B978-0-12-800900-0.00003-8)), whereby the neuronal and synaptic structures are weakened, and forgetfulness develops, after a certain triggering activity. ([Science Direct, 2018b](https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/long-term-depression)).

There are several forms of LTP and LTD classified by their mechanisms and their mode of induction ([Hammond, et al. 2015](https://doi.org/10.1016/B978-0-12-397032-9.00018-2)), and LTD can be temporary or permanent.

> LTD synergistically functions with long-term potentiation (LTP) to generate a balanced, stable memory mechanism. Although LTP plays a major role in the associative type of learning that occurs in the hippocampus and neocortex, LTD is a major player in the error-driven learning that occurs in the cerebellar cortex. Recent studies have revealed complex signal transduction processes underlying LTD. In the long run, LTD may lead to a loss of synapses, or to preservation as silent synapses that have recently been found to prevail in the cerebellar cortex ([Ito, 2009](https://doi.org/10.1016/B978-008045046-9.00807-X)).

To answer your question

> is it possible to purposefully and permanently forget a specific memory

It seems possible, and [Hammond, et al. (2015)](https://doi.org/10.1016/B978-0-12-397032-9.00018-2) discusses induction of LTD, however induction of LTD to forget a specific memory would be impossible at this present time that I can find.

## References

Dharani, K. (2015). Chapter 3 - Memory. *The Biology of Thought: A Neuronal Mechanism in the Generation of Thought–A New Molecular Model* p.53-74. doi: [10.1016/B978-0-12-800900-0.00003-8](https://doi.org/10.1016/B978-0-12-800900-0.00003-8)

Hammond, C., Goaillard, J-M., Debanne, D. & Gaiarsa, J-L. (2015). Chapter 18 - Synaptic Plasticity. *Cellular and Molecular Neurophysiology (Fourth edition)* p361-389. doi: [10.1016/B978-0-12-397032-9.00018-2](https://doi.org/10.1016/B978-0-12-397032-9.00018-2)

Ito, M. (2009). Long-Term Depression: Cerebellum. *Encyclopedia of Neuroscience*, p533-539. doi: [10.1016/B978-008045046-9.00807-X](https://doi.org/10.1016/B978-008045046-9.00807-X)

Mastin, L. (2018). *Long-Term Memory* [Online]  
Retreived from: <http://www.human-memory.net/types_long.html>

Science Direct (2018a). *Long Term Potentiation* [Online]  
Retreived from: <https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/long-term-potentiation>

Science Direct (2018b). *Long Term Depression* [Online]  
Retreived from: <https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/long-term-depression>

> **Comments:**
> **username_3**: LTP/D and the ultimate way in which memories are long-term stored are processes that are quite far apart. LTP is mainly studied in the hippocampus (short term memory) whereas the cortex holds the long-term memories. The latter relies on complex retrieval systems  
> **username_2**: @username_3 - From what I understand, whilst the hippocampus and cerebellum handle the processes of LTP/D, leading to a *"balanced, stable memory mechanism"* (Ito, 2009) both sort-term memory and long-term memory are held in the cortex. Dharani (2015) referenced in my answer also pointed out through recent research that LTD was found in other areas of cortex involved in memory and learning. Am I confused?  
> **username_3**: No you're not confused, I meant to say the LTP/D research has focused on the hippocampus as the process is relatively simple there. In the cortex things are much more complicated.  

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