Category: Memory

Short-term memory is what is in your mind right now while long-term memory is what gets stored away for days, months or years.

Short-term memory is the the ability to hold a small amount of information in the mind for a few moments.

For psychologists, it refers to things that are currently being used by your brain right now.

For example, as you’re reading this article the words you’ve read go into short-term memory for a very short period, you extract some meaning (hopefully) and then the meaning is either stored or discarded.

Typically, short-term memory is gone from the mind in a few seconds.

Unless, that is, it is transferred to long-term memory, which can last for many years.

Long-term memory, however, can be just as illusive, as most of us know to our cost.

Example of long-term memory failure

My memory continues to surprise me, and not usually in a good way.

I recently reread a book which I first read, and greatly enjoyed, about 13 years ago.

It is fiction by one of my favourite authors – the writing is vivid, the story exciting and the set-piece action breath-taking.

Despite all this I had almost no memory of reading the book the first time.

Almost everything about the book seems to have seeped away in the intervening years.

I couldn’t remember the plot, most of the characters or any of the scenes.

The only thing I vaguely remembered was the main character’s name, but I couldn’t be sure I hadn’t invented that memory, after all I couldn’t recall anything else about the book.

Short-term memory vs. long-term memory

This is an example of what Harvard psychologist Daniel L. Schacter calls the first deadly sin of memory: transience (Schacter, 1999).

Transience can be seen in both short- and long-term memory.

Short-term memory, for psychologists, means the things that are in your mind right now, and only those things.

On the other hand, long-term memory is anything you store to be retrieved at a later time.

Studies have shown that both types of memory can be extremely fragile over their respective timescales.

Short-term memory loss

A classic experiment on short-term memory loss was carried out by Peterson & Peterson (1959).

It demonstrates how quickly short-term memory loss occurs.

They asked participants to memorise a three-letter sequence, then count backwards in sets of threes.

Participants were then asked to try and recall the three-letter sequence after different lengths of time counting backwards.

Participants did surprisingly poorly on this test of short-term memory.

After only six seconds of counting backwards in threes, on average half of the original three letters had disappeared from memory.

By the time participants had been counting backwards for 12 seconds, less than 15% of the original memory remained.

Finally after 18 seconds it was all but gone — short-term memory loss was complete.

This experiment clearly shows how quickly information leaks out of short-term memory.

The experience of short-term memory loss is usually perfectly normal.

Size of short-term memory

The psychologist George A. Miller is famous for coming up with a magical number related to short-term memory.

What this magical number represents – 7 plus or minus 2 – is the number of items we can hold in our short-term memory.

So while most people can generally hold around seven numbers in short-term memory, almost everyone finds it difficult to hold ten digits in mind.

At the other end of the scale, 5 numbers is the bare minimum for what people can hold in short-term memory.

Long-term memory: slow forgetting

To return to my example of the novel, though, it seems to me that some aspects of the book must have become lodged in my long-term memory.

No doubt much was lost in short-term memory, but surely some of it must have stuck in long-term memory.

Otherwise I wouldn’t have been able to follow the story and would have ended up reading the first page again and again.

So, what types of processes affect how much we retain from long-term memory?

In fact, relatively little is known about how our long-term memory fades over substantial periods of time.

Thirteen years is a long time for an experimenter to wait just to find out if I can remember the details of that book.

Nevertheless, studies do suggest that forgetting probably follows a power function.

That means we lose a lot of information soon after it goes in, then, over time, the rate of forgetting slows down.

How short-term memory becomes long-term

Of course not all long-term memories are created equal, and so the reasons why we fail to recall information are many and varied.

Indeed, some psychologists have argued that we never really forget anything.

Perhaps, they say, the memory is still in our minds but we can no longer access it.

Cues are clearly important to retrieving long-term memories.

The smell of varnish might remind us of the day we spent canoeing in the rain, lost in solitary thought.

Conversely, some experiences can hinder the retrieval of certain long-term memories.

The long-term memory of a parent’s anger at our childish misdemeanour might completely block out the memory of what we actually did.

Long-term memory is certainly more likely to fade if we don’t use it.

The retrieval and rehearsal of long-term memories has been shown to enhance their storage.

Interestingly, there’s no actual evidence in humans that long-term memory which remains unrehearsed or unretrieved actually does dissipate over time.

Perhaps all our long-term memories really are still in there.

Gone, and forgotten

But even if my long-term memory of reading that book the first time is still in there, it’s doing a very good job of hiding.

Especially since rereading the book should be a massive cue to its recall.

Maybe we do completely forget or maybe I have just forgotten that I didn’t actually read the book in the first place.

Either way, perhaps I’ll be able to enjoy the same book all over again in another 13 years!

→ This post is part of a series on the seven sins of memory:

1. Short-Term Memory vs. Long-Term Memory: Definition And Examples
2. Absent-Mindedness: 2 Factors That Cause Forgetfulness
3. Tip-of-the-Tongue Phenomenon Or Lethologica
4. Misattribution: How Memories are Distorted and Invented
5. Suggestibility: How Memory Is Biased By Suggestions
   • False Memory: Dramatic Examples Of Fake Memories
6. Commitment and Consistency Bias: How It Warps Memory
7. Long-Term Memory: When Persistence Is A Curse

.

Some of the most widespread beliefs about memory are myths and misconceptions.

One of the classic criticisms levelled at psychology is that it’s just common sense.

And there’s nothing that winds up psychologists more than having this old saw repeated back to them.

If it’s true we should be able to ask the general public six easy questions about the psychology of, let’s say, memory, and they should do pretty well.

After all, everyone has a mind of their own and can introspect and see what’s going on inside it, so they should be able to answer these questions easily, shouldn’t they?

Myths about memory

Simons and Chabris (2011) had 1,838 Americans polled with six basic statements, testing some common myths about memory.

Great care was taken to try and get a representative sample of the general population.

Their responses were compared with those of almost 100 psychologists.

Amongst these were 16 professors with at least 10 years experience in researching memory.

The statements are all below in their original form:

1. “People suffering from amnesia typically cannot recall their own name or identity.”

Fully 83 percent of people agreed either ‘mostly’ or ‘strongly’ with this statement.

In contrast, all the experts disagreed ‘mostly’ or ‘strongly’ with this statement.

In fact, people suffering from amnesia normally can remember their own name and identity, so it is a myth about memory.

The reason people get this so wrong is probably because they are often exposed to incredibly inaccurate depictions of amnesia.

Films like ‘The Bourne Identity’ (and every sitcom ever made that uses an amnesia plot) are partly to blame; while films like ‘Memento’, with its much more accurate depiction of amnesia, are in the minority.

2. “In my opinion, the testimony of one confident eyewitness should be enough evidence to convict a defendant of a crime.”

37 percent of the public agreed, while all 16 experts disagreed.

Actually eyewitness testimony can be frighteningly inaccurate, so it is another of the myths about memory.

One of the problems with memory is that people are surprisingly suggestible.

Even relatively small differences in the way eyewitnesses are handled can have a huge impact on what they claim to have seen.

For a good example have a look at this article on suggestibility.

3. “Human memory works like a video camera, accurately recording the events we see and hear so that we can review and inspect them later.”

63 percent of the public agreed, while all 16 experts disagreed.

This is a surprisingly high percentage given how most people frequently have problems recalling basic facts.

In fact, it is one of the myths about memory, since it works nothing like a video camera.

In reality, what we recall is affected by our current emotional state, our motivations and so on.

And, of course, a lot of the time we can’t remember it at all.

See this article on the short-term memory vs. long-term memory.

4. “Hypnosis is useful in helping witnesses accurately recall details of crimes.”

55 percent of the public agreed, while 14 experts disagreed and 2 didn’t know or thought it was unclear.

Hypnosis is a bit more controversial, but still the public had a lot more faith in it than the psychologists.

Part of the problem with hypnosis is that it can make people incredibly suggestible to completely false information.

Through hypnosis, eyewitnesses can come to believe things that never happened.

One great example is the ‘lost in the mall‘ study.

5. “People generally notice when something unexpected enters their field of view, even when they’re paying attention to something else.”

78 percent of the public agreed and 13 experts disagreed, while 3 agreed.

This one was the most controversial for the experts, but probably because there’s little evidence about how often we fail to notice when something unexpected comes into view.

The general point here is that people are much more absent-minded than they think.

That’s because of the paradox that we don’t notice what we don’t notice.

For all the classic examples check out this article on absent-mindedness.

6. “Once you have experienced an event and formed a memory of it, that memory does not change.”

48 percent of the public agreed while 15 experts disagreed and one thought it was unclear.

This is yet another myth about memory.

Actually even so-called ‘flashbulb memories’—like where you were when Kennedy was shot—can be quite inaccurate or easily change over time.

For a great example of how malleable memories are, check out this previous article on misattribution, how memories are distorted and invented.

Not common sense

By and large, then, according to memory experts, all these statements are false — they are all myths about memory.

So, should anyone say to you: “psychology is just common sense”, try asking them if they agree with a couple of the above six statements.

If they do, your work is done.

You’ll have spotted that the context for these questions is often related to eyewitness testimony.

That’s because in court, lay beliefs about memory are so important. Simons and Chabris conclude by saying:

“The prevalence of mistaken beliefs in the general public implies that similar misunderstandings likely are common among jurors and could well lead to flawed analyses of testimony that involves memory. At least for these basic properties of memory, commonsense intuitions are more likely to be wrong than right.”

Try not to think about what kind of effect these mistaken models of how memory works have on our legal system and public life in general or you’re likely to become mighty depressed.

→ Continue reading: Facts About Memory: 10 Interesting Things You Should Know

Learning to play music can have a powerful effect on long-term memory and overall brain function.

Professional musicians show superior long-term memory compared with non-musicians, research shows.

Their brains are also capable of much faster neural responses in key areas of the brain related to decision-making, memory and attention.

The results were presented at the Society for Neuroscience annual meeting in Washington, DC (Schaeffer et al., 2014).

Dr Heekyeong Park, who led the study, said:

“Musically trained people are known to process linguistic materials a split second faster than those without training, and previous research also has shown musicians have advantages in working memory.

What we wanted to know is whether there are differences between pictorial and verbal tasks and whether any advantages extend to long-term memory.

If proven, those advantages could represent an intervention option to explore for people with cognitive challenges.”

Music and memory study

The 14 professional musicians in the study — all of whom had been playing for 15 years — were given a series of pictures and words to remember.

Their results on a long-term memory test were compared with a group of 15 non-musicians.

While they did the test, their neural responses were measured using electroencephalography (EEG) technology.

The musicians had the advantage in long-term memory for the pictures, although not the verbal items.

Measures of the musicians’ brain function also showed that their neural response was faster than non-musicians.

Areas in the mid-frontal region — those associated with decision-making — were between one-third and half-a-second faster.

In the parietal lobes — which are associated with the senses, memory and attention — their neural response were sometimes almost one second faster than non-musicians.

It’s not yet known why these advantages in processing and memory occur, but Dr. Park speculates that learning to navigate musical scores may be partly responsible.

This study adds to a growing body of evidence showing that musical training has a wonderful positive effect on cognitive abilities.

.

Scientists have found that phenolic compounds in this drink can help improve spatial memory.

One to three glasses of champagne each week could slow memory loss from ageing, research finds.

Scientists have found that phenolic compounds in champagne can help improve spatial memory.

The phenolic compounds come from the Pinot Noir and Pinot Meunier red grapes which are used alongside Chardonnay in the production of champagne.

The compounds affect the signals sent from the hippocampus to the cortex.

The compounds were found to slow the age-related decline in this signalling.

Professor Jeremy Spencer, an expert on phytochemicals and brain function, said:

“These exciting results illustrate for the first time that the moderate consumption of champagne has the potential to influence cognitive functioning, such as memory.

Such observations have previously been reported with red wine, through the actions of flavonoids contained within it.

However, our research shows that champagne, which lacks flavonoids, is also capable of influencing brain function through the actions of smaller phenolic compounds, previously thought to lack biological activity.

We encourage a responsible approach to alcohol consumption, and our results suggest that a very low intake of one to two glasses a week can be effective.”

The research was carried out on rodents, but Dr David Vauzour, one of the study’s authors, said:

“In the near future we will be looking to translate these findings into humans.

This has been achieved successfully with other polyphenol-rich foods, such as blueberry and cocoa, and we predict similar outcomes for moderate champagne intake on cognition in humans.”

The study was published in the journal Antioxidants and Redox Signalling (Corona et al., 2013)