Forget Me… Not!

A Simpsons' cartoon. The truth according to Homer Simpson? The caption reads: "Every time I learn something new, it pushes some old stuff out of my brain."Forgetting is Easy…

Do you feel overwhelmed with the amount of information you have to deal with?  Do you spend time drawing up a shopping list, only to forget it on the kitchen table when you leave the house?  I know I do.  In the words of Homer Simpson: “Every time I learn something new, it pushes some old stuff out of my brain.”  Don’t worry!  Scientists think that it is perfectly normal, and even an essential part of the brain’s learning process.

According to researchers from the University of Glasgow’s Institute of Neuroscience and Psychology, the new study found that our inability to hold onto new memories is essential to learning.  The findings were published in Current Biology.

 

Memory Instability

Researchers discovered that ‘memory instability‘ – which prevents us from holding onto new memories – was crucial to the brain’s ability to transfer experiences and skills to new situations.  However, memories that were stable, or complete, prevented knowledge transfer.  In other words, forgetting your experience is essential to being able to transfer your skills from one job to another.

First, the study participants learned one memory task at 9 am, followed quickly by another.  They were then re-tested 12 hours later at 9 pm on the initial memory task.

The initial task consisted in a word-list – a repeating sequence of 12 simple words.  The following consisted in skilled action – a new sequence of movements similar to that used when tapping out our PIN to get cash from an ATM.

 

From Actions to Words, and Back Again.

The study found that learning transferred from actions to words, and vice versa.  Learning a list of words helped participants learn a new skilled action.

The information transferred between these diverse situations was on a ‘higher abstract level‘, rather than simply transferring the specific knowledge of each situation.

Learning transferred only when a memory was unstable.

 

As the participants’ training progressed across three practice blocks, the researchers noted significant improvement in motor skills when the earlier word list and subsequent motor sequence shared a similar structure.  The researchers also used different methods to stabilise, or consolidate, participants’ memories.  When this was done, it was found that there was no memory transfer between different tasks.

The work showed that an unstable memory is a key component of the mechanism for learning transfer.  An unstable memory prevents learning from being rigidly linked to one task.  Instead, it allows learning to be applied flexibly.

 

Forgetting is Key to Learning

In this study, the researchers tested the link between a memory being unstable and the transfer of learning to a different type of memory task.  They measured how learning in one task transferred to, and thus improved learning in a subsequent task.

Learning transfer occurred from a motor skill to a word list task and, vice versa, from a word list to a motor skill task.  What was transferred was a high-level relationship between elements, rather than knowledge of the individual elements themselves.

As the participants’ training progressed across three practice blocks, the researchers noted a significant improvement in motor skills when the earlier word list and subsequent motor sequence shared a similar structure.

The researchers also used different methods to stabilise, or consolidate, participants’ memories.  When this was done it was found that there was no memory transfer between different tasks.

Stabilised memories consistently prevented transfer to the subsequent memory task, suggesting that the transfer of learning across diverse tasks is due to a ‘high-level representation’ that can only be formed when a memory is unstable.

 

A classic Forgetful Goldfish meme. The caption reads: "Gotta Buy Toilet Paper. Gotta Buy Toilet Paper. Gotta Buy Toilet Paper. Gotta Buy Toilet Paper. Gotta Buy Toilet Paper. Gotta Buy Toilet Paper." Then suddenly, "Buys a Packet of Cigarettes and Couple of Beers."Unstable Memories

Robertson and Mosha uncovered an important function of memory instability.  An unstable memory provides a window of opportunity for communication between memories, leading to the construction of a high-level or abstract memory representation, which allows the transfer of knowledge between memory tasks.  An unstable memory is in a privileged state: only when unstable can a memory communicate with and transfer knowledge to affect the acquisition of a subsequent memory.

A link between memory instability and the creation of high level abstract memory representations may explain the similarity in key areas of the brain, specifically those brain areas that are critical to memory instability and those for the creation of memory knowledge framework.

So, just as you ought to embrace your inner numpty, embrace your forgetfulness.  It’s actually a sign you’re learning!