How long does it take to lose a skill?
Hopes&Fears answers questions with the help of people who know what they are talking about. Today we wondered, when did I get so bad at bocce ball?
At some point in everyone's life, they return to a craft or ability they had once mastered only to discover that now...not so much. What once seemed effortless now requires tremendous effort for a much less potent result; our French has turned into Franish, our drum skills are less than satisfactory, our inability to solve a once-manageable differential equation is a sad reminder that math still exists. We wondered, why does this happen, and how long does it take? We talked with educators, engineers, neuroscientists, biomechanics experts, data junkies, and a Buddhist dharma teacher to try to parse exactly how long it might take to lose a skill.
Timothy A. Pychyl, Ph.D.
3M National Teaching Fellow, Director, Centre for Initiatives in Education, and Associate Professor, Department of Psychology at Carleton University
The length of time it takes to lose a skill is proportional to the time it took you to learn the skill. We see this in our lives all the times with the example of riding a bike or playing a musical instrument that we practiced for hours in our childhood. We don’t really lose these skills, although like our old bikes they “rust” a little. There can be a momentary hesitation when we sit down on the bike seat or at the keyboard, but there’s a muscle memory there that takes over. Sometimes we even marvel at how we can still do this, as we don’t really understand how. In contrast, if we’ve just developed a new skill, it’s quick to fade. The neural connections that encode this learning are neither extensive nor “deep.” We see this all of the time in our colleges and universities as students “cram for the test” and days later they are unable to remember the content or demonstrate the skill. It’s called surface learning for a reason, as it’s easily erased.
How long does it take to lose a skill? The answer isn’t that appealing, because it depends on the skill. I expect that some skills are so deep within us that even when brain disease processes rob us of our memories and even our ability to remember those around us, we can still demonstrate these skills. Paradoxical, isn’t it?
Dr. Adam Knight
Associate Professor of Biomechanics at Mississippi State University
From a motor learning perspective, once a person has acquired a skill, they typically do not lose their ability to perform that skill, unless there is a neurological or musculoskeletal injury or disease. Over time, their ability to perform the skill at a high level, or at the same level of performance they were at when they first learned or mastered the skill, is going to decrease (if they stop practicing the skill), but they should be able to still perform the skill. The supplementary motor area of our cerebral cortex (brain) is the part that helps construct movements based on internal motor memory (many people call this muscle memory, which is incorrect. Muscles cannot remember anything, but that’s a topic for another day).
For example, when you first learn a motor skill, like riding a bicycle or hitting a baseball or softball, your brain has to learn which limbs to use, which muscles to activate, when the muscles need to turn on and off, how much muscle force to produce, and how to coordinate the movement. With practice, this movement becomes more coordinated and the brain gains better control, and this internal motor memory is strengthened. So, when you want to perform the skill again, the supplementary motor area can organize the movement based on the internal motor memory that was created from previous experience. Just like anything else, this memory will fade some over time, and the longer you go between practicing the skill, the less efficient you are going to be at performing it. But, a person could go several years without riding a bicycle, and they would still be able to ride it due to the previous experience and motor memories from performing the skill.
Now, it’s difficult to say how much of the skill a person would lose within a set period of time. Some people are going to see more of a loss than others, and some people will perform better than others when first performing a skill after not doing it for a long time. There are many factors that will affect this, including the level of expertise the person originally achieved and their own motor abilities). That’s what makes us unique as humans; we are all different, but are bodies have an amazing ability to learn, remember and adapt.
Even over the short span of a summer, young minds can lose skills: for example, in math and reading. Thus, research supports the need for summer programs: “Most students lose about two months of grade level equivalency in mathematical computation skills over the summer months. Low-income students also lose more than two months in reading achievement, despite the fact that their middle-class peers make slight gains (Cooper, 1996).”
S. Lee Hong Ph.D.
Former Associate Professor of Physiology and Neuroscience at Ohio University and current data scientist
That really depends on the type of skill we're talking about. There are specific skills like riding a bicycle or unicycle, juggling, and swimming where you fail miserably at every attempt, and then suddenly... voila, you can perform the task perfectly. There's no real in-between, "I'm getting a little better" process. These skills tend to stay with you longer. Skills that you can incrementally get better at tend to go away more quickly. I guess, in some ways, skills that have to click are more likely to stick. It's not necessarily that languages use a different part of the brain, but more so in terms of coordination patterns of the muscles to make sounds.
One area that isn't widely discussed is how learning different forms of language can have differing long-lasting impacts. For example, it is possible that tonal languages, such as Chinese, might have different rates of learning and retention than Latin-based languages. Language is a tough one, mainly because languages aren't skills that click, yet, making a clicking sound with one's tongue to accurately convey a message will probably stick with you for life.
I think the only major important message is that skills do not have equal rates of decay. And, it isn't necessarily the case that more difficult skills are retained longer than others. It really is that distinction between those skills that have to "click" that are different from others.
Michael K. Gardner, Ph.D.
Professor of Education Psychology at the University of Utah
Skills are established through practice, and follow a “power law” of learning (Newell and Rosenbloom, 1981): time to perform the skill equals a constant times the number of trials of practice raised to a certain power. So, time decreases with practice (not a big surprise), but it decreases most in the early periods of practice and relatively less in the late periods of practice. I don’t have empirical evidence on the rate at which skills decrease, but it is likely a function of the amount of practice (highly practiced skills are lost less quickly than less practiced skills), and the amount of complexity of the skill (complex skills with more underlying components are likely lost more quickly due to the number of individual components that can be lost).
Perhaps the good news for your readers is that once a skill is established through practice, it can be relearned much more quickly than it was originally learned. Kolers and Perkins (1975) had subjects learn to read pages of inverted text. At first, it took subjects approximately 16 minutes to read a page of inverted text. After reading 200 pages of inverted text, their time to read a page had decreased to approximately 1.6 minutes. They brought the subjects back into the lab a year later. After a year, their first page of inverted text took them about 3 minutes to read. So there had been some loss of the skill over a year. However, it took them only 50 pages of reading inverted text to return to their prior rate of 1.6 minutes per page. The takeaway is that when someone comes back to a skill after years of not using it, there is often a relatively short warm up period during which the skill is re-established, and then performance returns to the same level as before.
Traumatic brain injury (TBI) can significantly affect many cognitive, physical, and psychological skills. Physical deficit can include ambulation, balance, coordination, fine motor skills, strength, and endurance. Cognitive deficits of language and communication, information processing, memory, and perceptual skills are common. Psychological status is also often altered. Adjustment to disability issues are frequently encountered by people with TBI.”
source: Centre for Neuro Skill
Po Chi Wu, Ph.D.
Princton University, Adjunct Professor of Mechanical and Aerospace Engineering
A highly valued skill, one that is a true passion, e.g., in the case of musical or sports talent, may never be lost. There are stories of prisoners of war who were able to perform [former skills, tasks] brilliantly after being freed because they had been able to train their minds despite years of torture and deprivation.
These examples lead my thoughts to the power of the mind. Even under circumstances where physical practice of skills, e.g., golf, are impossible, the mind can, with intense concentration, recreate the brain activity that would accompany actual muscular activities. This is a twist on the concept of “virtual reality” and is intensively researched in Olympic athletes.
Buddhist dharma teacher, presiding teacher at Dharmapunx NYC for over 10 years
I would say, first of all, it depends on what kind of skill we’re thinking about. The way I tend to break it down is explicit versus implicit skill, those that can be switched to potentially ingrained habits. For instance, we talk about the skill of riding a bike or swimming, which we now know can be retained by people with Alzheimer’s or people with significant cognitive impairment. We also know, from the work of Alan Shore, that what we learn in anticipating how people will behave, reading people’s body language and such, is developed in the crucial attachment period around month 6 to roughly 18.
All of these emotional beliefs - which could be called skills - are never lost. You don’t lose the early attachment trainings that people give you in the earliest phases of infancy. So, for example, a child that grows up in a secure environment where it’s trained to believe that people are emotionally tolerant and caring will develop this skill of discerning how to be spontaneous and trusting and exploring the world very early in life. A child that grows up in an early environment where people are unreliable, or absent, or even abusive, will learn to detect very early in life all of those attributes in humanity. And those skills, the hypervigilance, the disassociation, and those variations that come along with that early attachment experience, will never be lost either. So core emotional experiences that happen before the development of the left hemisphere aren’t lost.
Intellectual faculties fade all the time, and they are, of course, consolidated by the hippocampus, but over time, even throughout life, when we experience times of great stress, the left hemisphere and frontal lobes essentially get overwhelmed by fear impulses from the amygdala, and we go into automatic pilot, actions governed by the striatum and back of the brain. So we don’t have the cognitive abilities to enact higher skills. My emotional skills that I learned very young will still be in effect. I will have the core expectations of people that I learned very young in life when I’m under stress.
But when I’m under stress, my higher skills, based on intellectual reflection, based on discernment, wisdom, the skills of writing, and perhaps songwriting, those skills that have a higher degree of cognitive input—and by cognitive I mean the work of the rational left hemisphere, language and all that—those will be lost very quickly when I’m under stress. And as the hippocampus degrades, over the years, due to Alzheimer’s or to just the erosion of the nerve sheath, I will lose the ability to have or retain the sort of higher skills that I develop in my twenties and thirties, those skills like understanding some of the deeper concepts of modern psychology or neuroscience, stuff like that.