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ISSN 0031-5125DOI 10.2466/22.PMS.120v18x1
Perceptual & Motor Skills: Learning & Memory
THE WORKING MEMORY BENEFITS OF PROPRIOCEPTIVELY
DEMANDING TRAINING: A PILOT STUDY
1 , 2
ROSS G . ALLOWAY AND TRACY PACKIAM ALLOWAY
University of North Florida
Summary .— The aim of this study was to investigate the eff ect of propriocep-
tion on working memory. It was also of interest whether an acute and highly inten-
sive period of exercise would yield working memory gains. The training group
completed a series of proprioceptively demanding exercises. There were also con-
trol classroom and yoga groups. Working memory was measured using a backward
digit recall test. The data indicated that active, healthy adults who undertook acute,
proprioceptively demanding training improved working memory scores compared
to the classroom and yoga groups. One possible reason that the training yielded
signifi cant working memory gains could be that the training was proprioceptively
dynamic , requiring proprioception and at least one other factor—such as locomotion
or navigation—at the same time, which may have contributed to the improvements
in working memory performance.
Proprioception has been defi ned as the awareness of body orientation
and positioning ( Malliou, Gioftsidou, Pafi s, Beneka, & Godolias, 2004 ; see
Gibson, 1968 , for a more expansive defi nition). Impaired proprioception
has been shown to diminish balance and increase the likelihood of injury
( Robbins, Gou, & McClaran, 1992 ; Robbins, Waked, Gouw, & McClaran,
1995 ). In contrast, proprioceptively demanding training, including stretch-
ing, strengthening, plyometrics, and sports-specifi c agility drills, dramati-
cally reduced injury rates of the anterior cruciate ligament in a large-scale
study of over a thousand soccer players ( Mandelbaum, Silvers, Watanabe,
Knarr, Thomas, Griffi n, et al ., 2005 ). Elderly adults were found to bene-
fi t both physically and cognitively from a proprioceptively demanding in-
tervention when they undertook a regimen of balance training, exercising
with a narrow base of support, and completing an obstacle course ( Shu-
bert, McCulloch, Hartman, & Giuliani, 2010 ). Researchers found that par-
ticipants improved in balance measures and cognitive skills, including a
trail making task that measures visual scanning and mental fl exibility.
One key cognitive skill that has recently been associated with proprio-
ceptive skills is working memory, the ability to process and recall informa-
tion ( Goble, Mousigian, & Brown, 2012 ). Working memory capacity as a
© Perceptual & Motor Skills 2015
2015, 120, 3, 1-10.
1 Address correspondence to Tracy Packiam Alloway, University of North Florida, 1 UNF
Drive, Jacksonville, FL 32224 or e-mail ( t.alloway@unf.edu ).
2 The authors thank Jamie Guined and MovNat for providing access to the volunteers taking
part in the MovNat training, and Hillary McDonald for providing access to the volunteers
taking part in the yoga class. The authors declare that they have no fi nancial interest in and
are not fi nancially connected with MovNat.
R. G. ALLOWAY & T. P. ALLOWAY
2
function of individual diff erences throughout the lifespan has been found
to mediate outcomes in reasoning tasks (Salthouse, 1994), IQ scores ( Con-
way, Cowan, Bunting, Therriault, & Minkoff , 2002 ), academic attainment
( Alloway & Alloway, 2010 ), reading ( Siegel, 1994 ), and even building Lego
blocks ( Morrell & Park, 1993 ). Working memory varies across the lifespan
( Alloway & Alloway, 2013 ), and the decline of working memory has been
suggested as a possible explanation for the decrease in proprioceptive sen-
sibilities in older adults ( Goble, Coxon, Wenderoth, Van Impe, & Swin-
nen, 2009 ; Goble, Noble, & Brown, 2010 ). Working memory capacity can
also vary between individuals of the same age group ( Alloway & Gather-
cole, 2006 ), and evidence has suggested that these individual diff erences
may play a role in athletic performance (e.g., Vestberg, Gustafson, Mau-
rex, Ingvar, & Petrovic, 2012 ). Working memory is so crucial to sports per-
formance that when working memory becomes overloaded performance
declines ( Maxwell, Masters, & Eves, 2003 ). One reason that working mem-
ory may be so important for sports performance is that it allows athletes
to integrate and manage multiple proprioceptive-related variables, such
as judging distance, appropriate force, and joint alignment.
The aim of this pilot study was to extend existing research to investigate
the impact of proprioception specifi cally on working memory. While work-
ing memory can support proprioceptively demanding activities, it is unclear
whether proprioceptively demanding activities can, in turn, enhance work-
ing memory performance. While previous research has suggested that pro-
prioceptively demanding training for an older population (> 66 yr.) can be
cognitively benefi cial ( Shubert, et al ., 2010 ), it is unclear whether such ben-
efi ts would also be seen in physically active adults across a broad age range.
In order to investigate this issue, healthy adults completed a working memo-
ry test before and after participating in proprioceptively demanding exercis-
es focused on balance, body awareness, and effi ciently navigating through
a natural environment using a program called MovNat. It was of interest
whether an acute and highly intensive period of exercise would yield simi-
lar cognitive benefi ts, as reported using a 12-wk. proprioceptively demand-
ing program ( Shubert, et al ., 2010 ) and in other highly intensive periods (e.g.,
20 min.) of aerobic activity ( Garavan, Kelley, Rao, & Stein, 2000 ). The authors
confi rm that the present study was approved by an ethics review board. If
proprioceptively demanding exercises can benefi t cognitive performance:
Hypothesis 1 . An improvement in working memory scores is ex-
pected compared to those who engage in either propriocep-
tively demanding or static exercises.
Hypothesis 2 . An improvement in working memory scores is ex-
pected compared to those who engage in only the propriocep-
tively demanding exercises.
PROPRIOCEPTION AND WORKING MEMORY 3
M ETHOD
Participants
The participants in all of the following three groups were self-select-
ing. The proprioceptive training group comprised of 18 adults (14 men; age
range = 18–59 years with 67% between 18 and 39 years). Only one participant
had attended a MovNat workshop before. When asked about other regular
physical activity, 11 reported attending the gym during the week, engaging
in a range of activities including cardiovascular machines (e.g., treadmills),
using weights (free weights and machine), and CrossFit activities.
The control classroom group comprised of 27 adults (12 men; age
range = 18–39 years). None had attended a MovNat workshop before. Of
this group, 20 reported regularly attending the gym during the week, en-
gaging in a range of activities including using cardiovascular machines
(e.g., treadmills), engaging in resistance training (free weights and ma-
chine), and participating in group exercise classes.
The control yoga group comprised of 20 adults (4 men; age range = 18–
29 years). None had attended a MovNat workshop before. Of this group,
16 reported regularly attending the gym during the week, engaging in a
range of activities, including using cardiovascular machines (e.g., tread-
mills), engaging in resistance training (free weights and machine), and
participating in group exercise classes.
Materials
Working memory was measured using a paper and pencil version of
Backward Digit Recall taken from a standardized assessment, the Auto-
mated Working Memory Assessment ( Alloway, 2007 ). The individual re-
called a sequence of spoken digits in the reverse order. The test began with
recalling two numbers in backward order and is increased by one item
in each block, up until nine numbers per block. There were two trials in
each block, and the number stimuli were diff erent for each testing session.
Scoring was recorded in two ways. A span score was calculated based on
the highest block where the individual correctly recalled one of the two
trials. The number of correct trials was also recorded for each participant.
Test-retest reliability was .86 in a normative sample ( Alloway, 2007 ), and
convergent validity was established in Alloway, Gathercole, Kirkwood,
and Elliott (2009 ). The procedure was as follows: the experimenter called
out the numbers at a rate of one number per second and the participant
wrote down the number in backwards order. The scoring was conducted
by researchers who were blind to the control and training groups.
Procedure for Control Groups
There were two testing sessions for each control group. Session 1 pro-
vided a baseline of working memory performance. The participants in the
R. G. ALLOWAY & T. P. ALLOWAY
4
control groups then engaged with their respective activities. After comple-
tion, they were given the working memory test with a new set of numbers
(Session 2).
In the Classroom group, the participants were seated for approximate-
ly 2 hr. for a classroom-style lecture where new information was deliv-
ered. In the Yoga group the participants practiced Kipalu yoga, which is a
gentle Hatha yoga practice focusing on body posture and awareness. The
postures or asanas included seated, standing, and supine postures and in-
cluded isometric contraction and relaxation of diff erent muscle groups and
regulated breathing. Throughout the yoga session led by a trained yoga
practitioner, the participants were encouraged to be mindful of their body
position. They practiced at an intermediate level for approximately 1 hr.
Procedure for Training Group
The training group participated in three testing sessions. Session 1
provided a baseline assessment of working memory. After completing the
baseline testing, the training group participated in the series of physical
activities designed by MovNat for approximately 2 hr. They were then ad-
ministered the working memory test with new numbers (Session 2). They
completed an additional training session of approximately 2.5 hr. and were
then retested on the working memory test with new numbers (Session 3).
The MovNat activities can be categorized according to the follow-
ing four categories: balance, awareness of relative position of body parts/
joints, locomotive, and awareness of strength of eff ort. Each activity last-
ed around approximately 3 to 5 min. and was preceded with instructions
from a MovNat trainer.
Balance activities .— These were conducted on a narrow base of support
(a beam approximately 3 in. wide). Activities included walking forward,
backward, and laterally; moving from a squatting to standing position;
crawling forward and backward; and combining all movements together
as connected sequences.
Awareness of relative position of body parts .— This included paying at-
tention to posture and bases of support. With regard to posture, the par-
ticipants were cued to shift from rounded backs and concave chests, to
draw shoulder blades down and toward the back, with scapula retracted
and depressed, allowing chests to expand convexly. The participants were
cued to visualize their pelvis as a bowl of water being tilted forward to
spill over. They also lay prone on the ground and used their feet, shoul-
ders, and hands to create new bases of support; they repeated these move-
ments while supine.
Locomotive awareness .— This included running barefoot and focusing
on landing on the ball of the foot with bent knees, crawling contralaterally
(rather than ipsilaterally) forward and backward such that the right hand
PROPRIOCEPTION AND WORKING MEMORY 5
and left foot moved forward while the left hand and right foot stayed on
the ground and vice-versa, and navigating over and under 3 ft. high top-
cross bars.
Strength awareness exercises .— These included lifting and carrying. Dur-
ing lifting, the participants used muscular eff ort to consciously maintain
the spine in a straight column (in order to minimize sheer forces), maintain
pressure with abdominal bracing before the lift, and use the Valsalva tech-
nique to increase intra-thoracic pressure and maintain rigidity through-
out the lift. During carrying, the participants selected a kettle ball heavy
enough (25–100 lb., depending on the individual) to challenge a recruit-
ment of the CNS and muscle system, and force them to brace their abdo-
men while walking with the weight on their left or right shoulder. The par-
ticipants were asked to activate muscles on the side carrying the weight
and relax the opposite side.
Analyses
In order to confi rm that all three groups were at a similar cognitive
skill level at the baseline, between-group one-way analyses of variance
(ANOVAs) were conducted with working memory scores as the depen-
dent variable. Between-group mixed ANOVAs with working memory
scores as the dependent variable (repeated across testing times) tested hy-
potheses.
R ESULTS
Separate one-way ANOVAs were conducted on the span and trial
working memory scores to confi rm that the training and control groups
did not diff er signifi cantly with respect to their Session 1 scores ( Table
1 ). There were no signifi cant diff erences between the control and training
groups scores: working memory span ( F 2, 62 < 1) or working memory trials
( F 2, 62 < 1).
A series of mixed ANOVAs were conducted on the working memory
scores pre- and post-training as a function of group. For working memory
TABLE 1
D ESCRIPTIVE STATISTICS OF WORKING MEMORY (WM) SCORES AS A FUNCTION OF GROUP
Session
Control: Classroom Control: Yoga Training
WM Trials WM Span WM Trials WM Span WM Trials WM Span
M SD M SD M SD M SD M SD M SD
1 11.00 2.87 7.15 1.61 10.40 2.98 6.60 1.70 10.44 2.84 6.50 2.01
2 10.19 3.13 6.59 1.93 9.45 2.98 6.35 1.66 11.33 2.14 7.50 1.15
3 12.22 1.90 7.67 0.97
R. G. ALLOWAY & T. P. ALLOWAY
6
span scores, there was no signifi cant diff erence in performance between
the two times ( F 1, 62 = 0.08; p = .78), nor as a function of group ( F 2, 62 < 1).
However, the interaction was signifi cant ( F 2, 62 = 4.26, p = .02, η
2
p = 0.12). Post
hoc analyses indicated that working memory span scores between Ses-
sions 1 and 2 improved signifi cantly only for the training group ( p < .05).
For working memory trial scores, there was no signifi cant diff erence
in performance between the two times ( F 1, 62 < 1), nor as a function of group
( F 2, 62 < 1). However, the interaction was signifi cant ( F 2, 62 = 3.05, p = .05, η
2
p =
0.09). Post hoc analyses indicated that working memory trial scores be-
tween Sessions 1 and 2 showed a trend toward signifi cance only for the
training group ( p = .09).
The changes in working memory performance between Sessions 1
and 3 were also examined. With respect to working memory span scores,
a multivariate ANOVA (MANOVA) on all three testing sessions indicated
signifi cant improvements ( F 3, 15 = 417.66, p < .001, η
2
p = 0.99). Post hoc anal-
yses indicated improvements from Sessions 1 to 3 ( p < .01). An additiona l
MANOVA also indicated improvements in the working memory trials
( F 3, 15 = 318.23, p < .001, η
2
p = 0.99). Post hoc analyses indicated improvements
from Sessions 1 to 3 ( p < .01).
D ISCUSSION
Active, healthy adults who undertook acute, proprioceptively demand-
ing training had improved working memory scores compared to the class-
room and yoga control groups, supporting Hypothesis 2. One possible rea-
son that the training yielded signifi cant working memory gains could be that
the training was proprioceptively dynamic , requiring proprioception and at
least one other factor—such as locomotion or navigation—at the same time,
which may have contributed to the improvements in working memory per-
formance.
In contrast, the yoga group who engaged in proprioceptively static pos-
tures did not show working memory improvements (though see Gothe,
Pontifex, Hillman, & McAuley (2013) for improvements in related cognitive
functions, such as attention and inhibition; however, see Oken, Zajdel, Kishi-
yama, Flegal, Dehen, Haas, et al ., 2006 , a large-scale study where participants
underwent yoga training for 6 mo., but did not show improved working
memory). While executing yoga poses requires proprioceptive skills, includ-
ing balance and awareness of joint position ( Paterno, Myer, Ford, & Hewett,
2004 ), the practice is relatively static in comparison, and does not utilize loco-
motion or navigation. Proprioceptively dynamic training may place a great-
er demand on working memory, because as environment and terrain chang-
es the individual recruits working memory to update information to adapt
appropriately. For example, when participants were engaged in propriocep-
tively dynamic activities, such as playing soccer, they had higher cognitive
function (Shubert, et al ., 2009; also Vestberg, et al ., 2012 ).
PROPRIOCEPTION AND WORKING MEMORY 7
One question is how this pattern of fi ndings fi t with other research
that has reported cognitive benefi ts of yoga practice, especially Hatha
yoga, which is a similar practice to Kripalu yoga used in the present study.
Gothe, et al . (2013) and Gothe, Kramer, & McAuley (2014 ) reported that an
acute period (20 min.) of Hatha yoga improved working memory accura-
cy in their participants. There are numerous fi ndings indicating that yoga
can improve attention, and given that Gothe, et al . (2013) used a work-
ing memory task that involves attentional control, their improvements are
perhaps not surprising. In contrast, the working memory test used in the
present study has not been linked to attentional control ( Holmes, Hilton,
Place, Alloway, Elliott, & Gathercole, 2014 ).
Another possible reason is that the MovNat activities required both
attention to body position and physical exertion, which may activate the
prefrontal cortex, the neural substrate of working memory ( Bledowski,
Rahm, & Rowe, 2009 ; also Kane & Engle, 2002 ). Suzuki, Miyai, Ono, Oda,
Konishi, Kochiyama, et al . (2004 ) compared activation of the prefrontal
cortex measured by hemoglobin levels in walking and running, and found
that when participants walked on a treadmill they did not show any in-
creases in hemoglobin levels in the prefrontal cortex. However, when
they ran on the treadmill hemoglobin levels signifi cantly increased in the
prefrontal cortex. It is possible that the proprioceptive nature of gait and
speed changes may be closely linked to PFC activation.
While both chronic and acute periods of exercise have been found
to improve cognitive functioning ( Colcombe & Kramer, 2003 ; Hillman,
Snook, & Jerome, 2003 , respectively), this pilot study explored the eff ect
of proprioceptively demanding training on working memory. Howev-
er, there are some limitations that future research could address. First, it
would be useful to fi nd out if diff erent forms of proprioceptively demand-
ing activities are more eff ective for boosting working memory than oth-
ers, such as running or walking along a narrow platform. Second, addi-
tional measures of working memory, including visual-spatial measures,
can be included in future studies. Research shows that spatial movements
are linked to spatial memory ( Baddeley & Lieberman, 1980 ) while focus-
ing on visual stimuli is linked with visual memory ( Quinn & McConnell,
1996 ). By administering such tests, future research can determine if visual-
spatial and verbal working memory improve. An additional concern may
be that the training group comprised of volunteers, which may have infl u-
enced the results. Although all three groups were self-selecting, there may
have been diff erent motivational infl uences, as well as potential age ef-
fects. Future studies could address this concern by assigning participants
to the diff erent exercise conditions.
Finally, it would be useful to fi nd out how long the training needs to
be practiced to yield cognitive benefi ts. The present results indicated that
R. G. ALLOWAY & T. P. ALLOWAY
8
2 hr. of training improved working memory scores, but it possible that a
shorter duration can also result in a similar improvement. The issue of
duration and benefi ts is important because the shorter the time period re-
quired, the easier it would be to schedule proprioceptively demanding
training into daily activities (though see Oken, et al ., 2006 , for both quality-
of-life and physical improvements resulting from chronic exercise)
In summary, the present study suggests that proprioceptively de-
manding training can improve working memory performance. Given the
importance of working memory in sports ( Maxwell, et al ., 2003 ; Vestberg,
et al ., 2012 ), multitasking ( Watson & Strayer, 2010 ), learning ( Alloway &
Alloway, 2010 ; Alloway, Bibile, & Lau, 2013 ), and mental health ( Levens &
Gotlib, 2010 ), acute periods of such training may provide a working mem-
ory boost across a wide range of activities.
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Accepted April 28 , 2015 .