Effects of Long-term Tai Chi, Meditation,
and Aerobic Fitness Training on
Executive Attention Skills
Teresa Hawkes
Woollacott Laboratory
Human Physiology
Institute of Neuroscience
Background
• More efficient executive attention function has been
correlated with:
– Meditation training (Chan & Woollacott, 2007; Slagter et al, 2007;
Tang et al, 2008).
– Aerobic fitness training (Hatta, et al, 2005).
• Mechanisms underlying attentional improvement are
hypothesized to differ in the two skills:
– Meditation: long term practice results in plasticity in
microcircuits subserving the executive attention network
(Lazar, et al, 2005).
– Aerobic finess: improved blood-flow to brain.
• Executive attention is required for motor learning
(Halsband & Lange, 2006).
Sitting Meditation
Attention Function Benefits
• Numerous studies of meditation reveal
consistent evidence of state and trait training
effects including
– Enhanced executive function (Chan & Woollacott, 2007),
– Orienting (Jha et al, 2007),
– Management of attentional resources in the
attentional blink paradigm (Slagter, et al, 2007).
Aerobic Fitness
Executive Function Benefits
• Speed of information processing indexed by
P300 during visual or auditory oddball tasks
(Kamijo et al, 2004):
– latency and reaction time decreases
– accuracy increases
• Enhancement of reaction time and accuracy
on Erikson flanker tasks in older adults who
take up aerobic exercise (Hatta et al, 2005)
Tai Chi
• Is a form of moving meditation (Luskin, 2004).
• Requires motor learning, and thus executive attention
(Halsband & Lange, 2006)
• Same range of metabolic equivalents (METs) as Aerobic
Walking: 4-6 METs (Li, et al, 2001).
• Has been shown to be superior to aerobic walking for
cardiovascular function (Audette, et al, 2006).
• Improves neuromuscular and biomechanical responses to
perturbations in elders (Gatts & Woollacott, 2006, 2007).
• Improves tactile acuity (Kerr, et al, 2008).
• Improves immune function in elders (Irwin, et al, 2003).
Executive Attention
• Components (Miyake, et al, 2000; Hausdorff, et al, 2006)
– Inhibition (Tower of Hanoi, Stroop, Go No-go, Random
Number Generation)
– Updating (Random Number Generation, Operation
Span)
– Shifting (Stroop, Wisconsin Card Sort)
• Go No-go: Inhibition
– This component is required for Sitting Meditation
• Visuo-spatial Task Switch
– Inhibition, Updating, & Shifting
Question: Do different kinds of executive training
produce different training outcomes?
Summary & Knowledge Gap
• Tai Chi, a form of moving meditation, combines
both moderate aerobic exercise and executive
attention training.
• Therefore it could be hypothesized that Tai Chi
training will produce greater improvements in
executive function than meditation or aerobic
fitness training.
• In an uncontrolled study, Matthews & Williams,
2008 found positive correlation between Tai Chi
training and improvements in executive
attention function.
Hypothesis
• Executive attention performance, as measured on
a visuo-spatial task switch test (VSTS), will be
most efficient in Tai Chi experts, followed by
exercising meditators, with aerobic walkers and
meditators being equal, and all four groups
showing significantly more efficient performance
than sedentary control participants
• Efficient executive performance = % switch costs.
Methods
• Subjects: We are testing persons trained in Tai
Chi, meditation, meditation + exercise, and
aerobic fitness and comparing them to nonpracticing controls.
• Inclusion criteria: Experts must have 5 yrs+
training, 3x or more/wk, 50 min/session
experience.
• No history of physiological or cognitive
abnormalities.
• Subjects in the current data set are aged 28-69.
• We are working to education-match subjects.
Tests
• Visuo-spatial Task Switch (VSTS) with dense array
EEG (Multi-point Executive attention function)
• Sustained Attention Go No-go (Sitting Meditation
Proficiency – 1 point attention focus)
• Leg Kick Motor Control Assessment (Tai Chi
proficiency – motor attention function,
neuromuscular function, skeleto-muscular
integrity)
• Rockport 1-mile Walk (Cardiovascular fitness)
Visuo-Spatial Task Switch
Subject Instructions
(Mayr Laboratory, University of Oregon)
Meditation Proficiency
Sustained Attention Go No-go
(Smallwood, et al, 2008)
• Part 1
– 1 or 2 targets per block, 24 blocks
(test duration: 20-30 minutes).
• Part 2
1 = On Task: Made a mistake. Did not make a mistake
2 = Off Task: Tuned out. Maybe made an error. Zoned
out – have no idea.
Dependent variables: RT for non-targets (assessing ongoing
attention), efficacy of response inhibition, and % accuracy assessing
own performance.
Tai Chi Proficiency – Leg Kick
A ten camera system with 31 reflective markers (Motion Analysis Corporation, Santa Rosa, CA)
capture subject whole body motion at 60 Hz.
DVs: Hip & Torso angles; Coordination of body segments.
Rockport 1-mile walk
Subjects are fitted with an Athletic Connection Polar E600 heart rate monitor (Polar ElectroUSA). A chest strap with heart sensor sends information on heart rate and walk time to a wrist
recorder. (http://www.exrx.net/Calculators/Rockport.html: estimated VO2max, METs,
population average, performance rating.)
Preliminary results
Group n’s
– Tai Chi (n=9)
– Sitting Meditation (n=2)
– Meditation + Exercise (n=3)
– Aerobic Fitness (n=3)
– Sedentary (n=3)
Meditation Proficiency Test
Single Point Executive Attention Function
Tai Chi Proficiency
Leg Kick
Tai Chi 10y, 51 yo F
Med, 35 y, 69 yo M
Aerobics 35 y, 66 yo M
M+E, 30 y, 63 yo F
Sedentary, 28 yo F
Sedentary, 52 yo F
Hip Flexion Angle
Aerobic Capacity
Task Switch Costs
Inhibition, Shifting, and Updating (Miyake et al, 2000).
(Mayr Laboratory, Univ.Oregon)
Measurements: 1) 256-channel dense array EEG, 2) button press reaction time, 3) accuracy, and 4) RT for:
Rule 1: 144 trials. Rule 2: 144 trials. Rule 3: Switch trials - 288. No-switch trials - 288.
Limitations of the Pilot Study
• Limited number of participants (final number
will be 30 or more per group)
• Age-matched
• Education-matched
• Computer experience-matched
Trends
• Experts are outperforming all non-expert
subjects in each training modality.
• Very low switch costs (<8%) are clustered in
the Tai Chi group.
Acknowledgments
• Committee
–
–
–
–
Marjorie Woollacott – Adviser
Terry Takahashi
Li-Shan Chou
Paul van Donkelaar
• Research Assistant
– Wayne Manselle
• Undergraduate Research Assistant
– Jackson Blackburn
• Special Thanks
– All the individuals who volunteered their time as subjects and support staff.
• Funding
– Mind & Life Institute, Francisco J. Varela Award, 2008.
– Institute of Neuroscience, University of Oregon, Systems Training Grant, 2008-9.