Creating Better Learners by Driving Neuroplasticity

Améliorer les performances des apprenants grâce à la
plasticité cérébrale
Prof. Andrea A. Chiba University of California, San Diego

Temporal Dynamics of Learning OECD 2012

The goal of our Center:
To understand the role of time and timing in
learning

From the neuronal
and millisecond scale…

…to the brain
and year-long scale


Time is an organizing principle of the world
Le temps est un principe organisateur du monde
Ο χρόνος είναι µια οργανωτική αρχή του κόσµου

•  Sequences underlie much of
what we learn

•  The brain is organized 5+3x6=48 =oops!

according to temporal patterns
as is our world

•  The ability of the brain and the
world to integrate is crucial

THE CHILD JUMPED ON THE FROG.

THE FROG JUMPED ON THE CHILD.


Time is an organizing principle of the brain

STDP Spikes Local Field Potentials Cortical EEG


How are temporal sequences organized?

Temporal pattern & sequence

wi
Elements A B C D
Dt Dt Dt
1 2 3
time 

● Temporal patterns are learned and recognized
● Temporal pattern recognition is basic for perception,
language, and cognitive processing
● Deficiency in rapid temporal processing underlies
some learning deficits

Temporal Dynamics of Learning OECDInitiative 1
2012

How do brain circuits learn sequences?

Naive
model

OECD 2012

Time matters for processing…

say
Frequency

stay
100 ms

Time (milliseconds)

These wave forms are identical except for the artificially
inserted gap and a compensating shrinkage of the waveform.


Time matters for learning…
100
95
90
85
Percent Correct

SYLLABLE Tone Duration =
80
RANGE 75 msec
75 Tone 1 = 100 Hz,
PHONEME Tone 2 = 300 Hz
70 Control
RANGE
65 Language Impaired
< 40ms - Phonemes
60 40-350ms - Syllables
55
50
150

305
428

947

1466
1985

3023

3543

4062
8

15
30

60

Tallal & Piercy (1973) Nature.
Interstimulus Interval (ISI) in milliseconds

6-8 year old language impaired children can t do
the task at short ISI s: correlation, or causation?

Timescales of investigation
Ba
Da

Whisking
10s of msec Spikes
STDP
Phoneme processing

Neuromodulation
Motor action
100s of msec Perceptual decisions
Brain rhythms

Action selection
Seconds Prediction
Temporal Diff. learning
Reinforcement

Minutes LTP
Days Neurogenesis
Weeks Spacing effects
Years Expertise

Temporal Dynamics of Learning 11
OECD 2012

Clarke
County
School
District

•  The
Clarke
County
School
District
of
GA
implemented
the
Fast
ForWord

products
in
eight
schools
during
the
2006-‐2007
and
2007-‐2008
school
years.

•  2,257
students
had
their
reading
achievement
assessed
with
the
Criterion-‐
Referenced
Competency
Tests
(CRCT).
Some
students
used
Fast
ForWord

products,
others
served
as
a
comparison
group.

•  Based
on
CRCT
results,
on
average,
the
Fast
ForWord
parMcipants
made

greater
gains
than
the
comparison
group.

•  Following
Fast
ForWord
parMcipaMon
in
2006-‐2007,
40%
of
students
who

were
not
proficient
in
2006
crossed
the
proficiency
threshold
in
2007,

compared
to
27%
of
the
students
in
the
comparison
group.
These
results

were
replicated
by
students
who
first
used
Fast
ForWord
products
during

the
2007-‐2008
school
year:
42%
of
the
parMcipants
crossed
the
proficiency

threshold
in
2008,
compared
to
29%
of
the
students
in
the
comparison

group.


Clarke County School District: CRCT Results

806

804

Proficiency Threshold
802

Scale Score 800

798

796

794

792
2

0
2006 2007 2008

CRCT
Wave 1- Started Fast ForWord in 2006-2007
Wave 2- Started Fast ForWord in 2007-2008
Wave 3 - Did not start Fast ForWord
before 2008 CRCT

m08clrk03mf
longitudinal scaled score CRCT
wave 1 n=571
wave 2 n=758
wave 3 n=928

Brain Activation Improves Stimulus Fidelity in the Cortex

● Rodent Audition (Harris): Neural encoding of auditory temporal
patterns is highly nonlinear and depends on brain state.

Inactive brain state

synchronized EEG,
sleep, anesthesia

Active brain state

desynchronized EEG,
alertness, attention

State for effective
coding and learning
of temporal patterns?
From the Harris Lab
AM noise stimulus

2012

Rodent Audition (Harris): Neural encoding of auditory temporal
patterns is highly nonlinear and depends on brain state.

clicks clicks
Inactive Active
brain brain
state state

2012

Cortical Representation is Degraded in the Inactivated State

Auditory clicks: 400
inactivated 400
activated
400 400
350 350

Rate (Hz)
300 300

Cortex 250 250

200 200
200 200
150 150

100 100

50 50

0 0-1 0 1 2 3 4 5 6 0
0
-1 0 1 2 3 4 5 6
0 1 2 3 4 5 0 1 2 3 4 5

Thalamic Activity Represents the Stimulus in Both States

1000
inactivated 1000
activated
1000 1000
900 900
Thalamus
Rate (Hz)

800 800

700 700

600 600

500 500
500 500
400 400

300 300

200 200

100 100

0 0
0 -1 0 1 2 3 4 5 6 0 -1 0 1 2 3 4 5 6
0 1 2 3 4 5 0 1 2 3 4 5

Minces, Harris, Chiba
seconds seconds


Burst Spiking of a Single Cortical Neuron Modifies Global
Brain State

Li, Poo, and Dan, Science 2009

Temporal Dynamics of Learning Initiative 2
OECD 2012

Timescales of investigation
Ba
Da

Whisking
10s of msec Spikes
STDP
Phoneme processing

Neuromodulation
Motor action
Brain rhythms

Action selection
Seconds Prediction
Reinforcement

Minutes LTP
Days Neurogenesis
Years Expertise

Temporal Dynamics of Learning 18
OECD 2012

Gamma Power and Language Learning
April Benasich

•  Your brain is a giant oscillator
(Buzsaki)
•  EEG power in the gamma band of
this oscillation (~40Hz) has been
implicated in attention,
perception, memory, language,
and neural synchrony
•  Gamma power increases
throughout development.
•  Can we use gamma power in
toddlers to predict language
ability?


Resting Gamma Power at 36 months of age predictsPredicts
Resting Gamma Power In the Frontal Regions language
Preschool and 5 yearsScores
skills at 4 Language of age

From Benasich Lab with Harris


Brain dynamics matter for learning…
•  These results suggests brain
dynamics are important for
cognitive function
•  Early diagnosis means we can
now think about early
interventions - perhaps a
FastForWord for toddlers
that can ameliorate the
problems that these children
face.


• In an inactivated state, cortical processing of the
stimulus is degraded in Auditory, Visual, and
Tactile modalities.

• Thalamic processing of the stimulus is
maintained in the inactive state for auditory
information but not for visual.

• Stimulus fidelity is enhanced by an activated
brain state for all modalities.
• Cortical activation can be achieved via
neuromodulation from a subcortical source
(Basal Forebrain Acetylcholine) or locally (a
single bursting cortical neuron) or from training.
• Natural activation in the form of gamma
oscillations in babies predicts later language
acquisition.
• Early identification can allow for early
intervention.


How can we drive temporal processing at rapid timescales, while also driving
group synchrony ?
Gamelan, Attention, and Synchrony!


Synchronizing with an isochronous beat

Adjust following interval
Accordingly:
10s of ms

Target beat
Filter out
Non-targets

Player

Monitor unison
Estimate and with target beat:
reproduce interval: 10s of ms
100s of ms

10s of ms Details of note shaping, beat to beat alignment

100s of ms Note to note and beat to beat movement

10s of seconds Rhythmic or melodic motives or themes

minutes Melodic phrases and chord progressions

10s of minutes - hours Musical structures and compositions

Accurate synchrony and integration

Amongst players, too


Research Questions

1) Does ability to pay attention correlate with ability to synchronize in a group setting?

2) Is this correlation, if it exists, solely due to differences in attentional allocation
or do underlying differences in time processing also exist?

3) Since it is possible to improve one s ability to synchronize through group music
practice, can such improvements translate into measurable improvements in
attentional performance?


The Gamelan Project – preliminary study

Does ability to pay attention correlate with ability to synchronize in a group setting?


Experimental instrument: aluminum keys with piezoelectric film elements


Audio recording data


Examples of good and poor synchronizers using vector strength analysis

3

3
2

2
1

1
phase 0
poor

0
-1

-1
-2

-2
-3

-3
0 10 20 30 40 50 60

14

12

10

8

6

4

2

0
3

3
2

2
1

1
0
phase

0
good
-1

-1
-2

-2
-3

-3
0 10 20 30 40 50 60

14

12

10

8

6

4

2

0

Other measures

Swann teacher ratings

Psychometric tests

Results
A significant correlation was found across all measures

p<0.0025


Passive Listening.
Sounds are all the same. We only care about timing.

deviant


Example A

Short Condition

Long Condition
Voltage uV

standard
deviant

Temporal Dynamics of Learning Time OECD 2012

Example A

Short Condition

Long Condition
Voltage uV

Sensitivity to Time

standard
deviant

Temporal Dynamics of Learning Time OECD 2012

Synchronization
Subject drums to a steady beat, even when sounds are omitted.


Drumming Data

Accuracy


sound omitted

Time (seconds)


Conclusions:

•  There exists a correlation between the ability to
synchronize and classic measures of attention

•  We have developed measures of individual
differences in temporal processing at the behavioral
and neural level

•  These differences correlate with other cognitive
characteristics across individuals
•  A tool to measure the effects of musical training
on measures of attention and classroom performance


Neuroimaging techniques provide a window into
The structural development necessary for timing

Courtesy of Terry Jernigan

How does white matter maturation relate to readiness for
academic skills? Can development be facilitated?

Thus far, longitudinal DTI findings support continued microstructural change in
white matter during late adolescence, and suggest ongoing refinement of
projection and association fibers into early adulthood. Structural asymmetries are
correlated with measures several measures of academic performance.


Why does time matter?

•  Time matters for processing

•  Time matters for learning

•  Time matters for action

•  Thus, optimizing temporal processing is a key
feature of the ability to learn effectively


Timescales of investigation Ba

Da

Whisking
10s of msec Spikes
STDP
Phoneme processing

Neuromodulation
Motor action
Brain rhythms

Action selection
Seconds Prediction
Reinforcement

Minutes LTP
Days Neurogenesis
Years Expertise


What are the implications for
education?
Timing is an essential property of the world and
the brain and it must be optimal for optimal
learning to occur.

Plasticity is an inherent feature of the brain that
can be optimized and remediated through
specific types of behavioral training.

Basic aspects of our culture including music,
exercise, and enrichment may facilitate learning
and cognition. We should be circumspect before
removing them from the curriculum.


Creating Better Learners by Driving Neuroplasticity

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Creating Better Learners by Driving Neuroplasticity