(Image caption: A conceptual illustration demonstrates a key finding of a new study on brain activity: In computer simulations, applying targeted stimulation to the same region of the brain in different people resulted in different patterns of brain activity. Credit: Rebecca Farnham / Kanika Bansal / University at Buffalo)
Like instruments in an orchestra,
different parts of the human brain work together to help us perform the
functions of daily life, ranging from breathing and sleeping to reading,
walking and learning.
But which areas of the brain work in
harmony to accomplish certain types of tasks? And how does this
coordination vary from person to person?
A new study published on April 3 in Science Advances explores these questions.
research focuses on brain activity associated with nine cognitive
systems within the brain, each consisting of a network of brain regions
linked to certain functions. The auditory system, for example, helps us
process sound, whereas the ventral temporal association system is
thought to help us recognize objects, faces, colors and more.
using computational modeling to investigate the inner workings of the
brain,” says Sarah Muldoon, PhD, assistant professor of mathematics in
the University at Buffalo College of Arts and Sciences. “When one region
of the brain is stimulated, what other regions become active, and how
do these patterns of synchronization get distributed across cognitive
Muldoon led the collaborative study with Kanika Bansal,
PhD, who completed the work as a joint postdoctoral mathematics
researcher at UB and the U.S. Army Research Laboratory (ARL). Bansal is
now a postdoctoral researcher with ARL and Columbia University.
Two important findings about cognitive systems
complete the study, researchers mapped how different regions of the
brain were connected to one another in 30 different people via tracts of
tissue called white matter. (The specific connectivity pattern linking
different brain regions varies between individuals.)
scientists converted these maps into computational models of each
subject’s brain, and used computers to simulate what would happen when a
single region of a person’s brain was stimulated. The researchers then
used a mathematical framework, which they developed, to measure how
brain activity became synchronized across various cognitive systems in
The study had two broad findings:
patterns in brain activity may vary widely from person to person when
certain cognitive systems are activated. In contrast, activation of
other cognitive systems may result in repeatable patterns across
To explain further: In computer simulations, the
patterns of brain activity that emerged when some cognitive systems were
stimulated were highly stable across different people. This held true,
for example, for the auditory and medial default mode systems:
Stimulating one brain region in these systems typically resulted in
similar patterns of brain activity in different people in the
simulations, with a similar set of cognitive systems becoming active.
For other cognitive systems, such as the ventral temporal association
and frontoparietal systems, patterns of brain activity upon stimulation
varied a lot between people in computer simulations.
two different brain regions in the same cognitive system may result in
distinct patterns of large-scale brain activity in the same person — but
only for some cognitive systems (such as the auditory system).
For other cognitive systems, similar patterns of brain activity may
emerge regardless of which brain region you stimulate in that system.
This applies to the attention and subcortical systems, for example.
Probing the architecture of the mind
findings could be useful to cognitive scientists and health care
professionals. The study demonstrates, for example, why it may be
important for brain stimulation, a disease treatment technique, to be
both highly precise in terms of the location stimulated, and
personalized for different individuals.
“The brain is very
dynamic,” Bansal says. “Connections between different regions of the
brain can change with learning or deteriorate with age or neurological
disease. Connectivity also varies between people. Our research helps us
understand this variability and assess how small changes in organization
of the brain can affect large-scale patterns of brain activity related
to various cognitive systems.”
The study points to computational modeling as a powerful tool in cognitive science.
modeling enables us to do experiments that wouldn’t otherwise be
possible,” says Muldoon, who is a faculty member in UB’s Computational
and Data-Enabled Science and Engineering and Neuroscience programs in
addition to her position in the UB Department of Mathematics. “It is
simply not feasible to do these kinds of tests on real people so
computer simulations allow us to perform virtual experiments instead.”