2015 Conference
The Institute for Mind and Brain organized a one-day conference on Neural Plasticity
and Learning on Friday, October 23, 2015. The first in a series of annual forums for
highlighting current topics in neurocognition, presentations addressed topics ranging
from the basic science of neural plasticity to plasticity within specific cognitive
domains, application of neuromodulatory tools to enhance plasticity, and the role
of neural plasticity in cognitive rehabilitation. The conference featured four invited
speakers as well as invited contributions by local researchers.
Neural Plasticity and Learning
There is increased recognition of the neuro-plastic capacity of the human brain, as
demonstrated by changes in regional connectivity, cell density and even neurogenesis
in the adult human brain. Such plasticity may underlie learning, adaptation to changed
environments and even responses to physical and functional damage to the organism
itself. The one-day conference on Neural Plasticity and Learning invited researchers
to consider the following questions and more: To what extent can learning be stimulated by neurophysiological intervention? Which
neuroplastic processes are most conducive to maintenance of new information/skills,
versus fast acquisition? How do neuroplastic differences between children and adults
affect their learning capacity?
Under the sponsorship of the College of Arts and Sciences, the Institute for Mind
and Brain invited students, faculty and other researchers in the field to participate.
Featured Speakers
Paul Reber, Northwestern University
The memory systems of the brain include explicit, conscious memory and a separate
type of implicit learning from experience that occurs without awareness of the content
learned. These two different types of memory depend on different neural mechanisms,
but both contribute to our ability to learn complex cognitive abilities. The relatively
less studied mechanisms of implicit learning reflect the automatic, nonconscious extraction
of statistical regularities from the environment and from behavior. These processes
contribute to a wide variety of learning phenomena, including skills, habits, intuition,
language acquisition and cognitive rehabilitation. The neural basis of implicit learning
is hypothesized to depend on pervasive, inherent neuroplasticity throughout the brain
that adaptively reshapes neural processing. A broad model of human memory systems
will be presented together with examples of the consequences of this learning process
with implications of this model for understanding learning in complex, real-world
contexts.
Marcus Meinzer, University of Queensland, Australia
Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation
technique during which weak electrical currents are administered to the scalp to modulate
human brain function. I will review recent studies of our group that have successfully
used tDCS to (1) induce short- and long-term behavioural improvement in healthy young
and older individuals and patients with different medical conditions (2) and addressed
the neural underpinnings of those improvements using functional magnetic resonance
imaging.
Michal Ben-Shachar, Bar-Ilan University, Israel
Speech production and visual word recognition both rely on long range white matter
pathways which connect distant brain regions engaged in processing different aspects
of linguistic information. We use diffusion MRI to quantify structural properties
of white matter pathways in children and adults who have had typical or atypical development
of speech production or reading. We use targeted behavioral measures in the same individuals
to identify structure-function relationships. I will present recent data from our
studies of reading development in full term and preterm born children, as well as
new results from our ongoing studies of white matter pathways in adults who stutter.
We will discuss the contribution of these findings to our understanding of plasticity
and change in the extended language system during typical and atypical development.
Gottfried Schlaug, Beth Israel Deaconess Medical Center and Harvard Medical School
Plasticity of the auditory-motor system in health and disease.
USC Speakers
Rutvik Desai, University of South Carolina
Semantic memory is used pervasively in everyday life. I will discuss the idea that
on a long term evolutionary scale, semantic memory is built through plastic use of
systems originally dedicated for sensory and motor functions. Existing sensory and
motor systems are exploited to ground lexical concepts. Plasticity and flexibility
of semantic memory continues to exist at a short millisecond scale. I will discuss
experiments that show how activation of conceptual content and the nature of its grounding
changes in the face of immediate task demands and stimulus characteristics. These
data underscore the flexible and interactive nature of memory systems and brain organization
in general.
Julius Fridriksson, University of South Carolina
Neuropsychology was founded on the premise that localized brain damage could reveal
something about the function of the damaged regions. Many foundational studies were
based on this premise. For example, the cases of Mr. Leborgne (studied by Paul Broca)
and H.M. (studied by Brenda Milner et al.) provided some initial insights into the
cortical location of speech processing and memory, respectively. Although a strong
relationship has been revealed between certain behavioral impairments and localized
brain damage (e.g. in stroke), recent studies suggest structure and function are significantly
altered in brain regions not directly included in the frank lesion. I will discuss
some of our data that shed light on the relationship between cortical damage and altered
structure and function in both proximal and distal cortical regions with primary emphasis
on impaired language processing in persons with aphasia.
Jane Roberts, University of South Carolina
Fragile X syndrome is a single gene disorder associated with reduced protein expression
(FMRP) and a fairly well defined phenotype. Fragile X is the leading heritable cause
of intellectual disabilities and autism spectrum disorder. As such, it provides an
excellent model for examining cognitive profiles within a constrained single gene
disorder. Reading difficulties have been a hallmark feature of fragile X syndrome.
However, there is variability in the level of literacy attainment, and very little
research has examined the cognitive or genetic processes involved. I will present
findings from a series of studies from our group aimed at increased understanding
of multiple facets of reading including phonological awareness and potential mechanistic
factors of protein expression, autism severity and intellectual ability, looking at
growth trajectories.