Phonological awareness predicts activation patterns for print and speech.
Annals of Dyslexia, June, 2009 Vol. 59, No. 1, Pages 78-97.
Using fMRI, we explored the relationship between phonological awareness (PA), a measure of metaphonological knowledge of the segmental structure of speech, and brain activation patterns during processing of print and speech in young readers from 6 to 10 years of age. Behavioral measures of PA were positively correlated with activation levels for print relative to speech tokens in superior temporal and occipito-temporal regions. Differences between print-elicited activation levels in superior temporal and inferior frontal sites were also correlated with PA measures with the direction of the correlation depending on stimulus type: positive for pronounceable pseudowords and negative for consonant strings. These results support and extend the many indications in the behavioral and neurocognitive literature that PA is a major component of skill in beginning readers and point to a developmental trajectory by which written language engages areas originally shaped by speech for learners on the path toward successful literacy acquisition.
Authors: Stephen J. Frost, Nicole Landi, W. Einar Mencl, Rebecca Sandak , Robert K. Fulbright, Eleanor T. Tejada , Leslie Jacobsen, Elena L. Grigorenko, R. Todd Constable, Kenneth R. Pugh.
2008
Effects of Stimulus Difficulty and Repetition on Printed Word Identification: An fMRI Comparison of Nonimpaired and Reading-disabled Adolescent Cohorts
Journal of Cognitive Neuroscience, July, 2008, Vol. 20, No. 7, Pages 1146-1160.
Functional neuroimaging studies indicate that a primary marker of specific reading disability (RD) is reduced activation of left hemisphere (LH) posterior regions during performance of reading tasks. However, the severity of this disruption, and the extent to which these LH systems might be available for reading under any circumstances, is unclear at present. Experiment 1 examined the cortical effects of stimulus manipulations (frequency, imageability, consistency) that have known facilitative effects on reading performance for both nonimpaired (NI) and RD readers. Experiment 2 examined stimulus repetition, another facilitative variable, in an additional sample of adolescent NI and RD readers. For NI readers, factors that made words easier to process were associated with relatively reduced activation. For RD readers, facilitative factors resulted in increased activation in these same reading-related sites, suggesting that the LH reading circuitry in adolescent RD is poorly trained but not wholly disrupted.
Authors: Kenneth R. Pugh, Stephen J. Frost, Rebecca Sandak, Nicole Landi, Jay G. Rueckl, R. Todd Constable, Mark S. Seidenberg, Robert K. Fulbright, Leonard Katz, and W. Einar Mencl
2005
Examining reading development and reading
disability in English language learners: Potential contributions
from functional neuroimaging.
[ Neuroimaging studies have suggested that across different written
languages, skilled reading behavior is supported by similar, largely
left hemisphere (LH), networks. In addition, recent studies of reading
disability (RD) in monolingual readers, conducted in several languages,
suggest a common neurobiological signature for this syndrome (disruption
of LH posterior regions that support fluent reading). Thus, at the
neurobiological level of analysis, reading and its disorders appear
to be more similar than dissimilar across languages. In this article,
we consider the neurobiology of reading development and RD in English
language learners (ELL). There is some evidence suggesting that
fluent bilingual readers tend to engage primarily overlapping circuits
for both L1 and L2. There is, however, a paucity of neurobiological
research on both reading development and RD in this population.
Using the existing research on RD as a starting point, we consider
in this article how developmental neuroimaging techniques might
be applied to (1) help identify RD readers in the ELL populations,
and (2) provide neurobiological outcome measures to help evaluate
the efficacy of different approaches to the teaching of reading
in English. ]
Authors: Kenneth R. Pugh, Rebecca
Sandak, Stephen J. Frost, Dina Moore, and W. Einar Mencl
2004
Development of left occipitotemporal
systems for skilled reading in children after a phonologically-based
intervention.
[ A range of neurobiological investigations shows a failure of left
hemisphere posterior brain systems to function properly during reading
in children and adults with reading disabilities. Such evidence
of a disruption in the normal reading pathways provides a neurobiological
target for reading interventions. In this study, we hypothesized
that the provision of an evidence-based, phonologically mediated
reading intervention would improve reading fluency and the development
of the fast-paced occipitotemporal systems serving skilled reading.
]
Authors: Bennett A. Shaywitz, Sally
E. Shaywitz, Benita A. Blachman, Kenneth R. Pugh, Robert K. Fulbright,
Pawel Skudlarski, W. Einar Mencl, R. Todd Constable, John M. Holahan,
Karen E. Marchione, Jack M. Fletcher, G. Reid Lyon, and John C.
Gore
2001
Neurobiological studies of reading and
reading disability.
[ Evidence from neuroimaging studies, including our own, suggest
that skilled word identification in reading is related to the functional
integrity of two consolidated left hemisphere (LH) posterior systems:
a dorsal (temporo-parietal) circuit and a ventral (occipito-temporal)
circuit. This posterior system appears to be functionally disrupted
in developmental dyslexia. Relative to nonimpaired readers, reading-disabled
individuals demonstrate heightened reliance on both inferior frontal
and right hemisphere posterior regions, presumably in compensation
for the LH posterior difficulties. We propose a neurobiological
account suggesting that for normally developing readers, the dorsal
circuit predominates at first, and in conjunction with premotor
systems, is associated with analytic processing necessary for learning
to integrate orthographic with phonological and lexical-semantic
features of printed words. The ventral circuit constitutes a fast,
late-developing, word form system, which underlies fluency in word
recognition. ]
Authors: Kenneth R. Pugh, W. Einar
Mencl, Annette R. Jenner,
Leonard Katz, Stephen J. Frost, Jun Ren Lee,
Sally E. Shaywitz, Bennett A. Shaywitz
Neuroimaging studies of reading development
and reading disability.
[ Converging evidence from a number of neuroimaging studies, including
our own, suggest that fluent word identification in reading is related
to the functional integrity of two left hemisphere posterior systems:
a temporo-parietal system and a ventral occipito-temporal system.
These posterior systems are functioanlly disrupted in developmental
dyslexia. Reading disable, relative to nonimpaired, readers deomnstrate
heightened reliance on both inferior frontal and right hemisphere
posterior regions, presumably in compensation for the LH posterior
difficulties. We propose a neurobiological account suggesting that
for normally developing readers the temporo-parietal system predominates
at first, and is associated with aspects of processing critical
in learning to integrate orthography with phonological and lexical-semantic
features of printed words. The occipito-temporal system, by contrast,
constitues a fast, late-developing, word-identification system that
underlies fluent word recognition in skilled readers. ]
Authors: Kenneth R. Pugh, W. Einar Mencl, Annette
R. Jenner, Jun Ren Lee,
Leonard Katz, Stephen J. Frost,
Sally E. Shaywitz, Bennett A. Shaywitz
2000
An event-related neuroimaging study
distinguishing form and content in sentence processing.
[ Two coordinated experiments using functional Magnetic Resonance
Imaging (fMRI) investigated whether the brain represents language
form (grammatical structure) separately from its meaning content
(semantics). While in the scanner, 14 young, unimpaired adults listened
to simple sentences that were either nonanomalous or contained a
grammatical error (for example, *Trees can grew.), or a semantic
anomaly (for example, *Trees can eat.). A same/different tone pitch
judgment task provided a baseline that isolated brain activity associated
with linguistic processing from background activity generated by
attention to the task and analysis of the auditory input. Sites
selectively activated by sentence processing were found in both
hemispheres in inferior frontal, middle, and superior frontal, superior
temporal, and temporo-parietal regions. Effects of syntactic and
semantic anomalies were differentiated by some nonoverlapping areas
of activation: Syntactic anomaly triggered significantly increased
activity in and around Broca's area, whereas semantic anomaly activated
several other sites anteriorly and posteriorly, among them Wernicke's
area. These dissociations occurred when listeners were not required
to attend to the anomaly. The results confirm that linguistic operations
in sentence processing can be isolated from nonlinguistic operations
and support the hypothesis of a specialization for syntactic processing.
]
Authors: W. Ni, R. T. Constable,
W. E. Mencl and K. R. Pugh, R. K. Fulbright, S. E. Shaywitz, B.
A. Shaywitz, and J. C. Gore, D. Shankweiler
Functional neuroimaging studies of reading
and reading disability (Developmental dyslexia).
[ Converging evidence from a number of neuroimaging studies, including
our own, suggest that fluent word identification in reading is related
to the functional integrity of two consolidated left hemisphere
(LH) posterior systems: a dorsal (temporo-parietal) circuit and
a ventral (occipitotemporal) circuit. This posterior system is functionally
disrupted in developmental dyslexia. Reading disabled readers, relative
to nonimpaired readers, demonstrate heightened reliance on both
inferior frontal and right hemisphere posterior regions, presumably
in compensation for the LH posterior difficulties. We propose a
neurobiological account suggesting that for normally developing
readers the dorsal circuit predominates at first, and is associated
with analytic processing necessary for learning to integrate orthographic
features with phonological and lexical-semantic features of printed
words. The ventral circuit constitutes a fast, late-developing,
word identification system which underlies fluent word recognition
in skilled readers. ]
Authors: Kenneth R. Pugh, W. Einar
Mencl, Annette R. Jenner, Jun Ren Lee,
Leonard Katz, Stephen J. Frost, Sally E. Shaywitz, Bennett A. Shaywitz
The angular gyrus in developmental dyslexia:
Task-specific differences in functional connectivity within posterior
cortex.
[ Converging evidence from neuroimaging studies of developmental
dyslexia reveals dysfunction at posterior brain regions centered
in and around the angular gyrus in the left hemisphere. We examined
functional connectivity (covariance) between the angular gyrus and
related occipital and temporal lobe sites, across a series of print
tasks that systematically varied demands on phonological assembly.
Results indicate that for dyslexic readers a disruption in functional
connectivity in the language-dominant left hemisphere is confined
to those tasks that make explicit demands on assembly. In contrast,
on print tasks that do not require phonological assembly, functional
connectivity is strong for both dyslexic and nonimpaired readers.
The findings support the view that neurobiological anomalies in
developmental dyslexia are largely confined to the phonologicalprocessing
domain. In addition, the findings suggest that right hemisphere
posterior regions serve a compensatory role in mediating phonological
performance in dyslexic readers. ]
Authors: Kenneth R. Pugh, W. Einar
Mencl, Bennett A. Shaywitz, Sally E. Shaywitz,
Robert K. Fulbright, R. Todd Constable, Pawel Skudlarski, Karen
E. Marchione,
Annette R. Jenner, Jack M. Fletcher, Alvin M. Liberman,
Donald P. Shankweiler, Leonard Katz, Cheryl Lacadie, and John C.
Gore
1997
Predicting reading performance from
neuroimaging profiles: The cerebral basis of phonological effects
in printed word identification.
[ This study linked 2 experimental paradigms for the analytic study
of reading that heretofore have been used separately. Measures on
a lexical decision task designed to isolate phonological effects
in the identifieadon of printed words were examined in young adults.
The results were related to previously obtained measures of brain
activation patterns for these participants derived from functional
magnetic resonance imaging (fMRI). The fM1LI measures were taken
as the participants performed tasks that were designed to isolate
orthographic, phonological, and lexical-semantic processes in reading.
Individual differences in the magnitude of phonological effects
in word recognition, as indicated by spelling-to-sound regularity
effects on lexical decision latencies and by sensitivity to stimulus
length effects, were strongly related to differences in the degree
of hemispheric lateralization in 2 cortical regions. ]
Authors: Kenneth R. Pugh, Donald
P. Shankweiler, Leonard Katz, Bennett A. Shaywitz, Sally E. Shaywitz,
Jack M. Fletcher, Pawel Skudlarski, Robert K. Fulbright, R. Todd
Constable, Richard A. Bronen, Cheryl Lacadie, and John C. Gore