Classroom Phonological Awareness Instruction Improves
A short, intensive period of classroom phonological
awareness instruction in the first year of school can raise the literacy
profiles of children with and without spoken language difficulties, according to a study in the April 2013 issue of Language, Speech, and Hearing Services in Schools.
Despite strong investment in raising literacy achievement
for all children, significant inequalities in literacy persist in some of the
world's most advanced economies.
Researchers used a quasi-experimental design to measure the
phonological awareness, reading and spelling development of 129 5-year-olds.
Thirty-four children received 10 weeks of phonological awareness instruction
from their classroom teachers. Ninety-five children continued with their usual
reading program, which included phonics instruction but did not target
Children who received phonological awareness instruction
demonstrated superior literacy outcomes compared to children who followed the
usual literacy curriculum. Children with spoken language impairment showed
significant improvements in phonological awareness, reading and spelling, but had
a different response pattern to instruction compared to children with typical
language. Significantly, 6 percent of children who received phonological
awareness instruction experienced word decoding difficulties at the end of the
program, compared with 26 percent of the children who followed the usual
Children With Specific Language Impairment Vulnerable to
A study in the April 2013 issue of the Journal of Speech, Language, and Hearing Research replicates
previous findings that children with specific language impairment name pictures
more slowly than do chronological age-matched peers. But the results also
suggest that children with specific language impairment are more vulnerable to
increased competition from words with frequent phonotactic patterns, which also
come from dense phonological neighborhoods.
Rapid naming depends on two factors known to be problematic
for children with SLI—lexical retrieval and nonlinguistic speed of processing.
Although all studies implicate a speed-of-processing deficit as a contributing
factor, researchers do not agree on the influence of language factors. The
study aimed to explore word frequency and phonotactic pattern frequency as
potential lexical factors contributing to the naming deficits experienced by
children with SLI.
Researchers asked three groups of children—20 children with
SLI (median age 9 years, 8 months), 20 younger controls, and 20 chronological
age-matched peers—to name pictures whose labels varied by word and phonotactic
pattern frequency. Reaction time results revealed significant main effects of
group and word frequency. Effects due to word frequency were comparable for all
groups, but a significant interaction between group and phonotactic pattern
frequency revealed that phonotactic pattern frequency effects (that is, greater
vulnerability to increased competition from high-frequency and high-density
words) were greater for children with SLI than for vocabulary-matched children
or chronological age-matched peers.
Parent and Teacher Ratings Reveal Poor Executive Function in
Children With SLI
Parent and teacher perceptions of executive functioning in
children with specific language impairment align with prior findings of
executive function deficits documented on neuropsychological assessments and
experimental tasks, according to a study in the May 2013 issue of the American Journal of Speech-Language Pathology.
The results provide additional evidence of the relationship between language
abilities and executive functioning in early child development.
Researchers assessed 19 preschoolers with specific language
impairment and 19 age- and gender-matched typically developing peers, using the
Behavior Rating Inventory of Executive Function-Preschool Version, a rating
scale designed to investigate executive behaviors in everyday activities. The
participants' parents and teachers also completed the BRIEF–P.
Parents and teachers rated the executive functioning of
children with specific language impairment significantly worse than that of
controls. Adults' perceptions of the children's executive functioning significantly correlated with the children's language abilities.
Wide Dynamic Range Compression Improves Speech Recognition
In a systematic review, researchers found moderate evidence
suggesting that audibility is improved, and speech recognition either
maintained or improved, when a wide range of sounds is compressed into a
narrower range, as compared with simply making the sounds louder. The study,
published in the December 2012 issue of the American Journal of Audiology, found significant differences
between compression limiting and peak clipping on outcomes—that is, speech
recognition and self- or parent report—reported across the review.
Researchers developed two clinical questions. One addressed
the comparison of linear amplification with compression limiting (reducing
peaks in sound by compressing the signal) to linear amplification with peak
clipping (reducing peaks by limiting the maximum sound level). The second
compared wide dynamic range compression with linear amplification for outcomes
of audibility, speech recognition, speech and language, and self- or parent
report in children with hearing loss.
Researchers systematically searched 26 databases for studies
addressing a clinical question and meeting all inclusion criteria. They
evaluated studies for methodological quality, and effect sizes were reported or
calculated when possible. The search yielded eight studies. All eight studies
included comparisons of wide dynamic range compression to linear amplification,
and two of the eight provided comparisons of compression limiting versus peak
clipping. Researchers warn that further research is needed before conclusions
can be drawn confidently.
Cilia Research Opens New Avenues for Treating Hearing Loss
Experiments at Johns Hopkins University have unearthed clues
about which protein signaling molecules are allowed into hollow, hair-like
"antennae"—cilia—that alert cells to critical changes in their environments.
Researchers found that the size limit for entry is much greater than previously
thought, allowing most of a cell's proteins into cilia, according to a study published online in the journal Nature Chemical Biology on May 12, 2013.
Primary cilia protrude from most cells in a wide variety of
organisms, and defects in cilia have been implicated in everything from
polycystic kidney disease to vision and hearing loss. The researchers believe
that the specific collection of proteins in each cilium, customized to the
needs of each cell type, is determined by whether and how cilia keep proteins
inside once they enter—not which ones they allow in initially. Previous
research suggested a fixed pore at the base of a cilium allows only relatively
small molecules inside. By developing more sensitive experimental methods,
scientists demonstrated that molecules almost 10 times larger than those known
before could enter.
The researchers first engineered an anchor-like molecule
that selectively embedded itself in the membranes of cilia. On the inside end
of the anchor was half of a "molecular snapper." Inside the watery interior of the cell, the team placed fluorescent molecules of known size, fitted with the other half of the molecular snapper. If these fluorescent molecules entered cilia, they would carry their fluorescence with them and be trapped inside when the snappers clicked together, allowing the researchers to easily take images of them.
By repeating this experiment many times with molecules of
increasing size, the team was able to show that every molecular size they
tested was able to enter the cilia. The only difference between the molecules
of different sizes was their rate of entry: Smaller molecules entered more
quickly than larger ones.
Environmental Enrichment as Autism Treatment
In the first successful experiment with humans using a
treatment known as sensory-motor or environmental enrichment, researchers
documented marked improvement in young boys with autism when compared to
traditional behavioral therapies, according to research published online in the American Psychological Association journal Behavioral Neuroscience, May 20, 2013.
Researchers divided 28 boys with autism, ages 3 to 12, into
two groups based on age and autism severity. For six months, both groups
participated in standard behavioral therapy—but boys in one of the groups also
underwent daily environmental enrichment exercises.
Parents of children in the enrichment group—with the help of
kits containing scents, textured and household items, and
manipulatives—conducted two daily sessions of four to seven exercises involving
different combinations of sensory stimuli for touch, temperature, sight and
movement. Each session took 15 to 30 minutes to complete. The children also
listened to classical music once a day.
Following six months of treatment, 42 percent of the
children in the enrichment group significantly improved in behaviors such as
relating to people and responding to sights and sounds, compared to 7 percent
of the standard care group. The children in the enrichment group also improved
on scores for cognitive function, which covers aspects of perception and
reasoning, whereas the average scores for the children in the standard care
group decreased. In addition, 69 percent of parents in the enrichment group
reported improvement in their child's overall autism symptoms, compared to 31
percent of parents in the standard care group.
The researchers are conducting a larger randomized clinical
trial that includes girls. Another important next step will be to test
environmental enrichment therapy when a child is not also receiving other
standard treatments, the authors noted.
Shift of Language Function Impedes Post-Stroke Aphasia
In a study designed to differentiate why some stroke
patients recover from aphasia and others do not, investigators have found that
an active right hemisphere bodes poorly for language recovery. Patients who
recovered from aphasia returned to normal left-hemispheric language activation
patterns—a discovery that may open up new rehabilitation strategies—according
to results published in the July 2013 issue of Restorative Neurology and Neuroscience.
Researchers recruited 27 right-handed adults who experienced
a left-middle cerebral artery infarction at least one year prior to study
enrollment. After language testing, nine participants were considered to have
normal language ability and 18 considered to have aphasia. Participants
completed a battery of language tests and a semantic decision/tone decision
cognitive task during functional magnetic resonance imaging to map language
function and determine stroke volume.
The authors found that those who had stronger
left-hemispheric fMRI signals performed better on linguistic tasks than those
who had stronger signal shifts to the right hemisphere. As expected, they also
found a negative association between the size of the functional lesion and
performance on some linguistic tests. Right cerebellar activation was also
linked to better post-stroke language ability.
The authors say that although a shift to the non-dominant
right hemisphere may be associated with restored language function in children
who have experienced left-hemispheric injury or stroke, for adults such a shift
has been hypothesized to impede recovery. For adults, the left hemisphere may
be necessary for language function preservation and recovery. The fact that
left perisylvian lesion size is predictive of right-hemisphere activation may also
help to explain the study's findings.