85 research outputs found
Executive functioning and speech-language skills following long-term use of cochlear implants
Neurocognitive processes such as executive functioning (EF) may influence the development of speech-language skills in deaf children after cochlear implantation in ways that differ from normal-hearing, typically developing children. Conversely, spoken language abilities and experiences may also exert reciprocal effects on the development of EF. The purpose of this study was to identify EF domains that are related to speech-language skills in cochlear implant (CI) users, compared to normal-hearing peers. Sixty-four prelingually deaf, early-implanted, long-term users of CIs and 74 normal-hearing peers equivalent in age and nonverbal intelligence completed measures of speech-language skills and three domains of EF: working memory, fluency-speed, and inhibition-concentration. Verbal working memory and fluency-speed were more strongly associated with speech-language outcomes in the CI users than in the normal-hearing peers. Spatial working memory and inhibition-concentration correlated positively with language skills in normal-hearing peers but not in CI users. The core domains of EF that are associated with spoken language development are different in long-term CI users compared to normal-hearing peers, suggesting important dissociations in neurocognitive development
Verbal learning and memory in prelingually deaf children with cochlear implants
OBJECTIVE:
Deaf children with cochlear implants (CIs) show poorer verbal working memory compared to normal-hearing (NH) peers, but little is known about their verbal learning and memory (VLM) processes involving multi-trial free recall.
DESIGN:
Children with CIs were compared to NH peers using the California Verbal Learning Test for Children (CVLT-C).
STUDY SAMPLE:
Participants were 21 deaf (before age 6 months) children (6-16 years old) implanted prior to age 3 years, and 21 age-IQ matched NH peers.
RESULTS:
Results revealed no differences between groups in number of words recalled. However, CI users showed a pattern of increasing use of serial clustering strategies across learning trials, whereas NH peers decreased their use of serial clustering strategies. In the CI sample (but not in the NH sample), verbal working memory test scores were related to resistance to the build-up of proactive interference, and sentence recognition was associated with performance on the first exposure to the word list and to the use of recency recall strategies.
CONCLUSIONS:
Children with CIs showed robust evidence of VLM comparable to NH peers. However, their VLM processing (especially recency and proactive interference) was related to speech perception outcomes and verbal WM in different ways from NH peers
Executive Functioning Skills in Preschool-Age Children With Cochlear Implants
Purpose
The purpose of this study was to determine whether deficits in executive functioning (EF) in children with cochlear implants (CIs) emerge as early as the preschool years.
Method
Two groups of children ages 3 to 6 years participated in this cross-sectional study: 24 preschoolers who had CIs prior to 36 months of age and 21 preschoolers with normal hearing (NH). All were tested on normed measures of working memory, inhibition-concentration, and organization-integration. Parents completed a normed rating scale of problem behaviors related to EF. Comparisons of EF skills of children with CIs were made to peers with NH and to published nationally representative norms.
Results
Preschoolers with CIs showed significantly poorer performance on inhibition-concentration and working memory compared with peers with NH and with national norms. No group differences were found in visual memory or organization-integration. When data were controlled for language, differences in performance measures of EF remained, whereas differences in parent-reported problems with EF were no longer significant. Hearing history was generally unrelated to EF.
Conclusions
This is the first study to demonstrate that EF deficits found in older children with CIs begin to emerge as early as preschool years. The ability to detect these deficits early has important implications for early intervention and habilitation after cochlear implantation
Tracing the evolutionary stage of Bok globules: CCS and NH3
We pursue the investigation of a previously proposed correlation between
chemical properties and physical evolutionary stage of isolated low-mass
star-forming regions. In the past, the NH3/CCS abundance ratio was suggested to
be a potentially useful indicator for the evolutionary stage of cloud cores. We
aim to study its applicability for isolated Bok globules. A sample of 42 Bok
globules with and without signs of current star formation was searched for
CCS(2-1) emission, the observations were complemented with NH3 measurements
available in the literature and own observations. The abundance ratio of both
molecules is discussed with respect to the evolutionary stage of the objects
and in the context of chemical models. The NH3/CCS ratio could be assessed for
18 Bok globules and is found to be moderately high and roughly similar across
all evolutionary stages from starless and prestellar cores towards internally
heated cores harbouring protostars of Class 0, Class I or later. Bok globules
with extremely high CCS abundance analogous to carbon-chain producing regions
in dark cloud cores are not found. The observed range of NH3/CCS hints towards
a relatively evolved chemical state of all observed Bok globules.Comment: 12 pages, 6 figures, accepted for publication in Astronomy &
Astrophysic
Neural correlates of the processing of co-speech gestures
In communicative situations, speech is often accompanied by gestures. For example, speakers tend to illustrate certain contents of speech by means of iconic gestures which are hand movements that bear a formal relationship to the contents of speech. The meaning of an iconic gesture is determined both by its form as well as the speech context in which it is performed. Thus, gesture and speech interact in comprehension. Using fMRI, the present study investigated what brain areas are involved in this interaction process. Participants watched videos in which sentences containing an ambiguous word (e.g. She touched the mouse) were accompanied by either a meaningless grooming movement, a gesture supporting the more frequent dominant meaning (e.g. animal) or a gesture supporting the less frequent subordinate meaning (e.g. computer device). We hypothesized that brain areas involved in the interaction of gesture and speech would show greater activation to gesture-supported sentences as compared to sentences accompanied by a meaningless grooming movement. The main results are that when contrasted with grooming, both types of gestures (dominant and subordinate) activated an array of brain regions consisting of the left posterior superior temporal sulcus (STS), the inferior parietal lobule bilaterally and the ventral precentral sulcus bilaterally. Given the crucial role of the STS in audiovisual integration processes, this activation might reflect the interaction between the meaning of gesture and the ambiguous sentence. The activations in inferior frontal and inferior parietal regions may reflect a mechanism of determining the goal of co-speech hand movements through an observation-execution matching process
A study of three southern high-mass star-forming regions
Based on color-selected IRAS point sources, we have started to conduct a
survey of 47 high-mass star-forming regions in the southern hemisphere in 870um
dust continuum and molecular line emission in several frequency ranges between
290 GHz and 806 GHz. This paper describes the pilot study of the three sources
IRAS12326-6245, IRAS16060-5146, and IRAS16065-5158. To characterize the
physical and chemical properties of southern massive star-forming regions, the
three high-luminosity southern hemisphere hot cores were observed with APEX in
five frequency setups aimed at groups of lines from the following molecules:
CH3OH, H2CO, and CH3CN. Using the LTE approximation, temperatures, source
sizes, and column densities were determined through modeling of synthetic
spectra with the XCLASS program. Dust continuum observations were done with the
Large APEX BOlometer CAmera (LABOCA) at 870um and the 3mm continuum was imaged
with the ATCA. Based on the detection of high-excitation CH3CN lines and lines
from complex organic species, the three sources are classified as line rich,
hot core type sources. For all three, the modeling indicates that the line
emission emerges from a combination of an extended, cooler envelope, and a hot
compact component. All three sources show an overabundance of oxygen-bearing
species compared to nitrogen-bearing species. Based on the results obtained in
the three sources, which served as templates for the survey, the most promising
(and feasible) frequency setups for the remaining 44 sources were decided upon.Comment: 18 pages, 28 figures plus 23 pages online material; accepted for
publication in A&
Design and Bolometer Characterization of the SPT-3G First-year Focal Plane
During the austral summer of 2016-17, the third-generation camera, SPT-3G,
was installed on the South Pole Telescope, increasing the detector count in the
focal plane by an order of magnitude relative to the previous generation.
Designed to map the polarization of the cosmic microwave background, SPT-3G
contains ten 6-in-hexagonal modules of detectors, each with 269 trichroic and
dual-polarization pixels, read out using 68x frequency-domain multiplexing.
Here we discuss design, assembly, and layout of the modules, as well as early
performance characterization of the first-year array, including yield and
detector properties.Comment: Conference proceeding for Low Temperature Detectors 2017. Accepted
for publication: 27 August 201
Integration of iconic gestures and speech in left superior temporal areas boosts speech comprehension under adverse listening conditions
Iconic gestures are spontaneous hand movements that illustrate certain contents of speech and, as such, are an important part of face-to-face communication. This experiment targets the brain bases of how iconic gestures and speech are integrated during comprehension. Areas of integration were identified on the basis of two classic properties of multimodal integration, bimodal enhancement and inverse effectiveness (i.e., greater enhancement for unimodally least effective stimuli). Participants underwent fMRI while being presented with videos of gesture-supported sentences as well as their unimodal components, which allowed us to identify areas showing bimodal enhancement. Additionally, we manipulated the signal-to-noise ratio of speech (either moderate or good) to probe for integration areas exhibiting the inverse effectiveness property. Bimodal enhancement was found at the posterior end of the superior temporal sulcus and adjacent superior temporal gyrus (pSTS/STG) in both hemispheres, indicating that the integration of iconic gestures and speech takes place in these areas. Furthermore, we found that the left pSTS/STG specifically showed a pattern of inverse effectiveness, i.e., the neural enhancement for bimodal stimulation was greater under adverse listening conditions. This indicates that activity in this area is boosted when an iconic gesture accompanies an utterance that is otherwise difficult to comprehend. The neural response paralleled the behavioral data observed. The present data extends results from previous gesture-speech integration studies in showing that pSTS/STG plays a key role in the facilitation of speech comprehension through simultaneous gestural input
Tracking the spatial diffusion of influenza and norovirus using telehealth data: A spatiotemporal analysis of syndromic data
Background: Telehealth systems have a large potential for informing public health authorities in
an early stage of outbreaks of communicable disease. Influenza and norovirus are common viruses
that cause significant respiratory and gastrointestinal disease worldwide. Data about these viruses
are not routinely mapped for surveillance purposes in the UK, so the spatial diffusion of national
outbreaks and epidemics is not known as such incidents occur. We aim to describe the
geographical origin and diffusion of rises in fever and vomiting calls to a national telehealth system,
and consider the usefulness of these findings for influenza and norovirus surveillance.
Methods: Data about fever calls (5- to 14-year-old age group) and vomiting calls (≥ 5-year-old age
group) in school-age children, proxies for influenza and norovirus, respectively, were extracted
from the NHS Direct national telehealth database for the period June 2005 to May 2006. The
SaTScan space-time permutation model was used to retrospectively detect statistically significant
clusters of calls on a week-by-week basis. These syndromic results were validated against existing
laboratory and clinical surveillance data.
Results: We identified two distinct periods of elevated fever calls. The first originated in the
North-West of England during November 2005 and spread in a south-east direction, the second
began in Central England during January 2006 and moved southwards. The timing, geographical
location, and age structure of these rises in fever calls were similar to a national influenza B
outbreak that occurred during winter 2005–2006. We also identified significantly elevated levels of
vomiting calls in South-East England during winter 2005–2006.
Conclusion: Spatiotemporal analyses of telehealth data, specifically fever calls, provided a timely
and unique description of the evolution of a national influenza outbreak. In a similar way the tool
may be useful for tracking norovirus, although the lack of consistent comparison data makes this
more difficult to assess. In interpreting these results, care must be taken to consider other
infectious and non-infectious causes of fever and vomiting. The scan statistic should be considered
for spatial analyses of telehealth data elsewhere and will be used to initiate prospective geographical
surveillance of influenza in England.
The Earliest Phases of Star Formation (EPoS): a Herschel key project. The thermal structure of low-mass molecular cloud cores
Context. The temperature and density structure of molecular cloud cores are the most important physical quantities that determine the course of the protostellar collapse and the properties of the stars they form. Nevertheless, density profiles often rely either on the simplifying assumption of isothermality or on observationally poorly constrained model temperature profiles. The instruments of the Herschel satellite provide us for the first time with both the spectral coverage and the spatial resolution that is needed to directly measure the dust temperature structure of nearby molecular cloud cores.
Aims: With the aim of better constraining the initial physical conditions in molecular cloud cores at the onset of protostellar collapse, in particular of measuring their temperature structure, we initiated the guaranteed time key project (GTKP) ''The Earliest Phases of Star Formation'' (EPoS) with the Herschel satellite. This paper gives an overview of the low-mass sources in the EPoS project, the Herschel and complementary ground-based observations, our analysis method, and the initial results of the survey.
Methods: We study the thermal dust emission of 12 previously well-characterized, isolated, nearby globules using FIR and submm continuum maps at up to eight wavelengths between 100 {}m and 1.2 mm. Our sample contains both globules with starless cores and embedded protostars at different early evolutionary stages. The dust emission maps are used to extract spatially resolved SEDs, which are then fit independently with modified blackbody curves to obtain line-of-sight-averaged dust temperature and column density maps.
Results: We find that the thermal structure of all globules (mean mass 7 M) is dominated by external heating from the interstellar radiation field and moderate shielding by thin extended halos. All globules have warm outer envelopes (14-20 K) and colder dense interiors (8-12 K) with column densities of a few 10 cm. The protostars embedded in some of the globules raise the local temperature of the dense cores only within radii out to about 5000 AU, but do not significantly affect the overall thermal balance of the globules. Five out of the six starless cores in the sample are gravitationally bound and approximately thermally stabilized. The starless core in CB 244 is found to be supercritical and is speculated to be on the verge of collapse. For the first time, we can now also include externally heated starless cores in the L/L vs. T diagram and find that T {lt} 25 K seems to be a robust criterion to distinguish starless from protostellar cores, including those that only have an embedded very low-luminosity object. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Partially based on observations carried out with the IRAM 30 m Telescope, with the Atacama Pathfinder Experiment (APEX), and with the James Clerk Maxwell Telescope (JCMT). IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain). APEX is a collaboration between Max Planck Institut für Radioastronomie (MPIfR), Onsala Space Observatory (OSO), and the European Southern Observatory (ESO). The JCMT is operated by the Joint Astronomy Centre on behalf of the Particle Physics and Astronomy Research Council of the United Kingdom, the Netherlands Association for Scientific Research, and the National Research Council of Canada.Appendices A, B and C are available in electronic form at http://www.aanda.orgInterstellar matter and star formatio
- …