Exemplar Variability Facilitates Retention of Word Learning by Children With Specific Language Impairment.

Purpose: Variability in the input plays an important role in language learning. The current study examined the role of object variability for new word learning by preschoolers with specific language impairment (SLI). Method: Eighteen 4- and 5-year-old children with SLI were taught 8 new words in 3 short activities over the course of 3 sessions. Half of the children saw 3 identical objects corresponding to each new word during training (No Variability group); the other half of the children saw 3 different objects corresponding to each new word during training (High Variability group). Children completed vocabulary learning tests for objects seen during training and for new within-category objects that were never seen during training as a test of category generalization. Learning was assessed the day after each training activity, and retention was assessed 3 weeks after the last training session. Results: There were no group differences on trained or generalization items immediately following training sessions. However, children in the High Variability group demonstrated significantly better retention 3 weeks after experimental training. Conclusion: These findings demonstrate that object variability facilitates retention of new word learning by children with SLI. Supplemental Material: https://doi.org/10.23641/asha.5583979.

Neural Correlates of Morphology Acquisition through a Statistical Learning Paradigm.

The neural basis of statistical learning as it occurs over time was explored with stimuli drawn from a natural language (Russian nouns). The input reflected the "rules" for marking categories of gendered nouns, without making participants explicitly aware of the nature of what they were to learn. Participants were scanned while listening to a series of gender-marked nouns during four sequential scans, and were tested for their learning immediately after each scan. Although participants were not told the nature of the learning task, they exhibited learning after their initial exposure to the stimuli. Independent component analysis of the brain data revealed five task-related sub-networks. Unlike prior statistical learning studies of word segmentation, this morphological learning task robustly activated the inferior frontal gyrus during the learning period. This region was represented in multiple independent components, suggesting it functions as a network hub for this type of learning. Moreover, the results suggest that subnetworks activated by statistical learning are driven by the nature of the input, rather than reflecting a general statistical learning system.

An fMRI study of implicit language learning in developmental language impairment.

Individuals with developmental language impairment can show deficits into adulthood. This suggests that neural networks related to their language do not normalize with time. We examined the ability of 16 adults with and without impaired language to learn individual words in an unfamiliar language. Adults with impaired language were able to segment individual words from running speech, but needed more time to do so than their normal-language peers. ICA analysis of fMRI data indicated that adults with language impairment activate a neural network that is comparable to that of adults with normal language. However, a regional analysis indicated relative hyperactivation of a collection of regions associated with language processing. These results are discussed with reference to the Statistical Learning Framework and the sub-skills thought to relate to word segmentation.

Words to Sleep On: Naps Facilitate Verb Generalization in Habitually and Nonhabitually Napping Preschoolers.

A nap soon after encoding leads to better learning in infancy. However, whether napping plays the same role in preschoolers' learning is unclear. In Experiment 1 (N = 39), 3-year-old habitual and nonhabitual nappers learned novel verbs before a nap or a period of wakefulness and received a generalization test examining word extension to novel actors after 24 hr. Only habitual and nonhabitual nappers who napped after learning generalized 24 hr later. In Experiment 2 (N = 40), children learned the same verbs but were tested within 2-3 min of training. Here, habitual and nonhabitual nappers retained the mappings but did not generalize. The results suggest that naps consolidate weak learning that habitual and nonhabitual nappers would otherwise forget over periods of wakefulness.

Lack of Transmission among Close Contacts of Patient with Case of Middle East Respiratory Syndrome Imported into the United States, 2014.

In May 2014, a traveler from the Kingdom of Saudi Arabia was the first person identified with Middle East respiratory syndrome coronavirus (MERS-CoV) infection in the United States. To evaluate transmission risk, we determined the type, duration, and frequency of patient contact among health care personnel (HCP), household, and community contacts by using standard questionnaires and, for HCP, global positioning system (GPS) tracer tag logs. Respiratory and serum samples from all contacts were tested for MERS-CoV. Of 61 identified contacts, 56 were interviewed. HCP exposures occurred most frequently in the emergency department (69%) and among nurses (47%); some HCP had contact with respiratory secretions. Household and community contacts had brief contact (e.g., hugging). All laboratory test results were negative for MERS-CoV. This contact investigation found no secondary cases, despite case-patient contact by 61 persons, and provides useful information about MERS-CoV transmission risk. Compared with GPS tracer tag recordings, self-reported contact may not be as accurate.

Community Outbreak of HIV Infection Linked to Injection Drug Use of Oxymorphone--Indiana, 2015.

On January 23, 2015, the Indiana State Department of Health (ISDH) began an ongoing investigation of an outbreak of human immunodeficiency virus (HIV) infection, after Indiana disease intervention specialists reported 11 confirmed HIV cases traced to a rural county in southeastern Indiana. Historically, fewer than five cases of HIV infection have been reported annually in this county. The majority of cases were in residents of the same community and were linked to syringe-sharing partners injecting the prescription opioid oxymorphone (a powerful oral semi-synthetic opioid analgesic). As of April 21, ISDH had diagnosed HIV infection in 135 persons (129 with confirmed HIV infection and six with preliminarily positive results from rapid HIV testing that were pending confirmatory testing) in a community of 4,200 persons.

Evaluation of emergency drug releases from the Centers for Disease Control and Prevention Quarantine Stations.

The Centers for Disease Control and Prevention (CDC) Quarantine Stations distribute select lifesaving drug products that are not commercially available or are in limited supply in the United States for emergency treatment of certain health conditions. Following a retrospective analysis of shipment records, the authors estimated an average of 6.66 hours saved per shipment when drug products were distributed from quarantine stations compared to a hypothetical centralized site from CDC headquarters in Atlanta, GA. This evaluation supports the continued use of a decentralized model which leverages CDC's regional presence and maximizes efficiency in the distribution of lifesaving drugs.

Evaluation of emergency drug releases from the Centers for Disease Control and Prevention Quarantine Stations.

The Centers for Disease Control and Prevention (CDC) Quarantine Stations distribute select lifesaving drug products that are not commercially available or are in limited supply in the United States for emergency treatment of certain health conditions. Following a retrospective analysis of shipment records, the authors estimated an average of 6.66 hours saved per shipment when drug products were distributed from quarantine stations compared to a hypothetical centralized site from CDC headquarters in Atlanta, GA. This evaluation supports the continued use of a decentralized model which leverages CDC's regional presence and maximizes efficiency in the distribution of lifesaving drugs.

The development of nonadjacent dependency learning in natural and artificial languages.

Nonadjacent dependencies occur over one or more intervening units and require learners to track discontinuous sequential relationships. These discontinuous relationships are present at multiple levels in language (e.g., as seen in morphosyntactic dependencies and at the phonological level in vowel harmony). Experiments suggest that these dependencies are acquired using statistical learning mechanisms and that this learning is also affected by perceptual biases. Artificial and natural language studies have shown that infants are sensitive to these statistical regularities but there appear to be developmental constraints on learning. Developmental investigations have also examined how knowledge and processing of the intervening elements affect learning, and whether categories can be acquired using nonadjacent dependency information. WIREs Cogn Sci 2013, 4:511-522. doi: 10.1002/wcs.1244 CONFLICT OF INTEREST: The authors have declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website.