The causal role of left and right superior temporal gyri in speech perception in noise, a TMS study

Successful perception of speech in everyday listening conditions requires effective listening strategies to overcome common acoustic distortions, such as background noise. Convergent evidence from neuroimaging and clinical studies identify activation within the temporal lobes as key to successful speech perception. However, current neurobiological models disagree on whether the left temporal lobe is sufficient for successful speech perception or whether bilateral processing is required. We addressed this issue using TMS to selectively disrupt processing in either the left or right superior temporal gyrus (STG) of healthy participants to test whether the left temporal lobe is sufficient or whether both left and right STG are essential. Participants repeated keywords from sentences presented in background noise in a speech reception threshold task while receiving online repetitive TMS separately to the left STG, right STG, or vertex or while receiving no TMS. Results show an equal drop in performance following application of TMS to either left or right STG during the task. A separate group of participants performed a visual discrimination threshold task to control for the confounding side effects of TMS. Results show no effect of TMS on the control task, supporting the notion that the results of Experiment 1 can be attributed to modulation of cortical functioning in STG rather than to side effects associated with online TMS. These results indicate that successful speech perception in everyday listening conditions requires both left and right STG and thus have ramifications for our understanding of the neural organization of spoken language processing

The causal role of left and right superior temporal gyri in speech perception in noise : A Transcranial Magnetic Stimulation Study

Successful perception of speech in everyday listening conditions requires effective listening strategies to overcome common acoustic distortions, such as background noise. Convergent evidence from neuroimaging and clinical studies identify activation within the temporal lobes as key to successful speech perception. However, current neurobiological models disagree on whether the left temporal lobe is sufficient for successful speech perception or whether bilateral processing is required. We addressed this issue using TMS to selectively disrupt processing in either the left or right superior temporal gyrus (STG) of healthy participants to test whether the left temporal lobe is sufficient or whether both left and right STG are essential. Participants repeated keywords from sentences presented in background noise in a speech reception threshold task while receiving online repetitive TMS separately to the left STG, right STG, or vertex or while receiving no TMS. Results show an equal drop in performance following application of TMS to either left or right STG during the task. A separate group of participants performed a visual discrimination threshold task to control for the confounding side effects of TMS. Results show no effect of TMS on the control task, supporting the notion that the results of Experiment 1 can be attributed to modulation of cortical functioning in STG rather than to side effects associated with online TMS. These results indicate that successful speech perception in everyday listening conditions requires both left and right STG and thus have ramifications for our understanding of the neural organization of spoken language processing

A growing disconnection from nature is evident in cultural products

Human connection with nature is widely believed to be in decline, even though empirical evidence on the magnitude and temporal pattern of the change is scarce. Studying works of popular culture in English throughout the 20th century and later, we document a cultural shift away from nature, beginning in the 1950s. Since then, references to nature have been decreasing steadily in fiction, song lyrics, and film storylines. No parallel decline is observed in references to the human-made environment. These findings are cause for concern, not only because they imply foregone benefits from engagement with nature, but also because cultural products are agents of socialization that can evoke curiosity, respect, and concern for the natural world

Integrating multiple genome annotation databases improves the interpretation of microarray gene expression data

<p>Abstract</p> <p>Background</p> <p>The Affymetrix GeneChip is a widely used gene expression profiling platform. Since the chips were originally designed, the genome databases and gene definitions have been considerably updated. Thus, more accurate interpretation of microarray data requires parallel updating of the specificity of GeneChip probes. We propose a new probe remapping protocol, using the zebrafish GeneChips as an example, by removing nonspecific probes, and grouping the probes into transcript level probe sets using an integrated zebrafish genome annotation. This genome annotation is based on combining transcript information from multiple databases. This new remapping protocol, especially the new genome annotation, is shown here to be an important factor in improving the interpretation of gene expression microarray data.</p> <p>Results</p> <p>Transcript data from the RefSeq, GenBank and Ensembl databases were downloaded from the UCSC genome browser, and integrated to generate a combined zebrafish genome annotation. Affymetrix probes were filtered and remapped according to the new annotation. The influence of transcript collection and gene definition methods was tested using two microarray data sets. Compared to remapping using a single database, this new remapping protocol results in up to 20% more probes being retained in the remapping, leading to approximately 1,000 more genes being detected. The differentially expressed gene lists are consequently increased by up to 30%. We are also able to detect up to three times more alternative splicing events. A small number of the bioinformatics predictions were confirmed using real-time PCR validation.</p> <p>Conclusions</p> <p>By combining gene definitions from multiple databases, it is possible to greatly increase the numbers of genes and splice variants that can be detected in microarray gene expression experiments.</p

Transcranial magnetic stimulation and motor evoked potentials in speech perception research

Transcranial magnetic stimulation (TMS) has been employed to manipulate brain activity and to establish cortical excitability by eliciting motor evoked potentials (MEPs) in speech processing research. We will discuss the history, methodological underpinnings, key contributions, and future directions for studying speech processing using TMS and by eliciting MEPs. Furthermore, we will discuss specific challenges that are encountered when examining speech processing using TMS or by measuring MEPs. We suggest that future research may benefit from using TMS in conjunction with neuroimaging methods such as functional Magnetic Resonance Imaging or electroencephalography, and from the development of new stimulation protocols addressing cortico-cortical inhibition/facilitation and interhemispheric connectivity during speech processing

Subjective and Objective Assessment of Taste and Smell Sensation in Advanced Cancer

Context: Taste and smell abnormalities (TSA) occur throughout the cancer trajectory regardless of cancer primary site and contribute to cancer-associated malnutrition. TSA etiology is poorly understood. Tumor-related inflammation is a possible cause. Objective: This study examined the prevalence, characteristics, and severity of TSA in advanced cancer and explored the relationship between TSA and nutritional status. No previous study combined subjective and objective measures for both taste and smell assessment in this population. Method: Consecutive advanced cancer hospice patients were recruited. A modified version of the “Taste and Smell Survey” assessed subjective TSA. Validated taste strips and “Sniffin’ Sticks” were the objective measures. The abridged patient-generated subjective global assessment evaluated nutritional status. Results: A 93% prevalence of TSA in 30 patients with advanced cancer was identified. When subjective and objective evaluations were combined, 28 had taste abnormalities, 24 smell abnormalities, and 24 both. Taste changes included “persistent bad taste” (n ¼ 18) and changes in how basic tastes were perceived. Half reported smell was not “as strong” as prediagnosis, while more than half (n ¼ 16) had an objective smell abnormality. Most (97%) were at risk of malnutrition. Fatigue, dry mouth, early satiety, and anorexia were common nutrition-impact symptoms. No statistically significant relationship was found between TSA and malnutrition scores. Conclusions: TSA were highly prevalent. Subjective taste and smell changes did not always accord with objective TSA, suggesting both assessments are valuable. TSA characteristics varied, and particular foods tasted and smelled different and were not enjoyed as before. TSA are common, high-impact problems in advanced cancer

Prolonged duration of early antibiotic therapy in extremely premature infants.

BackgroundProlonged early antibiotics in extremely premature infants may have negative effects. We aimed to assess prevalence and outcomes of provision of prolonged early antibiotics to extremely premature infants in the absence of culture-confirmed infection or NEC.MethodsCohort study of infants from 13 centers born without a major birth defect from 2008-2014 who were 401-1000 grams birth weight, 22-28 weeks gestation, and survived ≥5 days without culture-confirmed infection, NEC, or spontaneous intestinal perforation. We determined the proportion of infants who received prolonged early antibiotics, defined as ≥5 days of antibiotic therapy started at ≤72 h of age, by center and over time. Associations between prolonged early antibiotics and adverse outcomes were assessed using multivariable logistic regression.ResultsA total of 5730 infants were included. The proportion of infants receiving prolonged early antibiotics varied from 30-69% among centers and declined from 49% in 2008 to 35% in 2014. Prolonged early antibiotics was not significantly associated with death (adjusted odds ratio 1.17 [95% CI: 0.99-1.40], p = 0.07) and was not associated with NEC.ConclusionsThe proportion of extremely premature infants receiving prolonged early antibiotics decreased, but significant center variation persists. Prolonged early antibiotics were not significantly associated with increased odds of death or NEC

A Waterborne Outbreak of Escherichia coli O157:H7 Infections and Hemolytic Uremic Syndrome: Implications for Rural Water Systems1

In the summer of 1998, a large outbreak of Escherichia coli O157:H7 infections occurred in Alpine, Wyoming. We identified 157 ill persons; stool from 71 (45%) yielded E. coli O157:H7. In two cohort studies, illness was significantly associated with drinking municipal water (town residents: adjusted odds ratio=10.1, 95% confidence intervals [CI]=1.8-56.4; visitors attending family reunion: relative risk=9.0, 95% CI=1.3-63.3). The unchlorinated water supply had microbiologic evidence of fecal organisms and the potential for chronic contamination with surface water. Among persons exposed to water, the attack rate was significantly lower in town residents than in visitors (23% vs. 50%, p<0.01) and decreased with increasing age. The lower attack rate among exposed residents, especially adults, is consistent with the acquisition of partial immunity following long-term exposure. Serologic data, although limited, may support this finding. Contamination of small, unprotected water systems may be an increasing public health risk

The role of hearing ability and speech distortion in the facilitation of articulatory motor cortex

Excitability of articulatory motor cortex is facilitated when listening to speech in challenging conditions. Beyond this, however, we have little knowledge of what listener-specific and speech-specific factors engage articulatory facilitation during speech perception. For example, it is unknown whether speech motor activity is independent or dependent on the form of distortion in the speech signal. It is also unknown if speech motor facilitation is moderated by hearing ability. We investigated these questions in two experiments. We applied transcranial magnetic stimulation (TMS) to the lip area of primary motor cortex (M1) in young, normally hearing participants to test if lip M1 is sensitive to the quality (Experiment 1) or quantity (Experiment 2) of distortion in the speech signal, and if lip M1 facilitation relates to the hearing ability of the listener. Experiment 1 found that lip motor evoked potentials (MEPs) were larger during perception of motor-distorted speech that had been produced using a tongue depressor, and during perception of speech presented in background noise, relative to natural speech in quiet. Experiment 2 did not find evidence of motor system facilitation when speech was presented in noise at signal-to-noise ratios where speech intelligibility was at 50% or 75%, which were significantly less severe noise levels than used in Experiment 1. However, there was a significant interaction between noise condition and hearing ability, which indicated that when speech stimuli were correctly classified at 50%, speech motor facilitation was observed in individuals with better hearing, whereas individuals with relatively worse but still normal hearing showed more activation during perception of clear speech. These findings indicate that the motor system may be sensitive to the quantity, but not quality, of degradation in the speech signal. Data support the notion that motor cortex complements auditory cortex during speech perception, and point to a role for the motor cortex in compensating for differences in hearing ability