The neural dynamics of speech perception: Dissociable networks for processing linguistic content and monitoring speaker turn-taking.

The neural circuitry for speech perception is well-characterized, yet the temporal dynamics therein are largely unknown. This timing information is critical in that spoken language almost always occurs in the context of joint speech (i.e., conversations) where effective communication requires the precise timing of speaker turn-taking-a core aspect of prosody. Here, we used event-related potentials to characterize neural activity elicited by conversation stimuli within a large, unselected adult sample (N=115). We focused on two stages of speech perception: inter-speaker gaps and speaker responses. We found activation in two known speech perception networks, with functional and neuroanatomical specificity: silence during inter-speaker gaps primarily activated the posterior pathway involving the supramarginal gyrus and premotor cortex, whereas hearing speaker responses primarily activated the anterior pathway involving the superior temporal gyrus. These data provide the first direct evidence that the posterior pathway is uniquely involved in monitoring speaker turn-taking.

Reduced or modified dietary fat for preventing cardiovascular disease.

BACKGROUND: Reduction and modification of dietary fats have differing effects on cardiovascular risk factors (such as serum cholesterol), but their effects on important health outcomes are less clear. OBJECTIVE: To assess the effect of reduction and/or modification of dietary fats on mortality, cardiovascular mortality, cardiovascular morbidity and individual outcomes including myocardial infarction, stroke and cancer diagnoses in randomised clinical trials of at least 6 months duration. SEARCH METHODS: For this review update, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Embase, were searched through to June 2010. References of Included studies and reviews were also checked. SELECTION CRITERIA: Trials fulfilled the following criteria: 1) randomized with appropriate control group, 2) intention to reduce or modify fat or cholesterol intake (excluding exclusively omega-3 fat interventions), 3) not multi factorial, 4) adult humans with or without cardiovascular disease, 5) intervention at least six months, 6) mortality or cardiovascular morbidity data available. DATA COLLECTION AND ANALYSIS: Participant numbers experiencing health outcomes in each arm were extracted independently in duplicate and random effects meta-analyses, meta-regression, sub-grouping, sensitivity analyses and funnel plots were performed. MAIN RESULTS: This updated review suggested that reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of cardiovascular events by 14% (RR 0.86, 95% CI 0.77 to 0.96, 24 comparisons, 65,508 participants of whom 7% had a cardiovascular event, I2 50%). Subgrouping suggested that this reduction in cardiovascular events was seen in studies of fat modification (not reduction - which related directly to the degree of effect on serum total and LDL cholesterol and triglycerides), of at least two years duration and in studies of men (not of women). There were no clear effects of dietary fat changes on total mortality (RR 0.98, 95% CI 0.93 to 1.04, 71,790 participants) or cardiovascular mortality (RR 0.94, 95% CI 0.85 to 1.04, 65,978 participants). This did not alter with sub-grouping or sensitivity analysis. Few studies compared reduced with modified fat diets, so direct comparison was not possible. AUTHORS' CONCLUSIONS: The findings are suggestive of a small but potentially important reduction in cardiovascular risk on modification of dietary fat, but not reduction of total fat, in longer trials. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups, should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates. The ideal type of unsaturated fat is unclear.

Reduced or modified dietary fat for preventing cardiovascular disease

ABSTRACT: BACKGROUND: Reduction and modification of dietary fats have differing effects on cardiovascular risk factors (such as serum cholesterol), but their effects on important health outcomes are less clear. OBJECTIVE: To assess the effect of reduction and/or modification of dietary fats on mortality, cardiovascular mortality, cardiovascular morbidity and individual outcomes including myocardial infarction, stroke and cancer diagnoses in randomised clinical trials of at least 6 months duration. METHODS: Search methods: For this review update, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Embase, were searched through to June 2010. References of Included studies and reviews were also checked. Selection criteria: Trials fulfilled the following criteria: 1) randomized with appropriate control group, 2) intention to reduce or modify fat or cholesterol intake (excluding exclusively omega-3 fat interventions), 3) not multi factorial, 4) adult humans with or without cardiovascular disease, 5) intervention at least six months, 6) mortality or cardiovascular morbidity data available. Data collection and analysis: Participant numbers experiencing health outcomes in each arm were extracted independently in duplicate and random effects meta-analyses, meta-regression, sub-grouping, sensitivity analyses and funnel plots were performed. MAIN RESULTS: This updated review suggested that reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of cardiovascular events by 14% (RR 0.86, 95% CI 0.77 to 0.96, 24 comparisons, 65,508 participants of whom 7% had a cardiovascular event, I2 50%). Subgrouping suggested that this reduction in cardiovascular events was seen in studies of fat modification (not reduction - which related directly to the degree of effect on serum total and LDL cholesterol and triglycerides), of at least two years duration and in studies of men (not of women). There were no clear effects of dietary fat changes on total mortality (RR 0.98, 95% CI 0.93 to 1.04, 71,790 participants) or cardiovascular mortality (RR 0.94, 95% CI 0.85 to 1.04, 65,978 participants). This did not alter with sub-grouping or sensitivity analysis. Few studies compared reduced with modified fat diets, so direct comparison was not possible. AUTHORS' CONCLUSIONS: The findings are suggestive of a small but potentially important reduction in cardiovascular risk on modification of dietary fat, but not reduction of total fat, in longer trials. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups, should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates. The ideal type of unsaturated fat is unclear.

Identifying a temporal threshold of tolerance for silent gaps after requests.

This study addresses whether there is a threshold, some particular length of silent gap between two speakers' turns, at which negative social attributions emerge. The effect of such inter-turn silence was tested by constructing dialogues where responses to requests were identical and affirmative so that study participants' (n = 380) ratings about "willingness" would be colored by lag time, not semantics. 100 ms intervals between 200 and 1200 ms were tested in a between groups design. There was a notable drop-off in ratings at 600 ms and a statistically significant difference in ratings between 700 and 800 ms.

Reduced or modified dietary fat for preventing cardiovascular disease.

BACKGROUND: Reduction and modification of dietary fats have differing effects on cardiovascular risk factors (such as serum cholesterol), but their effects on important health outcomes are less clear. OBJECTIVES: To assess the effect of reduction and/or modification of dietary fats on mortality, cardiovascular mortality, cardiovascular morbidity and individual outcomes including myocardial infarction, stroke and cancer diagnoses in randomised clinical trials of at least 6 months duration. SEARCH METHODS: For this review update, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE, were searched through to June 2010. References of Included studies and reviews were also checked. SELECTION CRITERIA: Trials fulfilled the following criteria: 1) randomised with appropriate control group, 2) intention to reduce or modify fat or cholesterol intake (excluding exclusively omega-3 fat interventions), 3) not multi factorial, 4) adult humans with or without cardiovascular disease, 5) intervention at least six months, 6) mortality or cardiovascular morbidity data available. DATA COLLECTION AND ANALYSIS: Participant numbers experiencing health outcomes in each arm were extracted independently in duplicate and random effects meta-analyses, meta-regression, sub-grouping, sensitivity analyses and funnel plots were performed. MAIN RESULTS: This updated review suggested that reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of cardiovascular events by 14% (RR 0.86, 95% CI 0.77 to 0.96, 24 comparisons, 65,508 participants of whom 7% had a cardiovascular event, I(2) 50%). Subgrouping suggested that this reduction in cardiovascular events was seen in studies of fat modification (not reduction - which related directly to the degree of effect on serum total and LDL cholesterol and triglycerides), of at least two years duration and in studies of men (not of women). There were no clear effects of dietary fat changes on total mortality (RR 0.98, 95% CI 0.93 to 1.04, 71,790 participants) or cardiovascular mortality (RR 0.94, 95% CI 0.85 to 1.04, 65,978 participants). This did not alter with sub-grouping or sensitivity analysis.Few studies compared reduced with modified fat diets, so direct comparison was not possible. AUTHORS' CONCLUSIONS: The findings are suggestive of a small but potentially important reduction in cardiovascular risk on modification of dietary fat, but not reduction of total fat, in longer trials. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups, should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates. The ideal type of unsaturated fat is unclear.

Reduced or modified dietary fat for preventing cardiovascular disease.

BACKGROUND: Reduction and modification of dietary fats have differing effects on cardiovascular risk factors (such as serum cholesterol), but their effects on important health outcomes are less clear. OBJECTIVES: To assess the effect of reduction and/or modification of dietary fats on mortality, cardiovascular mortality, cardiovascular morbidity and individual outcomes including myocardial infarction, stroke and cancer diagnoses in randomised clinical trials of at least 6 months duration. SEARCH STRATEGY: For this review update, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE, were searched through to June 2010. References of Included studies and reviews were also checked. SELECTION CRITERIA: Trials fulfilled the following criteria: 1) randomised with appropriate control group, 2) intention to reduce or modify fat or cholesterol intake (excluding exclusively omega-3 fat interventions), 3) not multi factorial, 4) adult humans with or without cardiovascular disease, 5) intervention at least six months, 6) mortality or cardiovascular morbidity data available. DATA COLLECTION AND ANALYSIS: Participant numbers experiencing health outcomes in each arm were extracted independently in duplicate and random effects meta-analyses, meta-regression, sub-grouping, sensitivity analyses and funnel plots were performed. MAIN RESULTS: This updated review suggested that reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of cardiovascular events by 14% (RR 0.86, 95% CI 0.77 to 0.96, 24 comparisons, 65,508 participants of whom 7% had a cardiovascular event, I(2) 50%). Subgrouping suggested that this reduction in cardiovascular events was seen in studies of fat modification (not reduction - which related directly to the degree of effect on serum total and LDL cholesterol and triglycerides), of at least two years duration and in studies of men (not of women). There were no clear effects of dietary fat changes on total mortality (RR 0.98, 95% CI 0.93 to 1.04, 71,790 participants) or cardiovascular mortality (RR 0.94, 95% CI 0.85 to 1.04, 65,978 participants). This did not alter with sub-grouping or sensitivity analysis.Few studies compared reduced with modified fat diets, so direct comparison was not possible. AUTHORS' CONCLUSIONS: The findings are suggestive of a small but potentially important reduction in cardiovascular risk on modification of dietary fat, but not reduction of total fat, in longer trials. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups, should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates. The ideal type of unsaturated fat is unclear.

The use of definite and indefinite articles by children with specific language impairment.

Among the grammatical limitations seen in English-speaking children with specific language impairment (SLI) is a prolonged period of using articles (e.g., a, the) inconsistently. Most studies documenting this difficulty have focused on article omission and have not made the distinction between definite and indefinite article contexts. In this study, there were 36 participants: 12 5-year-olds with SLI, 12 typically-developing children matched for age, and 12 younger, typically-developing children matched with participants in the SLI group according to mean length of utterance. All 36 children participated in a task requiring indefinite article use, and a task requiring use of the definite article, in which the referent of the noun had already been established in the discourse. The children with SLI showed less use of definite articles in particular, relative to both groups of typically-developing children. Substitutions as well as omissions were seen. The findings suggest that the article limitations of the children with SLI were attributable in part to an incomplete understanding of how definite articles are to be used.

The safety of metformin in heart failure.

OBJECTIVE: To examine the evidence regarding the safety of metformin in heart failure. DATA SOURCES: Searches in MEDLINE and International Pharmaceutical Abstracts were performed (1966-February 2007). Search terms included metformin, heart failure, lactic acidosis, clinical trials, and insulin resistance. STUDY SELECTION AND DATA EXTRACTION: Published studies and case reports that evaluated the causal link between metformin and lactic acidosis in patients with heart failure were selected for review. DATA SYNTHESIS: There were no case reports of patients who had metformin-associated lactic acidosis when heart failure was the only contraindication. Two large retrospective studies showed that metformin does not increase the risk of lactic acidosis in patients with heart failure. However, these retrospective analyses did not account for many important confounding variables. A reduction in mortality rates in metformin users with New York Heart Association Class III and IV heart failure was observed in one small (N = 94) prospective trial. CONCLUSIONS: Results from 3 trials suggest that metformin may be safe to use in heart failure. Large prospective trials are needed to provide conclusive evidence regarding metformin's safety. Until then, use of metformin in heart failure patients should not be recommended routinely. If it is used in patients with heart failure, they should be monitored closely for signs of lactic acidosis.

Perception of utterance relatedness during the first-word-period.

Interactions between six toddlers (aged 1;0 to 1;6) and adults were examined to ascertain adult perceptions of toddler utterance relatedness and to determine temporal and interactional features that underlie those perceptions. Five raters made judgments regarding relatedness of the child utterances to the previous adult utterances; 251 utterances were examined. Utterances judged by adults as related occurred within 4.25 seconds of the preceding adult utterance nearly 90% of the time. This study also points to the need for using interactional categories that go beyond describing utterance relatedness, and introduces terms (i.e. coparticipatory, initiation, narrowed focus) for doing so.

Qualitative differences among cancer clinical trial explanations.

This paper examines how medical oncologists present to breast cancer patients the option of participating in experimental treatment trials. The investigation takes a case study approach, comparing two contrasting presentations of the clinical trial option. One presentation constructs the experimental trial as a locally organized, joint physician-patient effort to determine "best" treatments, and minimizes uncertainty by oversimplification of the randomization process; the second presentation situates the clinical trial within the larger national research effort, underscores the uncertainty created by randomization, and casts non-enrollment as a reasonable option. These observations provide initial evidence that physician presentation of the clinical trial varies substantially and provides the first detailed look at actual discourse practices used in the United States to recruit patients to experimental protocols.