Sound quality measures for speech in noise through a commercial hearing aid implementing digital noise reduction

This brief report discusses the affect of digital noise reduction (DNR) processing on aided speech recognition and sound quality measures in 14 adults fitted with a commercial hearing aid. Measures of speech recognition and sound quality were obtained in two different speech-in-noise conditions (71 dBA speech, +6 dB SNR and 75 dBA speech, +1 dB SNR). The results revealed that the presence or absence of DNR processing did not impact speech recognition in noise (either positively or negatively). Paired comparisons of sound quality for the same speech in noise signals, however, revealed a strong preference for DNR processing. These data suggest that at least one implementation of DNR processing is capable of providing improved sound quality, for speech in noise, in the absence of improved speech recognition.     

Larger deficits in brain networks for response inhibition than for visual selective attention in attention deficit hyperactivity disorder (ADHD)

BACKGROUND: Brain activation differences between 12 control and 12 attention deficit hyperactivity disorder (ADHD) children (9- to 12-year-olds) were examined on two cognitive tasks during functional magnetic resonance imaging (fMRI). METHOD: Visual selective attention was measured with the visual search of a conjunction target (red triangle) in a field of distracters and response inhibition was measured with a go/no-go task. RESULTS: There were limited group differences in the selective attention task, with control children showing significantly greater intensity of activation in a small area of the superior parietal lobule region of interest. There were large group differences in the response inhibition task, with control children showing significantly greater intensity of activation in fronto-striatal regions of interest including the inferior, middle, superior and medial frontal gyri as well as the caudate nucleus and globus pallidus. CONCLUSION: The widespread hypoactivity for the ADHD children on the go/no-go task is consistent with the hypothesis that response inhibition is a specific deficit in attention deficit hyperactivity disorder.     

Sustained neural activity associated with cognitive control during temporally extended decision making

Decision making has both cognitive and affective components, but previous neuroimaging studies in this domain predominantly have focused on affect and reward. The current study examined a decision-making paradigm that placed strong demands on cognitive control processes by making reward payoffs contingent upon decision-making history. Payoffs were maximized by choosing the option that, paradoxically, was associated with a lower payoff on the immediate trial. Temporal integration requirements were manipulated by varying, across conditions, the window of previous trials over which the reward function was calculated. The cognitive demands of the task were hypothesized to engage neural systems responsible for integrating and actively maintaining actions and outcomes over time and the top-down biasing of response selection. Brain activation was monitored with functional magnetic resonance imaging (fMRI) using a mixed-blocked and event-related design to extract both transient and sustained neural responses. A network of brain regions commonly associated with cognitive control functions, including bilateral prefrontal cortex (PFC), bilateral parietal cortex, and medial frontal cortex, showed selectively sustained activation during the task. Increasing temporal integration demands led to a shift from transient to sustained activity in additional regions, including right hemisphere dorsolateral and frontopolar PFC. These results demonstrate the contribution of cognitive control mechanisms to temporally extended decision-making paradigms and highlight the benefits of decomposing activation responses into sustained and transient components.     

Brain morphometry using diffusion-weighted magnetic resonance imaging: application to schizophrenia

Loss of cortical gray matter is accompanied by a commensurate increase in the sulcal and intraventricular cerebrospinal fluid volume. On diffusion-weighted magnetic resonance imaging, this would be reflected as a higher apparent diffusion coefficient in affected brain regions. On the basis of the above premise, we suggest that the apparent diffusion coefficient may be used as a surrogate marker for the assessment of regional brain volume deficits. We demonstrate this approach by voxelwise analysis of registered apparent diffusion coefficient images from a group of 15 patients with schizophrenia and 15 age-matched healthy controls. We found widespread regional apparent diffusion coefficient increases in patients. Affected areas included the bilateral insular cortex, hippocampus, temporal lobe, and occipital areas. These results largely concur with previous findings of cortical volume deficits in schizophrenia.     

Selection of outcome assessment instruments for inpatients with severe and persistent mental illness

The purpose of this article is to describe a procedure to assist in selecting outcome measures for inpatients treated at a state psychiatric hospital. The procedure combines evidence-based criteria from the literature, instruments shown to be sensitive to change in clinical trials, and the perspectives of a multidisciplinary team of researchers, administrators, providers, and patient advocates. Recent efficacy and effectiveness studies were used to identify recurrently used outcome instruments. A computerized search of more than 30 bibliographic databases, such as PsycINFO, MEDLINE, Social SciSearch, and ERIC, was conducted for articles published between 1990 and 2002. Comparisons of the most frequently used instruments were made on seven criteria proposed as best-practice indicators, including sensitivity to change and robust psychometrics. The sample produced 110 measures. Rater-completed instruments were represented more often than patient-completed ones. However, considerable variability across both methods was found on the criteria. The limited resources associated with publicly funded inpatient facilities led to a recommendation to select at least one rater-completed and one patient-completed instrument.     

Teaching literacy and mathematics skills to adult psychiatric inpatients: an evaluation of the adult literacy program at Hawaii State Hospital

The Adult Literacy Program at Hawaii State Hospital utilized techniques drawn from the Morningside Model of Generative Instruction. In a study involving psychiatric inpatients, participants were taught reading, mathematics, or both over a 6- to 8-month time span. Using the Woodcock-Johnson Psychoeducational Battery-Revised, it was determined that nearly half of the participants demonstrated academic gains during the study period. Further, a behavioral observation system indicated that participants were on-task 80% of the observation time and staff engaged in positive interactions nearly 20% of the observation time. This study is the first of its kind to document any efficacy for academic instruction with a psychiatric inpatient population.     

A multisite randomized trial of the effects of physician education and organizational change in chronic asthma care: cost-effectiveness analysis of the Pediatric Asthma Care Patient Outcomes Research Team II (PAC-PORT II)

BACKGROUND: A decision to implement innovative disease management interventions in health plans often requires evidence of clinical benefit and financial impact. The Pediatric Asthma Care Patient Outcomes Research Team II trial evaluated 2 asthma care strategies: a peer leader-based physician behavior change intervention (PLE) and a practice-based redesign called the planned asthma care intervention (PACI). OBJECTIVE: To estimate the cost-effectiveness of the interventions. METHODS: This was a 3-arm, cluster randomized trial conducted in 42 primary care practices. A total of 638 children (age range, 3-17 years) with mild to moderate persistent asthma were followed up for 2 years. Practices were randomized to PLE (n = 226), PACI (n = 213), or usual care (n = 199). The primary outcome was symptom-free days (SFDs). Costs included asthma-related health care utilization and intervention costs. RESULTS: Annual costs per patient were as follows: PACI, USD 1292; PLE, USD 504; and usual care, USD 385. The difference in annual SFDs was 6.5 days (95% confidence interval [CI], -3.6 to 16.9 days) for PLE vs usual care and 13.3 days (95% CI, 2.1-24.7 days) for PACI vs usual care. Compared with usual care, the incremental cost-effectiveness ratio was USD 18 per SFD gained for PLE (95% CI, USD 5.21-dominated) and USD 68 per SFD gained for PACI (95% CI, USD 37.36-361.16). CONCLUSIONS: Results of this study show that it is possible to increase SFDs in children and move organizations toward guideline recommendations on asthma control in settings where most children are receiving controller medications at baseline. However, the improvements were realized with an increase in the costs associated with asthma care.     

Identifying high-risk asymptomatic diabetic patients who are candidates for screening stress single-photon emission computed tomography imaging

OBJECTIVES: The purpose of this study was to identify which asymptomatic diabetic patients are candidates for screening single-photon emission computed tomography (SPECT) imaging and to examine angiographic findings and mortality in patients according to SPECT imaging categories. BACKGROUND: Previously we reported a high percentage of abnormal and high-risk SPECT imaging scans in asymptomatic diabetic patients. METHODS: We examined the associations between several clinical and laboratory variables and a high-risk stress SPECT imaging scan in 1,427 asymptomatic diabetic patients without known coronary artery disease (CAD). Results of coronary angiography and long-term outcome were also analyzed. RESULTS: An abnormal stress SPECT imaging scan was present in 826 patients (58%) and a high-risk scan in 261 patients (18%). Multivariate analysis demonstrated that seven variables were independently associated with a high-risk scan (model chi-square=107, p <0.0001). The two most important variables were electrocardiogram (ECG) Q waves (adjusted chi-square=38.3, p <0.001) and peripheral arterial disease (PAD) (adjusted chi-square=13.9, p <0.001). Coronary angiography was performed in 127 (49%) high-risk SPECT imaging patients, 61% of whom had angiographic high-risk CAD. Annual mortality rates for patient subsets categorized by SPECT imaging scans were high-risk 5.9%, intermediate-risk 5.0%, and low-risk 3.6% (p <0.001 for differences between groups). CONCLUSIONS: High-risk findings on stress SPECT imaging were present in 18% of asymptomatic diabetic patients without known CAD. Patients with high-risk scans had a high prevalence of severe CAD and a high annual mortality rate. ECG Q waves and/or evidence of PAD identified the most suitable candidates for screening.     

Rule-based category learning is impaired in patients with Parkinson's disease but not in patients with cerebellar disorders

The basal ganglia and cerebellum have both been implicated in motor skill acquisition. Recent hypotheses concerning cognitive functions of the basal ganglia and cerebellum have emphasized that these subcortical structures may also contribute to nonmotor learning. To explore this issue, patients with Parkinson's disease (PD) and patients with cerebellar lesions (CB) were tested on two category-learning tasks. Identical stimulus displays were used for the two tasks, consisting of a reference line and target line. In the length task, the two categories were defined based on the length of the target line. In the distance task, the two categories were defined by the distance between the target and reference lines. Thus, both categories could be defined by a simple rule in which attention must be restricted to a single relevant dimension. Consistent with previous results, the patients with PD were impaired on both tasks compared with neurologically healthy controls. In contrast, the CB patients performed similar to the control participants. Model-based analyses indicate that the patients with PD were able to select the appropriate categorization rule, but that they adopted suboptimal category boundaries in both conditions and were more variable in the application of the selected rule. These results provide an important neuropsychological dissociation on a non-motor-learning task between the effects of basal ganglia and cerebellar lesions. Moreover, the modeling work suggests that at least part of the Parkinson patients' impairment on these tasks reflect a tendency to exhibit strong response biases.