MNPmApp: An image analysis tool to quantify mononuclear phagocyte distribution in mucosal tissues.

Mononuclear phagocytes (MNPs) such as dendritic cells and macrophages perform key sentinel functions in mucosal tissues and are responsible for inducing and maintaining adaptive immune responses to mucosal pathogens. Positioning of MNPs at the epithelial interface facilitates their access to luminally-derived antigens and regulates MNP function through soluble mediators or surface receptor interactions. Therefore, accurately quantifying the distribution of MNPs within mucosal tissues as well as their spatial relationship with other cells is important to infer functional cellular interactions in health and disease. In this study, we developed and validated a MATLAB-based tissue cytometry platform, termed "MNP mapping application" (MNPmApp), that performs high throughput analyses of MNP density and distribution in the gastrointestinal mucosa based on digital multicolor fluorescence microscopy images and that integrates a Monte Carlo modeling feature to assess randomness of MNP distribution. MNPmApp identified MNPs in tissue sections of the human gastric mucosa with 98 ± 2% specificity and 76 ± 15% sensitivity for HLA-DR+ MNPs and 98 ± 1% specificity and 85 ± 12% sensitivity for CD11c+ MNPs. Monte Carlo modeling revealed that mean MNP-MNP distances for both HLA-DR+ and CD11c+ MNPs were significantly lower than anticipated based on random cell placement, whereas MNP-epithelial distances were similar to randomly placed cells. Surprisingly, H. pylori infection had no significant impact on the number of HLA-DR and CD11c MNPs or their distribution within the gastric lamina propria. However, our study demonstrated that MNPmApp is a reliable and user-friendly tool for unbiased quantitation of MNPs and their distribution at mucosal sites.

Psychophysiological responses to potentially annoying heating, ventilation, and air conditioning noise during mentally demanding work.

Exposure to noise-or unwanted sound-is considered a major public health issue in the United States and internationally. Previous work has shown that even acute noise exposure can influence physiological response in humans and that individuals differ markedly in their susceptibility to noise. Recent research also suggests that specific acoustic properties of noise may have distinct effects on human physiological response. Much of the existing research on physiological response to noise consists of laboratory studies using very simple acoustic stimuli-like white noise or tone bursts-or field studies of longer-term workplace noise exposure that may neglect acoustic properties of the noise entirely. By using laboratory exposure to realistic heating, ventilation, and air conditioning (HVAC) noise, the current study explores the interaction between acoustic properties of annoying noise and individual response to working in occupational noise. This study assessed autonomic response to two acoustically distinct noises while participants performed cognitively demanding work. Results showed that the two HVAC noises affected physiological arousal in different ways. Individual differences in physiological response to noise as a function of noise sensitivity were also observed. Further research is necessary to link specific acoustic characteristics with differential physiological responses in humans.

Listener characteristics differentially affect self-reported and physiological measures of effort associated with two challenging listening conditions.

Listeners vary in their ability to understand speech in adverse conditions. Differences in both cognitive and linguistic capacities play a role, but increasing evidence suggests that such factors may contribute differentially depending on the listening challenge. Here, we used multilevel modeling to evaluate contributions of individual differences in age, hearing thresholds, vocabulary, selective attention, working memory capacity, personality traits, and noise sensitivity to variability in measures of comprehension and listening effort in two listening conditions. A total of 35 participants completed a battery of cognitive and linguistic tests as well as a spoken story comprehension task using (1) native-accented English speech masked by speech-shaped noise and (2) nonnative accented English speech without masking. Masker levels were adjusted individually to ensure each participant would show (close to) equivalent word recognition performance across the two conditions. Dependent measures included comprehension tests results, self-rated effort, and electrodermal, cardiovascular, and facial electromyographic measures associated with listening effort. Results showed varied patterns of responsivity across different dependent measures as well as across listening conditions. In particular, results suggested that working memory capacity may play a greater role in the comprehension of nonnative accented speech than noise-masked speech, while hearing acuity and personality may have a stronger influence on physiological responses affected by demands of understanding speech in noise. Furthermore, electrodermal measures may be more strongly affected by affective response to noise-related interference while cardiovascular responses may be more strongly affected by demands on working memory and lexical access.

Listening effort: Are we measuring cognition or affect, or both?

Listening effort is increasingly recognized as a factor in communication, particularly for and with nonnative speakers, for the elderly, for individuals with hearing impairment and/or for those working in noise. However, as highlighted by McGarrigle et al., International Journal of Audiology, 2014, 53, 433-445, the term "listening effort" encompasses a wide variety of concepts, including the engagement and control of multiple possibly distinct neural systems for information processing, and the affective response to the expenditure of those resources in a given context. Thus, experimental or clinical methods intended to objectively quantify listening effort may ultimately reflect a complex interaction between the operations of one or more of those information processing systems, and/or the affective and motivational response to the demand on those systems. Here we examine theoretical, behavioral, and psychophysiological factors related to resolving the question of what we are measuring, and why, when we measure "listening effort." This article is categorized under: Linguistics > Language in Mind and Brain Psychology > Theory and Methods Psychology > Attention Psychology > Emotion and Motivation.