Attention effects on auditory scene analysis: insights from event-related brain potentials

Sounds emitted by different sources arrive at our ears as a mixture that must be disentangled before meaningful information can be retrieved. It is still a matter of debate whether this decomposition happens automatically or requires the listener’s attention. These opposite positions partly stem from different methodological approaches to the problem. We propose an integrative approach that combines the logic of previous measurements targeting either auditory stream segregation (interpreting a mixture as coming from two separate sources) or integration (interpreting a mixture as originating from only one source). By means of combined behavioral and event-related potential (ERP) measures, our paradigm has the potential to measure stream segregation and integration at the same time, providing the opportunity to obtain positive evidence of either one. This reduces the reliance on zero findings (i.e., the occurrence of stream integration in a given condition can be demonstrated directly, rather than indirectly based on the absence of empirical evidence for stream segregation, and vice versa). With this two-way approach, we systematically manipulate attention devoted to the auditory stimuli (by varying their task relevance) and to their underlying structure (by delivering perceptual tasks that require segregated or integrated percepts). ERP results based on the mismatch negativity (MMN) show no evidence for a modulation of stream integration by attention, while stream segregation results were less clear due to overlapping attention-related components in the MMN latency range. We suggest future studies combining the proposed two-way approach with some improvements in the ERP measurement of sequential stream segregation.     

Context effects as auditory contrast

Three experiments are reported that collectively show that listeners perceive speech sounds as contrasting auditorily with neighboring sounds. Experiment 1 replicates the well-established finding that listeners categorize more of a [d–g] continuum as [g] after [l] than after [r]. Experiments 2 and 3 show that listeners discriminate stimuli in which the energy concentrations differ in frequency between the spectra of neighboring sounds better than those in which they do not differ. In Experiment 2, [alga–arda] pairs, in which the energy concentrations in the liquid-stop sequences are H(igh) L(ow)–LH, were more discriminable than [alda–arga] pairs, in which they are HH–LL. In Experiment 3, [da] and [ga] syllables were more easily discriminated when they were preceded by lower and higher pure tones, respectively—that is, tones that differed from the stops’ higher and lower F3 onset frequencies—than when they were preceded by H and L pure tones with similar frequencies. These discrimination results show that contrast with the target’s context exaggerates its perceived value when energy concentrations differ in frequency between the target’s spectrum and its context’s spectrum. Because contrast with its context does more that merely shift the criterion for categorizing the target, it cannot be produced by neural adaptation. The finding that nonspeech contexts exaggerate the perceived values of speech targets also rules out compensation for coarticulation by showing that their values depend on the proximal auditory qualities evoked by the stimuli’s acoustic properties, rather than the distal articulatory gestures.     

Islam offline—living ‘The message’ behind the screens

This article is an ethnographic account of the Social Section of Arabic language Islam Online. It focuses on what Krüger has called the ‘hidden knowledge’ of religious websites. Drawing on longitudinal fieldwork in the Islam Online offices in Cairo, Egypt, this article brings forth and analyzes rich data about Islam Online employees’ work practices and meaning-making activities. Drawing on an organizational ethnographic approach, this article highlights new aspects of this influential Islamic website. More specifically, the author employs Linde’s concept of an ‘institutional narrative’ to conceptualize and analyze the strong institutional identity and corporate values that are in play in everyday work practices. Focusing on key tropes such as ‘the message’, ‘professional’, ‘pluralistic’, and ‘pioneers’, the article demonstrates how Islam Online’s Islamist institutional narrative includes a creation story and set of organizational values that play out in the execution of work tasks. Moreover, the author argues that the objective of the emic concept of “the message” is to contribute to both self- and societal-reform in the Arab world, and that Islam Online’s own work environment represents a micro-cosmos of this ideal.     

Prevalence estimation of school bullying with the Olweus Bully/Victim Questionnaire

The key aim of the present research was to study the “functionality” of two global variables in the Olweus Bully/Victim Questionnaire and to examine the appropriateness of different cutoff points of these variables for prevalence estimation. Several empirical and conceptual analyses strongly attested to the functionality of the two selected variables in terms of construct validity and selected measurement properties. Similarly, a number of analyses indicated that (having been bullied/having bullied other students) “2 or 3 times a month” was a reasonable and useful lower‐bound cutoff point. With this cutoff point, “involved” students, victims, and bullies differed very markedly and in clearly different ways from “non‐involved” students in conceptually related variables. Prevalence estimates derived in this way can be conveniently obtained, have a reasonably well‐defined meaning, can be easily understood by users, and can be reproduced unambiguously by different researchers/administrators and at different times. An important background for the article is the fact that several common methods, including peer nominations, are not well suited for prevalence estimation. Prevalence data for victims, bullies, and bully‐victims are also presented. All data were derived from the New Bergen Project Against Bullying, comprising a sample of 5,171 students from 37 schools in the town community of Bergen, Norway. At the time of the data collection, the spring of 1997, the 2,544 girls and 2,627 boys were in grades 5 through 9, with modal ages of 11 through 15 years. Aggr. Behav. 29:239–268, 2003. © 2003 Wiley‐Liss, Inc.     

Saying and believing: the norm commonality assumption

Philosophical Studies - One very popular assumption in the epistemological literature is that belief and assertion are governed by one and the same epistemic norm. This paper challenges this claim....     

Symptoms of attention‐deficit/hyperactivity disorder in first‐time expectant women: Relations with parenting cognitions and behaviors

The relationship between maternal symptoms of attention‐deficit/hyperactivity disorder (ADHD) and parenting cognitions and behaviors was studied in 86 first‐time expectant women. Women high on ADHD symptoms were less likely to be married, less likely to have obtained at least some university education, and less likely to report that they wanted to get pregnant at the time they became pregnant. As predicted, ADHD symptoms were positively correlated with symptoms of anxiety and depression, and predicted less positive prenatal expectations regarding the infant and the future maternal role and lower maternal self‐efficacy. Contrary to predictions, ADHD did not predict any incremental variance in maternal stressful life events or social support. Symptoms of ADHD were negatively correlated with attendance at recommended prenatal checkups, but were unrelated to other behaviors during pregnancy. Findings suggest that even prior to any contact with their infant, women with ADHD symptoms have maladaptive cognitions regarding their expectations of motherhood and parenting abilities. As a result, they may benefit from early interventions that focus on attenuating the potential negative effects that these maladaptive cognitions might have on the mother‐infant relationship and later developmental outcomes for their children.     

Differential effects of age on prospective and retrospective memory tasks in young, young-old, and old-old adults

Remembering to do something in the future (termed prospective memory) is distinguished from remembering information from the past (retrospective memory). Because prospective memory requires strong self-initiation, Craik (1986) predicted that age decrements should be larger in prospective than retrospective memory tasks. The aim of the present study was to assess Craik's prediction by examining the onset of age decline in two retrospective and three prospective memory tasks in the samples of young (18-30 years), young-old (61-70 years), and old-old (71-80 years) participants recruited from the local community. Results showed that although the magnitude of age effects varied across the laboratory prospective memory tasks, they were smaller than age effects in a simple three-item free recall task. Moreover, while reliable age decrements in both retrospective memory tasks of recognition and free recall were already present in the young-old group, in laboratory tasks of prospective memory they were mostly present in the old-old group only. In addition, older participants were more likely to report a retrospective than prospective memory failure as their most recent memory lapse, while the opposite pattern was present in young participants. Taken together, these findings highlight the theoretical importance of distinguishing effects of ageing on prospective and retrospective memory, and support and extend the results of a recent meta-analysis by Henry, MacLeod, Phillips, and Crawford (2004).