Exact tests for the rasch model via sequential importance sampling

Rasch proposed an exact conditional inference approach to testing his model but never implemented it because it involves the calculation of a complicated probability. This paper furthers Rasch’s approach by (1) providing an efficient Monte Carlo methodology for accurately approximating the required probability and (2) illustrating the usefulness of Rasch’s approach for several important testing problems through simulation studies. Our Monte Carlo methodology is shown to compare favorably to other Monte Carlo methods proposed for this problem in two respects: it is considerably faster and it provides more reliable estimates of the Monte Carlo standard error.This Research was supported in part by National Science Foundation grant DMS-0203762 and a University of Pennsylvania Research Foundation grant.The authors are grateful to Don Burdick for helpful comments. In addition, the authors wish to thank the editor, the associate editor, and the referees for their helpful suggestions.This revised article was published online in August 2005 with the PDF paginated correctly.     

Disruption by speech of serial short-term memory: The role of changing-state vowels

Serial short-term memory is markedly impaired by the presence of irrelevant speech so long as the successive tokens within the irrelevant speech are phonologically (or acoustically) dissimilar (Jones & Macken, 1995b). In two experiments in which consonant—vowel—consonant syllables were used as irrelevant speech tokens, we sought to evaluate the relative disruptive potency of changes in the final consonant only (Experiment 1), in the initial consonant, or in the vowel portion (Experiment 2) of each token. The results suggest that the vowel changes are the dominant source of disruption. This dominance may be explained, at least in part, by the role played by vowel sounds in the perceptual organization of speech and, in turn, the particular propensity for vowel changes to yield information about serial order. The results are consistent also with the view that the factors that promote order encoding in sound are also the ones that promote disruption.     

Arousal and the Bakan vigilance task: The effects of noise intensity and the presence of others

The joint effects of social setting and loud noise on task performance are examined. In a modified version of the Bakan vigilance task subjects were required to detect a sequence of two identical even digits and to report the two digits preceding the signal. Two types of acoustic environment were compared: loud noise at 90 dBC and quiet noise at 60 dBC. Two types of social setting were employed: “pair” where two subjects worked in the same room on similar tasks, and “single” where a subject performed the task alone. The effects of noise and the presence of another did not interact. Loud noise increased the speed of responses to signals early in the task. This effect is attributed to noise-induced arousal. There was a higher incidence of recall errors in pre-signal digits when subjects were in pairs. This effect is attributed to distraction. This research was part of a series of studies sponsored by the Social Science Research Council (Grant HR 5563 awarded to Dr. A.J. Chapman and Dr. D.M. Jones).     

Disruption of visual short-term memory by changing-state auditory stimuli: The role of segmentation

Typically, serial recall performance can be disrupted by the presence of an irrelevant stream of background auditory stimulation, but only if the background stream changes over time (the auditory changing-state effect). It was hypothesized that segmentation of the auditory stream is necessary for changing state to be signified. In Experiment 1, continuous random pitch glides failed to disrupt serial recall, but glides interrupted regularly by silence brought about the usual auditory changing-state effect. In Experiment 2, a physically continuous stream of synthesized vowel sounds was found to have disruptive effects. In Experiment 3, the technique of auditory induction showed that preattentive organization rather than critical features of the sound could account for the disruption by glides. With pitch glides, silence plays a preeminent role in the temporal segmentation of the sound stream, but speech contains corr-elated-time-varying changes in frequency and amplitude that make silent intervals superfluous.     

Examining the relationship between use of sexually explicit media and sexual risk behavior in a sample of men who have sex with men in Norway

The purpose of this study was to investigate consumption patterns of gay‐oriented sexually explicit media (SEM) among men who have sex with men (MSM) in Norway, with a particular emphasis on a possible relationship between gay SEM consumption and HIV risk behavior. Participants included 529 MSM living in Norway recruited online to complete a SEM consumption and sexual risk survey. Of the 507 participants who responded to the all items measuring exposure to SEM, 19% reported unprotected anal intercourse with a casual partner (UAI) in last 90 days, and 14% reported having had sero‐discordant UAI. Among those with UAI experience, 23% reported receptive anal intercourse (R‐UAI) and 37% reported insertive anal intercourse (I‐UAI). SEM consumption was found to be significantly associated with sexual risk behaviors. Participants with increased consumption of bareback SEM reported higher odds of UAI and I‐UAI after adjusting for other factors using multivariable statistics. MSM who started using SEM at a later age reported lower odds of UAI and I‐UAI than MSM who started earlier. Future research should aim at understanding how MSM develop and maintain SEM preferences and the relationship between developmental and maintenance factors and HIV sexual risk behavior.     

Behavioral Health Services Influence Medical Treatment Utilization Among Primary Care Patients with Comorbid Substance Use and Depression

Although research has shown benefits of integrating psychological care in primary care settings, it is unclear how this form of treatment impacts individuals with comorbid substance use and depression. The findings are also mixed concerning how frequently this comorbid population seeks primary care services. This study examined the associations between substance use, depression, and medical treatment utilization among 224 primary care patients. The aim of the investigation was twofold. First, to determine if depression increases medical treatment utilization among patients with substance use disorders; second, to evaluate if behavioral health treatment reduces medical service utilization. A moderated mediation model with bootstrapping analyses revealed that depression strengthened the relationship between substance use and primary care treatment utilization (both medical and behavioral health). The model also indicated that behavioral health services were associated with fewer primary care visits for individuals with comorbid substance use and depression. Clinical and social implications are discussed.     

Misremembering emotion: Inductive category effects for complex emotional stimuli

Memories of objects are biased toward what is typical of the category to which they belong. Prior research on memory for emotional facial expressions has demonstrated a bias towards an emotional expression prototype (e.g., slightly happy faces are remembered as happier). We investigate an alternate source of bias in memory for emotional expressions – the central tendency bias. The central tendency bias skews reconstruction of a memory trace towards the center of the distribution for a particular attribute. This bias has been attributed to a Bayesian combination of an imprecise memory for a particular object with prior information about its category. Until now, studies examining the central tendency bias have focused on simple stimuli. We extend this work to socially relevant, complex, emotional facial expressions. We morphed facial expressions on a continuum from sad to happy. Different ranges of emotion were used in four experiments in which participants viewed individual expressions and, after a variable delay, reproduced each face by adjusting a morph to match it. Estimates were biased toward the center of the presented stimulus range, and the bias increased at longer memory delays, consistent with the Bayesian prediction that as trace memory loses precision, category knowledge is given more weight. The central tendency effect persisted within and across emotion categories (sad, neutral, and happy). This article expands the scope of work on inductive category effects to memory for complex, emotional stimuli.     

Retrieval from memory: vulnerable or inviolable?

We show that retrieval from semantic memory is vulnerable even to the mere presence of speech. Irrelevant speech impairs semantic fluency--namely, lexical retrieval cued by a semantic category name--but only if it is meaningful (forward speech compared to reversed speech or words compared to nonwords). Moreover, speech related semantically to the retrieval category is more disruptive than unrelated speech. That phonemic fluency--in which participants are cued with the first letter of words they are to report--was not disrupted by the mere presence of meaningful speech, only by speech in a related phonemic category, suggests that distraction is not mediated by executive processing load. The pattern of sensitivity to different properties of sound as a function of the type of retrieval cue is in line with an interference-by-process approach to auditory distraction.     

Broken expectations: violation of expectancies, not novelty, captures auditory attention

The role of memory in behavioral distraction by auditory attentional capture was investigated: We examined whether capture is a product of the novelty of the capturing event (i.e., the absence of a recent memory for the event) or its violation of learned expectancies on the basis of a memory for an event structure. Attentional capture-indicated by disruption of a focal visually presented serial recall task-was found when the voice conveying a concurrent irrelevant auditory sequence changed every 5 recall trials (from male to female or vice versa). There was no evidence of attentional capture when the irrelevant sequence was first encountered and hence novel; capture occurred only when an expectation for a particular voice had been learned and then violated. Furthermore, with the increasing predictability of (and hence expectancy for) the voice changes across the experimental session, the capture response diminished only to be reinstated when that session-wide expectation was itself violated by a break in the change-every-5-trials pattern. The results highlight the critical role of learned expectations, as opposed to novelty detection, in behavioral auditory attentional capture.     

Access Through Compensation: Emancipatory View of a Mathematics Learning Disability

Abstract

In this article, we provide a novel view of mathematics learning disability (MLD) by studying a student with an MLD (Dylan) who had compensated so effectively that she was able to major in statistics. We push back on the dominant deficit model used in studies of MLD, and consider issues of access and compensation from a Vygotskian theoretical frame. Through 8 videotaped interview sessions, we identified that Dylan’s primary difficulties were with mathematical notation and number sense, which resulted in issues accessing standard mathematical forms. Analysis revealed 8 compensatory strategies that Dylan used to address these issues of access. We frame our approach as emancipatory research. Dylan was involved in all phases of the study’s design, implementation, analysis, and dissemination, and is the second author. This work acknowledges that individuals with disabilities have research agendas of their own and have critical insight to share about the lived experience of their disability.