Magnitude judgments of loudness change for discrete, dynamic, and hybrid stimuli.

Recent investigations of loudness change within stimuli have identified differences as a function of direction of change and power range (e.g., Canévet, Acustica, 62, 2136-2142, 1986; Neuhoff, Nature, 395, 123-124, 1998), with claims of differences between dynamic and static stimuli. Experiment 1 provides the needed direct empirical evaluation of loudness change across static, dynamic, and hybrid stimuli. Consistent with recent findings for dynamic stimuli, quantitative and qualitative differences in pattern of loudness change were found as a function of power change direction. With identical patterns of loudness change, only quantitative differences were found across stimulus type. In Experiment 2, Points of Subjective loudness Equality (PSE) provided additional information about loudness judgments for the static and dynamic stimuli. Because the quantitative differences across stimulus type exceed the magnitude that could be expected based upon temporal integration by the auditory system, other factors need to be, and are, considered.

Evaluation of a neuropsychological screen in an incarcerated population.

The Brief Neuropsychological Cognitive Examination (BNCE) is a screening device designed to rapidly assess neuropsychological functioning. The availability of an effective and efficient screen for neuropsychological and/or cognitive disorders is an important concern within various settings such as correctional facilities, where there are likely to be large numbers of individuals in need of evaluation. In the current study the utility of the BNCE in detecting cognitive impairments among a clinical sample of incarcerated individuals was evaluated by comparing performance on this instrument to performance on measures of general cognitive functioning. Results indicate that the BNCE demonstrates some utility in its ability to determine those in need of further evaluation of cognitive functioning.

Backward recognition masking as a general type of interference in needed poststimulus processing.

Auditory backward recognition masking (ABRM) has been argued to reflect interference in the storage and/or processing of a short-lived sensory form of information and has been viewed as a relatively invariant attribute of auditory pitch processing for very brief stimuli that are minimally separated in frequency (DeltaF). In contrast, the present study demonstrates that ABRM reflects interference with several basic principles of auditory processing. Measured in terms of target tone duration, rather than DeltaF, ABRM is demonstrated for target stimuli representing the interval of a musical fifth and masker-target stimulus intervals of a musical third, with thresholds ranging from approximately 22 to 55 msec and psychometric functions that are indicative of more than one contributing factor. On the basis of common underlying principles, the possibility that the threshold for the identification of temporal order of onset reflects ABRM and possible implications for the perception of complex stimuli, including speech, are discussed.

Auditory event perception: the source-perception loop for posture in human gait.

There is a small but growing literature on the perception of natural acoustic events, but few attempts have been made to investigate complex sounds not systematically controlled within a laboratory setting. The present study investigates listeners' ability to make judgments about the posture (upright-stooped) of the walker who generated acoustic stimuli contrasted on each trial. We use a comprehensive three-stage approach to event perception, in which we develop a solid understanding of the source event and its sound properties, as well as the relationships between these two event stages. Developing this understanding helps both to identify the limitations of common statistical procedures and to develop effective new procedures for investigating not only the two information stages above, but also the decision strategies employed by listeners in making source judgments from sound. The result is a comprehensive, ultimately logical, but not necessarily expected picture of both the source-sound-perception loop and the utility of alternative research tools.

Contextual relative temporal duration judgment: an investigation of sequence interruptions.

How do listeners judge relative duration? There currently are three primary classes of proposed timing mechanisms: interval based (judgments of discrete events), beat based (judgments of beat synchrony), and oscillator based (judgments of relative phase or synchrony). In the present research, these mechanisms were examined in terms of predictions both about how an induction sequence of preceding intervals affects relative temporal duration comparison in a simple, two-interval task and about how a pause (e.g., an interstimulus interval) within the presented sequence affects relative temporal duration judgment. Results indicated that a relative temporal judgment was best when all intervals preceding the to-be-judged interval were equal in duration to the to-be-judged interval. Results also indicated that whereas short pauses significantly impair a relative temporal duration judgment, long pauses generally do not reduce the effectiveness of the induction sequence. The results are not entirely consistent with current conceptualizations of any of the proposed mechanisms but can be fully accommodated with simple modifications to the oscillator-based mechanism.

Signal detection theory analyses of semantic priming in word recognition.

Word recognition, semantic priming, and cognitive impenetrability research have used signal detection theory (SDT) measures to separate perceptual and postperceptual processes. In the D. Norris (1986) checking model and model simulation (D. Norris, 1995), priming alters only postperceptual word decision criteria: Stimulus-related priming reduces uncertainty, increasing sensitivity; stimulus-unrelated priming increases false alarms more than hits, reducing sensitivity. This work is cited as strong evidence that criterion changes can alter perceptual sensitivity and that SDT is inappropriate for investigating complex cognitive processes. The authors' current SDT ideal observer analysis of the model demonstrates that related priming does not directly alter sensitivity and that unrelated priming increases only false-alarm rate, reducing sensitivity. This analysis provides new perspectives on SDT concepts of complex decision processing.

"Nonparametric" A' and other modern misconceptions about signal detection theory.

Many modern descriptions of signal detection theory (SDT) are, at best, distorted caricatures of the Gaussian equal-variance model of SDT (G-SDT). The distortions have sometimes led to important, but unwarranted, conclusions about the nature of cognitive processes. Some researchers reject using d' and beta because of concerns about the validity of explicit underlying assumptions (that are shared with most inferential statistics), instead using either the supposedly "nonparametric" measures of A' and B" or measures known to confound ability and bias. The origins, development, and underlying assumptions of SDT are summarized, then contrasted with modern distortions and misconceptions. The nature and interpretation of common descriptive statistics for sensitivity and bias are described along with important pragmatic considerations about use. A deeper understanding of SDT provides researchers with tools that better evaluate both their own findings and the validity of conclusions drawn by others who have utilized SDT measures and analyses.

Change detection in multi-voice music: the role of musical structure, musical training, and task demands.

This study evaluated the relationship between primitive and scheme-driven grouping (A. S. Bregman, 1990) by comparing the ability of different listeners to detect single note changes in 3-voice musical compositions. Primitive grouping was manipulated by the use of 2 distinctly different compositional styles (homophony and polyphony). The effects of scheme-driven processes were tested by comparing performance of 2 groups of listeners (musicians and nonmusicians) and by varying task demands (integrative and selective listening). Following previous studies, which had tested only musically trained participants, several variables were manipulated within each compositional style. The results indicated that, although musicians demonstrated a higher sensitivity to changes than did nonmusicians, the 2 groups exhibited similar patterns of sensitivity under a variety of conditions.