The chronometry of attention-modulated processing and automatic mismatch detection.
ABSTRACT Event-related potentials were recorded from normal subjects in an auditory selective attention task. Targets were rare longer (170-ms) tones of a designated pitch, embedded in a sequence of 100-ms standard tones. The effects of attention-modulated processing were evident in the event-related potentials elicited by the standards. Those to relevant standards were similar for easy (1000 Hz vs. 2000 Hz) and hard (1000 Hz vs. 1030 Hz) pitch separations, and were more negative frontocentrally than those to irrelevant standards. Difference waveforms (attended minus unattended standards) revealed Nd, a negative deflection that was earlier in latency for the easy task (onset, 120 ms; peak, 250 ms) than for the hard task (onset, 250 ms; peak, 350 ms). The speed of detection of the deviant longer tones was insensitive to the attention-modulated processes indexed by Nd. Median reaction time did not differ between tasks, although there were more misses and false alarms in the hard task (and nearly all of the latter were to the irrelevant longer tones). Neither direction of attention nor task difficulty affected the latency of mismatch negativity, N2, or P3 (as identified in difference waveforms: attended or unattended longer tones minus their respective standards). The data suggest that performance was guided by two independent but converging processes, automatic mismatch detection of the longer tone and attention-modulated processing of pitch, followed by selection of response.
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ABSTRACT: Information-processing models of human performance are often categorized as discrete or continuous, with continuous models currently in vogue. This paper presents a three-part analysis of discrete and continuous models. Part 1 considers the definitions of the terms discrete and continuous, and concludes that a dichotomous categorization of models is a serious oversimplification for three reasons. First, discreteness and continuity are not themselves dichotomous properties, but rather two extremes between which there can be intermediate cases. Second, there are many different senses in which information-processing models can be described as discrete or continuous (or somewhere in between), and the same model may be relatively discrete in some senses and relatively continuous in others. Third, any complete model of an information-processing task assumes several different processing stages, of which some could be relatively discrete (in any given sense) and others relatively continuous. Part 2 reviews evidence commonly cited in support of continuous models. Many of the findings can be reconciled with fully discrete models, and the rest require continuity only in certain very limited senses. In particular, there is no compelling evidence against the discrete stage assumption of the Additive Factor Method (AFM) of Sternberg (1969a,b). Part 3 reviews recent evidence supporting discrete models, some of which specifically supports the discrete stage assumption. In the light of this evidence and the shortcomings of the evidence reviewed in Part 2, it is concluded that it is premature to abandon discrete models in favor of continuous ones.Acta Psychologica 07/1988; 67(3):191-257. · 2.26 Impact Factor
- Psychological Review 05/1988; 95(2):183-237. · 9.80 Impact Factor
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ABSTRACT: Stimulus selection during selective listening on the basis of simple physical stimulus features is reflected by an event-related potential (ERP) component called the processing negativity (PN). PN has been proposed to indicate a matching or comparison process between the physical features of the stimulus and an 'attentional trace,' an actively formed and maintained temporary neuronal representation of the features defining the relevant stimuli. According to this theory, the smaller is the difference between the eliciting stimulus and that represented by the attentional trace, the longer time is the stimulus processed, and thus the larger in amplitude and longer in duration is the PN elicited. The relevant stimuli, perfectly matching with the attentional trace, and therefore eliciting the largest and longest-duration PN, are selected for further processing. In the present study, the relevant and irrelevant stimuli differed in pitch, and the magnitude of this pitch separation was varied between different stimulus blocks. The results support the afore-mentioned matching or comparison hypothesis of selective attention by showing that PN is not elicited only by the relevant stimuli but even by irrelevant stimuli, and further that the latter PN is larger in amplitude and longer in duration the more similar the irrelevant stimuli are to the relevant stimuli. This PN, however, was smaller than that to the relevant stimuli even for very small separations, reflecting high accuracy of the discrimination function of the attentional trace mechanism proposed to underly selective listening. The termination of the PN to the irrelevant stimuli was followed by a positivity which thus partly explained the difference (Nd) between the ERPs to the relevant and irrelevant stimuli.Electroencephalography and Clinical Neurophysiology 12/1987; 68(6):458-70.