Auditory Detection Task Research Articles

P121 Event-related potential P3 as a measure of resource allocation in concurrent visual tracking and auditory signal detection tasks in parkinson's disease

P121 Event-related potential P3 as a measure of resource allocation in concurrent visual tracking and auditory signal detection tasks in parkinson's disease

Pathophysiologic findings in nonretarded autism and receptive developmental language disorder.

In nonretarded autistic, receptive developmental language disordered, and normal subject groups, we recorded in auditory and visual target detection tasks two neurophysiological components of the event-related brain potential, Nc and P3b. Existent research shows that, in normals, Nc and P3b appear early in development, are associated with attention and memory processes, and are endogenous which means that they are triggered by internal, consciously initiated attentional and cognitive mechanisms and that they can be triggered even by the omission of sensory stimulation so long as it has meaning or importance for the subject. In this report, Nc and P3b were recorded in response to auditory and visual stimulation and to the omission of auditory and visual stimulation. Consistent with the hypothesis that non-retarded autism involves abnormal attentional and cognitive responses to important information, P3b was found to be smaller than normal and Nc was small and often absent in the nonretarded autistic group even under the condition when no auditory language or sensory processing was required. Receptive developmental language disorder has been linked with difficulties in processing sequences of auditory stimuli, and in this study P3b was found to be somewhat enlarged in this group even under the conditions when P3b was elicited by stimuli separated by 1 sec and also when P3b was elicited by the omission of stimulation.

Brain indicators of altered attention and information processing in schizophrenic patients.

Late components of brain event-related potentials reflect aspects of selective attention, stimulus evaluation, and possibly memory update mechanisms. Several of these components were measured during an auditory target detection task, performed by 20 schizophrenic and 20 normal subjects. Both the amplitude of those components and a more general late amplitude measure were significantly reduced in schizophrenics, for both target and non-target stimuli. One general late amplitude measure, from the scalp vertex, could alone correctly classify 85% of patients and 95% of controls. The source of these differences may lie in a protracted positive potential shift.

Reality testing and auditory hallucinations: a signal detection analysis.

The hypothesis that hallucinators are deficient in the metacognitive skill of reality testing was tested using the methodology of signal detection theory. In Expt 1 undergraduate subjects scoring high or low on a scale measuring predisposition to hallucination were tested on an auditory signal detection task. High scorers on the scale were found to differ from low scorers on a measure of perceptual bias but not on a measure of sensitivity. In Expt 2 a similar methodology was used with hallucinating and non-hallucinating schizophrenic patients, with similar results. These results support the hypothesis that hallucinators or subjects highly disposed towards hallucination are deficient in reality testing and are therefore prone to identify imaginary events as real.

Performance differences among the intervals in forced-choice tasks.

Listeners were tested on a variety of three-interval, forced-choice auditory detection and discrimination tasks. Differences in performance were frequently found among the three intervals, with best performance in the third interval, and worst in the first. This result is at odds with the common assumptions of Signal Detection Theory that signals are equally detectable no matter which interval they are presented in, and that a decision is simply made by picking the interval with the largest likelihood ratio. An experimental technique is described by which central and peripheral determinants of the interval effect might be distinguished.

Cautiousness and hearing acuity in elderly women: A signal detection approach

Hearing loss in elderly women was investigated with respect to measures of sensory and decision processes in an auditory signal detection task. A 1000Hz signal was used as the stimulus and a 6-point response category scale was employed. Subject biases were obtained from 6 normal hearing and 6 moderately hearing impaired elderly adults (65–76 yr). Results indicated that the subjects set a conservative criterion, regardless of hearing loss, and tended to use a binary decision process.

Effect of subliminal visual material on an auditory signal detection task.

An experiment assessed the effect of subliminally embedded, visual material on an auditory detection task. 22 women and 19 men were presented tachistoscopically with words designated as "emotional" or "neutral" on the basis of prior GSRs and a Word Rating List under four conditions: (a) Unembedded Neutral, (b) Embedded Neutral, (c) Unembedded Emotional, and (d) Embedded Emotional. On each trial subjects made forced choices concerning the presence or absence of an auditory tone (1000 Hz) at threshold level; hits and false alarm rates were used to compute non-parametric indices for sensitivity (A') and response bias (B"). While over-all analyses of variance yielded no significant differences, further examination of the data suggests the presence of subliminally "receptive" and "non-receptive" subpopulations.

A subcortical correlate of P300 in man

Event-related potentials in visual and auditory target detection tasks were recorded simultaneously from the scalp, somatosensory thalamus and periaqueductal gray in a chronic pain patient with electrodes implanted subcortically for therapeutic purposes. Short latency tactile responses confirmed the location of the thalamic electrodes. Rare auditory stimuli which were detected by the subject were accompanied by a prominent P300 component at the scalp, and by negative activity at the subcortical sites with the same latency as the scalp positivity. This activity was not seen in responses to frequent non-target stimuli and was not dependent on an overt motor response. Similarly, rare visual stimuli generated a scalp P300 and negative activity subcortically; both scalp and subcortical waves had a longer latency than in the auditory experiment. The reaction time was similarly longer to visual targets. These data are inconsistent with a hippocampal generator for P300, but are consistent with a generator in the thalamus or more dorsally located structures.

The setting and maintenance of criteria representing levels of confidence.

The theory of criterion setting developed by the 1st author and T. C. Williams (see record 1984-08523-001), which postulates control of decision criteria by a long- and 2 short-term mechanisms, can provide an account of sequential dependencies. The theory is applied to the question of whether criteria are all set and maintained in the same way or whether they fall into 2 groups, controlled in accordance with different rules. Evidence from 2 experiments, with 6 18–32 yr old Ss, using an auditory detection task indicates that (1) the short-term (tracking) mechanism that responds to momentary change in the probability of the signal primarily controls the (categorical) criterion that determines the category of response (yes or no) and (2) the criteria that determine levels of confidence are maintained at constant separations from the categorical criterion. A new sequential dependency, the criterion divergence effect, is reported. It is shown that this is mediated by sequentially determined changes in sensitivity, and a model for this is derived.

EFFECT OF SUBLIMINAL VISUAL MATERIAL ON AN AUDITORY SIGNAL DETECTION TASK

An experiment assessed the effect of subliminally embedded, visual material on an auditory detection task. 22 women and 19 men were presented tachistoscopically with words designated as “emotional” or “neutral” on the basis of prior GSRs and a Word Rating List under four conditions: (a) Unembedded Neutral, (b) Embedded Neutral, (c) Unembedded Emotional, and (d) Embedded Emotional. On each trial subjects made forced choices concerning the presence or absence of an auditory tone (1000 Hz) at threshold level; hits and false alarm rates were used to compute non-parametric indices for sensitivity (A′) and response bias (B″). While over-all analyses of variance yielded no significant differences, further examination of the data suggests the presence of subliminally “receptive” and “non-receptive” subpopulations.

Cognitive effects of passive smoking.

The cognitive performance of 32 non-smoking subjects was tested on two separate occasions. In one condition subjects performed on a modified Wilkinson auditory detection task and attempted a modified Raven's progressive matrices test whilst sitting in a room with a confederate who was smoking cigarettes. In the second, non-smoky, condition the subjects undertook parallel forms of the two tests but were in a clean environment with the same confederate who did not smoke. The results indicated a significant reduction in performance on both tests in the smoky over the non-smoky condition. Furthermore, the data from the detection task indicated that the confederate had a significant influence on the level of this reduction. Implications of these results are discussed, particularly with respect to the roles of carbon monoxide and of social variables in mediating the performance reduction.

Perceptual interference and facilitation with auditory imagery.

It has been claimed both that (1) imagery selectivelyinterferes with perception (because images can be confused with similar stimuli) and that (2) imagery selectivelyfacilitates perception (because images recruit attention for similar stimuli). However, the evidence for these claims can be accounted for without postulating either image-caused confusions or attentional set. Interference could be caused by general and modality-specific capacity demands of imaging, and facilitation, by image-caused eye fixations. The experiment reported here simultaneously tested these two apparently conflicting claims about the effect of imagery on perception in a way that rules out these alternative explanations. Subjects participated in a two-alternative forced-choice auditory signal detection task in which the target signal was either the same frequency as an auditory image or a different frequency. The possible effects of confusion and attention were separated by varying the temporal relationship between the image and the observation intervals, since an image can only be confused with a simultaneous signal. We found selective facilitation (lower thresholds) for signals of the same frequency as the image relative to signals of a different frequency, implying attention recruitment; we found no selective interference, implying the absence of confusion. These results also imply that frequency information is represented in images in a form that can interact with perceptual representations.

Individual differences in the ability to focus and divide attention

This research deals with individual differences in the ability to focus and divide attention. Eighty-five subjects performed visual search and auditory detection tasks in three conditions: single channel, focused attention, and divided attention. Reaction time (RT) was fastest in the single channel condition, intermediate in the focused attention condition, and longest in the divided attention condition, and these effects were much stronger in the auditory than the visual task. Correlations among RTs in the three conditions were very high within modality (>.88), and lower between modalities (.5 to .6). The correlational data was well fit by a model that included separate factors for the visual and auditory tasks. Measures from the three attentional conditions within each modality loaded equally on these factors. The data provided no evidence for distinct abilities to divide or focus attention.

Attending to multiple sources of information: I. The integration of information in decision making

Information relevant to a decision is often available from several sources, such as different sensory modalities or different spatial locations. Processing or utilization of such information is often selective in that some sources seem to have more influence on a decision or response than others. Many different theoretical mechanisms have been proposed to account for such selective (i.e., attentional) aspects of human information processing. This paper considers theoretical mechanisms which operate to integrate separate sources of information in order to make a binary decision. In particular, these mechanisms are studied in simple visual and auditory detection tasks as well as a Bayesian decision problem. Data from these experiments reject the idea that one integrates the relevant information from several sources prior to making a decision. Rather, one seems to form separate decisions about the information from each source and then integrate these decisions in order to select a response.

Event-related potentials in a two-interval forced-choice detection task.

In an attempt to elucidate the nature of the subject’s strategy in a two-interval forcedchoice auditory detection task, event-related potentials were studied at two intensities which yielded mean accuracies of 82% and 98%. Subjects reported the observation interval in which they judged the signal to be present and the confidence of the judgment. Principal components varimax analyses yielded four components: a CZ maximal P300, a Slow Wave, a slow negative shift, and a late negative component. The P300 amplitude findings suggest that different strategies are utilized for high-confidence and low-confidence detections. At high confidence, P300 amplitude is large for the observation interval in which the signal is presented, indicating a strategy involving serial independent detection. However, the P300 latency findings at high confidence suggest that absence of the signal in the first observation interval is nonetheless noted: P300 latency in response to signal presence is shorter for the second observation interval than for the first observation interval. At low confidence, P300 is small or absent for both observation intervals, indicating a deferred decision, presumably arrived at through comparison of the two percepts.

Event-related potentials and auditory signal detection: their diurnal variation for morning-type and evening-type subjects.

ABSTRACTThe relationship between detection performance and various Event‐Related Potential (ERP) components was investigated in an auditory threshold detection task at 4 times of day (9 a.m., 1 p.m. 5 p.m., and 9 p.m.) for 7 morning‐type and 7 evening‐type subjects. Measurements were made of oral temperature, detection efficiency (P(A)), response bias(β), the N115 and the P190 components following a warning stimulus, and the P450and the Slow Wave (SW) associated with correct signal‐present decisions. For oral temperature and detection efficiency an upward diurnal trend was observed which tended to interact with subject type. For both the amplitude and the latency of the N115 and the P190 components intra‐session decrement was found. The P190 latency decreased monotonically over the day. While the diurnal trend of the amplitude and latency of the Nl15 resembled that of the SW amplitude, reaching a relative maximum in the afternoon. The P450 showed no diurnal variation. Furthermore, the P450 and SW also differed as a function of the level of decision confidence. The P450 amplitude increased and its latency decreased with an increasing confidence level, whereas the SW amplitude decreased. The diurnal variations of the N115 and the SW are discussed in terms of fluctuating amounts of processing involved in different aspects of the task.

Automatic and controlled attention processes in auditory target detection.

Shiffrin and Schneider proposed a general theory of attention that postulates the existence of automatic and controlled search processes. They concluded that automatic processes develop when the mapping between stimuli and responses is consistent and controlled processing occurs when the mapping is varied. The effects of consistent and varied mapping were examined in an auditory target detection task. Subjects listened for one or three target letters embedded in a stream of dichotic letter pairs. Subjects responded faster and made fewer errors under the consistent mapping (CM) condition than under the varied mapping (VM) condition, and the effect of memory set size decreased over practice in the CM condition but not the VM condition. The results are discussed in terms of automatic and controlled processes involved in recognition of target stimuli. A review of research on auditory target detection suggests that the development of automatic processes may account for some apparent discrepancies in the literature.

P3 latency in threshold signal detection

The EOG, EEG(Cz, Pz) and response latencies were obtained from ten subjects in an auditory threshold detection task with a signal probability of 0.5. In order to minimize any interaction of signal condition (signal-presence vs. signal-absence) and uncertainty about the moment of signal occurrence (temporal equivocation), the observation period was marked with a cue light. The single-trial latencies of the P3 component associated with correct signal-present and signal-absent decisions were assessed on the basis of the cross-covariance functions of the EEG epochs and a template of the P3. Trials with values of covariance smaller than a criterion value were discarded. The mean and dispersion of the P3 latency proved larger for signal-absent than for signal-present trials, while the mean values of covariance were smaller for signal-absent than for signal-present trials. In addition, the mean and dispersion of the P3 proved smaller for high confidence than for medium confidence signal-present trials. Nearly all these effects also proved significant for the response latency. The single-trial P3 latencies were positively correlated with the response latencies of the same trials. The observed latency variations of the P3 were interpreted in terms of changes in the detectability of the stimulus events. It was concluded that the signal condition had a significant effect upon the latency of the P3 associated with signal-present and signal-absent decisions over and above that due to temporal equivocation.

Effect of reinforcement on infants' performance in an auditory detection task.

Centre for Research in Human DevelopmentUniversity of Toronto, Mississauga, Ontario, CanadaLocalization responses to octave-band noises with center frequencies at 400 and4000 Hz were obtained from 12-month-old infants, first without reinforcementand with a 5-sec response interval and then with reinforcement and an unlimitedresponse interval. The percentage of correct responses was substantially greaterin the reinforced than in the nonreinforced condition. In a second experiment,12-month-old infants were tested in nonreinforced and reinforced sessions, as inthe previous experiment, with the exception that both sessions incorporated the5-sec response interval. Again, performance was superior in the reinforced ses-sion. It is suggested that auditory detection techniques that omit reinforcementmay be yielding attentional thresholds rather than thresholds of audibility.

Effect of reinforcement on infants' performance in an auditory detection task.

Effect of reinforcement on infants' performance in an auditory detection task.