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PubMed2005

Maternal self-efficacy and experimentally manipulated infant difficulty effects on maternal sensory sensitivity: a signal detection analysis.

The impact of differences in maternal self-efficacy and infant difficulty on mothers' sensitivity to small changes in the fundamental frequency of an audiotaped infant's cry was explored in 2 experiments. The experiments share in common experimental manipulations of infant difficulty, a laboratory derived measure of maternal efficacy (low, moderate, and high illusory control), and the use of signal detection methodology to measure maternal sensory sensitivity. In Experiment 1 (N = 72), easy and difficult infant temperament was manipulated by varying the amount of crying (i.e., frequency of cry termination) in a simulated child-care task. In Experiment 2 (N = 51), easy and difficult infant temperament was manipulated via exposure to the solvable or unsolvable pretreatment of a learned helplessness task to mirror mothers' ability to soothe a crying infant. In both experiments, only mothers with high illusory control showed reduced sensory sensitivity under the difficult infant condition compared with the easy infant condition.

Adult↗

PubMed1990

[Studies on cross correlation coefficient of fetal heart rate and fetal movement signals detected by ultrasonic Doppler fetal actocardiograph].

Cross correlation coefficients of fetal heart rate (FHR) and fetal movement (FM) signals detected by ultrasonic Doppler actocardiograph were studies. Actocardiographic output was stored in a floppy disk through an AD converter. The parameters for every 5 minute period were calculated in 461 periods for 68 normal pregnant women at 14 to 41 weeks of gestation. 1) Between FHR acceleration (ACC) and the maximum coefficient, the averages for the maximum coefficients in 5 minute periods without and with ACC were 0.141 and 0.275, respectively. The respective lag time averages were 13.1 and 7.6 seconds. These results may indicate that the FHR ACC temporarily follow FM with a time lag of several seconds in the active state. 2) The largest value for the maximum coefficients and the lag times in each examination were investigated according for each gestational week. The coefficients increased and the lag times decreased as gestation advanced. 3) The coefficients in the periods showing typical fetal breathing movement and fetal hiccups were very small. Periodic fetal suckling observed with real-time B mode showed large coefficient with a 3 sec' delay in FM.

Female↗

PubMed2003

Fuzzy signal detection theory: analysis of human and machine performance in air traffic control, and analytic considerations.

This paper applies fuzzy SDT (signal detection theory) techniques, which combine fuzzy logic and conventional SDT, to empirical data. Two studies involving detection of aircraft conflicts in air traffic control (ATC) were analysed using both conventional and fuzzy SDT. Study 1 used data from a preliminary field evaluation of an automated conflict probe system, the User Request Evaluation Tool (URET). The second study used data from a laboratory controller-in-the-loop simulation of Free Flight conditions. Instead of assigning each potential conflict event as a signal (conflict) or non-signal, each event was defined as a signal (conflict) to some fuzzy degree between 0 and 1 by mapping distance into the range [0, 1]. Each event was also given a fuzzy membership, [0, 1], in the set 'response', based on the perceived probability of a conflict or on the colour-coded alert severity. Fuzzy SDT generally reduced the computed false alarm rate for both the human and machine conflict systems, partly because conflicts just outside the conflict criterion used in conventional SDT, were defined by fuzzy SDT as a signal worthy of some attention. The results illustrate the potential of fuzzy SDT to provide, especially in exploratory data analysis, a more complete picture of performance in aircraft conflict detection and many other applications. Alternative analytic methods also using fuzzy SDT concepts are discussed.

Aircraft↗

PubMed2002

Fear, disgust, and information processing in specific phobia: the application of signal detection theory.

A growing body of research suggests that individuals with small animal and blood-injection-injury (BII) phobias respond to phobia-relevant stimuli with a combination of fear and disgust. Despite the recognition that disgust may serve a functional role in phobic avoidance behavior, little is known about biased information processing for disgust-related material. Two studies examined recognition memory, using signal detection analyses, for phobia-relevant and general disgust pictures. Study I failed to find differences between spider phobics, BII phobics, and nonphobics in discrimination ability (d') and response bias (c) for spider, surgical, and two categories of general disgust pictures. Results indicated that all participants responded in a liberal manner toward surgical and disgust pictures, whereas they responded more conservatively when judging spider pictures. Study 2 also failed to find differences between BII phobics and nonphobics in discrimination ability and response bias for surgical and disgust pictures presented at 500 and 50 ms exposure durations. All participants again adopted a liberal response bias toward surgical and disgust pictures, although only under the 500 ms stimulus presentation condition. These results do not suggest the presence of preferential information processing of phobia-relevant or general disgust elicitors among phobic participants. The functional value of disgust-mediated information processing biases is questioned given the available literature. Implications and suggestions for continued information processing research for fearful and disgusting stimuli in specific phobia are outlined.

Adolescent↗

PubMed2004

Signal-detection analyses of conditional discrimination and delayed matching-to-sample performance.

Quantitative analyses of stimulus control and reinforcer control in conditional discriminations and delayed matching-to-sample procedures often encounter a problem; it is not clear how to analyze data when subjects have not made errors. The present article examines two common methods for overcoming this problem. Monte Carlo simulations of performance demonstrated that both methods introduced systematic deviations into the results, and that there were genuine risks of drawing misleading conclusions concerning behavioral models of signal detection and animal short-term memory.

Animals↗

PubMed2002

African American women and men at high and low risk for hypertension: a signal detection analysis of NHANES III, 1988-1994.

BACKGROUND: African Americans have some of the highest rates of hypertension in the world. This study identified subgroups of U.S. African American women and men with particularly high and low rates of hypertension. METHODS: Data are presented for 1,911 Black women and 1,657 Black men, ages 25-84 from the Third National Health and Nutrition Examination Survey, 1988-1994. Signal detection methodology identified high and low risk subgroups; stratified analyses characterized the population of hypertensives. RESULTS: We identified 12 distinct subgroups with highly variable rates of hypertension (11-78%). The two groups with the highest rates of hypertension (>70% hypertensive) were more likely to be middle aged or older, less educated, overweight or obese (>80%), physically inactive (50%), and to have diabetes (28 and 100% diabetic). The two groups with the lowest hypertension rates (<18% hypertensive) were more likely to be younger, but were also overweight or obese (>50%). Among hypertensives, those who were uncontrolled and not on antihypertensive medications were distinguished by their male gender, younger age, and infrequent contact with a physician. CONCLUSIONS: Hypertension rates vary substantially within African Americans, illustrating the need for effective weight management, diabetes control, and increased access to health care for those at highest risk.

Adult↗

PubMed1979

Signal probability, reinforcement and signal detection.

Five pigeons were trained to detect differences in light intensity. Two stimuli, S1 and S2, differing in intensity, were arranged on the center key of a three-key chamber according to set probabilities. A peck on the center key turned on the two side keys. When S1 was presented on the center key, a peck on the left key was "correct" and when S2 was presented, a peck on the right key was "correct." Correct responses produced reinforcement and incorrect responses produced 3-second blackout. Detection performance was measured under three procedures. The first was a standard signal-detection design in which the probability of S1 was varied and the number of reinforcements obtained for correct responses to S1 was allowed to covary. In the second procedure, the probability of S1 was again varied but the distribution of reinforcements between the two choices was kept equal. In the third procedure, probability of S1 was held constant while the distribution of reinforcements was varied between the two choices. Changes in response bias were a function of variations in the relative reinforcement ratio for the choice responses and not a function of variations in the probability of stimulus presentation. Discriminability remained constant across the three procedures.

Animals↗

PubMed2006

The role of knowledge and motivation in symptom identification accuracy among schizophrenic patients: application of signal detection theory.

OBJECTIVE: Many people with schizophrenia have poor awareness of their symptoms, a problem that may result from lack of knowledge about their illness and/or unwillingness to acknowledge it. The present study assessed the joint influence of lack of knowledge and motivated denial in schizophrenic patients' low symptom awareness. METHOD: Schizophrenic patients (N = 85) and normal control participants (N = 35) identified psychotic symptoms and general stress symptoms in a symptom checklist. The signal detection theory was applied to assess levels of sensitivity (which would be knowledge-mediated) and judgment biases (which would probably be motivated). RESULTS: Compared with normal control participants, schizophrenic patients had lower sensitivity and greater aversion to classify a symptom as a psychotic symptom. CONCLUSIONS: These findings suggest that both lack of knowledge and motivated denial are involved in schizophrenic patients' low symptom awareness.

Adult↗

PubMed2006

Effects of misleading questions and hypnotic memory suggestion on memory reports: a signal-detection analysis.

In 2002, the first author and colleagues reported data indicating that both hypnosis and misleading questions decreased the accuracy of memory reports and decreased "don't know" response rates, that the effects of misleading questions were significantly greater than those of hypnosis, and that the two effects were additive. Using a sample of 194 undergraduate students, the present study replicated the findings that misleading questions reduce accuracy and "don't know" responding but failed to replicate the negative effect of hypnosis on memory reports. Signal detection analysis indicated that misleading questioning produced decreased sensitivity accompanied by higher response bias, though affecting sensitivity more than producing a criterion shift.

Adolescent↗

PubMed1982

Temporal auditory acuity in blind and sighted subjects: a signal detection analysis.

Temporal auditory sensitivity was compared in five adventitiously blind and five normally sighted subjects in a signal-detection paradigm. Following determination of individual auditory flutter fusion (AFF) thresholds the subjects were required to make forced-choice responses between a fluttering and fused white noise under stimulus probabilities of 0.25, 0.50, and 0.75. From these data indices of sensory sensitivity (d') and response bias (Beta) were computed and compared. Analysis indicated no significant differences in auditory sensitivity between the two groups. These findings further weaken the traditional hypothesis of sensory compensation.

Adolescent↗

PubMed1984

Effects of intertrial interval, orientation, and adaptation on orientation discrimination measured with a yes-no signal detection paradigm.

Orientation discriminations were measured with a 3.8-cpd sinusoidal grating stimulus and a yes-no signal-detection procedure. Analysis showed that such discriminations are independent of light-adaptation conditions and of intertrial interval over the 2- to 8-sec. range of values explored. However, they are strongly influenced by the orientation where measurements are made (the "oblique effect").

Adaptation, Ocular↗

PubMed2006

How high should total pain-relief score be to obviate the need for analgesic remedication in acute pain? Estimation using signal detection theory and individual-patient meta-analysis.

BACKGROUND: A pain relief score 50% of the maximum is often used as a clinically meaningful outcome in meta-analyses of analgesic trials. This arbitrary value requires validation. OBJECTIVE: To determine the optimum pain relief score for predicting pain relief sufficient to obviate the need for analgesic remedication in acute post-surgical pain. DESIGN: Individual-patient meta-analysis of randomized controlled trials and use of signal detection theory to identify the optimum cut-off point on the total pain relief score (TOTPAR). Analgesic remedication was used as the clinical outcome. DATA SOURCES: Seven parallel-group, active and placebo-controlled trials of minor analgesics. RESULTS: The predictive value of the TOTPAR score [expressed as a percentage of the maximum score (%maxTOTPAR)] for remedication was excellent for all the trials. The pooled estimate of the area under the receiver operating curve, an index of discriminative power, was outstanding 0.96 (95% CI 0.95-0.97). The pooled estimate of the optimal %maxTOTPAR for predictive purposes was 44.11 (95% CI 44.00-44.23). CONCLUSION: The analysis suggests that the arbitrary 50% cut-off point TOTPAR score often used in meta-analyses of analgesic trials in dental pain is reasonably acceptable. This is different to the 33% cut-off point reported for analgesic trials of acute breakthrough cancer pain and some chronic pain states such as diabetic neuropathy and postherpetic neuralgia. These differences deserve careful consideration when reading reports of analgesic trials and meta-analyses. Remedication itself should be considered as the preferred outcome measure for analgesic trials.

Acetaminophen↗

PubMed2002

Women's perceptions of the outcome of weight loss diets: a signal detection approach.

OBJECTIVE: Evolutionary psychology suggests that body shape is as important as body size and that, in women, certain body shapes are considered more attractive, specifically a waist-to-hip ratio (WHR) of about 0.70. Research has shown that the WHR does not change as a result of weight loss diets although it may be that women who diet do not appreciate this. We hypothesized that women would report diet outcomes that included shape change. This was investigated using a signal detection paradigm. METHOD: Two groups of female participants (high and low WHRs) were presented with images with high and low WHRs and were asked to choose images they could resemble through dieting. RESULTS: Both groups of women selected low WHR images as the outcome of their diets, supporting theories of evolutionary psychology. DISCUSSION: We conclude that women in the high WHR group may find adherence to diets problematic because the desired change in shape does not occur.

Adult↗

PubMed1999

Spatial signal detection in rats is differentially disrupted by delta-9-tetrahydrocannabinol, scopolamine, and MK-801.

Cannabinoid receptors have been implicated as having important roles in human cognitive processes, especially memory and attention. While some work has studied the effects of the active ingredient in marijuana, delta-9-tetrahydrocannabinol (THC), on short-term memory, no work has examined the involvement of these receptors in mediating attention. Therefore, the present study compared the effects of THC on the performance by rats of an operant spatial signal detection task with those of cholinergic muscarinic antagonist scopolamine and glutamatergic NMDA antagonist MK-801, both compounds known to influence attention and other cognitive processes in rats. These experiments were conducted in a two lever operant chamber in which a cue lamp was mounted over each lever. The rats were pretrained to respond rapidly on the corresponding lever following a rapid presentation of the cue lamp above it. The stimulus was presented in a random order of three durations (100, 300 or 1000 ms) to measure detectability of the stimulus under saline, THC (1.0 or 2.0 mg/kg i.p.), scopolamine (0.06-0.25 mg/kg i.p.), or MK-801 (0.06-0.25 mg/kg i.p.). THC significantly and selectively disrupted stimulus detection accuracy at the 100 ms stimulus duration, but did not influence response bias or the rate of responding. Scopolamine and MK-801 both produced alteration in errors of omission and position bias. These data suggest that THC produces an impairment in visual attention and that the nature of this impairment is qualitatively different from that produced by muscarinic-receptor or NMDA-receptor antagonism.

Animals↗

PubMed1999

A generalized signal detection model to predict rational variation in base rate use.

The predominant models of rational behavior currently used to analyze a large class of experiments imply that subjects neglect or place insufficient weight on base rates when making probabilistic judgments. We argue that the evidence is inadequate for this conclusion because the models make needlessly restrictive assumptions about how base rates should be used. The restrictive assumptions stem from a misuse of Bayes' rule that ignores specific aspects of how the proportions arose. We develop a model of rational behavior that generalizes signal detection theory to reflect the environment subjects routinely face and we reexamine the relevant experimental literature. Variation observed in subjects' responses to base rate information is explained by the present rational model more fully than by extant models.

Adult↗

PubMed1995

Mapping the perceptual magnet effect for speech using signal detection theory and multidimensional scaling.

Recent experiments have demonstrated that the category goodness of speech sounds strongly influences perception in both adult and infants [Kuhl, Percept. Psychophys. 50, 93-107 (1991); Kuhl et al., Science 255, 606-608 (1992)]. Stimuli judged as exceptionally good instances of phonetic categories (prototypes) make neighboring tokens in the vowel space seem more similar, exhibiting a perceptual magnet effect. Three experiments further examined the perceptual magnet effect in adults. Experiment 1 collected goodness and identification judgments for 13 variants of the vowel /i/. Experiment 2 used signal detection theory to assess the discrimination of these tokens using a bias-free measure (d'). Experiment 3 employed multidimensional scaling (MDS) to geometrically model the distortion of the perceptual space due to the magnet effect. The results demonstrated a strong relationship between category goodness and discrimination. Vowel tokens receiving high goodness ratings in experiment 1 were more difficult to discriminate in experiment 2 and were more tightly clustered in the MDS solutions of experiment 3. These findings support the existence of a perceptual magnet effect, and may help explain some aspects of first language learning in infants and second language learning in adults.

Humans↗

PubMed1993

Cerebral asymmetry and hypnosis: a signal-detection analysis of divided visual field stimulation.

Brightness discriminations in a divided-field paradigm were examined with a signal-detection procedure in three sessions, the second with hypnosis. Practiced, hypnotically susceptible Ss were subdivided into high- (n = 6) and medium- (n = 5) susceptible groups on the basis of a susceptibility scale monitored throughout the hypnosis session. High-susceptible Ss showed increases in d' in the left visual field (right hemisphere) with hypnosis, whereas medium-susceptible Ss showed bilateral enhancements. Beta remained invariant in both groups across three sessions but was higher in the left visual field. The results provide evidence of altered brain function with hypnosis and an association of focal right hemispheric changes with high susceptibility and, through the invariance of beta, fail to support the attribution of perceptual changes to attitudinal, nonstate factors.

Adult↗

PubMed2000

Work stressors and alcohol consumption among white-collar workers: a signal detection approach.

OBJECTIVE: Previous findings regarding the relationship between work stress and alcohol consumption are inconsistent and inconclusive. One of the primary reasons for the inconsistency of the findings is that simple models, such as multiple regression analysis or analysis of variance (ANOVA), have been conventionally adopted in studies examining the relationship between work stressors and alcohol consumption. Since higher order interactions of multiple work stressors, which lead to heavy alcohol consumption, might not be fully uncovered within the framework of a multiple regression analysis or ANOVA, another approach to exploring the interactions of work stressors is presented in this study. METHOD: A signal detection analysis method was used to evaluate higher order interactions of work stress variables and to obtain basic information on 465 Japanese male white-collar workers. RESULTS: Of 11 work stressor or work position variables, four significant predictors of heavy alcohol consumption were identified. CONCLUSIONS: Two procedures were successfully performed in this study: (1) evaluating several higher order interactions of work stressors associated with heavy alcohol consumption, and (2) obtaining basic information to permit dividing the subjects into subgroups for further analysis using models and independent variables unique to each subgroup.

Adult↗