PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Signal Detection, Psychological”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources

Strategies optimize the detection of motion transients.

Strategies are implicitly formed when a task is consistent and can be used to improve performance. To investigate how strategies can alter perceptual performance, I trained animals in a reaction time (RT) detection task in which the probability of a fixed duration motion pulse appearing varied over time in a consistent manner. Consistent with previous studies suggesting the implicit representation of task timing, I found that RTs were inversely related to the probability of the pulse appearing and decreased with training. I then inferred the sensory integration underlying responses using behavioral reverse correlation analysis. This analysis revealed that training and anticipation optimized detection by improving the correlation between sensory integration and the spatiotemporal extent of the motion pulse. Moreover, I found that these improvements in sensory integration could largely explain observed changes in the distribution of RT with training and anticipation. These results suggest that training can increase detection performance by optimizing sensory integration according to implicitly formed representations of the likelihood and nature of the stimulus.

Animals↗

Effects of breathing air at 4 atm abs: evidence for a change in strategy.

The effect of breathing air at 4 atm abs on two tasks was investigated. For the recognition memory task, subjects learned a list of symbols in anticipation of a recognition test. The second task was a speed test in which subjects were instructed to detect all occurrences of a given target. A signal detection analysis of performance to the recognition test showed that sensitivity index was invariant, but the criterion (beta) became stricter under hyperbaric pressure. For the speed test, the results showed that under pressure the error rate increased progressively with time while the working speed remained constant. It is argued that strategic variables may be particularly sensitive to the hyperbaric environment.

Analysis of Variance↗

Quantitative relation between conflict and response inhibition in the Flanker task.

The 2001 conflict monitoring hypothesis of Botvinick and colleagues posits that the amount of conflict raised by incongruent stimuli in a flanker task affects subsequent cognitive control, such as response inhibition. The present experiment yielded empirical evidence of the quantitative relation between conflict and response inhibition. Participants judged the direction of a target arrow flanked by distractor arrows presented above and below the target. The amount of conflict was manipulated by varying the distance between the target and the directional distractors. Analysis showed that response times were longer for incongruent trials than for congruent trials, and response times on incongruent trials were longer for the small distance than for the large distance conditions. In addition, the response times in congruent trials became longer as the amount of conflict in the preceding trial increased. These results are consistent with Botvinick, et al.'s hypothesis that the conflict-detection mechanism determines the amount of response inhibition depending on the amount of conflict. Responses on incongruent trials were faster and more accurate when the preceding trial was incongruent than when it was congruent, and the size of this response facilitation was not influenced by the amount of conflict. These results suggest that the conflict detection mechanism modulates the subsequent behaviors by two forms of control which are differently affected by the amount of conflict.

Adult↗

Effects of familiarity level and repetition on recognition accuracy.

Theories of recognition memory based on signal detection theory posit that a recognition decision is similar to a psychophysical judgment. Like a judgment of stimulus brightness or loudness, a recognition judgment is based on the value of a unidimensional signal computed for the test item. This signal has been called the strength or familiarity value. One prediction of these models is that the ability to discriminate between a studied and nonstudied test item depends on the ability to detect the difference in their familiarities. This ability in turn is influenced by the items' familiarity levels; discrimination should become more difficult as the familiarity of both items increases. This prediction was supported in 3 experiments using a forced-choice procedure. Also, accuracy was higher when the list contained repeated items rather than a comparable number of distinct items.

Humans↗

A theory of attending and reinforcement in conditional discriminations.

A model of conditional discrimination performance (Davison & Nevin, 1999) is combined with the notion that unmeasured attending to the sample and comparison stimuli, in the steady state and during disruption, depends on reinforcement in the same way as predicted for overt free-operant responding by behavioral momentum theory (Nevin & Grace, 2000). The rate of observing behavior, a measurable accompaniment of attending, is well described by an equation for steady-state responding derived from momentum theory, and the resistance to change of observing conforms to predictions of momentum theory, supporting a key assumption of the model. When probabilities of attending are less than 1.0, the model accounts for some aspects of conditional-discrimination performance that posed problems for the Davison-Nevin model: (a) the effects of differential reinforcement on the allocation of responses to the comparison stimuli and on accuracy in several matching-to-sample and signal-detection tasks where the differences between the stimuli or responses were varied across conditions, (b) the effects of overall reinforcer rate on the asymptotic level and resistance to change of both response rate and accuracy of matching to sample in multiple schedules, and (c) the effects of fixed-ratio reinforcement on accuracy. Some tests and extensions of the model are suggested, and the role of unmeasured events in behavior theory is considered.

Attention↗

Is vision continuous with cognition? The case for cognitive impenetrability of visual perception.

Although the study of visual perception has made more progress in the past 40 years than any other area of cognitive science, there remain major disagreements as to how closely vision is tied to cognition. This target article sets out some of the arguments for both sides (arguments from computer vision, neuroscience, psychophysics, perceptual learning, and other areas of vision science) and defends the position that an important part of visual perception, corresponding to what some people have called early vision, is prohibited from accessing relevant expectations, knowledge, and utilities in determining the function it computes--in other words, it is cognitively impenetrable. That part of vision is complex and involves top-down interactions that are internal to the early vision system. Its function is to provide a structured representation of the 3-D surfaces of objects sufficient to serve as an index into memory, with somewhat different outputs being made available to other systems such as those dealing with motor control. The paper also addresses certain conceptual and methodological issues raised by this claim, such as whether signal detection theory and event-related potentials can be used to assess cognitive penetration of vision. A distinction is made among several stages in visual processing, including, in addition to the inflexible early-vision stage, a pre-perceptual attention-allocation stage and a post-perceptual evaluation, selection, and inference stage, which accesses long-term memory. These two stages provide the primary ways in which cognition can affect the outcome of visual perception. The paper discusses arguments from computer vision and psychology showing that vision is "intelligent" and involves elements of "problem solving." The cases of apparently intelligent interpretation sometimes cited in support of this claim do not show cognitive penetration; rather, they show that certain natural constraints on interpretation, concerned primarily with optical and geometrical properties of the world, have been compiled into the visual system. The paper also examines a number of examples where instructions and "hints" are alleged to affect what is seen. In each case it is concluded that the evidence is more readily assimilated to the view that when cognitive effects are found, they have a locus outside early vision, in such processes as the allocation of focal attention and the identification of the stimulus.

Agnosia↗

Dual-process models of associative recognition in young and older adults: evidence from receiver operating characteristics.

In 3 experiments, young and older adults studied lists of unrelated word pairs and were given confidence-rated item and associative recognition tests. Several different models of recognition were fit to the confidence-rating data using techniques described by S. Macho (2002, 2004). Concordant with previous findings, item recognition data were best fit by an unequal-variance signal detection theory model for both young and older adults. For both age groups, associative recognition performance was best explained by models incorporating both recollection and familiarity components. Examination of parameter estimates supported the conclusion that recollection is reduced in old age, but inferences about age differences in familiarity were highly model dependent. Implications for dual-process models of memory in old age are discussed.

Adult↗

Neighborhood frequency does affect performance in the Reicher task: encoding or decision?

Three experiments using the Reicher task show that performance on low-frequency words is disrupted if the incorrect alternative forms a higher frequency word. This neighborhood frequency effect occurs for both energy and pattern masks and for different sets of items. When the upcoming word is primed and its accessibility is enhanced, the neighborhood frequency effect is eliminated. Experiments 4a and 4b tested the neighborhood frequency effect using a same-different task and a signal-detection analysis. Neighborhood frequency affected the decision criterion but not the sensitivity of the perceptual system. Experiment 5 showed that many words with a frequency in the range from 1 to 5 per million are not recognized out of context. These results are consistent with the hypothesis that frequency effects in the Reicher task are caused by a bias in the decision system and can be simulated with the stochastic activation-verification model.

Adult↗

Six regularities of source recognition.

In recent work, researchers have shown that source-recognition memory can be incorporated in an extended signal detection model that covers both it and item-recognition memory (A. Hilford, M. Glanzer, K. Kim, & L. T. DeCarlo, 2002). In 5 experiments, using learning variables that have an established effect on item recognition, the authors tested further implications of that extended model. The results establish 6 source-recognition regularities that support the model. An important regularity in that set is the linkage of source and item recognition: Any learning variable that increases item recognition increases source recognition.

Humans↗

Regularities of source recognition: ROC analysis.

Source memory has become the focus of a growing number of investigations in a variety of fields. An appropriate model for source memory is, therefore, of increasing importance. A simple 2-dimensional signal-detection model of source recognition is presented. The receiver operating characteristics (ROCs) obtained from 3 experiments are then used to test the model. The data demonstrate 3 regularities: convex ROCs, z-ROCs with linear slopes of 1.00, and slightly concave z-ROCs. Two of these regularities support the model. The 3rd requires a revision of the model. This revised model is fitted to the data. The implications of these regularities for other theories are also discussed.

Adolescent↗

Receiver operating characteristics in the lexical decision task: evidence for a simple signal-detection process simulated by the multiple read-out model.

This study provides further evidence for the hypothesis that performance in the lexical decision task is based on the output of a signal detection mechanism, as implemented by the multiple read-out model of word recognition (MROM; J. Grainger & A. M. Jacobs, 1996). We extend the MROM to allow predictions of receiver operating characteristics in a data-limited variant of the lexical decision task and show that the model provides accurate descriptions of the data. Our results challenge all models of word recognition that do not include a familiarity assessment mechanism. They also suggest that under data-limited conditions a deadline mechanism for generating "no" responses in the lexical decision task may not necessarily be functional.

Decision Making↗

The systematic discrepancy between A' for overall recognition and remembering: a dual-process account.

Signal detection accounts of recognition assume that all item endorsements arise from the assessment of a single continuous indication of memory strength, even when subjects claim to categorically separate items accompanied by contextual recollection from those that are not (viz., remembering vs. knowing). Dissociations of these response types are held to occur because the former require a higher response criterion for item strength than does the latter. Meta-analytic and individual subject data suggest that when the A' metric is used, accuracy for remembering can systematically deviate from that of overall responding for individual subjects. This occurs because, unlike the symmetric and rigid receiver-operating characteristic (ROC) implied under A', empirical ROCs are asymmetric and plastic. A dual-process model predicted that the magnitude of the deviation would vary as a systematic function of the proportion of overall recognition accompanied by subjective remember reports for individual subjects. The predictions were confirmed using multiple regression on Monte Carlo and experimental data sets and were also shown to generalize to the double equal-threshold, single high-threshold [i.e., H - FA; (H - FA)/(1 - FA)], and the equal variance signal detection d' corrections. The unequal variance signal detection model was also shown to mirror the data, but only under the post hoc assumption that every subject adopts a very similar remember criterion placement rule. The results demonstrate that the systematic failure of tightly constrained models of recognition constitutes valuable regression data for more complex models and simultaneously highlights why single-point measures of accuracy are unsuitable as summaries across conditions or groups. Furthermore, the results show that remember rates carry unique information regarding the underlying processes governing individual subject performance that cannot be gleaned from the overall hit and false alarm rates in isolation.

Data Interpretation, Statistical↗

Sum-difference theory of remembering and knowing: a two-dimensional signal-detection model.

In the remember-know paradigm for studying recognition memory, participants distinguish items whose presentations are episodically remembered from those that are merely familiar. A one-dimensional model postulates that remember responses are just high-confidence old judgments, but a meta-analysis of 373 experiments shows that the receiver operating characteristic (ROC) curves predicted by this model have the wrong slope. According to the new sum-difference Theory of remembering and knowing (STREAK), old items differ from new ones in both global and specific memory strength: The old-new judgment is based on a weighted sum of these dimensions, and the remember- know judgment is based on a weighted difference. STREAK accounts for the form of several novel kinds of ROC curves and for existing remember-know and item-recognition data.

Humans↗

Modeling associative recognition: a comparison of two-high-threshold, two-high-threshold signal detection, and mixture distribution models.

A 2-high-threshold signal detection (HTSDT) model, a mixture distribution (SON) model, and 2-high-threshold (HT) models with responses distributed over 1 or several response categories were fit to results of 6 experiments from 2 studies on associative recognition: R. Kelley and J. T. Wixted (2001) and A. P. Yonelinas (1997). HTSDT assumes that associative recognition is based on conscious recollection and familiarity assessment, whereas according to SON and HT, associative information results in a shift of familiarity. The modeling results cast doubt on the prominent role of conscious recollection, and as far as models are valid, parameter estimation suggests 2 processes in associative recognition: a shift in familiarity that is due to associative information and the determination of the source of familiarity of pairs.

Association↗

Phantom ROC: Recollection rejection in a hybrid conjoint recognition signal detection model.

The present experiments test predictions of dual process models with regards to recollection rejection using a model called phantom ROC. Participants studied pictures and then took a recognition test in which they were presented with targets (i.e., the exact picture presented), related lures (i.e., the same object but from a different angle), and unrelated lures (i.e., objects that had not been shown). For each item, participants answered both standard recognition and meaning recognition questions. In Experiment 1 participants studied pictures under either full attention or divided attention. In Experiment 2 some participants were told that no object was shown twice (i.e., mutual exclusivity instructions), while others were told that both camera angles might have been shown for some objects (no mutual exclusivity instructions). The present experiments provide three converging measures, all of which are consistent with dual process models that propose a recollection rejection mechanism.

Attention↗

On the importance of models in interpreting remember-know experiments: comments on Gardiner et al.'s (2002) meta-analysis.

From a meta-analysis of recognition experiments using the remember-know-guess paradigm, Gardiner, Ramponi, and Richardson-Klavehn (2002) reported two findings that they viewed as evidence against the one-dimensional model for that paradigm: (1) Memory strength increased when know responses were added to remember responses, decreasing when guess responses were also included. (2) The accuracy of guess responses was correlated with the location of the old-new criterion in the one-dimensional model for the paradigm, implying that guesses were influenced by decision processes. We question both findings. The first result is contradicted by a signal-detection (SDT) analysis, which shows that both know and guess responses reduced estimated memory strength. The discrepancy results from the properties of A', the measure of accuracy used by Gardiner et al., which we argue is flawed. The second result follows directly from the one-dimensional model, in which accuracy and response criteria are fixed. The authors' reasons for rejecting the one-dimensional model are thus not persuasive, but it can nonetheless be rejected because ROC curves implied by the data are inconsistent with ROCs derived from ratings experiments. A two-dimensional SDT model (Rotello, Macmillan, & Reeder, 2004) accounts for both sets of data. The analysis illustrates the importance of models in interpreting remember--know data.

Bias↗

Testing theories of recognition memory by predicting performance across paradigms.

Signal-detection theory (SDT) accounts of recognition judgments depend on the assumption that recognition decisions result from a single familiarity-based process. However, fits of a hybrid SDT model, called dual-process theory (DPT), have provided evidence for the existence of a second, recollection-based process. In 2 experiments, the authors tested predictions of DPT and SDT by comparing the invariance of parameter estimates between yes/no (Y/N) and 2-alternative forced-choice (2AFC) testing paradigms. Both experiments showed DPT recollection estimates in Y/N to be poorly correlated with recollection estimates in 2AFC. In Experiment 2, SDT predictions explained more variance than DPT predictions. The authors evaluate and discuss the extent to which each model possesses theoretical validity versus computational flexibility in curve fitting.

Forecasting↗

The effects of aging on reaction time in a signal detection task.

The effects of aging on response time are examined in 2 simple signal detection tasks with young and older subjects (age 60 years and older). Older subjects were generally slower than young subjects, and standard Brinley plot analyses of response times showed typical results: slopes greater than 1 and (mostly) negative intercepts. R. Ratcliff, D. Spieler, and G. McKoon (2000) showed that the slopes of Brinley plots measure the relative standard deviations of the distributions of response times for older versus young subjects. Applying R. Ratcliff's (1978) diffusion model to fit the response times, their distributions, and response accuracy, it was found that the larger spread in older subjects' response times and their slowness relative to young subjects comes from a 50-ms slowing of the nondecision components of response time and more from conservative settings of response criteria.

Adolescent↗