Effects of decision criterion on response latencies of binary decisions

The effects of decision criterion on response latencies of binary decisions were examined. The stimuli comprised two, partly overlapping, “normal” distributions of either two-digit numbers or tonal frequencies. Individual stimuli were randomly sampled from the distributions, and subjects had to decide from which distribution the stimulus was sampled. The decision goal was to maximize the expected gain using three different payoff matrices. Decision latencies with and without prior knowledge of optimal decision criteria were measured. In a control task, subjects were asked only to label stimuli as being either above or below the optimal criteria (without regard for a posteriori probabilities or expected gain). The relation between criterion and latency was examined by means of a trial-by-trial analysis of the stimuli and the responses. Response latency was inversely related both to the distance between the stimulus and the decision criterion and to the probability of the response elicited by the stimulus. Response latencies showed a maximum at the criterion in all conditions. These results were obtained with different stimulus modalities (tones or numbers), different discriminability levels within the auditory modality, and ifferent decision tasks. It is proposed that the decision criterion is the primary determinant of response latencies of binary decisions.     

SDT analysis of binary decisions and sensory intensity ratings to noxious thermal stimuli

During three sessions, each of 24 Ss responded to noxious thermal stimuli, using the following judgments: binary decision, S responded “high” or “low”; sensory intensity rating, S rated his sensory experience along a thermal intensity continuum; and concurrent report, S’s binary decision was followed by an intensity rating. The binary-decision d’ was significantly higher than the rating d′, suggesting that Ss could not maintain multiple thermal criteria in a consistent fashion. The criteria for pain obtained with single and concurrent intensity rating judgments did not differ. These results suggest that the most efficacious and valid method for the study of experimental pain is to obtain concurrent responses, and to use binary decisions to compute d’ and sensory intensity ratings to locate S’s criterion for reporting pain.     

Does implicit speech in same-different decisions extend to nonsense forms?

A previous study (Klapp, 1971) demonstrated that response latencies for same-different decisions involving printed words and numbers depend on the number of syllables needed for pronunciation. In the present experiment, Ss first learned to associate one- or two-syllable words to nonsense form stimuli. After extensive overlearning, the Ss were transferred to a same-different decision task involving these nonsense forms. Latencies were independent of number of syllables in the learned response. This was interpreted as showing that the Ss did not use the responses to mediate their same-different decisions, in contrast to the apparent implicit pronunciation for decisions involving printed words and numbers.     

Time perception and word recognition: an elaboration of the time-criterion account

Past research suggests that a time criterion guides responding in speeded word recognition tasks. The time-criterion account has been challenged, however, because it incorrectly predicts equivalent latencies for stimuli of differing difficulty when those stimuli are presented in the same trial block. By requiring participants to perform a lexical decision or naming task but to respond only once they had estimated that 1 sec had elapsed, we investigated the idea that stimulus difficulty effects in response latency might be at least partially due to time perception processes. Consistent with this idea, the participants produced shorter estimates of 1-sec intervals when processing easier stimuli (i.e., time seemed to pass faster when easier stimuli were processed). The implication is that understanding speeded word recognition performance will require looking beyond processes involved in acquiring information about the presented stimulus and examining more general response processes.     

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.     

The distortion of criteria after decision-making

The results of two experiments indicate that decision-makers separately distort their interpretations of decision criteria and evaluations of information in a manner that justifies their decisions. In Study 1, participants reported a yes/no decision either before or after they rated the applicable decision criterion and problem information. Participants distorted their criterion and information ratings more when they reported their decisions before, rather than after, they rated the decision criterion and problem information. Study 2 demonstrated that distortion of decision criterion ratings occurred after a decision had been made whereas distortion of information evaluations occurred during the process of reaching a decision. These results are consistent with a two-stage model of decision-making in which the distortion of decision criteria is distinct from the distortion of decision information.     

Breaking the rules in perceptual information integration

We develop a broad theoretical framework for modelling difficult perceptual information integration tasks under different decision rules. The framework allows us to compare coactive architectures, which combine information before it enters the decision process, with parallel architectures, where logical rules combine independent decisions made about each perceptual source. For both architectures we test the novel hypothesis that participants break the decision rules on some trials, making a response based on only one stimulus even though task instructions require them to consider both. Our models take account of not only the decisions made but also the distribution of the time that it takes to make them, providing an account of speed-accuracy tradeoffs and response biases occurring when one response is required more often than another. We also test a second novel hypothesis, that the nature of the decision rule changes the evidence on which choices are based. We apply the models to data from a perceptual integration task with near threshold stimuli under two different decision rules. The coactive architecture was clearly rejected in favor of logical-rules. The logical-rule models were shown to provide an accurate account of all aspects of the data, but only when they allow for response bias and the possibility for subjects to break those rules. We discuss how our framework can be applied more broadly, and its relationship to Townsend and Nozawa’s (1995) Systems-Factorial Technology.     

认知闭合需要、框架效应与决策偏好

在带有模糊性的决策情境中,决策者个人的认知特征会对其判断决策产生重要影响。通过实验的方法,考察了认知闭合需要和特征框架效应对个体决策偏好的影响。93名工商管理硕士（MBA）参与了实验,研究的结果支持了本研究的3个假设,即认知闭合需要与特征框架效应不仅对被试的决策偏好存在显著的影响,而且二者还存在显著的交互作用。具体来说,研究发现,在模糊情境中：高认知闭合需要的被试偏好于立刻做出决策,而低认知闭合需要的被试偏好于暂缓做出决策;接收到正向框架信息的被试偏好于立刻做出决策,而接收到负向框架信息的被试偏好于暂缓做出决策;认知闭合需要与特征框架对被试的决策偏好还存在显著的交互作用。研究结论为根据个体认知闭合需要的水平来选拔决策者、利用框架效应来影响个体的信息加工方式进而提高决策质量提供了理论依据     

Use of markov-encoded sequential information in numerical signal detection

Twelve Ss made binary decisions with feedback on numbers from one of two normal distributions with equal variances and unequal means. Sequences of distribution choices corresponded to first-order two-state Markov processes with probabilities of change of state of p₁ = p₂ = .50, p₁ = p₂ = .75, and p₁ = p₂ = .25. Performance was best (in d’ terms) when p₁ = p₂ ≠ .50. First-order sequential response dependencies tended to mirror the first-order stimulus dependencies. Violations of a fixed cutoff point decision rule were concentrated in the region of the average critical point, with a bandwidth of about 1/2σ, in which violations were strikingly more frequent than would be expected if they had occurred randomly. These results imply that in this task Ss are using a criterion-band decision rule instead of a fixed cutoff point rule, and that they are basing decisions in the region of the criterion band on information extracted from the sequence of decisions presented to them. The average bandwidth is generally different from the optimum bandwidth used by an ideal O in combining the two sources of information.     

The mental number line electrified: brain potentials in a numerical flanker task

It has been suggested that the mental representation of numbers is spatial in nature such that numbers are ordered on a mental number line. In the present investigation we use a variant of the Eriksen flanker task requiring a magnitude decision (smaller or larger than 5) for a central target number by pressing a response button with the right or left hand. The target number is flanked by irrelevant distracters that are either identical to the target, different from the target but biasing the same response, or different from the target and biasing a different response. Response latencies and event-related brain potentials were obtained in a group of healthy adults. Besides the typical response congruency effects on response latency and the N2 component of the ERP, we observed several other effects. First, numerical distance of the target to the standard 5 influenced decision latencies and amplitude and latency of the P3 component with smaller distances leading to longer decision latencies, longer P3 latencies and smaller P3 amplitudes. Second, smaller numerical distance between target and distracters led to faster decisions for response congruent and to slower decisions for response-incongruent trials. For response-incongruent trials P3 amplitude was small/large and P3 latency was long/short for small/large distances. These findings underscore the spatial character of number representation and further show that the relation between targets and distracters, although task irrelevant, is assessed automatically with facilitatory and inhibitory effects driven by spatial distance on the mental number line.     

How race affects evidence accumulation during the decision to shoot

The biasing role of stereotypes is a central theme in social cognition research. For example, to understand the role of race in police officers’ decisions to shoot, participants have been shown images of Black and White males and instructed to shoot only if the target is holding a gun. Findings show that Black targets are shot more frequently and more quickly than Whites. The decision to shoot has typically been modeled and understood as a signal detection process in which a sample of information is compared against a criterion, with the criterion set for Black targets being lower. We take a different approach, modeling the decision to shoot as a dynamic process in which evidence is accumulated over time until a threshold is reached. The model accounts for both the choice and response time data for both correct and incorrect decisions using a single set of parameters. Across four studies, this dynamic perspective revealed that the target’s race did not create an initial bias to shoot Black targets. Instead, race impacted the rate of evidence accumulation with evidence accumulating faster to shoot for Black targets. Some participants also tended to be more cautious with Black targets, setting higher decision thresholds. Besides providing a more cohesive and richer account of the decision to shoot or not, the dynamic model suggests interventions that may address the use of race information in decisions to shoot and a means to measure their effectiveness.     

Speed-accuracy tradeoff in double stimulation: Effects on the first response

A single-stimulation and two double-stimulation response conditions were compared using explicit payoff matrices to vary speed-accuracy tradeoff. Under accuracy payoff, response latency (RT(1)) to the first stimulus increased as ISI dropped but accuracy remained high and relatively constant. Under speed payoff, RT(1) was only slightly affected by ISI but accuracy dropped as ISI decreased. Transmitted information rates consistently reflected detrimental effects of short ISI. In double stimulation, but not in single stimulation, error response latency exceeded correct response latency. Furthermore, error response latencies were found to be far more variable and more sensitive to changes in speed-accuracy condition than were correct response latencies. Finally, under both speed and accuracy conditions, response latency to the first of two successive stimuli was faster if a response was also required to the second stimulus. Implications of the data for possible models of double-stimulation speed-accuracy tradeoff are considered.     

On the dynamic nature of response criterion in recognition memory: effects of base rate, awareness, and feedback

The authors examined whether participants can shift their criterion for recognition decisions in response to the probability that an item was previously studied. Participants in 3 experiments were given recognition tests in which the probability that an item was studied was correlated with its location during the test. Results from all 3 experiments indicated that participants' response criteria were sensitive to the probability that an item was previously studied and that shifts in criterion were robust. In addition, awareness of the bases for criterion shifts and feedback on performance were key factors contributing to the observed shifts in decision criteria. These data suggest that decision processes can operate in a dynamic fashion, shifting from item to item.     

Electrophysiological evidence for priming in response to words and pseudowords in first and second language

The study purpose was to indicate when language-specific processing first occurs and how first and second language priming processes interact. Event-related potentials were recorded from 14 normal native Hebrew speakers, in a variation of lexical decision task, to pairs of stimuli (S1, S2) in Hebrew, English, Hebrew pseudowords, and English pseudowords. Although no behavioral priming was observed, priming by pseudowords in either language affected both N400 and the late positive component of event related potential. N1 and P2 latencies were longer to S2 in semantically related pairs, indicating that language-specific processing may take place as early as auditory cortex. Different processing of first and second language was evident only in response to pseudowords.     

Diagnosticity,confidence, and the need for information

Recent research has suggested that people prefer to use the most diagnostic available information as the basis for their choices and decisions, and are most confident in those decisions when information is highly diagnostic. However, the effect of information diagnosticity on the need for additional information has yet to be investigated; that is, in an optional stopping task, will the amount of information requested depend upon information diagnosticity? Three models of the role of diagnosticity in information use were examined; expected value, a confidence criterion, and information cost. Subjects attempted to categorize stimuli with the aid of information of varying costs and diagnosticity levels. They requested more information when it was obtained at a low cost. More importantly, across cost conditions, subjects consistently requested greater amounts of information when that information was of a low diagnosticity. These data seem most consistent with use of a confidence criterion that is adjusted for information costs.     

The psychophysics of contingency assessment

The authors previously described a procedure that permits rapid, multiple within-participant evaluations of contingency assessment (the "streamed-trial" procedure, M. J. C. Crump, S. D. Hannah, L. G. Allan, & L. K. Hord, 2007). In the present experiments, they used the streamed-trial procedure, combined with the method of constant stimuli and a binary classification response, to assess the psychophysics of contingency assessment. This strategy provides a methodology for evaluating whether variations in contingency assessment reflect changes in the participant's sensitivity to the contingency or changes in the participant's response bias (or decision criterion). The sign of the contingency (positive or negative), outcome density, and imposition of an explicit payoff structure had little influence on sensitivity to contingencies but did influence the decision criterion. The authors discuss how a psychophysical analysis can provide a better understanding of findings in the literature such as mood and age effects on contingency assessment. They also discuss the relation between a psychophysical approach and an associative account of contingency assessment.     

Across the thin blue line: police officers and racial bias in the decision to shoot

Police officers were compared with community members in terms of the speed and accuracy with which they made simulated decisions to shoot (or not shoot) Black and White targets. Both samples exhibited robust racial bias in response speed. Officers outperformed community members on a number of measures, including overall speed and accuracy. Moreover, although community respondents set the decision criterion lower for Black targets than for White targets (indicating bias), police officers did not. The authors suggest that training may not affect the speed with which stereotype-incongruent targets are processed but that it does affect the ultimate decision (particularly the placement of the decision criterion). Findings from a study in which a college sample received training support this conclusion.     

Interpreting the parameters of the diffusion model: an empirical validation

The diffusion model (Ratcliff, 1978) allows for the statistical separation of different components of a speeded binary decision process (decision threshold, bias, information uptake, and motor response). These components are represented by different parameters of the model. Two experiments were conducted to test the interpretational validity of the parameters. Using a color discrimination task, we investigated whether experimental manipulations of specific aspects of the decision process had specific effects on the corresponding parameters in a diffusion model data analysis (see Ratcliff, 2002; Ratcliff & Rouder, 1998; Ratcliff, Thapar, & McKoon, 2001, 2003). In support of the model, we found that (1) decision thresholds were higher when we induced accuracy motivation, (2) drift rates (i.e., information uptake) were lower when stimuli were harder to discriminate, (3) the motor components were increased when a more difficult form of response was required, and (4) the process was biased toward rewarded responses.     

A comparison of hyponym and synonym decisions

Is class inclusion (hyponymy) a more primitive or simpler semantic relation than synonymy? This question was addressed by comparing the time required to identify examples of the two relations in a semantic decision task. In two experiments subjects made truelfalse decisions about statements of the form “An A is a B.” In Experiment 1 category-member and synonym pairs were randomly intermixed; there was no difference between the two relations. In Experiment 2 one group was presented with the two relations randomly intermixed, as in Experiment 1 (mixed condition), while two other groups were each presented with just one of the relations (separate condition). In the separate condition responses were faster to class inclusion than to synonym pairs, while in the mixed condition there was no difference, as in Experiment 1. The results suggest that class inclusion may be a simpler relation than synonymity, although the difference may simply reflect the use to which the two relations are put in common use. The fact that the difference occurred in the separate but not in the mixed conditions suggests that the latencies reflected the evaluation of the relations against a decision criterion rather than directly reflecting lexical organization or everyday usage.     

Encoding and retrieval processes in normal children and retarded adolescents

Information processing capabilities of normal and retarded individuals were studied within the context of a modified Sternberg recognition memory task. Presentation of items in the memory set was self-paced, and stimulus exposure times and response latencies were recorded.It was found that normal and retarded individuals spent the same amount of time processing subspan lists during input to the memory system; however, the normal subjects spent less time retrieving information from that system than did the retarded subjects. Part of the superiority of normal subjects was attributable to their higher scanning speeds during the stimulus comparison stage of memory retrieval. The scanning strategy of normal and retarded subjects, on the other hand, was found to be the same: serial and exhaustive. It was further demonstrated that the binary decision stage of retrieval was not related to differences in intelligence.