Stimulus disparity and punisher control of human signal-detection performance

The present experiment examined the effects of varying stimulus disparity and relative punisher frequencies on signal detection by humans. Participants were placed into one of two groups. Group 3 participants were presented with 1:3 and 3:1 punisher frequency ratios, while Group 11 participants were presented with 1:11 and 11:1 punisher frequency ratios. For both groups, stimulus disparity was varied across three levels (low, medium, high) for each punisher ratio. In all conditions, correct responses were intermittently reinforced (1:1 reinforcer frequency ratio). Participants were mostly biased away from the more punished alternative, with more extreme response biases found for Group 11 participants compared to Group 3. For both groups, estimates of discriminability increased systematically across the three disparity levels and were unaffected by the punisher ratios. Likewise, estimates of response bias and sensitivity to the punisher ratios were unaffected by changes in discriminability, supporting the assumption of parameter invariance in the Davison and Tustin (1978) model of signal detection. Overall, the present experiment found no relation between stimulus control and punisher control, and provided further evidence for similar but opposite effects of punishers to reinforcers in signal-detection procedures.     

A Signal Detection Model for Multiple-Choice Exams

A model for multiple-choice exams is developed from a signal-detection perspective. A correct alternative in a multiple-choice exam can be viewed as being a signal embedded in noise (incorrect alternatives). Examinees are assumed to have perceptions of the plausibility of each alternative, and the decision process is to choose the most plausible alternative. It is also assumed that each examinee either knows or does not know each item. These assumptions together lead to a signal detection choice model for multiple-choice exams. The model can be viewed, statistically, as a mixture extension, with random mixing, of the traditional choice model, or similarly, as a grade-of-membership extension. A version of the model with extreme value distributions is developed, in which case the model simplifies to a mixture multinomial logit model with random mixing. The approach is shown to offer measures of item discrimination and difficulty, along with information about the relative plausibility of each of the alternatives. The model, parameters, and measures derived from the parameters are compared to those obtained with several commonly used item response theory models. An application of the model to an educational data set is presented.     

Adults' memories of childhood: Affect,knowing, and remembering

Adult questionnaire respondents reported, for each of a number of events, if they had experienced that event during childhood and, if so, if they remembered the experience or merely knew it had happened. Respondents also rated the emotion of each event and judged whether they would remember more about each reportedly experienced event if they spent more time trying to do so. Study 1 respondents were 96 undergraduates, whereas Study 2 tested 93 community members ranging widely in age. Respondents often reported no recollections of reportedly experienced events. Reportedly experienced events rated as emotional were more often recollected than those rated as neutral, and those rated as positive were more often recollected than those rated as negative. Predicted ability to remember more was related to current memory. Claims of remembering reportedly experienced events increased with age, but predicted ability to remember more about them declined with age.     

Learning new vocabulary during childhood: Effects of semantic training on lexical consolidation and integration

Research suggests that word learning is an extended process, with offline consolidation crucial for the strengthening of new lexical representations and their integration with existing lexical knowledge (as measured by engagement in lexical competition). This supports a dual memory systems account, in which new information is initially sparsely encoded separately from existing knowledge and integrated with long-term memory over time. However, previous studies of this type exploited unnatural learning contexts, involving fictitious words in the absence of word meaning. In this study, 5- to 9-year-old children learned real science words (e.g., hippocampus) with or without semantic information. Children in both groups were slower to detect pauses in familiar competitor words (e.g., hippopotamus) relative to control words 24 h after training but not immediately, confirming that offline consolidation is required before new words are integrated with the lexicon and engage in lexical competition. Children recalled more new words 24 h after training than immediately (with similar improvements shown for the recall and recognition of new word meanings); however, children who were exposed to the meanings during training showed further improvements in recall after 1 week and outperformed children who were not exposed to meanings. These findings support the dual memory systems account of vocabulary acquisition and suggest that the association of a new phonological form with semantic information is critical for the development of stable lexical representations.     

Intuitive Covariation Assessment of the Illusory Correlation

Most of the research concerned with the illusory correlation is modeled after the seminal work of D. L. Hamilton and R. K. Gifford (1976). However, S. A. Haslam and C. McGarty (1994) have voiced concerns over the dependent measures used within this paradigm. Therefore, in this study, the authors tested a new dependent variable that has high face validity. This measure was modeled after the work of J. R. McGahan and R. Wight (1989) and consisted of a set of propositional statements representing either the illusory correlation, the contingency opposite the illusory correlation, or the noncontingency. A second purpose of this study was to validate other studies that have used dependent measures modeled after the work of J. R. McGahan and R. Wight (1989). Demonstrating that this measure can be used to detect a well-documented phenomenon (i.e., the illusory correlation) would strengthen the results and conclusions from other studies. To this end, results from 2 experiments indicate that this measure does provide a valid alternative to those measures that are commonly used in illusory correlation studies. The results thereby give credence to other studies that have used similar dependent measures.     

It takes one to know one: Relationship between lie detection and psychopathy

We investigated primary and secondary psychopathy and the ability to detect high-stakes, real-life emotional lies in an on-line experiment (N = 150). Using signal detection analysis, we found that lie detection ability was overall above chance level, there was a tendency towards responding liberally to the test stimuli, and women were more accurate than men. Further, sex moderated the relationship between psychopathy and lie detection ability; in men, primary psychopathy had a significant positive correlation with the ability to detect lies, whereas in women there was a significant negative correlation with deception detection. The results are discussed with reference to evolutionary theory and sex differences in processing socio-emotional information.     

Attentional biases using the body in the crowd task: Are angry body postures detected more rapidly?

Research using schematic faces has consistently demonstrated attentional biases towards threatening information (angry faces), which are accentuated for individuals with higher levels of anxiety. However, research has yet to reveal whether this is the case for other nonverbal channels of communication. In the research reported here, ninety-five undergraduates completed a body in the crowd task analogous to the face in the crowd task, to examine whether attentional biases for threat existed for schematic body postures. Participants demonstrated faster detection of threat. A discrepant angry posture in a neutral crowd was identified quicker than a discrepant happy posture in a neutral crowd. This effect was pronounced for individuals with higher self-reported levels of trait anxiety. Results also demonstrated evidence of delayed disengagement from threat. Individuals were slower (i.e., more distracted) by identical crowds of angry postures rather than happy or neutral crowds and were slower to detect a discrepant neutral posture among an angry crowd than neutral among a happy crowd. These findings are the first to establish threat biases using body postures in a visual search paradigm. The results are in accordance with previous research using schematic face stimuli. Theoretical and practical implications are discussed.     

Attentional bias in high- and low-anxious individuals: Evidence for threat-induced effects on engagement and disengagement

Attentional bias to threatening visual stimuli (words or pictures) is commonly present in anxious individuals, but not in non-anxious people. There is evidence to show that attentional bias to threat can be induced in all individuals when threat is imposed by threat not of symbolic nature, but by cues that predict aversive stimulation (loud noise or electric shock). However, it is not known whether attentional bias in such situations is still influenced by individual differences in anxiety. This question was addressed in two experiments using a spatial cuing task in which visual cues predicted the occurrence of an aversive event consisting of a loud human scream. Speeded attentional engagement to threat cues was positively correlated with trait anxiety in Experiment 1. Experiment 2 showed that speeded attentional engagement was present only in participants selected for high anxiety but not in low-anxious participants. In both experiments, slower disengagement from threat cues was found in all participants, irrespective of their trait anxiety levels.     

Threat ≠ prevention,challenge ≠ promotion: The impact of threat,challenge and regulatory focus on attention to negative stimuli

The purpose of the current experiment was to distinguish between the impact of strategic and affective forms of gain- and loss-related motivational states on the attention to negative stimuli. On the basis of the counter-regulation principle and regulatory focus theory, we predicted that individuals would attend more to negative than to neutral stimuli in a prevention focus and when experiencing challenge, but not in a promotion focus and under threat. In one experiment (N = 88) promotion, prevention, threat, or challenge states were activated through a memory task, and a subsequent dot probe task was administered. As predicted, those in the prevention focus and challenge conditions had an attentional bias towards negative words, but those in promotion and threat conditions did not. These findings provide support for the idea that strategic mindsets (e.g., regulatory focus) and hot emotional states (e.g., threat vs. challenge) differently affect the processing of affective stimuli.     

Mechanisms of visual threat detection in specific phobia

People with anxiety or stress-related disorders attend differently to threat-relevant compared with non-threat stimuli, yet the temporal mechanisms of differential allocation of attention are not well understood. We investigated two independent mechanisms of temporal processing of visual threat by comparing spider-phobic and non-fearful participants using a rapid serial visual presentation task. Consistent with prior literature, spider phobics, but not non-fearful controls, displayed threat-specific facilitated detection of spider stimuli relative to negative stimuli and neutral stimuli. Further, signal detection analyses revealed that facilitated threat detection in spider-phobic participants was driven by greater sensitivity to threat stimulus features and a trend towards a lower threshold for detecting spider stimuli. However, phobic participants did not display reliably slowed temporal disengagement from threat-relevant stimuli. These findings advance our understanding of threat feature processing that might contribute to the onset and maintenance of symptoms in specific phobia and disorders that involve visual threat information more generally.