Evidence of differential performance on simultaneous and sequential lineups for individuals with autism-spectrum traits

Given the impaired facial recognition of autistic individuals, we examined whether certain autism-spectrum traits affected eyewitness identification performance in a general adult population. In a sample of 120 individuals, levels of autism-spectrum traits were examined in relation to performance on simultaneous vs. sequential lineups using a signal detection paradigm. For simultaneous lineups, total Autism Spectrum Quotient (AQ) scores and scores on the excessive Attention to detail subscale were related to fewer hits and a more conservative response criterion. Attention to detail interacted with lineup type in that it was significantly related to improved discrimination accuracy and a less conservative response criterion in sequential lineups, but with impaired discrimination accuracy and a more conservative response criterion in simultaneous lineups. Higher AQ scores on the Attention switching subscale resulted in fewer hits, lower discrimination accuracy, and a more conservative response criterion with sequential lineups. Additionally, partial disguises led to more false alarms but not decreased accuracy. More thorough investigations of the effect of lineup type on identifications are needed before policy changes are recommended.     

The right hemisphere advantage in visual change detection depends on temporal factors

What accounts for the Right Hemisphere (RH) functional superiority in visual change detection? An original task which combines one-shot and divided visual field paradigms allowed us to direct change information initially to the RH or the Left Hemisphere (LH) by deleting, respectively, an object included in the left or right half of a scene presented centrally. We manipulated the perceptual salience and semantic relevance of the change as well as the duration of the Inter-Stimulus Interval (ISI) between the scenes in order to clarify the role of the RH in memory and attention processes, and to explore whether lengthening the ISI would enhance the contribution of the LH. When analyzing data collapsed over the two levels (high vs. low) of salience and of relevance, changes were better detected in the left visual field (lvf) than in the right visual field (rvf) in the case of a short ISI, while no difference emerged in the case of a long ISI. Moreover, lengthening the ISI resulted in a performance decrement in the lvf, both for accuracy and response speed. The fact that the RH superiority was limited to short intervals indicates that stimulus-driven orienting contributes more than perceptual processing to this hemispheric asymmetry. When considering perceptual and semantic properties of the change, the effect of the ISI duration seemed to specifically emerge in the case of low relevance, with an enhancement of accuracy in the rvf when comparing the long with the short ISI. This suggests that the ISI influence on hemispheric performance operates on different levels.     

Plateaus,Dips, and Leaps: Where to Look for Inventions and Discoveries During Skilled Performance

The framework of plateaus, dips, and leaps shines light on periods when individuals may be inventing new methods of skilled performance. We begin with a review of the role performance plateaus have played in (a) experimental psychology, (b) human–computer interaction, and (c) cognitive science. We then reanalyze two classic studies of individual performance to show plateaus and dips which resulted in performance leaps. For a third study, we show how the statistical methods of Changepoint Analysis plus a few simple heuristics may direct our focus to periods of performance change for individuals. For the researcher, dips become the marker of exploration where performance suffers as new methods are invented and tested. Leaps mark the implementation of a successful new method and an incremental jump above the path plotted by smooth and steady log–log performance increments. The methods developed during these dips and leaps are the key to surpassing one's teachers and acquiring extreme expertise.     

When should clinicians switch treatments? An application of signal detection theory to two treatments for women with alcohol use disorders

Statistical application of signal detection theory has been used to study the clinical utility of early treatment response in a range of treatments and psychiatric disorders. The current study sought to examine the predictive value of weekly within-treatment drinking using receiver operator curves (ROCs) and zero-inflated Poisson (ZIP) regression in 102 women with alcohol use disorders (AUDs) randomized to either alcohol behavioral individual treatment (ABIT; n = 52) or alcohol behavioral couples treatment (ABCT; n = 50). ROC analyses indicated that failure to achieve or sustain abstinence by the end-of-treatment and one-year follow-up was predicted with reasonable accuracy by week 4 percent days abstinent (PDA) in ABIT. ZIP models yielded similar results with evidence for within-treatment PDA with week 6 PDA predicting both the abstinence as well as percent days drinking at the end-of-treatment and one-year follow-up. Within-treatment PDA was a significantly better predictor of outcomes for ABIT than ABCT, despite a better overall treatment response for ABCT. Implications for stepped care models of alcohol treatment are discussed and recommendations for future research made. When Should Clinicians Switch Treatments: An Application of Signal Detection Theory to Two Treatments for Women with Alcohol Use Disorders.     

Applying signal-detection theory to the study of observer accuracy and bias in behavioral assessment

We evaluated the feasibility and utility of a laboratory model for examining observer accuracy within the framework of signal-detection theory (SDT). Sixty-one individuals collected data on aggression while viewing videotaped segments of simulated teacher-child interactions. The purpose of Experiment 1 was to determine if brief feedback and contingencies for scoring accurately would bias responding reliably. Experiment 2 focused on one variable (specificity of the operational definition) that we hypothesized might decrease the likelihood of bias. The effects of social consequences and information about expected behavior change were examined in Experiment 3. Results indicated that feedback and contingencies reliably biased responding and that the clarity of the definition only moderately affected this outcome.     

Learning of syllable-object relations by preverbal infants: The role of temporal synchrony and syllable distinctiveness

The role of temporal synchrony and syllable distinctiveness in preverbal infants’ learning of word-object relations was investigated. In Experiment 1, 7- and 8-month-olds (N = 64) were habituated under conditions where two similar-sounding syllables, /tah/ and /gah/, were spoken simultaneously with the motions of one of two sets of objects (synchronous) or out of phase with the motions (asynchronous). On test trials, 8-month-olds, but not 7-month-olds, showed learning of the relations in the synchronous condition but not in the asynchronous condition. Furthermore, in Experiment 2, following habituation to one of the synchronous syllable-object pairs, 7-month-olds (n = 8) discriminated the syllables and the objects. In Experiment 3, following habituation to two distinct syllables, /tah/-/gih/ or /gah/-/tih/, paired with identical objects, 7-month-olds (n = 40) showed learning of the relations, again only in the synchronous condition. Thus, synchrony, which mothers naturally provide between words and object motions, facilitated the mapping onto objects of similar-sounding syllables at 8 months of age and distinct syllables at 7 months of age. These findings suggest an interaction between infants’ synchrony and syllable distinctiveness perception during early word mapping development.     

The development of mentalistic gaze understanding

Very young infants are sensitive to and follow other people's gaze. By 18 months children, like chimpanzees, apparently represent the spatial relationship between viewer and object viewed: they can follow eye‐direction alone, and react appropriately if the other's gaze is blocked by occluding barriers. This paper assesses when children represent this relationship as psychological in nature. Studies examining sensitivity to gaze, gaze following, and explicit judgement of gaze direction are reviewed. The evidence suggests that neither infants nor chimpanzees represent gaze as psychological. It is concluded that mentalistic gaze understanding develops from the age of 3 years. Copyright © 2006 John Wiley & Sons, Ltd.     

Analysis of a two-alternative force-choice signal detection theory model

A basic problem in psychophysics is recovering the mean internal response and noise amplitude from sensory discrimination data. Since these components cannot be estimated independently, several indirect methods were suggested to resolve this issue. Here we analyze the two-alternative force-choice method (2AFC), using a signal detection theory approach, and show analytically that the 2AFC data are not always suitable for a reliable estimation of the mean internal responses and noise amplitudes. Specifically, we show that there is a subspace of internal parameters that are highly sensitive to sampling errors (singularities), which results in a large range of estimated parameters with a finite number of experimental trials. Four types of singular models were identified, including the models where the noise amplitude is independent of the stimulus intensity, a situation often encountered in visual contrast discrimination. Finally, we consider two ways to avoid singularities: (1) inserting external noise to the stimuli, and (2) using one-interval forced-choice scaling methods (such as the Thurstonian scaling method for successive intervals).     

Processing time predictions of current models of perception in the classic additive factors paradigm

This article explores the consequences for factorial additivity in a Sternberg [(1969). The discovery of processing stages: Extensions of donders method In: W.G. Koster (Ed.), Attention and performance II, Acta Psychologica, 30, 276-315] additive-factors paradigm of the assumptions adopted by models of perception that relate the representation of a stimulus to decision time. Three example models, signal detection theory with the latency-distance hypothesis, stochastic general recognition theory, and a random walk model of exemplar classification, are interrogated to determine what type of interaction they predict factors will yield in a hypothetical factorial (choice) reaction time experiment in which the ‘empirical’ factors’ effects are manifest as parameter changes. All frameworks make the critical assumption that decision time depends on the perceptual representation of the stimulus as well as the architecture. As a consequence, nonadditivity of factors thought to affect different “stages” in the classical approach emerges within the current modeling approach. The nature of this influence is revealed through analytic investigations and simulation. Earlier empirical findings of failures of selective influence that have defied adequate explanation are reinterpreted in light of the present findings.