Recollection is a continuous process: Evidence from plurality memory receiver operating characteristics

Is recollection a continuous/graded process or a threshold/all-or-none process? Receiver operating characteristic (ROC) analysis can answer this question as the continuous model and the threshold model predict curved and linear recollection ROCs, respectively. As memory for plurality, an item's previous singular or plural form, is assumed to rely on recollection, the nature of recollection can be investigated by evaluating plurality memory ROCs. The present study consisted of four experiments. During encoding, words (singular or plural) or objects (single/singular or duplicate/plural) were presented. During retrieval, old items with the same plurality or different plurality were presented. For each item, participants made a confidence rating ranging from “very sure old”, which was correct for same plurality items, to “very sure new”, which was correct for different plurality items. Each plurality memory ROC was the proportion of same versus different plurality items classified as “old” (i.e., hits versus false alarms). Chi-squared analysis revealed that all of the plurality memory ROCs were adequately fit by the continuous unequal variance model, whereas none of the ROCs were adequately fit by the two-high threshold model. These plurality memory ROC results indicate recollection is a continuous process, which complements previous source memory and associative memory ROC findings.     

An evaluation of recollection and familiarity in Alzheimer’s disease and mild cognitive impairment using receiver operating characteristics

There is a need to investigate exactly how memory breaks down in the course of Alzheimer’s disease (AD). Examining what aspects of memorial processing remain relatively intact early in the disease process will allow us to develop behavioral interventions and possible drug therapies focused on these intact processes. Several recent studies have worked to understand the processes of recollection and familiarity in patients with mild cognitive impairment (MCI) and very mild AD. Although there is general agreement that these patient groups are relatively unable to use recollection to support veridical recognition decisions, there has been some question as to how well these patients can use familiarity. The current study used receiver operating characteristic (ROC) curves and a depth of processing manipulation to understand the effect of MCI and AD on the estimates of recollection and familiarity. Results showed that patients with MCI and AD were impaired in both recollection and familiarity, regardless of the depth of encoding. These results are discussed in relation to disease pathology and in the context of recent conflicting evidence as to whether familiarity remains intact in patients with MCI. The authors highlight differences in stimuli type and task difficulty as possibly modulating the ability of these patients to successfully use familiarity in support of memorial decisions.     

Eyewitness identification in simultaneous and sequential lineups: an investigation of position effects using receiver operating characteristics

For decades, sequential lineups have been considered superior to simultaneous lineups in the context of eyewitness identification. However, most of the research leading to this conclusion was based on the analysis of diagnosticity ratios that do not control for the respondent’s response criterion. Recent research based on the analysis of ROC curves has found either equal discriminability for sequential and simultaneous lineups, or higher discriminability for simultaneous lineups. Some evidence for potential position effects and for criterion shifts in sequential lineups has also been reported. Using ROC curve analysis, we investigated the effects of the suspect’s position on discriminability and response criteria in both simultaneous and sequential lineups. We found that sequential lineups suffered from an unwanted position effect. Respondents employed a strict criterion for the earliest lineup positions, and shifted to a more liberal criterion for later positions. No position effects and no criterion shifts were observed in simultaneous lineups. This result suggests that sequential lineups are not superior to simultaneous lineups, and may give rise to unwanted position effects that have to be considered when conducting police lineups.     

Symmetry of receiver operating characteristic curves and Kullback–Leibler divergences between the signal and noise populations

It is shown that the symmetry of the receiver operating characteristic curve implies that the Kullback–Leibler divergences between the signal and noise populations are equal when the arguments are interchanged.     

The world turns at 33 and 45: Defining simple cutoff scores for the Negative Acts Questionnaire–Revised in a representative sample

Workplace bullying is a serious hazard in every day working life that needs to be assessed carefully. In order to achieve such a goal, both victims of severe bullying as well as targets of less intensive bullying need to be identified, the latter in order to prevent further escalation into severe bullying. Previous research has mainly offered simple and crude measures of who is and who is not a victim of bullying. In this article we show how cutoff scores for the scale Negative Acts Questionnaire–Revised (NAQ-R) can be calculated. Based on a representative sample of the Norwegian workforce, we formulated 2 cutoff points or thresholds for the NAQ-R with a Receiver Operation Characteristic curve. Employees with a score lower than 33 are not bullied, employees with a score between 33 and 45 may be considered as being bullied occasionally, and employees who score above 45 can be considered to be victims of workplace bullying. As the NAQ-R is used in more than 300 research projects worldwide, we hope to inspire other scholars to define similar cutoff points. In addition, we hope that clear cutoff scores may be of assistance to practitioners for designing interventions regarding workplace bullying in line with the identified problems.