Stability and consistency of children’s event recall

The purpose of the study was to investigate consistency of recall across different tasks of event recall (similar to eyewitness tasks) and stability of performance across two different events. Additionally, developmental differences in consistency and stability were explored. 6-, 8-, and 10-year-old children were subsequently shown two different events (videos) and were questioned about each event in two separate interviews. For both videos, performance levels in free recall, unbiased cued recall, and suggestibility were at similar levels, with older children generally outperforming younger children. As to intertask consistency of recall, there were significant correlations between correct free recall and correct unbiased cued recall but not between correct free recall and yielding to suggestive questions. All three measures of eyewitness performance showed significant group stability (test-retest correlations) across the two interviews, regardless of age. However, individual stability (lability) was lower, which points to moderate individual differences in stability across the two interviews. The findings are discussed in terms of underlying cognitive skills and the problem of predicting a single child’s memory performance in real cases of eyewitness testimony.     

Categorization by groups and individuals

Categorization is a core psychological process that is central to decision making. While a substantial amount of research has been conducted to examine individual categorization behavior, little is known about how the outputs of individual and group categorization may differ. Four experiments demonstrate that group categorization differs systematically from individual categorization in the structural dimension of category breadth: categorizing the same set of items, groups tend to create a larger number of smaller categories than individuals. This effect of social context is a function of both taskwork and teamwork. In terms of taskwork, groups’ greater available knowledge mediates differences in category breadth between individuals and groups by increasing utilized knowledge (study 2). In terms of teamwork, task conflict moderates the effect of social context on category breadth (study 3). Moreover, the experience of categorizing individually or in a group influences individuals’ subsequent judgments (study 4).     

Positional Sequences in Two-Choice Discrimination Problems with Non-Positional Cues

Individuals seem to differ in their ability to maintain consistent performance. This is obviously an important attribute of behavior that has been largely neglected by researchers. There is, however, some evidence to suggest that, in certain types of situations, the behaviors of the mental retardate are characterized by a relatively high degree of variability. Two studies are reported here that deal with some of the developmental implications of intraindividual variability. In one study, involving retardates, reliability and generality of response consistency were examined in reaction time, time estimation, and digit span tasks. It was shown that individual differences in consistency are reliable and that these generalize across tasks. A second experiment was concerned with the developmental aspects of variability. First-, third-, and fifth-grade pupils and college students were given many trials on a reaction-time task. A variety of measures, reflecting typical performance, limit of performance, and variability, were computed for each subject. The ability to react quickly shows a developmental trend not only with respect to overall performance, but also in the efficiency with whichthe individual maintains his optimal level of responding.     

Organizational Citizenship and Mood: An Experimental Test of Perceived Job Breadth1

This study examined the impact of induced mood and fairness on the categorization of Organizational Citizenship Behaviors (OCBs). Positive mood and perceptions of fair job conditions were predicted to lead to broader categorization of job tasks. Mood, procedural, and distributive justice were manipulated. Participants in a positive mood were more likely than were participants in a negative mood to label extra‐role job tasks as in‐role. This supports the notion that employees in a positive mood may inadvertently engage in OCBs because such behaviors are perceived to be part of the job. No differences in categorization were found between positive and neutral mood conditions, indicating that participants in the negative condition were more narrow in categorization breadth than were those in the positive condition in distinguishing in‐role behaviors from extra‐role behaviors.     

Memory storage and retrieval processes in category learning

The detailed course of learning is studied for categorization tasks defined by independent or contingent probability distributions over the features of category exemplars. College-age subjects viewed sequences of bar charts that simulated symptom patterns and responded to each chart with a recognition and a categorization judgment. Fuzzy, probabilistically defined categories were learned relatively rapidly when individual features were correlated with category assignment, more slowly when only patterns carried category information. Limits of performance were suboptimal, evidently because of capacity limitations on judgmental processes as well as limitations on memory. Categorization proved systematically related to feature and exemplar probabilities, under different circumstances, and to similarity among exemplars of categories. Unique retrieval cues for exemplar patterns facilitated recognition but entered into categorization only at retention intervals within the range of short-term memory. The findings are interpreted within the framework of a general array model that yields both exemplar-similarity and feature-frequency models as special cases and provides quantitative accounts of the course of learning in each of the categorization tasks studied.     

Routine cognitive errors: a trait-like predictor of individual differences in anxiety and distress

Five studies (N=361) sought to model a class of errors--namely, those in routine tasks--that several literatures have suggested may predispose individuals to higher levels of emotional distress. Individual differences in error frequency were assessed in choice reaction-time tasks of a routine cognitive type. In Study 1, it was found that tendencies toward error in such tasks exhibit trait-like stability over time. In Study 3, it was found that tendencies toward error exhibit trait-like consistency across different tasks. Higher error frequency, in turn, predicted higher levels of negative affect, general distress symptoms, displayed levels of negative emotion during an interview, and momentary experiences of negative emotion in daily life (Studies 2-5). In all cases, such predictive relations remained significant with individual differences in neuroticism controlled. The results thus converge on the idea that error frequency in simple cognitive tasks is a significant and consequential predictor of emotional distress in everyday life. The results are novel, but discussed within the context of the wider literatures that informed them.     

Implications of ongoing neural development for the measurement of the error‐related negativity in childhood

Event‐related potentials (ERPs) have been proposed as biomarkers capable of reflecting individual differences in neural processing not necessarily detectable at the behavioral level. However, the role of ERPs in developmental research could be hampered by current methodological approaches to quantification. ERPs are extracted as an average waveform over many trials; however, actual amplitudes would be misrepresented by an average if there was high trial‐to‐trial variability in signal latency. Low signal temporal consistency is thought to be a characteristic of immature neural systems, although consistency is not routinely measured in ERP research. The present study examined the differential contributions of signal strength and temporal consistency across trials in the error‐related negativity (ERN) in 6‐year‐old children, as well as the developmental changes that occur in these measures. The 234 children were assessed annually in kindergarten, 1st, and 2nd grade. At all assessments signal strength and temporal consistency were highly correlated with the average ERN amplitude, and were not correlated with each other. Consistent with previous findings, ERN deflections in the averaged waveform increased with age. This was found to be a function of developmental increases in signal temporal consistency, whereas signal strength showed a significant decline across this time period. In addition, average ERN amplitudes showed low‐to‐moderate stability across the three assessments whereas signal strength was highly stable. In contrast, signal temporal consistency did not evidence rank‐order stability across these ages. Signal strength appears to reflect a stable individual trait whereas developmental changes in temporal consistency may be experientially influenced.     

Routine cognitive errors: A trait-like predictor of individual differences in anxiety and distress

Five studies (N=361) sought to model a class of errors—namely, those in routine tasks—that several literatures have suggested may predispose individuals to higher levels of emotional distress. Individual differences in error frequency were assessed in choice reaction-time tasks of a routine cognitive type. In Study 1, it was found that tendencies toward error in such tasks exhibit trait-like stability over time. In Study 3, it was found that tendencies toward error exhibit trait-like consistency across different tasks. Higher error frequency, in turn, predicted higher levels of negative affect, general distress symptoms, displayed levels of negative emotion during an interview, and momentary experiences of negative emotion in daily life (Studies 2–5). In all cases, such predictive relations remained significant with individual differences in neuroticism controlled. The results thus converge on the idea that error frequency in simple cognitive tasks is a significant and consequential predictor of emotional distress in everyday life. The results are novel, but discussed within the context of the wider literatures that informed them.     

Sources of Dual-Task Interference: Evidence From Human Electrophysiology

When an individual attempts to perform two tasks at the same time, the tasks often interfere with each other. This interference has been studied for several decades with the psychological refractory period paradigm, in which two targets that require independent responses are presented on each trial, separated by a variable delay period; interference typically takes the form of increased response times for the second target at short interstimulus delays. The present study used electrophysiological recordings to determine whether a specific index of perception and categorization (the P3 wave) is delayed in the same manner as response times. Although response times for the second target were found to be greatly delayed at short interstimulus intervals, the P3 wave was not substantially delayed. This finding indicates that there was minimal interference during target identification and categorization and that the prolongation of response times in this paradigm primarily reflects a delay in a relatively late process, such as response selection.     

Sorting food labels and describing properties of categories: stability of results between and within subjects

The purpose of this research is to improve understanding of the consistency of the categorization process in cognitive psychology. To investigate the temporal stability of the categorization process between and within subjects, 100 participants (M = 22.1 yr., SD = 2.1) were required to sort 65 food labels into groups and to explain their grouping. The sorting and property generation of food labels were compared by conducting two sessions (with a 15-day interval) to assess within-subject variability. Two groups of participants were compared to assess between-subjects variability. The results from the sorting task showed excellent stability between and within subjects. Conversely, the property generation task showed high variability. It is concluded that the tasks involved different types of knowledge. The sorting task appeared to generate good agreement and to involve more stable knowledge. The task of producing properties may involve other mechanisms. This paper discusses the results in light of cognitive and pragmatic theories.     

Variability and its sources in infant categorization

Variability of infants’ categorization performance and potential sources of this variability were investigated. Using data from 13 categorization studies employing a habituation-of-looking paradigm with infants 3, 5, 6, and 9 months of age, a method for establishing a categorization criterion was developed and then used to classify individual infants as “categorizers” for particular tasks. Logistic regression analyses were then used to identify demographic and information-processing variables that predicted “categorizer” classification. Variables that increased the odds of being classified as a categorizer were gender, number of habituation trials, and duration of peak look during habituation; total looking time during habituation decreased the odds of categorizer classification. These findings are discussed in the context of individual differences in information processing.     

Effects of classification context on categorization in natural categories

The patterns of classification of borderline instances of eight common taxonomic categories were examined under three different instructional conditions to test two predictions: first, that lack of a specified context contributes to vagueness in categorization, and second, that altering the purpose of classification can lead to greater or lesser dependence on similarity in classification. The instructional conditions contrasted purely pragmatic with more technical/quasi-legal contexts as purposes for classification, and these were compared with a no-context control. The measures of category vagueness were between-subjects disagreement and within-subjects consistency, and the measures of similarity-based categorization were category breadth and the correlation of instance categorization probability with mean rated typicality, independently measured in a neutral context. Contrary to predictions, none of the measures of vagueness, reliability, category breadth, or correlation with typicality were generally affected by the instructional setting as a function of pragmatic versus technical purposes. Only one subcondition, in which a situational context was implied in addition to a purposive context, produced a significant change in categorization. Further experiments demonstrated that the effect of context was not increased when participants talked their way through the task, and that a technical context did not elicit more all-or-none categorization than did a pragmatic context. These findings place an important boundary condition on the effects of instructional context on conceptual categorization.     

Labels and object categorization in six- and nine-month-olds: tracking labels across varying carrier phrases

Language shapes object categorization in infants. This starts as a general enhanced attentional effect of language, which narrows to a specific link between labels and categories by twelve months. The current experiments examined this narrowing effect by investigating when infants track a consistent label across varied input. Six-month-old infants (N = 48) were familiarized to category exemplars, each presented with the exact same labeling phrase or the same label in different phrases. Evidence of object categorization at test was only found with the same phrase, suggesting that infants were not tracking the label’s consistency, but rather that of the entire input. Nine-month-olds (N = 24) did show evidence of categorization across the varied phrases, suggesting that they were tracking the consistent label across the varied input.     

The stability of validity coefficients over time: Ackerman's (1988) model and the general aptitude test battery

This study examined P. L. Ackerman's (1988) model of skill acquisition within an applied setting. Differences were examined between jobs on the basis of task consistency: changes in performance variability across experience, learning curves, and stability of ability-performance correlations across experience. Results showed the degree of task consistency influenced the shape of learning curves, with jobs composed of primarily consistent tasks improving more rapidly and reaching asymptote sooner. In addition, trends in ability-performance correlations were moderated by the degree of task consistency within ajob. Specifically, forjobs with primarily consistent tasks, general cognitive ability best predicted early performance whereas psychomotor ability best predicted later performance. In contrast, general cognitive ability was the strongest predictor across experience for jobs with primarily inconsistent tasks.     

Movement Synchrony Influences Intergroup Relations in a Minimal Groups Paradigm

Studies show that synchronizing movements with others encourages a collective social identity, leading to increased cooperation within a group. The current study investigated whether movement synchrony impacts social categorization and cooperation across intergroup boundaries. Two 3-person groups were brought together under movement synchrony conditions designed to emphasize different social categorizations of the aggregate: all individuals moved to the same beat, each minimal group moved to a different beat, or each individual moved to a different beat. Results demonstrate that movement synchrony influenced social categorization and cooperation across intergroup boundaries. Implications for approaches to intergroup relations using movement synchrony are noted.     

Separating perceptual processes from decisional processes in identification and categorization

Four observers completed perceptual matching, identification, and categorization tasks using separable-dimension stimuli. A unified quantitative approach relating perceptual matching, identification, and categorization was proposed and tested. The approach derives from general recognition theory (Ashby & Townsend, 1986) and provides a powerful method for quantifying the separate influences of perceptual processes and decisional processes within and across tasks. Good accounts of the identification data were obtained from an initial perceptual representation derived from perceptual matching. The same perceptual representation provided a good account of the categorization data, except when selective attention to one stimulus dimension was required. Selective attention altered the perceptual representation by decreasing the perceptual variance along the attended dimension. These findings suggest that a complete understanding of identification and categorization performance requires an understanding of perceptual and decisional processes. Implications for other psychological tasks are discussed.     

Separating perceptual processes from decisional processes in identification and categorization.

Four observers completed perceptual matching, identification, and categorization tasks using separable-dimension stimuli. A unified quantitative approach relating perceptual matching, identification, and categorization was proposed and tested. The approach derives from general recognition theory (Ashby & Townsend, 1986) and provides a powerful method for quantifying the separate influences of perceptual processes and decisional processes within and across tasks. Good accounts of the identification data were obtained from an initial perceptual representation derived from perceptual matching. The same perceptual representation provided a good account of the categorization data, except when selective attention to one stimulus dimension was required. Selective attention altered the perceptual representation by decreasing the perceptual variance along the attended dimension. These findings suggest that a complete understanding of identification and categorization performance requires an understanding of perceptual and decisional processes. Implications for other psychological tasks are discussed.     

There are many ways to be rich: Effects of three measures of semantic richness on visual word recognition

Previous studies have reported that semantic richness facilitates visual word recognition (see, e.g., Buchanan, Westbury, & Burgess, 2001; Pexman, Holyk, & Monfils, 2003). We compared three semantic richness measures--number of semantic neighbors (NSN), the number of words appearing in similar lexical contexts; number of features (NF), the number of features listed for a word's referent; and contextual dispersion (CD), the distribution of a word's occurrences across content areas-to determine their abilities to account for response time and error variance in lexical decision and semantic categorization tasks. NF and CD accounted for unique variance in both tasks, whereas NSN accounted for unique variance only in the lexical decision task. Moreover, each measure showed a different pattern of relative contribution across the tasks. Our results provide new clues about how words are represented and suggest that word recognition models need to accommodate each of these influences.     

Orthographic influences in spoken word recognition: The consistency effect in semantic and gender categorization tasks

According to current models, spoken word recognition is driven by the phonological properties of the speech signal. However, several studies have suggested that orthographic information also influences recognition in adult listeners. In particular, it has been repeatedly shown that, in the lexical decision task, words that include rimes with inconsistent spellings (e.g., /-ip/ spelled -eap or -eep) are disadvantaged, as compared with words with consistent rime spelling. In the present study, we explored whether the orthographic consistency effect extends to tasks requiring people to process words beyond simple lexical access. Two different tasks were used: semantic and gender categorization. Both tasks produced reliable consistency effects. The data are discussed as suggesting that orthographic codes are activated during word recognition, or that the organization of phonological representations of words is affected by orthography during literacy acquisition.