Automaticity and eyewitness accuracy: a 10- to 12-second rule for distinguishing accurate from inaccurate positive identifications

Eyewitness researchers have shown that witnesses accurately choosing the culprit out of a lineup reach their decisions more quickly than those erroneously choosing an innocent individual. However, this research is silent regarding how quickly or slowly witnesses must be, in absolute terms, to indicate that they are accurate or inaccurate. Across 4 studies, the authors discovered that a time boundary of roughly 10 to 12 s best differentiated accurate from inaccurate positive identifications. Witnesses making their identification faster than 10 to 12 s were nearly 90% accurate; those taking longer were roughly 50% accurate. This finding is consistent with previous research showing that accurate witnesses are more likely than inaccurate witnesses to reach their decisions automatically, that is, quickly, without conscious thought or effort.     

Molecular analyses of the principal components of response strength

Killeen and Hall (2001) showed that a common factor called strength underlies the key dependent variables of response probability, latency, and rate, and that overall response rate is a good predictor of strength. In a search for the mechanisms that underlie those correlations, this article shows that (a) the probability of responding on a trial is a two-state Markov process; (b) latency and rate of responding can be described in terms of the probability and period of stochastic machines called clocked Bernoulli modules, and (c) one such machine, the refractory Poisson process, provides a functional relation between the probability of observing a response during any epoch and the rate of responding. This relation is one of proportionality at low rates and curvilinearity at higher rates.     

Effects of caffeine on performance of low intensity tasks

31 college age men and women who consume less than three caffeinated beverages per week agreed to participate as subjects in research on the effects of acute caffeine intake on low intensity task performance. All subjects performed two randomly administered test conditions: (1) caffeine (5 mg/kg) and (2) placebo on separate visits following an initial 1-hr. orientation visit. Subjects were administered the beverage 30 min. prior to performing 12 separate tests assessing basic mathematics, simple response, logical reasoning, hand-eye coordination, and spatial and assembly skills. The Spielberger State Anxiety test was administered immediately after consuming the test beverage and once again at posttest. Analysis showed that caffeine did not significantly affect performance on all tests with the exception of the peripheral awareness (hand-eye coordination) test on which performance was higher after ingesting caffeine. The placebo treatment produced no effect on state anxiety, which contrasted with a significant rise in anxiety after caffeine consumption. State anxiety values were significantly greater after caffeine treatment relative to the placebo at pretest, and this difference persisted at posttest. These results demonstrated that the dose of caffeine increased scores on state anxiety for individuals who consumed less than three caffeinated beverages weekly but had very little effect on performance of low intensity tasks, except for a hand-eye coordination test involving peripheral awareness. Perhaps longer continuous performance of more demanding tasks would be more sensitive.     

Ethical and practical considerations in managing incidental findings in functional magnetic resonance imaging

Functional magnetic resonance imaging has emerged as a powerful tool for mapping the neurologic underpinnings of sensory, motor and cognitive function. Much of this evolution carries assumptions about the subject population under study and, in particular, the neurologic status of subjects entered into studies either as healthy controls or as belonging to a specific disease group. Recent reports of incidental MRI abnormalities in normal volunteers for fMRI studies have brought to attention a variety of practical challenges and ethical dilemmas for researchers, many of whom are not physicians and most of whom have no formal radiological training. We propose a minimum standard for consenting subjects in fMRI protocols, and consider strategies over the longer term that call for expert physician participation, archiving of incidental findings including false positives, and the adoption of guidelines for handling variation in neural activations or performance that appear outside expected norms.     

Action-based and vision-based selection of input: Two sources of control

In the first part of this paper we review evidence suggesting that there exists a mechanism that selects input on the basis of its similarity to the required action. This response-based input selection differs from the more established space- and object-based input selection in that it is not constrained by the structure of the input. Our evidence suggests that the two-choice Stroop effect is caused by this response-based selection mechanism. By contrast, it is known that the flanker effect is determined by the space- and object- based selection mechanisms. We explore whether the conflict resolution of the Stroop and flanker tasks is different as well by embedding these two tasks in a PRP (Psychological Refractory Period) paradigm. We show that the Stroop and the PRP effects are additive whereas the flanker and the PRP effects are underadditive, suggesting that the processes in charge of the conflict resolution in the Stroop and the flanker tasks are indeed different. We discuss possible reasons for this difference, and discuss possible ways in which the response-based mechanism can be implemented in information processing models.     

An examination of organizational and team commitment in a self-directed team environment

A model hypothesizing differential relationships among predictor variables and individual commitment to the organization and work team was tested. Data from 485 members of sewing teams supported the existence of differential relationships between predictors and organizational and team commitment. In particular, intersender conflict and satisfaction with coworkers were more strongly related to team commitment than to organizational commitment. Resource-related conflict and satisfaction with supervision were more strongly related to organizational commitment than to team commitment. Perceived task interdependence was strongly related to both commitment foci. Contrary to prediction, the relationships between perceived task interdependence and the 2 commitment foci were not significantly different. Relationships with antecedent variables help explain how differential levels of commitment to the 2 foci may be formed. Indirect effects of exogenous variables are reported.     

Childhood Gender Nonconformity and Body Dissatisfaction in Gay and Heterosexual Men

Although researchers have long hypothesized a relation between gender role orientation (i.e., masculinity and femininity) and body dissatisfaction, findings have been inconsistent. The current study employed a measure of recalled childhood gender nonconformity to examine gender role behaviors in association with body dissatisfaction among an ethnically diverse (76% Caucasian, 2% African American, 8% Asian, and 16.4% Hispanic American) group of predominantly college-aged males of both homosexual (n = 129) and heterosexual (n = 52) orientation. Consistent with past research, gay males reported more body dissatisfaction and recalled more childhood gender atypical behaviors (e.g., disliking athletics, playing with dolls). Group differences in body dissatisfaction, however, disappeared when childhood gender nonconformity was statistically controlled, suggesting childhood atypical gender role behavior may place males at greater risk for adult body dissatisfaction. A within-group analysis also found that a high feminine subtype of gay males had greater body dissatisfaction than less feminine subtypes had. Results support the assertion that gender role behaviors may contribute to body dissatisfaction among gay males.     

The Factor Structure of the Beavers Interactional Scales

Confirmatory factor analysis and regression analyses of the Beavers Interactional Scales did not appear to support the model offered by its developers, namely, several specified family attributes contributing respectively to two global factors of Family Competence and Family Style. Moreover, regression analysis indicated that only three of 12 items predicted raters' assessments of Global Family Health, and one of seven items predicted Global Family Style. Individuals interested in the family dynamic centripetal/centrifugal might best think of that as a unitary entity and rate it accordingly.     

Selection and inhibition in infancy: evidence from the spatial negative priming paradigm

We used a spatial negative priming (SNP) paradigm to examine visual selective attention in infants and adults using eye movements as the motor selection measure. In SNP, when a previously ignored location becomes the target to be selected, responses to it are impaired, providing a measure of inhibitory selection. Each trial consisted of a prime and a probe, separated by 67, 200, or 550 ms interstimulus intervals (ISIs). In the prime, a target was accompanied by a distractor. In the probe, the target appeared either in the location formerly occupied by the distractor (ignored repetition) or in another location (control). Adults exhibited the SNP effect in all three ISI conditions, producing slower saccade latencies on ignored repetition versus control trials. The SNP effect obtained for infants only under 550 and 200 ms ISI conditions. These results suggest that important developments in visual selection are rooted in emerging inhibitory mechanisms.