The effect of corpus size in predicting reaction time in a basic word recognition task: Moving on from Kučera and Francis

Word frequency is one of the strongest determiners of reaction time (RT) in word recognition tasks; it is an important theoretical and methodological variable. The Ku?era and Francis (1967) word frequency count (derived from the 1-million-word Brown corpus) is used by most investigators concerned with the issue of word frequency. Word frequency estimates from the Brown corpus were compared with those from a 131-million-word corpus (the HAL corpus; conversational text gathered from Usenet) in a standard word naming task with 32 subjects. RT was predicted equally well by both corpora for high-frequency words, but the larger corpus provided better predictors for low- and medium-frequency words. Furthermore, the larger corpus provides estimates for 97,261 lexical items; the smaller corpus, for 50,406 items.     

The Effect of Backloading Instructions on Eyewitness Identification from Simultaneous and Sequential Lineups

The sequential lineup is multifaceted, including serial presentation of faces, multiple decisions, and often backloading (indicating to an eyewitness that a lineup contains more photos than there actually are). We evaluated the effect of backloading instructions on response bias and sensitivity with an eyewitness identification paradigm. Importantly, we included an ‘undisclosed’ condition that provided no information to participants about the number of lineup members to expect. Experiment 1 (N = 780) tested sequential lineups; Experiment 2 (N = 532) tested simultaneous lineups. As predicted, signal detection analysis showed that backloading induced participants to be more conservative in choosing from both lineup types, but did not affect d′. We conclude that the criminal justice system should be mindful of this shift in response bias, as it has implications for both guilty and innocent suspect identifications. Copyright © 2016 John Wiley & Sons, Ltd.     

The Influence of Perpetrator Exposure Time and Weapon Presence/Timing on Eyewitness Confidence and Accuracy

Crimes can occur in a matter of seconds, with little time available for an eyewitness to encode a perpetrator's face. The presence of a weapon can further exacerbate this situation. Few studies have featured mock crimes of short duration, especially with a weapon manipulation. We conducted an experiment to investigate the impact of weapon presence and short perpetrator exposure times (3 vs. 10 seconds) on eyewitness confidence and accuracy. We found that recall concerning the perpetrator was worse when a weapon was present, replicating the weapon focus effect. However, there was no effect on eyewitness identification accuracy. Calibration analyses revealed that all conditions produced a strong confidence–accuracy relationship. Confidence–accuracy characteristic curves illustrated almost perfect accuracy for suspect identifications at the highest levels of confidence. We conclude that weapon presence during a brief crime does not necessarily result in negative consequences for either eyewitness identification accuracy or the confidence–accuracy relationship. Copyright © 2016 John Wiley & Sons, Ltd.     

Searching for the sequential line-up advantage: a distinctiveness explanation

Gronlund ( 2005 ) proposed that one factor leading to a sequential line-up advantage could be the greater likelihood of recollecting distinctive information about a perpetrator when using a sequential line-up. Since then questions have been raised about the robustness of the sequential advantage and the possible moderating role of line-up fairness and suspect position. We manipulated these factors as well as suspect/target distinctiveness in two experiments. A sequential advantage occurred only after encoding a distinctive target, both for biased line-ups (Experiment 1) and fair line-ups (Experiment 2). Remember-Know results were consistent with the greater use of a recall-to-reject strategy in target-absent sequential line-ups. This provided support for the first process-based explanation of the sequential line-up advantage. No consistent position effects were found, but this might be due to the line-up recognition paradigm used, in which each participant viewed a line-up for each of several targets. Theory-based explorations of eyewitness identification are necessary to continue to delineate the underpinnings of the sequential line-up advantage.     

Pattern of perceived stress and anxiety in pregnancy predicts preterm birth.

OBJECTIVE: To determine whether the pattern of prenatal stress, as compared to prenatal stress assessed at a single gestational time point, predicts preterm delivery (PTD). DESIGN: Perceived stress and anxiety were assessed in 415 pregnant women at 18-20 and 30-32 weeks' gestation. MAIN OUTCOME MEASURES: Gestational length was determined by last menstrual period and confirmed by early pregnancy ultrasound. Births were categorized as preterm (< 37 weeks) or term. RESULTS: At neither assessment did levels of anxiety or perceived stress predict PTD. However, patterns of anxiety and stress were associated with gestational length. Although the majority of women who delivered at term exhibited declines in stress and anxiety, those who delivered preterm exhibited increases. The elevated risk for PTD associated with an increase in stress or anxiety persisted when adjusting statistically for obstetric risk, pregnancy-related anxiety, ethnicity, parity, and prenatal life events. CONCLUSIONS: These data suggest that the pattern of prenatal stress is an important predictor of PTD. More generally, the findings support the possibility that a decline in stress responses during pregnancy may help to protect mother and fetus from adverse influences associated with PTD.     

Familialism, social support, and stress: positive implications for pregnant Latinas

This study examined the association of familialism, a cultural value that emphasizes close family relationships, with social support, stress, pregnancy anxiety, and infant birth weight. Foreign-born Latina (n = 31), U.S.-born Latina (n = 68), and European American (n = 166) women living in the United States participated in a prospective study of pregnancy in which they completed measures of familialism, social support, stress, and pregnancy anxiety during their second trimester. As expected, Latinas scored higher on familialism than European Americans. Familialism was positively correlated with social support and negatively correlated with stress and pregnancy anxiety in the overall sample. As predicted, however, the associations of familialism with social support and stress were significantly stronger among Latinas than European Americans. Moreover, higher social support was associated with higher infant birth weight among foreign-born Latinas only. Implications of cultural values for relationships and health are discussed.     

Systematic covariation of the parameters in the near-miss to Weber's law, pointing to a new law

The exponent in the power function modeling of the near-miss to Weber's law is known to depend on several experimental factors, such as tone frequency and the presence or absence of noise. This paper presents data that confirm a theoretical argument that the near-miss exponent also depends on the definition of ‘just-noticeably different’ used empirically. Intensity discrimination data were collected for pure, 1000-Hz tones presented in quiet. Referent sound pressure levels ranged from 40 to 80 dB SPL in 10-dB steps. For each referent, the tone judged louder than the referent with probability equal to ν was determined, with ν ranging from 0.16 to 0.84. It was found that the power function exponent decreases monotonically with ν. Moreover, it was found that the two power law parameters co-vary systematically with ν, implying a submodel that has an interesting fixed-point property.     

Examination of the Relationship Between Self-Efficacy and Affect at Varying Levels of Aerobic Exercise Intensity

Although proposed as an explanation for increases in positive and decreases in negative affect, little evidence supports the notion of a stronger efficacy-affect relationship as acute aerobic exercise intensity increases. Relationships between self-efficacy (SE), positive affect (PA), and negative affect (NA) were examined with respect to 3 randomly assigned conditions: (a) no exercise (control), (b) cycling at 55% VO_2max, and (c) cycling at 70% VO_2max. Twenty subjects (age = 22.6 years; M VO_2max= 47.8 ml · kg⁻¹· min⁻¹) participated in each. Preexercise SE predicted in-task NA and postexercise PA in the 55% condition and postexercise PA in the 70% condition ( ps < .05). Although SE significantly increased from pre- to postexercise, in-task affect failed to predict these increases in SE. These data suggest that in a fit college-aged population, a stronger reciprocal relationship between preexercise SE, in-task affect, and postexercise SE does not exist with increasing levels of exercise intensity. Contrary to self-efficacy theory, no evidence was found for a reciprocal relationship. However, the relationship between efficacy and affect was such that when collapsed across conditions and time, subjects with higher SE scores reported lower NA ( p < .05).     

The Psychometric Properties of the Swedish Version of the General Self-Efficacy Scale: A Rasch Analysis Based on Adolescent Data

Self-efficacy describes people’s belief in their own ability to perform the behaviors required to produce a desired outcome. The purpose of this study was to examine the psychometric properties of the Swedish version of the General Self-Efficacy Scale (GSES) with an adolescent sample, using Rasch analysis. The scale was examined with a focus on invariant functioning along the latent trait as well as across sample groups. The data were collected 2009 and 2010 among 3764 students aged between 13 and 15 years, in the 7^th to 9^th grade, in compulsory schools in the municipality of Karlstad, Sweden. The item fit was acceptable, the categorization of the items worked well and the scale worked invariantly between years of investigations. Although the GSES worked well as a whole, there was some evidence of misfit indicating room for improvements. The targeting may be improved by adding more questions of medium difficulty. Also, further attention needs to be paid to the dimensionality of the GSES as well as to whether the psychometric properties of GSES are affected by using more recent data.