Summation of reinforcement rates when conditioned stimuli are presented in compound

Three experiments used delay conditioning of magazine approach in rats to examine the summation of responding when two conditioned stimuli (CSs) are presented together as a compound. The duration of each CS varied randomly from trial-to-trial around a mean that differed between the CSs. This meant that the rats' response rate to each CS was systematically related to the reinforcement rate of that CS, but remained steady as time elapsed during the CS (Harris & Carpenter, 2011; Harris, Gharaei, & Pincham, 2011). When the rats were presented with a compound of two CSs that had been conditioned separately, they responded more during the compound than during either of the CSs individually. More significantly, however, in all three experiments, the rats responded to the compound at the same rate as they responded to a third CS that had been reinforced at a rate equal to the sum of the reinforcement rates of the two CSs in compound. We discuss the implications of this finding for associative models (e.g., Rescorla & Wagner, 1972) and rate-based models (Gallistel & Gibbon, 2000) of conditioning.     

A Developmental Shift in Black-White Differences in Depressive Affect across Adolescence and Early Adulthood: The influence of early adult social roles and socio-economic status

This study examined black-white differences in growth of depressive affect using a longitudinal sample of middle-class, suburban US subjects (n = 956) that spanned from adolescence to early adulthood. Specifically, this study examined whether black-white differences in growth of depressive affect shift over time, and the extent to which that shift, if any, was associated with racial differences in the rate and mental health consequences of early adult social roles (e.g., living arrangements, work/college status, and single-parenthood) and socio-economic status (SES). As expected, growth in depressive affect pivoted around the onset of early adulthood, with the trajectory pivoting upward for Black Americans and downward for White Americans. Due to deficits in SES, the relation between challenging early adult social roles - under/unemployment in particular - and growth in depressive affect was more positive for Black Americans. This differential "vulnerability" appears to underlie racial differences in early adult growth (and by connection contribute to racial differences in growth pivot). The extent to which Black Americans were at a greater risk (relative to White Americans) for an upward pivot increased as the number of challenging roles increased. Black Americans facing only optimal early adult social roles were not at a greater risk, while those facing only challenging social roles were at the greatest risk.     

Perception–production relationships and phase correction in synchronization with two-interval rhythms

Two experiments investigated the effects of interval duration ratio on perception of local timing perturbations, accuracy of rhythm production, and phase correction in musicians listening to or tapping in synchrony with cyclically repeated auditory two-interval rhythms. Ratios ranged from simple (1:2) to complex (7:11, 5:13), and from small (5:13 = 0.38) to large (6:7 = 0.86). Rhythm production and perception exhibited similar ratio-dependent biases: rhythms with small ratios were produced with increased ratios, and timing perturbations in these rhythms tended to be harder to detect when they locally increased the ratio than when they reduced it. The opposite held for rhythms with large ratios. This demonstrates a close relation between rhythm perception and production. Unexpectedly, however, the neutral “attractor” was not the simplest ratio (1:2 = 0.50) but a complex ratio near 4:7 (= 0.57). Phase correction in response to perturbations was generally rapid and did not show the ratio-dependent biases observed in rhythm perception and production. Thus, phase correction operates efficiently and autonomously even in synchronization with rhythms exhibiting complex interval ratios.     

Ability-performance relationships in education and employment settings: critical tests of the more-is-better and the good-enough hypotheses

The nature of the relationship between ability and performance is of critical importance for admission decisions in the context of higher education and for personnel selection. Although previous research has supported the more-is-better hypothesis by documenting linearity of ability-performance relationships, such research has not been sensitive enough to detect deviations at the top ends of the score distributions. An alternative position receiving considerable attention is the good-enough hypothesis, which suggests that although higher levels of ability may result in better performance up to a threshold, above this threshold greater ability does not translate to better performance. In this study, the nature of the relationship between cognitive ability and performance was examined throughout the score range in four large-scale data sets. Monotonicity was maintained in all instances. Contrary to the good-enough hypothesis, the ability-performance relationship was commonly stronger at the top end of the score distribution than at the bottom end.     

Inferential Precision in Single-Case Time-Series Data Streams: How Well Does the EM Procedure Perform When Missing Observations Occur in Autocorrelated Data?

The case-based time-series design is a viable methodology for treatment outcome research. However, the literature has not fully addressed the problem of missing observations with such autocorrelated data streams. Mainly, to what extent do missing observations compromise inference when observations are not independent? Do the available missing data replacement procedures preserve inferential integrity? Does the extent of autocorrelation matter? We use Monte Carlo simulation modeling of a single-subject intervention study to address these questions. We find power sensitivity to be within acceptable limits across four proportions of missing observations (10%, 20%, 30%, and 40%) when missing data are replaced using the Expectation-Maximization Algorithm, more commonly known as the EM Procedure (Dempster, Laird, &; Rubin, 1977). This applies to data streams with lag-1 autocorrelation estimates under 0.80. As autocorrelation estimates approach 0.80, the replacement procedure yields an unacceptable power profile. The implications of these findings and directions for future research are discussed.     

The Role of Anxiety Sensitivity and Mindful Attention in Anxiety and Worry About Bodily Sensations Among Adults Living With HIV/AIDS

The current study examined cognitive factors that may be relevant to understanding anxiety and worry about bodily sensations among an HIV/AIDS population. Specifically, this investigation tested the main and interactive effects of anxiety sensitivity and mindful attention on anxious arousal, bodily vigilance, interoceptive fear, and HIV symptom distress among 164 adults with HIV/AIDS. Results indicated that anxiety sensitivity was positively related to anxious arousal, bodily vigilance, and interoceptive fear, but not HIV symptom distress. Mindful attention was negatively related to anxious arousal, interoceptive fear, and HIV symptom distress, but not bodily vigilance. These main effects for anxiety sensitivity and mindful attention were evident after controlling for disease stage, years with HIV, and demographic variables. There were no interactive effects between anxiety sensitivity and mindful attention. Results are discussed in terms of the clinical implications for identifying and treating anxiety and worry about bodily sensations among adults with HIV/AIDS. Limitations of this study include the use of cross-sectional data and self-report assessments.     

Recognition confidence under violated and confirmed memory expectations

Individuals' memory experiences typically covary with those of others' around them, and on average, an item is more likely to be familiar if a companion recommends it as such. Although it would be ideal if observers could use the external recommendations of others' as statistical priors during recognition decisions, it is currently unclear how or if they do so. Furthermore, understanding the sensitivity of recognition judgments to such external cues is critical for understanding memory conformity and eyewitness suggestibility phenomena. To address this we examined recognition accuracy and confidence following cues from an external source (e.g., "Likely Old") that forecast the likely status of upcoming memory probes. Three regularities emerged. First, hit and correct-rejection rates expectedly fell when participants were invalidly versus validly cued. Second, hit confidence was generally higher than correct-rejection confidence, regardless of cue validity. Finally, and most noteworthy, cue validity interacted with judgment confidence such that validity heavily influenced the confidence of correct rejections but had no discernible influence on the confidence of hits. Bootstrap-informed Monte Carlo simulation supported a dual process recognition model under which familiarity and recollection processes counteract to heavily dampen the influence of external cues on average reported confidence. A 3rd experiment tested this model using source memory. As predicted, because source memory is heavily governed by contextual recollection, cue validity again did not affect confidence, although as with recognition it clearly altered accuracy.     

Managing motivational conflict: How self-esteem and executive resources influence self-regulatory responses to risk

This article explores how self-esteem and executive resources interact to determine responses to motivational conflict. One correlational and 3 experimental studies investigated the hypothesis that high and low self-esteem people undertake different self-regulatory strategies in "risky" situations that afford opportunity to pursue competing goals and that carrying out these strategies requires executive resources. When such resources are available, high self-esteem people respond to risk by prioritizing and pursuing approach goals, whereas low self-esteem people prioritize avoidance goals. However, self-esteem does not influence responses to risk when executive resources are impaired. In these studies, risk was operationalized by exposing participants to a relationship threat (Studies 1 and 2), by using participants' self-reported marital conflict (Study 3), and by threatening academic competence (Study 4). Executive resources were operationalized as cognitive load (Studies 1 and 2), working memory capacity (Study 3), and resource depletion (Study 4). When executive resources were ample, high self-esteem people responded to interpersonal risk by making more positive relationship evaluations (Studies 1, 2, and 3) and making more risky social comparisons following a personal failure (Study 4) than did low self-esteem people. Self-esteem did not predict participants' responses when executive resources were impaired or when risk was absent. The regulatory function of self-esteem may be more resource-dependent than has been previously theorized. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Linguistic correlates of social anxiety disorder

The goal of this study was to examine the linguistic correlates of social anxiety disorder (SAD). Twenty-four individuals with SAD (8 of them with a generalised subtype) and 21 non-anxious controls were asked to give speeches in front of an audience. The transcribed speeches were examined for the frequency of negations, I-statements, we-statements, negative emotion words, and positive emotion words. During their speech, individuals with either SAD subtype used positive emotion words more often than controls. No significant differences were observed in the other linguistic categories. These results are discussed in the context of evolutionary and cognitive perspectives of SAD.     

Can fluency be interpreted as novelty? Retraining the interpretation of fluency in recognition memory

Stimuli that are processed fluently tend to be regarded as more familiar and are more likely to be classified as old on a recognition test compared with less fluent stimuli. Recently it was shown that the standard relationship between fluency and positive recognition judgments can be reversed if participants are trained that previously studied stimuli are associated with lower levels of fluency. Under such conditions, fluent stimuli are more likely to be classified as new on a recognition test (C. Unkelbach, 2006), which suggests that the interpretation of fluency is malleable and context dependent. Five experiments investigated the resilience of this reversed fluency effect. Using 2 different fluency manipulations, the finding of a reversed fluency effect after training was replicated. However, it was also found that the reversal depends on explicit feedback during training and is specific to the particular fluency manipulation used during training. Moreover, it was found that the reversal did not generalize to similar memory judgments. The balance of experimental results suggest that the standard interpretation of fluency as indicating higher levels of familiarity is quite stable and is resistant to reinterpretation.