3-minute smartphone-based and tablet-based psychomotor vigilance tests for the assessment of reduced alertness due to sleep deprivation

The psychomotor vigilance test (PVT) is widely used to measure reduced alertness due to sleep loss. Here, two newly developed, 3-min versions of the psychomotor vigilance test, one smartphone-based and the other tablet-based, were validated against a conventional 10-min laptop-based PVT. Sixteen healthy participants (ages 22–40; seven males, nine females) completed a laboratory study, which included a practice and a baseline day, a 38-h total sleep deprivation (TSD) period, and a recovery day, during which they performed the three different versions of the PVT every 3 h. For each version of the PVT, the number of lapses, mean response time (RT), and number of false starts showed statistically significant changes across the sleep deprivation and recovery days. The number of lapses on the laptop was significantly correlated with the numbers of lapses on the smartphone and tablet. The mean RTs were generally faster on the smartphone and tablet than on the laptop. All three versions of the PVT exhibited a time-on-task effect in RTs, modulated by time awake and time of day. False starts were relatively rare on all three PVTs. For the number of lapses, the effect sizes across 38 h of TSD were large for the laptop PVT and medium for the smartphone and tablet PVTs. These results indicate that the 3-min smartphone and tablet PVTs are valid instruments for measuring reduced alertness due to sleep deprivation and restored alertness following recovery sleep. The results also indicate that the loss of sensitivity on the 3-min PVTs may be mitigated by modifying the threshold defining lapses.     

Effect of intermittent reinforcement on acquisition and retention in delayed matching-to-sample in pigeons

Experiments 1 and 2 involved independent groups that received primary reinforcement after a correct match with a probability of 1.0, .50 or .25. Correct matches that did not produce primary reinforcement produced a conditioned reinforcer. Both experiments revealed little evidence that acquisition or retention was adversely affected by use of intermittent reinforcement. Experiment 3 involved a group that received 100% reinforcement and two others that received 25% reinforcement, one of which received conditioned reinforcement and the other did not. Following acquisition and retention testing, birds in group 100% and group 25% with conditioned reinforcement were exposed to 25% reinforcement and no conditioned reinforcement. Results revealed that conditioned reinforcement was important in promoting acquisition but was irrelevant in maintaining performance. It was concluded that intermittent reinforcement, especially when combined with conditioned reinforcement during acquisition, supports levels of acquisition and retention comparable to that of continuous reinforcement. Theoretically, the findings are consistent with an extension of Blough's instance-based theory of discrimination performance and, practically, they suggest that use of intermittent reinforcement could result in increased efficiency and economy in labs using delayed matching.     

Support for anterior temporal involvement in semantic error production in aphasia: new evidence from VLSM

Semantic errors in aphasia (e.g., naming a horse as “dog”) frequently arise from faulty mapping of concepts onto lexical items. A recent study by our group used voxel-based lesion-symptom mapping (VLSM) methods with 64 patients with chronic aphasia to identify voxels that carry an association with semantic errors. The strongest associations were found in the left anterior temporal lobe (L-ATL), in the mid- to anterior MTG region. The absence of findings in Wernicke’s area was surprising, as were indications that ATL voxels made an essential contribution to the post-semantic stage of lexical access. In this follow-up study, we sought to validate these results by re-defining semantic errors in a manner that was less theory dependent and more consistent with prior lesion studies. As this change also increased the robustness of the dependent variable, it made it possible to perform additional statistical analyses that further refined the interpretation. The results strengthen the evidence for a causal relationship between ATL damage and lexically-based semantic errors in naming and lend confidence to the conclusion that chronic lesions in Wernicke’s area are not causally implicated in semantic error production.     

Outsourcing inspiration: The performance effects of ideological messages from leaders and beneficiaries

Although ideological messages are thought to inspire employee performance, research has shown mixed results. Typically, ideological messages are delivered by leaders, but employees may be suspicious of ulterior motives—leaders may merely be seeking to inspire higher performance. As such, we propose that these messages are often more effective when outsourced to a more neutral third party—the beneficiaries of employees’ work. In Study 1, a field quasi-experiment with fundraisers, ideological messages from a beneficiary—but not from two leaders—increased performance. In Study 2, a laboratory experiment with an editing task, participants achieved higher task and citizenship performance when an ideological message was delivered by a speaker portrayed as a beneficiary vs. a leader, mediated by suspicion. In Study 3, a laboratory experiment with a marketing task, the beneficiary source advantage was contingent on message content: beneficiaries motivated higher task and citizenship performance than leaders with prosocial messages but not achievement messages.     

Can We Consume Our Way Out of Climate Change? A Call for Analysis

The problem of climate change is analyzed as a manifestation of economic growth, and the steady-state economy of ecological economics is proposed as a system-wide solution. Four classes of more specific solutions are described. In the absence of analysis, cultural inertia will bias solutions in favor of green consumption as a generalized solution strategy. By itself, green consumption is a flawed solution to climate change because it perpetuates or even accelerates economic growth that is incompatible with a sustainable culture. Addressing climate change requires an integration of regulatory, energy efficiency, skill-based, and dissemination solutions. Behavioral scientists are encouraged to work with others in ecological economics and other social sciences who recognize cultural reinvention as a means of achieving sustainability.     

Postulates for revising BDI structures

The process of rationally revising beliefs in the light of new information is a topic of great importance and long-standing interest in artificial intelligence. Moreover, significant progress has been made in understanding the philosophical, logical, and computational foundations of belief revision. However, very little research has been reported with respect to the revision of other mental states, most notably propositional attitudes such as desires and intentions. In this paper, we present a first attempt to formulate a general framework for understanding the revision of mental states. We develop an abstract belief-desire-intention model of agents, and introduce a notion of rationality for this model. We then present a series of formal postulates characterizing the processes of adding beliefs, desires, and intentions, updating costs and values, and removing beliefs, desires, and intentions. We also investigate the computational complexity of several problems involving the abstract model and comment on algorithms for revision.     

Living in the Borderlands—An Identity and a Proposal

Abstract :  We live in the borderlands, a place not of separation but of coming together, of connection. The continuing efforts to discern what it means to express who we are as religious people, and what it means regarding the religious identity of those who live in the borderlands is the focus of this study. In many ways, this identity is one that is in the process of being restored, renewed, and reaffirmed after many years of a combination of benign neglect and overt suppression.     

Characteristics of Dieting and Nondieting Adolescents in a Psychiatric Inpatient Setting

  The clinical and psychosocial characteristics of 239 dieting and nondieting adolescents (61% female; mean age=15.3) recruited from an inpatient psychiatric setting were examined. Dieting adolescents were compared to nondieting adolescents on exercise frequency, weight control behaviors, risky behaviors, psychiatric comorbidity and distress, eating disorder symptomatology, smoking, coping, and family factors. While dieters did not statistically differ from nondieters on scores of body mass index, dieting youth reported greater levels of self-reported distress, poorer coping, greater eating disorder symptomatology, and were more likely to engage in extreme weight control behaviors. In addition, dieting was associated with higher rates of major depression (58% vs 34%) and eating disorders (14% vs 1%). Among adolescent smokers, dieters endorsed smoking as a weight control behavior. Engaging in risky behaviors or familial factors did not differentiate dieters from nondieters. Given the number of negative correlates associated with dieting in adolescents, identifying dieting and weight control behaviors in clinical settings may prove to be an effective strategy in the development of prevention and intervention efforts for youth.     

Construct Validity of the Balloon Analogue Risk Task (BART): Relationship with MDMA Use by Inner-City Drug Users in Residential Treatment

In a program of research assessing the validity of the balloon analogue risk task (BART; C. W. Lejuez et al., 2002) as a measure of risk taking, the BART was administered to a sample of inner-city drug users in residential treatment (n = 76). Construct validity of the BART was evaluated by measuring risk-taking behavior and 3,4-methylenedioxymethamphetamine (MDMA) use while controlling for self-reported impulsivity, sensation seeking, polysubstance use, and demographic variables. Supporting the construct validity of the BART, while controlling for interrelated variables in the context of logistic regression analyses, (BART) risk-taking propensity accounted for significant incremental variance in differentiating MDMA users from non-users. BART scores, polysubstance use, and younger age were most associated with MDMA use, and together these variables were associated with 91% classification accuracy in predicting MDMA use.