Dilatation in the femoral vascular bed does not cause retrograde relaxation of the iliac artery in the anaesthetized pig

Aim:  We tested the hypothesis that dilatation of a feeding artery may be elicited by transmission of a signal through the tissue of the arterial wall from a vasodilated peripheral vascular bed. Methods:  In eight pentobarbital anaesthetized pigs, acetylcholine (ACh, an endothelium-dependent vasodilator) was injected intra-arterially above (upstream) and below (downstream) a test segment of the left iliac artery, the diameter of which was measured continuously by sonomicrometry. Results:  Under control conditions, ACh injections upstream and downstream of the test segment caused dilatation. Downstream injection dilated the peripheral arterioles, resulting in increased blood flow and proximal dilatation. This is a shear stress, nitric oxide (NO)-dependent response. The experiment was then repeated after applying a stenosis to prevent the increased flow caused by downstream injection of ACh; the stenosis was placed either above the site of diameter measurement to allow retrograde conduction, or below that site to prevent distally injected ACh reaching the measurement site. Under these conditions, downstream injection of ACh had a minimal effect on the shear stress of the test segment with no increase in test segment diameter. This was not due to endothelial damage or dysfunction as injection of ACh upstream still caused a large increase in test segment diameter. Conclusions:  Our results indicate that dilatation of the feeding artery of a vasodilated bed is caused by increased shear stress within the feeding artery and not via a signal transmitted through the arterial wall from below

Decision landscapes:Visualizing mouse-tracking data

Computerized paradigms have enabled gathering rich data on human behaviour, including information on motor execution of a decision, e.g. by tracking mouse cursor trajectories. These trajectories can reveal novel information about ongoing decision processes. As the number and complexity of mouse-tracking studies increase, more sophisticated methods are needed to analyse the decision trajectories. Here, we present a new computational approach to generating decision landscape visualizations based on mouse-tracking data. A decision landscape is an analogue of an energy potential field mathematically derived from the velocity of mouse movement during a decision. Visualized as a three-dimensional surface, it provides a comprehensive overview of decision dynamics. Employing the dynamical systems theory framework, we develop a new method for generating decision landscapes based on arbitrary number of trajectories. This approach not only generates three-dimensional illustration of decision landscapes, but also describes mouse trajectories by a number of interpretable parameters. These parameters characterize dynamics of decisions in more detail compared with conventional measures, and can be compared across experimental conditions, and even across individuals. The decision landscape visualization approach is a novel tool for analysing mouse trajectories during decision execution, which can provide new insights into individual differences in the dynamics of decision making

The Study of Rule-Governed Behavior and Derived Stimulus Relations: Bridging the Gap

The concept of rule-governed behavior or instructional control has been widely recognized for many decades within the behavior-analytic literature. It has also been argued that the human capacity to formulate and follow increasingly complex rules may undermine sensitivity to direct contingencies of reinforcement, and that excessive reliance upon rules may be an important variable in human psychological suffering. Although the concept of rules would appear to have been relatively useful within behavior analysis, it seems wise from time to time to reflect upon the utility of even well-established concepts within a scientific discipline. Doing so may be particularly important if it begins to emerge that the existing concept does not readily orient researchers toward potentially important variables associated with that very concept. The primary purpose of this article is to engage in this reflection. In particular, we will focus on the link that has been made between rule-governed behavior and derived relational responding, and consider the extent to which it might be useful to supplement talk of rules or instructions with terms that refer to the dynamics of derived relational responding

Non-verbal IQ Gains from Relational Operant Training Explain Variance in Educational Attainment: An Active-Controlled Feasibility Study

Research suggests that training relational operant patterns of behavior can lead to increases in general cognitive ability and educational outcomes. Most studies to date have been under-powered and included proxy measures of educational attainment. We attempted to extend previous findings with increased experimental control in younger children (aged 6.9–10.1 years). Participants (N = 49) were assigned to either a relational training or chess control group. Over 5 months, teachers assigned class time to complete either relational training or play chess. Those who were assigned relational training gained 8.9 non-verbal IQ (NVIQ) points, while those in the control condition recorded no gains (dppc2 = .99). Regression analyses revealed that post-training NVIQ predicted reading test scores (conducted approximately 1 month later) over and above baseline NVIQ in the experimental condition only, consistent with what we might expect in a full test of far transfer towards educational outcomes

The roles of financial threat, social support, work stress, and mental distress in dairy farmers’ expectations of injury

Farming is dangerous, with fatalities among the highest in any occupation. Farmers often work alone, for long hours, with unreliable equipment and in difficult weather conditions with hazardous chemicals and livestock. In addition, farmers make large financial commitments exposing them to high levels of financial risk. Exposure to such financial risk can give rise to subjective experiences of financial threat (FT) that are psychologically challenging. The current study attempted to characterize the role that FT plays in farm injuries. One hundred and twenty one dairy farmers completed a battery of questionnaires assessing FT, social support (SS), depression, anxiety, farm job stress, and health and safety beliefs. Mental distress directly predicted farmers\u27 expectations of injury and a direct effect of non-financial farm stress (FS) approached significance. Mental distress mediated these relationships as evidenced by significant indirect effects of FS and FT, and SS served to reduce distress. These findings support calls for interventions designed to reduce FS and FT and increase SS for farmers

Testing the Validity of the Implicit Relational Assessment Procedure and the Implicit Association Test: Measuring Attitudes Toward Dublin and Country Life in Ireland

The current study aimed to test the validity of the Implicit Relational Assessment Procedure (IRAP), as compared to the Implicit Association Test (IAT), by assessing the attitudes of Dublin dwellers and rural dwellers toward Dublin and country life. Discrimination between the two groups for the IAT was marginally significant. The IRAP discriminated significantly between the two groups based on an interaction effect, which showed that rural dwellers had a strong bias toward country life but Dublin dwellers did not show the same bias toward Dublin life. The IRAP data correlated moderately with the explicit measures, but the IAT did not. The findings support the IRAP as a potentially useful measure of implicit attitudes

Mutual Entailment of Temporal Relations in Younger and Older Adults: Reversing Order Judgments

For temporal relations, mutually entailed relations are different to those directly trained; we learn that A occurred before B and derive that B occurred after A. Deriving such relations results in lower accuracy and slower response speeds compared to derived relations identical to those trained. The ability of an individual to derive relations different to those trained is a measure of relational flexibility and predicts performance on standard cognitive tests. In the current study, 23 younger (M = 19 years) and 23 older (M = 61 years) participants observed pairs of stimuli presented consecutively (A B) and then evaluated statements including the stimuli in the same (A BEFORE B) or reversed order (B AFTER A). Judgements on reversed ( after ) statements resulted in lower accuracy and slower response speeds than those presented in the same order ( before ) for both older and younger groups. Older adults exhibited deficits in relational flexibility compared to younger adults, such as slower progression through experimental phases, particularly in correctly responding to reversed statements. Older participants also demonstrated higher error rates on foil statements and responded more slowly than younger participants. The findings suggest that older adults may benefit from training strategies focused on relational flexibility.peer-reviewed2017-05-1