The relative law of effect: effects of shock intensity on response strength in multiple schedules

Key pecking of four birds was reinforced with food according to a two-component multiple variable-interval 1-minute variable-interval 4-minute schedule. In addition, key pecking was punished by a brief shock according to a variable-interval 30-second schedule during both components of the multiple schedule. The intensity of the shock was varied. For all birds, punishment had a stronger suppressive effect on the responding maintained by the leaner food schedule, and the ratio of responding during the two components of the multiple schedule became closer to the ratio of reinforcement as shock intensity was increased, as the relative law of effect predicts. At the higher shock intensity, there was some evidence that the ratio of responses overmatched the ratio of reinforcements.     

Context dependent changes in the reinforcing strength of schedule-induced drinking.

Previous experiments show that the opportunity to engage in schedule-induced responding is reinforcing. In this experiment, the reinforcing strength of schedule-induced drinking was measured. Four rats were trained on a concurrent-chain schedule. The two terminal links provided food pellets on identical fixed-time schedules. In addition, one terminal link also provided the opportunity to press a button that operated a water dipper. In this link, the rats showed polydipsic drinking. Button-pressing rate for polydipsic drinking was a bitonic function of pellet rate, and it was possible to describe the relationship with a slightly modified version of the matching equation for primary reinforcement. This equation also closely fit the data from other studies. Initial-link response rates, however, did not appear to be influenced by the availability of water in the terminal links. Control conditions suggested that the reinforcing strength of polydipsia was strongly bound to the context provided by periodic food reinforcement.     

Response rate, latency, and resistance to change

Pigeons were trained on a multiple variable-interval/variable-interval schedule with pacing contingencies that generated high response rates in one component and low response rates in the other. Timeout periods separated the schedule components. During resistance-to-change tests, response-independent food was presented during the timeout periods, and the duration of that food presentation was varied among test sessions. Response rates in the schedule components decreased and latencies to the first response increased as a function of the duration of food presentations during the timeout. Both dependent measures changed about the same amount relative to their own baseline levels. The conclusions are that baseline response rates controlled by pacing contingencies are equally resistant to change, given equal reinforcement densities, and latency is a sensitive measure of resistance to change.     

Functional recovery of skilled forelimb use in rats obliged to use the impaired limb after grafting of the frontal cortex lesion with homotopic fetal cortex

The long-term effect of transplanting embryonic frontal cortex into a unilateral frontal cortex lesion has been studied in adult rats. Before surgery, activity in an open field, muscular strength of both forelimbs, and performance in a paw-reaching-for-food task were scored in 26 rats. In 21 animals a unilateral cortex lesion was then made in the forelimb motor area of the hemisphere contralateral to the preferred paw in the paw-reaching-for-food task, while the other 5 animals were sham-operated. On retesting, the lesion animals changed the preferred paw. A solid homotopic transplant of embryonic tissue (embryonic day 17) was then placed in the lesion cavity in 11 of the lesion rats. Three months later neither lesion alone nor lesion plus transplantation affected open field behavior and muscular strength, but the lesion permanently affected performance in the paw-reaching-for-food task, as shown by a change of preferred paw and a functional deficit in the paw contralateral to the lesion. Transplantation ameliorated the deficits caused by the lesion, but this was only evident when animals were forced to reach with the paw contralateral to the lesion plus transplant. The behavioral results were independent of the size of the lesion and graft. Connections between graft and host tissue were studied by means of the fluorescent tracer 1,1'-dioctadecyl-3,3,3'3'-tetramethylindocarbocyanine perchlorate (DiI). A dense array of labeled fibers was found in the host cortex adjacent to the transplant. The results suggest that functional recovery depends on grafting but is only evident when the animal is obliged to use the affected limb.     

Populism vs. elitism: social consensus and social status as bases of attitude certainty

This study examined the effects of social consensus and social status on attitude certainty that is conceptualized multi-dimensionally as perceived clarity and correctness of one's attitude. In a mock opinion exchange about a social issue, participants were either supported (high consensus) or opposed (low consensus) by most of the confederates. They were informed that their opinion (high status) or their opponents' opinion (low status) had the alleged psychological significance indicative of future success. Post-experimental attitude clarity was significantly greater when attitudinal position was associated with high rather than low status. Attitude correctness was interactively affected by social status and social consensus. Supporting the compensatory effect hypothesis, attitude correctness was comparable across the levels of social consensus as long as they were associated with high status, and across the levels of social status as long as they were associated with high social consensus.     

We're Closer than I Thought: Social Network Heterogeneity,Morality, and Political Persuasion

Literature in the area of social networks indicates that increases in perceived social network attitudinal heterogeneity generate increased openness to attitude change. Recent evidence in the area of morality, however, shows that morally based attitudes are particularly resistant to persuasion and can result in the rejection of disagreeing others. Positing that considering morality would reduce network influence, an experiment varied moral cues presented along with a non‐network persuasive message while holding the actual content constant. Results demonstrate that morality and network composition interact to predict persuasion, such that when people are not cued to consider morality increased network heterogeneity predicts increased persuasion, but when identical messages are presented in a way that invokes morality the impact of network heterogeneity disappears or even reverses marginally. This interactive effect was replicated in two very different political issues: gay adoption and nationalized healthcare. Implications for persuasion by morally motivated sources independent of the effects of specific moral arguments are discussed.     

It’s how you say it – The extended Theory of Planned Behaviour explains active transport use in cardiac patients depending on the type of self-report in a hypothesis-generating study

Physical activity (PA) plays an essential part in the secondary prevention of persons with coronary heart disease (CHD). A substantial amount of PA can be gained through increasing the use of active transport modes (walking or cycling for at least 10 min/day) in CHD patients’ daily routine, benefiting the mortality and morbidity rate as well as the environment. The current study aims to investigate the utility of the Theory of Planned Behaviour (TPB) framework extended with habit strength, in understanding the behavioural intention and the behaviour of using active transport modes during the daily travel routine of CHD patients. A cross-sectional survey was conducted from 131 CHD patients. The behaviour was measured using three self-report methods; 1) scale measure, the walking or cycling frequency, 2) direct ATS (Active Travel Score, PA calculated by the directly reported aggregated time spent per day for walking or cycling for travel purposes), and 3) indirect ATS (PA calculated by combining the duration spent on trips by walking and cycling from the self-reported one-day travel diary). Additionally, the participants completed surveys on the direct measures of TPB constructs and habit strength. The results indicated that the TPB constructs explained a 38% variance in the intention to use active transport modes of CHD patients, by which the variance increased to 59% with the addition of habit strength. On the contrary, different behavioural measures were explained differently by TPB and habit strength. The scale measure of behaviour was best predicted (up to 21%) by TPB and habit strength. However, the direct and indirect measures of behaviour were poorly explained (up to 3% and 10% only, respectively). Habit strength moderated the relationship between behaviour (scale measure) and behavioural intention. Surprisingly, higher behavioural intention resulted in a lower behavioural frequency when the habit strength to be active is low. This suggests a limited control over the behaviour thus indicating the intention-behaviour gap. The current study findings highlight the inconsistent predictive utility of TPB across different types of behavioural self-report measures, targeted at the use of active transport modes in CHD patients. However, considering this study as hypothesis-generating, further research is necessary to replicate and extend these findings.     

Associations between older maternal age,use of sanctions,and children’s socio-emotional development through 7, 11, and 15 years

In developed countries more women are giving birth later in life and this trend has been linked with perinatal medical risks as well as with improved psychosocial adaptation. This study examined whether older maternal age was associated with less use of sanctions and with positive child outcome at age 7, 11, and 15. A random population sample of 4741 mothers from the Danish Longitudinal Survey of Children was used. Data were obtained through face-to-face interviews and self-report questionnaires. Older maternal age was associated with less frequent use of verbal and physical sanctions towards children at age 7 and 11. At age 15 this association remained significant for verbal sanctions but not physical sanctions. Older maternal age was associated with fewer behavioral, social and emotional difficulties in children at age 7 and at age 11 but not at age 15. The associations reported were significant independently of all observed demographic and socioeconomic characteristics.