The importance of subject control in reinforcing brain stimulation

A comparison between the reinforcement strength of self-administered and externally imposed brain stimulation was undertaken. Rats performed on a chain schedule in order to receive brain stimulation, either selfadministered or imposed, during the second component of the chain. Response rates during the first component of the chain schedule indicated that self-stimulation was more reinforcing than imposed stimulation. In addition, contrast, both positive and negative, seemed to be present. It was concluded that reinforcement strength may be enhanced when the subject controls the presentation of reinforcement.     

Limits to preference and the sensitivity of choice to rate and amount of food

Studies of choice holding food‐amount ratio constant while varying food‐rate ratio within sessions showed that local changes in preference depend on relative amount of food. The present study investigated whether sensitivity of choice to food‐rate ratio and sensitivity to food‐amount ratio are independent of one another when food‐rate ratios are varied across sessions and food‐amount ratios are varied within sessions. Food deliveries for rats’ presses on the left and right levers were scheduled according to three different food‐rate ratios of 1:1, 9:1, and 1:9; each food‐rate ratio lasted for 106 sessions and was arranged independently of seven food‐amount ratios (7:1, 6:2, 5:3, 4:4, 3:5, 2:6, and 1:7 food pellets) occurring within sessions in random sequence. Each amount ratio lasted for 10 food deliveries and was separated from another by a 60‐s blackout. Sensitivity to rate ratio was high (1.0) across food deliveries. Sensitivity to amount ratio was low when food rates were equal across alternatives, but was high when rate ratio and amount ratio opposed one another. When rate ratio and amount ratio went in the same direction, choice ratio reached an elevenfold limit which reduced sensitivity to approximately zero. We conclude that three factors affect sensitivity to amount: (1) the limit to preference, (2) the equal effect on preference of amounts greater than four pellets, and (3) the absence of differential effects of switches in amount in the equal‐rates (1:1) condition. Taken together, these findings indicate that rate and amount only sometimes combine independently as additive variables to determine preference when amount ratios vary frequently within sessions.     

Acceptance and Commitment Therapy and Implementation Intentions Increase Exercise Enjoyment and Long-Term Exercise Behavior Among Low-Active Women

The current study evaluated the long-term effectiveness of acceptance and commitment therapy (ACT) for promoting exercise behavior in comparison with planning in the form of implementation intentions (forming situational cues and action plans as to when, where, and how to incorporate exercise). We expected both interventions to increase exercise behavior (assessed using the Godin Leisure-Time Exercise Questionnaire; Godin and Shephard 1985) from baseline to 6-months post-intervention, but expected only ACT to also increase exercise enjoyment (assessed using the Physical Activity Enjoyment Scale; Kendzierski and DeCarlo 1991). A total of 32 women, randomized to receive a single session of either ACT training or instructions to form implementation intentions for exercise activities, took part in this study. The participants were contacted by email 6-months following the intervention to determine the amount of self-reported exercise. As expected, exercise amount increased in both groups. Contrary to our expectations, both groups also increased in exercise enjoyment. This study provides initial evidence that exercising can be increased through an ACT intervention. ACT and implementation intentions may both be effective and brief interventions for promoting exercise behavior and exercise-related enjoyment in low-active women. Future research needs to establish the psychosocial and personality factors that lead to the effectiveness of ACT and implementation intentions.     

Continuous Response Monitoring of Relative Time-to-Contact Judgments: Does Effective Information Change During an Approach Event?

In many previous studies of time-to-contact (TTC) judgments of approaching objects, a response was measured after observers viewed the entire event and was used to infer the informational basis for the judgment. Such measures primarily reflect the information used at the end of the approach event and may not reveal whether observers used different information at different times during the event. Evidence indicates that observers use multiple information sources and that the effectiveness of information varies with distance. We introduce a method in which observers continuously report which of 2 approaching objects would reach them first, throughout the approach. We identified the occurrence and time of response reversals. Most observers changed their relative TTC judgments during the event. The pattern of responses indicated that observers did not use tau early during the approach when objects were far and did not use optical size later when the objects were closer. Most observers relied on either optical size or optical expansion rate early during the approach and expansion rate later during the event, although there were individual differences. A single relative TTC judgment measured after observers view an approach event may not reflect judgments or their informational basis throughout the entire event.     

Resurgence is greater following a return to the training context than remaining in the extinction context

The present study examined whether resurgence of a previously reinforced target response upon removing alternative reinforcement would be greater when (1) returning to the original training context (ABA context changes) versus (2) remaining in the analogue treatment context in which the alternative response was differentially reinforced (ABB context changes). Experiment 1 arranged reinforcement of button pressing with points exchangeable for money in university students. Experiment 2 arranged reinforcement of lever pressing with food for rats. Experiment 3 arranged reinforcement of responses to a touchscreen with small bites of food with children diagnosed with ASD. Overall, resurgence of target responding tended to be greater when returning to the original training context (A) than when remaining in the analogue treatment context (B). These findings suggest context changes with differential reinforcement treatments could exacerbate the recurrence of problem behavior resulting from reductions in treatment integrity through failure to reinforce appropriate behavior.     

The Influence of Existential Threat and Tolerance Salience on Anti‐Islamic Attitudes in American Politics

Fierce public discussion has centered on anti‐Islamic attitudes and tolerance in America and the West more broadly. The present research explored whether the awareness of mortality (a common theme in politics, e.g., war/terrorism, health care, abortion, and so on) and tolerance salience might influence (1) the endorsement of anti‐Islamic attitudes in American politics and (2) political orientation. Study 1 (n = 79) was conducted in lab and Study 2 (preregistered, n = 396) replicated it online; both obtained the same results. In a neutral‐value‐prime condition, American participants reminded of mortality (vs. control topic) more strongly endorsed a Congressman’s anti‐Islamic statements about Rep. Ellison. However, in a tolerance‐value‐prime condition, participants reminded of mortality maintained their acceptance of Rep. Ellison’s beliefs and practices. Political orientation was not impacted. Implications for terror management theory (TMT), other theories of existential dynamics and motivated conservative political ideology, and both recent and contemporary American politics are discussed.     

Reducing faking on personality tests: Testing a new faking‐mitigation procedure in a U.S. job applicant sample

Faking has remained a major concern for organizations using self‐report personality measures for selection. Scholars recenlty developed a new middle‐warning faking‐mitigation procedure. The present replication study was the first field test in the United States using 193 applicants for an entry‐level position in a New York‐based consulting firm. Results replicated most of Fan et al.'s findings including (a) the middle‐warning significantly lowered fakers' personality scores over retesting, whereas the control message had little influence on nonfakers; (b) the above warning effect carried over to personality scales that were not retested; and (c) the persistent tendency of potential fakers rising to the top of personality score distribution was weakened. In addition, applicants' perceptions were not being negatively affected by the warning.     

Escape from rich‐to‐lean transitions: Stimulus change and timeout

Extended pausing during discriminable transitions from rich‐to‐lean conditions can be viewed as escape (i.e., rich‐to‐lean transitions function aversively). In the current experiments, pigeons’ key pecking was maintained by a multiple fixed‐ratio fixed‐ratio schedule of rich or lean reinforcers. Pigeons then were provided with another, explicit, mechanism of escape by changing the stimulus from the transition‐specific stimulus used in the multiple schedule to a mixed‐schedule stimulus (Experiment 1) or by producing a period of timeout in which the stimulus was turned off and the schedule was suspended (Experiment 2). Overall, escape was under joint control of past and upcoming reinforcer magnitudes, such that responses on the escape key were most likely during rich‐to‐lean transitions, and second‐most likely during lean‐to‐lean transitions. Even though pigeons pecked the escape key, they paused before doing so, and the latency to begin the fixed ratio (i.e., the pause) remained extended during rich‐to‐lean transitions. These findings suggest that although the stimulus associated with rich‐to‐lean transitions functioned aversively, pausing is more than simply escape responding from the stimulus.