Control by the auditory or the visual element of a compound discriminative stimulus: effects of feedback.

Groups of pigeons were trained to depress a treadle in the presence of a compound stimulus consisting of a tone and a red houselight (a) to avoid electric shock, or (b) to obtain grain. Immediate, exteroceptive feedback was equated for avoidance and appetitive groups within an experiment, but varied across experiments from elevation of a nonilluminated feeder to darkening of the chamber, termination of the tone, and elevation of an illuminated feeder. Responding in the absence of the compound stimulus postponed its next occurrence. After performance had stabilized, the degree to which each element controlled treadle pressing was determined. Generally, in the appetitive tests, the red light controlled much more responding than did the tone, but in the avoidance tests, the tone controlled more responding than did the red light.     

Acquisition and maintenance of postshock response pattern in nondiscriminated avoidance with rats

Five experimentally naive albino rats were placed under a nondiscriminated lever-press avoidance schedule in which the delay to the next shock for responses after a shock was longer than the delay for responses after a response. Four rats acquired the postshock response pattern and maintained it for a prolonged period. The results revealed that postshock responding was under operant control and was not purely shock-elicited. It was suggested that the two kinds of response-shock interval, i.e. the shock-response-shock interval and the response-response-shock interval, could and should be independently controlled in nondiscriminated avoidance schedules.     

Avoidance,induction, and the illusion of reinforcement

Environmental events that impact reproductive success may be called phylogenetically important events (PIEs). Some promote reproductive success, like mates and food; others threaten reproductive success, like predators and injury. Beneficial PIEs induce activities that enhance them, and detrimental PIEs induce activities that mitigate or avoid them. Free-operant avoidance relies on electric shock as a proxy for injury, a PIE. One theory takes avoidance behavior to be reinforced by its reducing shock rate. A more complete explanation is that avoidance both reduces shock rate and is induced by the PIEs it usually prevents. Shocks received act in concert with shock-rate reduction, in a feedback system. Four parametric data sets were analyzed to show that avoidance is induced by received shock rate according to power functions. Avoidance is not reinforced at all; avoidance is induced by its failures. Induction explains not only avoidance itself, but also phenomena unique to avoidance, like warmup and effects of unavoidable shock. Induction explains behavior more generally than reinforcement, because induction explains not only food-maintained operant and nonoperant behavior, but also shock-maintained behavior, including avoidance. Reinforcement fails to explain behavior when reinforcement is defined as strengthening by consequences. Induction erases the distinction between consequences and antecedents.     

Parents‐in‐law's topic avoidance: Understanding the role of interaction goals and relational characteristics

Utilizing dual logic from a multiple goals and relational turbulence theory, this study examined parents‐in‐law's interaction goals for topic avoidance with their children‐in‐law. Data from 159 parents‐in‐law revealed that multiple and conflicting goals were associated with parents‐in‐law's topic avoidance. Furthermore, relational parameters (i.e., relational uncertainty and partner influence) were associated with the goals in‐laws pursued. Results augment theorizing on a multiple goals perspective, relational turbulence, and topic avoidance, as well as theoretically ground the study of in‐law communication.     

Crash avoidance and driver assistance technologies – Are they used?

Crash avoidance technologies have potential to mitigate collisions, and actual crash reductions have been identified for some systems. This study measured observed on-off rates of these technologies as an indicator of use, with a focus on lane maintenance systems (i.e., designed to keep vehicles within lanes by warning, braking, and/or steering) and studied factors that might increase their acceptance and use. Vehicles from nine manufacturers fitted with lane maintenance systems were observed at service departments during 2016. Systems were turned on in 51% of 983 vehicles. The activation rate was higher for systems with braking/steering interventions and vibrating warnings and decreased with total mileage. Large proportions of front crash prevention (93%), blind spot monitoring (99%), rear cross-traffic alert (97%), and driver monitoring alert (90%) systems were enabled, and most optional settings were set to factory defaults. Owner surveys linked to observations showed that drivers who had lane maintenance systems turned off believed warnings were distracting and unnecessary compared with drivers whose systems were on.     

Activation of adenosine receptors in the posterior cingulate cortex impairs memory retrieval in the rat

Adenosine A1 and A2A receptor agonists and antagonists have been reported to alter learning and memory. The aim of our study was to investigate the involvement of adenosinergic system in memory retrieval into posterior cingulate cortex (PCC) of Wistar rats. To clarify this question, we tested specifics agonist and antagonists of adenosine A1 and A2A receptors in rats submitted to a one-trial inhibitory avoidance task. The stimulation of adenosine A1 and A2A receptors by CPA and CGS21680, respectively, impaired memory retrieval for inhibitory avoidance task, into PCC. These findings provide behavioral evidence for the role of adenosinergic system in the memory retrieval into PCC.     

Reward dominance among children with disruptive behavior disorders

Investigated was a deficit in avoidance learning in situations of competing rewards and punishments in boys with behavior disorders. This learning style has been found to differentiate adults with psychopathy and controls and has been labeled reward dominance. The present study investigated the reward dominance paradigm in a group of 9- to 13-year-old boys with disruptive behavior disorders (N=21) and a normal control group (N=22). Subjects played four computer games programmed to provide the subject with a steadily decreasing ratio of rewards to punishments. Although the groups did not differ initially on the number of trials played, significant group differences emerged when measures of anxiety were included in the analysis. That is, boys with disruptive behavior disorders played more trials (reward dominance) only when the effect of anxiety was controlled. These findings are consistent with Gray's biobehavioral theory of personality and are also consistent with research indicating that anxiety is an important marker for a distinct subgroup of children with behavior problems.     

Contingency-shaped and rule-governed behavior: instructional control of human loss avoidance

Instructions can override the influence of programmed schedules of reinforcement. Although this finding has been interpreted as a limitation of reinforcement schedule control in humans, an alternative approach considers instructional control, itself, as a phenomenon determined by subjects' reinforcement histories. This approach was supported in a series of experiments that studied instructional and schedule control when instructions either did or did not accord with the schedule of reinforcement. Experiment I demonstrated that accurate instructions control discriminative performances on multiple avoidance schedules, and that such control persists in a novel discrimination. Experiments II and III showed that elimination of instruction-following occurs when inaccurate instructions cause subjects to contact a monetary loss contingency. Experiment IV demonstrated the reinforcing properties of accurate instructions. Skinner's view of rule-governed behavior is consistent with these findings, and can be extended to account for many aspects of instructional control of human operant behavior.     

Acceleration and suppression of rats' responding to avoid foot shock and tail shock

Signalled response-independent shocks were superimposed on rats' wheel-turn responding to avoid shock administered to their feet through a grid floor or to their tails through fixed electrodes. In Experiment I, a tone paired with response-independent foot shock increased responding in three of four rats; a tone paired with tail shock increased responding in only one of four rats and suppressed responding in two rats. In Experiment II, a tone presented randomly with respect to response-independent shock had no reliable effect on responding to avoid foot shock or tail shock. In Experiment III, tail shock and foot shock were compared in a within-subject design while the temporal pattern of responding during conditioned stimuli was recorded. Responding during the conditioned stimulus preceding foot shock was characterized by initial suppression of responding at tone onset, followed by increased responding just before response-independent shock. Responding was suppressed throughout the conditioned stimulus preceding tail shock. Foot shock elicited bursts of responding, but tail shock did not.