The effects of response cost and response restriction on a multiple-response repertoire with humans

In two experiments a multiple-response repertoire of four free-operant responses was developed with university students as subjects using monetary gain as reinforcement. Following baseline, one of the responses was reduced either by making monetary loss contingent upon it (response cost) or by removing it from the repertoire (response restriction). In Experiment 1 a multielement baseline design was employed in which baseline and restriction or response-cost contingencies alternated semirandomly every 3 minutes. In Experiment 2 a reversal design was employed (i.e., baseline, restriction or response cost, then baseline), and each response required a different amount of effort. Both experiments had the following results: (a) The target response decreased substantially; (b) most nontarget responses increased, and the rest remained near their baseline levels; and (c) no support was found for Dunham's hierarchical, most frequent follower, or greatest temporal similarity rules. For several subjects, the least probable responses during baseline increased most, and the most probable responses increased least. Furthermore, in Experiment 2, responses with the lowest frequency of reinforcement increased most (for all 7 subjects), and those with the greatest frequency of reinforcement increased least (for 5 subjects).     

The cognitive load of physical activity in individuals with high and low tolerance to effort: An ecological paradigm to contrast stepping on the spot and stepping through space

Performing a physical activity means dealing with the challenges and difficulties occurring during the task. The more a person possesses the cognitive ability to deal with the complexity of the task, the more that person will be able to face the difficulties in activity regulation. However, no studies have been designed to investigate the cognitive dimension of physical activity. In the present study, we present an original in-task methodology that offers the means to assess the cognitive and physical load of a physical activity. Through the application of a dual task paradigm, we report in-task changes in cognitive abilities and physiological experiences in low and high tolerant individuals during the practice of one of two whole-body stepping tasks. The findings confirmed that stepping through space is a physical activity that requires more cognitive resources and is perceived as more cognitively and physically challenging than stepping on the spot. We demonstrated also that the tolerance to effort, which is a psychological factor, plays a non-negligible role in the way the activity sessions were experienced. The affective states in low tolerant individuals were always more negative than those reported by high tolerant individuals. Our findings argue for the existence of a cognitive dimension to physical activity with tolerance to effort being a moderator of individuals’ affective experience to exercise.     

The effects of mortality salience on escalation of commitment

Based on propositions derived from terror management theory (TMT), the current study proposes that people who are reminded of their mortality exhibit a higher degree of self-justification behavior to maintain their self-esteem. For this reason, they could be expected to stick with their previous decisions and invest an increasing amount of resources in those decisions, despite the fact that negative feedback has clearly indicated that they might be on a course toward failure (i.e., "escalation of commitment"). Our experiment showed that people who were reminded of their mortality were more likely to escalate their level of commitment by maintaining their current course of action. Two imaginary scenarios were tested. One of the scenarios involved deciding whether to send additional troops into the battlefield when previous attempts had failed; the other involved deciding whether to continue developing an anti-radar fighter plane when the enemy had already developed a device to detect it. The results supported our hypothesis that mortality salience increases the tendency to escalate one's level of commitment.     

Comparing the effects of differential reinforcement of other behavior and response-cost contingencies on tics in youth with tourette syndrome

Tics are rapid, repetitive, stereotyped movements or vocalizations that arise from neurobiological dysfunction and are influenced by environmental factors. Although persons with tic disorders often experience aversive social reactions in response to tics, little is known about the behavioral effects of such consequences. Along several dimensions, the present study compared the effects of two treatments on tics: response cost (RC) and differential reinforcement of other behavior (DRO). Four children with Tourette syndrome were exposed to free-to-tic baseline, DRO, RC, and quasibaseline rebound evaluation conditions using an alternating treatments design. Both DRO and RC produced substantial decreases in tics from baseline levels. No differential effects of DRO and RC contingencies were seen on self-reported stress or in the strength of the reflexive motivating operation (i.e., premonitory urge) believed to trigger tics, and neither condition produced tic-rebound effects. Implications of these findings and directions for future research are discussed.     

熟练汉-英双语者的语码切换机制—— 来自短语水平的证据

以熟练汉-英双语者为被试, 考察了在短语水平上语码切换的机制及切换代价的来源。结果表明：(1)汉语与英语表示空间方所的短语的差异和表示量的短语的对应与否影响语码切换过程, 但对于两种语言的切换代价的影响不显著, 表明语码切换代价未受特定语言的语法特征影响; (2)熟练汉-英双语者在短语水平上表现出语码切换代价的不对称性：切换至熟练语言的代价比切换至非熟练语言的代价大; (3)熟练汉-英双语者的切换代价源于两种语言短语的激活和竞争, 支持非特定语言选择假说, 可以用抑制控制模型来解释。整个研究表明, 熟练双语者的语码切换代价源于语言表征系统之外。     

Temporal texture of associative encoding modulates recall processes

Binding aspects of an experience that are distributed over time is an important element of episodic memory. In the current study, we examined how the temporal complexity of an experience may govern the processes required for its retrieval. We recorded event-related potentials during episodic cued recall following pair associate learning of concurrently and sequentially presented object-picture pairs. Cued recall success effects over anterior and posterior areas were apparent in several time windows. In anterior locations, these recall success effects were similar for concurrently and sequentially encoded pairs. However, in posterior sites clustered over parietal scalp the effect was larger for the retrieval of sequentially encoded pairs. We suggest that anterior aspects of the mid-latency recall success effects may reflect working-with-memory operations or direct access recall processes, while more posterior aspects reflect recollective processes which are required for retrieval of episodes of greater temporal complexity.     

Is “Inhibition of Return” due to the inhibition of the return of attention?

Inhibition of Return (IOR) is usually explained in terms of orienting–reorienting of attention, emphasizing an underlying mechanism that inhibits the return of attention to previously selected locations. Recent data challenge this explanation to the extent that the IOR effect is observed at the location where attention is oriented to, where no reorienting of attention is needed. To date, these studies have involved endogenous attentional selection of attention and thus indicate a dissociation between the voluntary attention of spatial attention and the IOR effect. The present work demonstrates a dissociation between the involuntary orienting of spatial attention and the IOR effect. We combined nonpredictive peripheral cues with nonpredictive central orienting cues (either arrows or gaze). The IOR effect was observed to operate independent of involuntary spatial orienting. These data speak against the “reorienting hypothesis” of IOR. We suggest an alternative explanation whereby the IOR effect reflects a cost in detecting a new event (the target) at the location where another event (a cue) was coded before.     

Task-switching cost and repetition priming: Two overlooked confounds in the fixed-set procedure of the Sternberg paradigm and how they affect memory set-size effects

Subjects performed Sternberg-type memory recognition tasks (Sternberg paradigm) in four experiments. Category-instance names were used as learning and testing materials. Sternberg's original experiments demonstrated a linear relation between reaction time (RT) and memory-set size (MSS). A few later studies found no relation, and other studies found a nonlinear relation (logarithmic) between the two variables. These deviations were used as evidence undermining Sternberg's serial scan theory. This study identified two confounding variables in the fixed-set procedure of the paradigm (where multiple probes are presented at test for a learned memory set) that could generate a MSS RT function that was either flat or logarithmic rather than linearly increasing. These two confounding variables were task-switching cost and repetition priming. The former factor worked against smaller memory sets and in favour of larger sets whereas the latter factor worked in the opposite way. Results demonstrated that a null or a logarithmic RT-to-MSS relation could be the artefact of the combined effects of these two variables. The Sternberg paradigm has been used widely in memory research, and a thorough understanding of the subtle methodological pitfalls is crucial. It is suggested that a varied-set procedure (where only one probe is presented at test for a learned memory set) is a more contamination-free procedure for measuring the MSS effects, and that if a fixed-set procedure is used, it is worthwhile examining the RT function of the very first trials across the MSSs, which are presumably relatively free of contamination by the subsequent trials.