Monetary rewards influence retrieval orientations

Reward anticipation during learning is known to support memory formation, but its role in retrieval processes is so far unclear. Retrieval orientations, as a reflection of controlled retrieval processing, are one aspect of retrieval that might be modulated by reward. These processes can be measured using the event-related potentials (ERPs) elicited by retrieval cues from tasks with different retrieval requirements, such as via changes in the class of targeted memory information. To determine whether retrieval orientations of this kind are modulated by reward during learning, we investigated the effects of high and low reward expectancy on the ERP correlates of retrieval orientation in two separate experiments. The reward manipulation at study in Experiment 1 was associated with later memory performance, whereas in Experiment 2, reward was directly linked to accuracy in the study task. In both studies, the participants encoded mixed lists of pictures and words preceded by high- or low-reward cues. After 24?h, they performed a recognition memory exclusion task, with words as the test items. In addition to a previously reported material-specific effect of retrieval orientation, a frontally distributed, reward-associated retrieval orientation effect was found in both experiments. These findings suggest that reward motivation during learning leads to the adoption of a reward-associated retrieval orientation to support the retrieval of highly motivational information. Thus, ERP retrieval orientation effects not only reflect retrieval processes related to the sought-for materials, but also relate to the reward conditions with which items were combined during encoding.     

Worms under cover: relationships between performance in learning tasks and personality in great tits (Parus major)

In animals, individual differences in learning ability are common and are in part explained by genetic differences, developmental conditions and by general experience. Yet, not all variations in learning are well understood. Individual differences in learning may be associated with elementary individual characteristics that are consistent across situations and over time, commonly referred to as personality or temperament. Here, we tested whether or not male great tits (Parus major) from two selection lines for fast or slow exploratory behaviour, an operational measure for avian personality, vary in their learning performance in two related consecutive tasks. In the first task, birds had to associate a colour with a reward whereas in the second task, they had to associate a new colour with a reward ignoring the previously rewarded colour. Slow explorers had shorter latencies to approach the experimental device compared with fast explorers in both tasks, but birds from the two selection lines did not differ in accomplishing the first task, that is, to associate a colour with a reward. However, in the second task, fast explorers had longer latencies to solve the trials than slow explorers. Moreover, relative to the number of trials needed to reach the learning criteria in the first task, birds from the slow selection line took more trials to associate a new colour with a reward while ignoring the previously learned association compared with birds from the fast selection line. Overall, the experiments suggest that personality in great tits is not strongly related to learning per se in such an association task, but that birds from different selection lines might express different learning strategies as birds from the different selection lines were differently affected by their previous learning performance.     

Substance use disinhibition associated with economically rational decisions to quit a boring task

Preferences for smaller immediate rewards over larger delayed rewards have been associated with a range of negative outcomes, including substance use problems. The present research investigated a potential association between substance use disinhibition and preferences for an immediate reward in a situation where the delayed reward was not the largest. Participants recruited from Amazon Mechanical Turk were required to perform a boring, repetitive task for 25 min in order to earn a $3 bonus. Alternatively, they could quit at any time to receive half the bonus. However, when one fourth the task remained, participants were offered the choice between (a) quitting the boring task for a $3 bonus, and (b) continuing the boring task for a $3 bonus. Participants who chose the economically superior option of quitting the task scored higher on a measure of substance use disinhibition and on the Disinhibition facet of Zuckerman’s Sensation Seeking Scale.     

Predicting transfer from training performance.

The research in this paper was designed to examine the extent to which improvement on a training task can be used to predict performance on a transfer task. This aim involved evaluating the proposition that when old skills are executed in the context of new tasks, they continue to improve as if stimulus conditions have not changed. That is, power functions that describe improvement on old skills during their initial acquisition should predict further improvement on these skills during their execution in new tasks. Three experiments were performed to achieve the aim of testing this proposition. Experiment 1 revealed that old skills were executed slower in the context of a new task than was predicted on the basis of training performance. Hence improvement in the old skills appeared to be disrupted by performance of the new task. Experiment 2 was designed to examine whether this disruption was due to an increase in complexity in the task from training to transfer, or simply due to any change in task. The results suggested that any change may cause some disruption, but this disruption was greatest with an increase in task complexity. Experiment 3 was designed to examine two variables that may affect the magnitude of this effect: the relative change in task complexity from training to transfer, and the amount of practice on a task prior to a change in task. The results indicated that only the former variable had any effect. In all three experiments no effects on performance accuracy were noted, and response times in the transfer tasks eventually returned to levels predicted by training learning functions. These results were interpreted as indicating that old skills do continue to improve in new tasks as if conditions are not altered, but that disruptions caused by transfer are related to performance overheads associated with reconceptualising the task.     

Performance among different types of myocontrolled tasks is not related

Studies on myocontrolled assistive technology (AT), such as myoelectric prostheses, as well as rehabilitation practice using myoelectric controlled interfaces, commonly assume the existence of a general myocontrol skill. This is the skill to control myosignals in such a way that they are employable in multiple tasks. If this skill exists, training any myocontrolled task using a certain set of muscles would improve the use of myocontrolled AT when the AT is controlled using these muscles. We examined whether a general myocontrol skill exists in myocontrolled tasks with and without a prosthesis. Unimpaired, right-handed adults used the sEMG of wrist flexors and extensors to perform several tasks in two experiments. In Experiment 1, twelve participants trained a myoelectric prosthesis-simulator task and a myocontrolled serious game for five consecutive days. Performance was compared between tasks and over the course of the training period. In Experiment 2, thirty-one participants performed five myocontrolled tasks consisting of two serious games, two prosthesis-simulator tasks and one digital signal matching task. All tasks were based on tasks currently used in clinical practice or research settings. Kendall rank correlation coefficients were computed to analyze correlations between the performance on different tasks. In Experiment 1 performance on the tasks showed no correlation for multiple outcome measures. Rankings within tasks did not change over the training period. In Experiment 2 performance did not correlate between any of the tasks. Since performance between different tasks did not correlate, results suggest that a general myocontrol skill does not exist and that each myocontrolled task requires a specific skill. Generalization of those findings to amputees using AT should be done with caution since in both experiments unimpaired participants were included. Moreover, training duration in Experiment 2 was short. Our findings indicate that training and assessment methods for myocontrolled AT use should focus on tasks frequently performed in daily life by the individual using the AT instead of merely focusing on training myosignals.     

Tests of an indifference rule in variable‐delay and double‐reward choice procedures with humans

Four hundred and fifty participants were recruited from Amazon Mechanical Turk across 3 experiments to test the predictions of a hyperbolic discounting equation in accounting for human choices involving variable delays or multiple rewards (Mazur, 1984, 1986). In Experiment 1, participants made hypothetical choices between 2 monetary alternatives, 1 consisting of a fixed delay and another consisting of 2 delays of equal probability (i.e., a variable‐delay procedure). In Experiment 2, participants made hypothetical monetary choices between a single, immediate reward and 2 rewards, 1 immediate and 1 delayed (i.e., a double‐reward procedure). Experiment 3 also used a double‐reward procedure, but with 2 delayed rewards. Participants in all 3 experiments also completed a standard delay‐discounting task. Finally, 3 reward amounts were tested in each type of task ($100, $1000, and $5000). In the double‐reward conditions (Experiments 2 and 3), the results were in good qualitative and quantitative agreement with Mazur's model (1984, 1986). In contrast, when participants made choices involving variable delays (Experiment 1), there was relatively poor qualitative and quantitative agreement with this model. These results, along with our previous findings, suggest the structure of questions in hypothetical tasks with humans can be a strong determinant of the choice pattern.     

Spatial working memory load affects counting but not subitizing in enumeration

The present study investigated whether subitizing reflects capacity limitations associated with two types of working memory tasks. Under a dual-task situation, participants performed an enumeration task in conjunction with either a spatial (Experiment 1) or a nonspatial visual (Experiment 2) working memory task. Experiment 1 showed that spatial working memory load affected the slope of a counting function but did not affect subitizing performance or subitizing range. Experiment 2 showed that nonspatial visual working memory load affected neither enumeration efficiency nor subitizing range. Furthermore, in both spatial and nonspatial memory tasks, neither subitizing efficiency nor subitizing range was affected by amount of imposed memory load. In all the experiments, working memory load failed to influence slope, subitizing range, or overall reaction time. These findings suggest that subitizing is performed without either spatial or nonspatial working memory. A possible mechanism of subitizing with independent capacity of working memory is discussed.     

Motivational and cognitive determinants of control during conflict processing

Previous studies suggest that both reward anticipation and expected or experienced conflicts activate cognitive control. The present study investigated how these factors interact during conflict processing. In two experiments, participants performed a variant of the Stroop task, receiving performance-dependent monetary rewards in some blocks. In addition, we manipulated the level of conflict-triggered reactive and expectancy-driven proactive control: In Experiment 1, we compared the Stroop effect after previously congruent and incongruent trials to examine the conflict adaptation effect (reactive control). We found that the level of motivation did not interact with conflict adaptation. In Experiment 2, we varied the proportion of congruent and incongruent trials to manipulate conflict expectancy (proactive control). The data suggest the effects of motivation to be less pronounced under conditions of high conflict expectancy. We conclude that the interaction of motivation with cognitive determinants of control depends on whether these activate proactive or reactive control processes.     

Motivated semantic control: Exploring the effects of extrinsic reward and self-reference on semantic retrieval in semantic aphasia

Recent insights show that increased motivation can benefit executive control, but this effect has not been explored in relation to semantic cognition. Patients with deficits of controlled semantic retrieval in the context of semantic aphasia (SA) after stroke may benefit from this approach since ‘semantic control’ is considered an executive process. Deficits in this domain are partially distinct from the domain-general deficits of cognitive control. We assessed the effect of both extrinsic and intrinsic motivation in healthy controls and SA patients. Experiment 1 manipulated extrinsic reward using high or low levels of points for correct responses during a semantic association task. Experiment 2 manipulated the intrinsic value of items using self-reference, allocating pictures of items to the participant (‘self’) or researcher (‘other’) in a shopping game before participants retrieved their semantic associations. These experiments revealed that patients, but not controls, showed better performance when given an extrinsic reward, consistent with the view that increased external motivation may help ameliorate patients’ semantic control deficits. However, while self-reference was associated with better episodic memory, there was no effect on semantic retrieval. We conclude that semantic control deficits can be reduced when extrinsic rewards are anticipated; this enhanced motivational state is expected to support proactive control, for example, through the maintenance of task representations. It may be possible to harness this modulatory impact of reward to combat the control demands of semantic tasks in SA patients.     

Age differences in response selection for pure and mixed stimulus-response mappings and tasks

Two experiments examined effects of mixed stimulus-response mappings and tasks for older and younger adults. In Experiment 1, participants performed two-choice spatial reaction tasks with blocks of pure and mixed compatible and incompatible mappings. In Experiment 2, a compatible or incompatible mapping was mixed with a Simon task for which the mapping of stimulus color to location was relevant and stimulus location was irrelevant. In both experiments, older adults showed larger mixing costs than younger adults and larger compatibility effects, with the differences particularly pronounced in Experiment 1 when location mappings were mixed. In mixed conditions, when stimulus location was relevant, older adults benefited more than younger adults from complete repetition of the task and stimulus from the preceding trial. When stimulus location was irrelevant, the benefit of complete repetition did not differ reliably between age groups. The results suggest that the age-related deficit associated with mixing mappings and tasks is primarily due to older adults having more difficulty separating task sets that activate conflicting response codes.     

Assessing absentmindedness: Prospective memory complaint and impairment in middle-aged adults

In two experiments, metamemorial differences between prospective and retrospective memory performance were examined. Participants in Experiment 1 were recruited through newspaper advertisements and comprised middle-aged women who experienced exceptional problems in prospective remembering. Experiment 2 involved self-reporters and nonreporters of retrospective memory problems, who were selected from a large population-based sample of middle-aged adults. In both experiments, memory performance was assessed by using a variety of tasks, including five retrospective memory tasks and three prospective memory tasks that varied in level of realism and retrieval support. In both experiments, there were selective differences in memory performance, so that participants who experienced (retrospective or prospective) memory problems showed impaired performance in prospective, but not in retrospective, memory tasks. These findings suggest that memory for future intentions provides a more sensitive task criterion than does memory for past events for assessing individual differences in self-reports of episodic memory problems. Task-specific differences in reliance on frontally mediated executive processes might underlie these differences.     

奖赏预期调节局部注意干扰效应

局部注意干扰效应(Localized attentional interference, LAI)是指在视觉搜索任务中同时搜索在空间上分离的两个目标时, 或者目标周围存在一个无关奇异项时, 这两个关键刺激相距较近时产生的干扰现象。本实验采用视觉搜索范式, 探讨了奖赏预期对局部注意干扰效应的影响。实验1采用双目标搜索任务, 要求被试判断搜索画面中两个奇异项刺激的形状是否相同。结果显示奖赏条件和无奖赏条件都表现出显著的距离主效应, 随着目标间距离增大, 被试的正确率提高, 反应时下降。同时, 在远距离时, 奖赏条件下的正确率高于无奖赏条件, 而在近距离时, 奖赏条件下的正确率反而低于无奖赏条件, 即, 奖赏条件下局部注意干扰效应反而增大。高动机状态增强了两个目标的表征, 反而不利于解决局部注意干扰效应。实验2采用单目标搜索任务, 要求被试判断特定目标的方位并忽略另一无关奇异项刺激。与实验1不同的是, 实验2仅在无奖赏条件下观察到显著的距离主效应, 即被试行为表现在远距离时更好; 而在奖赏条件下, 被试在近距离和远距离的表现一样好, 即没有局部注意干扰效应。这说明在奖赏预期条件, 个体可以有效抑制分心物刺激的干扰, 将注意集中于目标刺激的加工, 从而对局部注意干扰效应产生调节。整个研究表明, 奖赏整体上能够提高对任务相关刺激的表征, 并抑制任务无关刺激, 虽然这并不总是能够提高任务表现。     

The role of exploration in win-shift and win-stay performance on a radial maze

Win-shift spatial memory tasks in a radial maze reinforce animals for avoiding previously visited rewarded arms; win-stay tasks reinforce them for returning to those arms. Win-shift tasks have generally been found much easier to perform, and this may be explained either in terms of foraging models which postulate avoidance of locations where food has been found, or in terms of the predominance of spontaneous alternation (exploration). Experiment 1 examined spontaneous alternation behavior in the radial maze as a function of whether the first visit to an arm had been rewarded or not, and showed that alternation was more probable after nonreward than after reward in both hungry and thirsty rats (a result which conflicts with the foraging account of the win-shift superiority). Experiment 2 replicated the finding that win-stay discrimination performance was inferior to win-shift. A manipulation (lengthening the delay between initial and test choices) which weakens spontaneous alternation, reduced, but did not reverse, the win-shift superiority. In Experiment 3, in order to eliminate the influence of spontaneous alternation, versions of the win-stay and win-shift tasks were devised in which, unlike the original task, all arms were familiar at the choice trial. Under those conditions win-stay was performed better than win-shift. It is concluded that spontaneous alternation plays a major role in many spatial memory tasks, and that the results can best be accounted for by combining principles of exploration and simple associative learning, without recourse to foraging models.     

Pavlovian reward learning elicits attentional capture by reward-associated stimuli

Feature–reward association elicits value-driven attentional capture (VDAC) regardless of the task relevance of associated features. What are the necessary conditions for feature–reward associations in VDAC? Recent studies claim that VDAC is based on Pavlovian conditioning. In this study, we manipulated the temporal relationships among feature, response, and reward in reward learning to elucidate the necessary components of VDAC. We presented reward-associated features in a variety of locations in a flanker task to form a color–reward association (training phase) and then tested VDAC in a subsequent visual search task (test phase). In Experiment 1, we showed reward-associated features in a task display requiring response selection and observed VDAC, consistent with most previous studies. In Experiment 2, features presented at a fixation display before a task display also induced VDAC. Moreover, in Experiment 3, we reduced the time interval between features and rewards so that features appeared after a task display and we obtained marginally significant VDAC. However, no VDAC was observed when features and rewards were simultaneously presented in a feedback display in Experiments 4 and 5, suggesting that a direct association between feature and reward is not sufficient for VDAC. These results are in favor of the idea that response selection does not mediate feature–reward association in VDAC. Moreover, the evidence suggests that the time interval of feature and reward is flexible with some restriction in the learning of feature–reward association. The present study supports the hypothesis that theories of Pavlovian conditioning can account for feature–reward association in VDAC.     

The interactive effects of locus of control and situational stress upon performance accuracy and time

The present paper sought to clarify the conceptual relationship between expectancy for personal control, stress, and behavioral reactions to stress. Expectancy for control was assessed as a personality characteristic of internal control; stress was experienced as strong environmental interruptions, disturbances, and unpredictable obstacles encountered during the performance of assigned tasks. Subjects were junior high school aged students who attempted to complete three academic type tasks during one of two levels of stress or a base line, no stress, condition. Analyses of the data included: (a) internal subjects were capable of sustaining task performance under high stress, but external students experienced performance decrements as stress increased; (b) time to complete the mathematics task reflected a facilitating effect of stress for internals but a debilitating effect for externals; (c) performance differences between internal and external students, in the absence of differences in reported anxiety, could be attributed to the stronger reward expectancies possessed by the internal individual. Interpretation of the data suggested an interactive relationship between type of stress (threat to ego vs. threat to instrumental performance) and expectancy for control in the influencing of behavior reactions to stress.     

Monitoring source in an unconscious plagiarism paradigm

Current laboratory paradigms used to assess unconscious plagiarism consist of three tasks. First, participants generate solutions to a puzzle task with a partner (initial generation task); second, they recall their individual contribution (recall-own task); and third, they attempt to create new solutions that were not offered previously (generate-new task). An analysis of these tasks indicated that they differ in terms of the source monitoring they require. The two generative tasks require less differentiated information (e.g., familiarity) and relatively lax decision criteria. The recall-own task, however, demands more differentiated information and more extended decision criteria. In two experiments, factors known to influence source monitoring were manipulated. Consistent with the analysis, no effects were associated with the generative tasks. Recall-own plagiarisms increased when self- and other-generated solutions were difficult to distinguish (Experiment 1) and decreased when the two sources were easier to distinguish (Experiment 2).     

Reward priming of temporal preparation

Recent studies have demonstrated a strong impact of reward on the expectancy of future target locations or features. In this study, we examined whether reward would have similar effects on temporal preparation. In two experiments, participants completed a reaction time task with a variable interval between a warning stimulus and the target stimulus. After each trial they were awarded either low or high reward which was converted to cash after the experiment. Crucially, reward magnitude was assigned randomly and was unrelated to task performance. Nevertheless, across experiments, the results revealed that reward modified future temporal preparation, especially in participants that could be identified as highly motivated. These findings generalize the principles of reward priming to the temporal domain.     

Effects of ongoing task context and target typicality on prospective memory performance: the importance of associative cueing

Two experiments examined whether prospective memory performance is influenced by contextual cues. In our automatic activation model, any information available at encoding and retrieval should aid recall of the prospective task. The first experiment demonstrated an effect of the ongoing task context; performance was better when information about the ongoing task present at retrieval was available at encoding. Performance was also improved by a strong association between the prospective memory target as it was presented at retrieval and the intention as it was encoded. Experiment 2 demonstrated boundary conditions of the ongoing task context effect, which implicate the association between the ongoing and prospective tasks formed at encoding as the source of the context effect. The results of this study are consistent with predictions based on automatic activation of intentions.     

An analysis of stereotypy during prevocational instruction of an adolescent with severe mental retardation

An adolescent with severe retardation was observed during participation in several vocational tasks. The vocational tasks were comprised of repeating sequences of work-related responses. Across two experiments, conditions that are typical in the training of vocational tasks in special education and adult vocational programs were manipulated and the effects of these conditions on rates of vocational sequences completed and rates of stereotypic behavior were assessed. In Experiments 1 and 2, the adolescent was reinforced with a food item following the completion of vocational sequences under two alternating reinforcement contingencies. Under one contingency, the adolescent performed with frequent errors and under the other, often performed without errors. In Experiment 3, the adolescent participated with another student in a different vocational task on alternating days and in an alternating sequence of work conditions in each task. In one condition, both adolescents had vocational materials nearly continuously present and the teacher prompted and reinforced both adolescents as needed. In the other condition, the vocational materials were presented to the adolescents on an alternating basis, and the teacher prompted and reinforced first one and then the other. Across both experiments, increased competence reflected as high rate, error free, and consistent vocational performances were associated with low rates of stereotypic behavior when compared to conditions with less competent performances, and with leisure periods in Experiment 3. © 1997 John Wiley & Sons, Ltd.     

Effects of ongoing task context and target typicality on prospective memory performance: The importance of associative cueing

Two experiments examined whether prospective memory performance is influenced by contextual cues. In our automatic activation model, any information available at encoding and retrieval should aid recall of the prospective task. The first experiment demonstrated an effect of the ongoing task context; performance was better when information about the ongoing task present at retrieval was available at encoding. Performance was also improved by a strong association between the prospective memory target as it was presented at retrieval and the intention as it was encoded. Experiment 2 demonstrated boundary conditions of the ongoing task context effect, which implicate the association between the ongoing and prospective tasks formed at encoding as the source of the context effect. The results of this study are consistent with predictions based on automatic activation of intentions.