Context and rule manipulations on the Wason selection task

‘Food and drinks’ is a thematic content known not to produce differential performance to abstract content on the Wason selection task. To examine the effects of context on problem responses, this content was set in a ‘diet’ context, predicted to produce differential performance, and this context was compared both with the ‘food and drinks’ presentation previously used and with abstract content. Additionally, both conditional and universal rules were used, producing six cells to the design, 12 subjects being tested in each cell. Results revealed a significant difference between the rules (in the form a rule by content interaction), content having a significant effect only when the conditional rules were used. For these rules, subjects made significantly more correct solutions in the diet condition than in the abstract condition, whereas there was no evidence of differential performance between the (other) thematic and the abstract condition. Although it is admitted that no satisfactory explanation of the rule differences seems apparent, the effect of context observed is encouraging for this line of research. It is concluded that, as subjects are shown to be capable of coding the general idea of a counter-example into relevant specific selections, they are quite capable of solving the task, but that they fail to do so unless the solution is cued by, and its outcome would be consistent with, their pre-existing belief structures.     

The influence of decision task and deliberation style on the verdict of the juries

The influence of decision task and deliberation style on the verdict of the juries. In the Kameda's Deliberation Style Model the emission of verdicts of responsibility when the deliberation style of the juries (elemental/compound) and the type of decision task (disjunctive/conjunctive) are jointly manipulated, is favoured in certain conditions. Given the consequences that these approaches could have in real judicial processes, this model is analyzed using a manslaughter crime under the Spanish judicial context conditions (nine members juries and seven or five members majorities emitting a verdict of guilty or not guilty, respectively). The obtained results indicated a better operation of the model when a conjunctive decision task was demanded.     

Disrupting reconsolidation: pharmacological and behavioral manipulations

We previously demonstrated that disrupting reconsolidation by pharmacological manipulations "deleted" the emotional expression of a fear memory in humans. If we are to target reconsolidation in patients with anxiety disorders, the disruption of reconsolidation should produce content-limited modifications. At the same time, the fear-erasing effects should not be restricted to the feared cue itself considering that fear generalization is a main characteristic of anxiety disorders. In Experiment I and Experiment I(b), we addressed these issues using a within-subject differential startle fear conditioning paradigm and a test of fear generalization. In Experiment II, we tested whether a behavioral approach targeting the reconsolidation through extinction learning was also effective in weakening the original fear memory. A behavioral procedure is evidently preferred over drug manipulations provided that similar effects can be obtained. Here, the extinction procedure subsequent to retrieval did not "erase" the emotional expression of the fear memory as the retrieval techniques (i.e., reminder shocks and reacquisition) unveiled a return of the startle fear response to the fear-relevant stimuli. In contrast, β-adrenergic receptor blockade during reconsolidation selectively deleted the fear-arousing aspects of the memory (i.e., startle fear response) along with its category-related information. The pharmacological manipulation rendered the core memory trace too weak to observe fear generalization after successful reacquisition. Hence, relearning following the disruption of reconsolidation seems to be qualitatively different from initial learning. Our findings demonstrate that disrupting reconsolidation by pharmacological manipulations, although selective, undermines the generalization of fear, a key feature of anxiety disorders.     

Effects of some physiological and pharmacological manipulations on shock- facilitated mouse killing by onychomys leucogaster (Northern grasshopper mouse)

Onychomys leucogaster (northern grasshopper mice) were induced to kill mice with response-contingent shock, and the effects of several physiological, pharmacological, and endocrinological variables were assessed. Lesions of the septum facilitated mouse killing, while lesions of the amygdala abolished spontaneous mouse killing and delayed shock-facilitated killing. Chlorpromazine (2.5–5 mg/kg) and chlordiazepoxide (5–10 mg/kg) facilitated mouse killing on postdrug trials but did not affect killing when the animals were drugged. Adrenalectomy, castration, and castration adrenalectomy did not alter the frequency of kill nor were sex-related differences in killing noted. These results were compared to those found by others studying the effects of lesions and drugs on mouse killing by rats.     

Effects of response selection on the task repetition benefit in task switching

A task switch typically leads to worse performance than a repetition does. This shift cost can be reduced with sufficient task preparation time, but a residual cost usually remains. We propose that a large part of this residual cost is caused by an activation bias produced by response selection processes in the preceding trial. In our experiments, we manipulated response selection requirements using a go/no-go methodology. The residual shift cost disappeared after no-go trials, suggesting that response selection is crucial to establish an activation bias for the current category-response rules and that this bias persists into the next trial. A comparison with a go-only group confirmed this analysis by revealing no differences in preparatory strategy due to the inclusion of no-go trials. In addition, no-go trials had no significant effects on subsequent trials in a single-task experiment, suggesting that no-go trials are not coded as a task different from go trials and that there is no inhibition of the prepared task in a no-go trial. We thus conclude that a persisting activation bias of response rules plays a major role in task switching.     

Online attentional-focus manipulations in a soccer-dribbling task: implications for the proceduralization of motor skills

A focus of attention on the step-by-step control of a skill has been shown to be detrimental to experts' performance but to have no significant effect on novices' performance (e.g., S. L. Beilock, T. H. Carr, C. MacMahon, & J. L. Starkes, 2002), contrary to the results of manipulations of the direction of attentional focus (e.g., G. Wulf, M. H?ss, & W. Prinz, 1998). In previous studies, researchers have not separated the focus of attention from the nature of the instruction provided or the skill level of the participants. In the present experiment, 10 skilled and 10 less skilled soccer players dribbled a ball after receiving instructions directing attention to an internal, skill-relevant feature (foot); an internal, skill-irrelevant feature (arm); or a skill-irrelevant task (word-monitoring). Performance was evaluated in relation to a no-attentional-focus control condition. For skilled performers, an internal focus on the arms and feet interfered with performance. For less skilled performers, an internal, yet skill-relevant, focus of attention (foot) did not degrade performance, whereas attention to the arms and word monitoring had a detrimental effect. No significant differences were observed across the three attentional manipulations when the skilled performers used the nondominant foot. The results generally supported the deautomization of skills hypothesis.     

Effects of anxiety on task switching: Evidence from the mixed antisaccade task

According to the attentional control theory of anxiety (Eysenck, Derakshan, Santos, & Calvo, 2007), anxiety impairs performance on cognitive tasks that involve the shifting function of working memory. This hypothesis was tested using a mixed antisaccade paradigm, in which participants performed single-task and mixed-task versions of the paradigm. The single task involved the completion of separate blocks of anti- and prosaccade trials, whereas in the mixed task, participants completed anti- and prosaccade trials in a random order within blocks. Analysis of switch costs showed that high-anxious individuals did not exhibit the commonly reported paradoxical improvement in saccade latency, whereas low-anxious individuals did. The findings are discussed within the framework of attentional control theory.     

Pending intentions: Effects of prospective task encoding on the performance of another task

A number of recent studies casts doubt on the empirical separability of processes of task preparation from the actual execution of the respective task. We report two experiments in which we separated the precueing of a task from its execution by an intervening task. In addition, for the precued task we employed imperative stimuli that in most cases were associated with a competing task, making the execution of this task dependent on an internal representation of the information provided by the precue. Under these conditions, the performance of the intervening task suffered specific interference as a function of its relation to the precued task. This suggests that the encoding of the precue resulted in specific preparation for the precued task. Furthermore, the transition between the intervening task and the precued task was associated with relatively small costs that did not vary as a function of the interval that separated the two tasks. This also suggests that a great deal of preparation for the second task already took place during the encoding of the precue. Further observations suggest that the resolution of the interference between a memory-based task representation, as well as a perceptually induced task representation, and the representation of the currently relevant task took place on the level of individual task features.     

Effects of task duration on sensitivity to sleep deprivation using the multi-attribute task battery

Several factors affect the sensitivity to sleep deprivation in the performance of computerized tests. Two of these are task complexity and duration. Complexity can improve sensitivity by increasing the demands required to complete the task, but it can also decrease sensitivity by improving the subject’s motivation. The effects of task duration are more predictable in that longer tests generally are more susceptible to deprivation effects than shorter ones. The impact of task duration on an interesting, but complex, aviation simulation was examined here. By breaking down data from 30-min multi-attribute task battery administrations into the first, second, and third 10 min of performance, it was shown that tests shorter than 30 min underestimate the impact of sleep loss on performance. This was especially evident in measures of time-out and tracking errors.     

Free recall in boys of normal and poor reading levels as a function of task manipulations

Free recall of reading disabled boys, ages 9 to 11 years, was compared with that of boys showing no reading difficulty. During a baseline trial, poor readers recalled less items and tended to show less recall organization than normals. Recall and category clustering in a second trial were highest following a manipulation designed to produce semantic encoding of items and lowest when children were required to focus on items' physical features. In a condition requiring free sort prior to recall, reading disabled boys failed to organize or study as effectively as normals. Rather than lacking the ability to use semantic relations as a strategy for grouping items, the reading disabled had difficulty in spontaneously generating effective study techniques.     

Effects of task on the perceptual organization of sentences

Children and college students listened to sentences and responded to a question or a probe word after each sentence. To prevent Ss from using different perceptual strategies in performing the two tasks, question items and probe items were presented in mixed lists. In the probe task, the relationship between sentence structure and correct response latencies resembled the findings of an earlier study with block lists. The results from the question task were less similar to those obtained earlier, perhaps because, with mixed lists, Ss tended to organize all sentences in a manner especially suited to the probe task. A different type of organization might be used in the process of comprehending a sentence solely for the purpose of answering questions.     

A left-ear disadvantage for the presentation of irrelevant sound: manipulations of task requirements and changing state

Three experiments attempted to clarify the effect of altering the spatial presentation of irrelevant auditory information. Previous research using serial recall tasks demonstrated a left-ear disadvantage for the presentation of irrelevant sounds (). Experiments 1 and 2 examined the effects of manipulating the location of irrelevant sound on either a mental arithmetic task () or a missing-item task (; Experiment 4). Experiment 3 altered the amount of change in the irrelevant stream to assess how this affected the level of interference elicited. Two prerequisites appear necessary to produce the left-ear disadvantage; the presence of ordered structural changes in the irrelevant sound and the requirement for serial order processing of the attended information. The existence of a left-ear disadvantage highlights the role of the right hemisphere in the obligatory processing of auditory information.     

Effects of diazepam on a belief-updating task

This study examined the effects of a minor tranquilizer, diazepam, on a cognitive task that involved the updating of beliefs. On this task, subjects are first asked to express their strength of belief in a hypothesis and then to update this on the basis of new evidence. Past research has shown that revision of beliefs can be affected by many variables including the strength with which the initial belief is held, whether new information is perceived as positive or negative vis-à-vis the hypothesis, and the order in which evidence is processed. The purpose of this study was to assess whether a tranquilizer, diazepam, would affect the updating of beliefs, and specifically whether it would dampen the extent to which people revise their opinions. 12 healthy subjects participated in four experimental sessions, in which they received diazepam (0.14 mg/kg) or placebo and completed an updating task in which they received information in either of two orders, positive-negative or negative-positive. In each session, subjects saw a different experimental stimulus determined by a Latin-square design, and also completed pre- and postdrug mood questionnaires. Analysis showed order of presentation induced a recency effect similar to that obtained in previous studies, and the diazepam produced significant tranquilizer-like effects on self-report questionnaires. However, the diazepam had no effect on the updating task. These findings indicate that previously reported order effects in the belief updating task are robust and unaffected by a drug that has known sedative and memory-impairing properties.     

Effects of monetary incentives on task switching

In two experiments, effects of incentives on task switching were investigated. Incentives were provided as a monetary bonus. In both experiments, the availability of a bonus varied on a trial-to-trial basis. The main difference between the experiments relates to the association of incentives to individual tasks. In Experiment 1, the association of incentives to individual tasks was fixed. Under these conditions, the effect of incentives was largely due to reward expectancy. Switch costs were reduced to statistical insignificance. This was true even with the task that was not associated with a bonus. In Experiment 2, there was a variable association of incentives to individual tasks. Under these conditions, the reward expectancy effect was bound to conditions with a well-established bonus-task association. In conditions in which the bonus-task association was not established in advance, enhanced performance of the bonus task was accompanied by performance decrements with the task that was not associated with a bonus. Reward expectancy affected mainly the general level of performance. The outcome of this study may also inform recently suggested neurobiological accounts about the temporal dynamics of reward processing.     

Influence of prime-probe stimulus onset asynchrony and prime precuing manipulations on semantic priming effects with words in a lexical-decision task

The present research examines semantic priming from attended and unattended parafoveal words. Participants made a lexical decision in response to a single central target. The target was preceded by two parafoveal prime words, with one of them (the attended prime) being precued by a peripheral cue. The main variables manipulated across experiments were cue informativeness (valid vs. neutral cues) and stimulus onset asynchrony (SOA) between prime and probe (200, 300, 600, or 1,000 ms). The results showed (a) reliable semantic priming from both attended and ignored prime words and (b) that the ignored priming effects were either negative or positive, depending on both the prime-probe SOA and cue informativeness. The present findings are discussed in relation to inhibitory versus episodic retrieval models of negative priming.     

Effects of task factors on selection by color in the rapid serial visual presentation (RSVP) task

In five experiments, we examined task factors influencing selection by color in a rapid serial visual presentation (RSVP) task. Participants were required to respond to the presence or case of a target letter presented within an RSVP sequence, and they were cued as to the color in which that target was most likely to occur. The first two experiments explored the effect of task difficulty. It was found that a change from the discrimination of upper- versus lowercase targets to the detection of an exact shape had no influence on the color-cuing effect. In contrast, increasing letter set discriminability and decreasing color discriminability reduced the color-cuing effect considerably, although they did not eliminate it. In the third and fourth experiments, the frequency of valid trials was reduced, removing the incentive to use the color information. Again, a small benefit remained, indicating partially automatic and strategic color-processing components. Finally, the fifth experiment showed that an increase in perceptual load had no influence on the color-cuing effect. Together, these five experiments provide further evidence of the robustness of direct selection by color.     

Effects of delay of prospective memory cues in an ongoing task on prospective memory task performance

To address the mixed results reported in previous studies, the present experiments examined forgetting in prospective memory (PM) by manipulating the delay between the PM instructions and cue presentation in event-based PM tasks. PM performance was measured for delays of 2–20 min in Experiment 1 and for delays of approximately 1–10 min in Experiment 2. Experiment 2 included both focal and nonfocal PM tasks, and speed on the ongoing task was measured to examine evidence for monitoring processes across the delays tested. The results suggest that nonfocal PM performance follows a nonlinear forgetting function (i.e., rapid decline for shorter delays and slower decline for longer delays) when tested over delays from 1 to 20 min. No effect of delay was seen for the focal task tested in Experiment 2 from 1 to 10 min. In Experiment 2, ongoing-task costs were also found for the first delay but not for longer delays, suggesting that monitoring was significantly reduced between 1 and 2.5 min of the ongoing-task trials.     

Effects of grouping on the pupillary response in a short-term memory task

Subjects heard strings of nine digits for immediate recall, either at a monotone 1/sec. rate or in groups of three digits separated by pauses. Concurrent measurements of pupil size show a steady dilation in the monotone condition, and brief dilation-constriction waves during the pauses of grouped presentation. The results are consistent with hypotheses concerning rehearsal in the two modes of presentation. Pupillary dilations apparently accompany episodes of covert rehearsal.     

Effects of anxiety on inferential reasoning task performance

Three experiments were conducted in which high anxiety and low anxiety subjects were required to construct inferences. In Experiment 1 there was no anxiety-related performance deficit when inferring a necessary anaphoric relation, a process argued to be automatic. Experiments 2 and 3 involved the verification of unnecessary inferences, a process argued to involve the utilization of the working memory system. In both Experiments 2 and 3 there was an anxiety-related performance deficit. The results are consistent with a working memory-oriented account of anxiety-related performance effects, as deficits were restricted to capacity-demanding tasks.     

Effects of posttraining ethanol on an appetitive task

The present study examined the effects of posttraining ethanol administration upon retention of an appetitive task using a variety of retention behaviors associated with the task. Male C57BL/6J mice were individually trained to find a cheese pellet placed in the corner of an open field. Five behavioral measures were used including locomotor activity counts, rearings, grooming episodes, approaches to the cheese pellet, and latency to consume the cheese pellet. Immediately after training, mice were injected intraperitoneally with saline or 2.0 g/kg of ethanol and then returned to their home cage in which four "intruder" mice were added for 2 h after training. On subsequent testing days (1, 6, 14, and 51 days posttraining), mice were returned to the original training environment and the five behaviors were measured. Both saline- and ethanol-treated mice habituated to the initially novel test environment at similar rates as indicated by decreased exploratory behavior (locomotor activity and rearings). In contrast, a divergence in the latency to consume the cheese pellet was observed: Saline-treated mice behaved as though the cheese was rewarding (decreased latency to eat the pellet), while the ethanol group behaved as though the cheese was aversive (increased latency to eat the pellet). Taken with previous studies, these results demonstrate that posttraining ethanol can have strikingly different effects on retention depending on the task, the measure of retention used, and the underlying neural structures involved.