Pop-out and pop-in: Visual working memory advantages for unique items

Attentional control is thought to play a critical role in determining the amount of information that can be stored and retrieved from visual working memory (VWM). We tested whether and how task-irrelevant feature-based salience, known to affect the control of visual attention, affects VWM performance. Our results show that features of a task-irrelevant color singleton are more likely to be recalled from VWM than non-singleton items and that this increased memorability comes at a cost to the other items in the display. Furthermore, the singleton effect in VWM was negatively correlated with an individual’s baseline VWM capacity. Taken together, these results suggest that individual differences in VWM storage capacity may be partially attributable to the ability to ignore differences in task-irrelevant physical salience.     

Changes in the Social Responsibility Attitudes of Engineering Students Over Time

This research explored how engineering student views of their responsibility toward helping individuals and society through their profession, so-called social responsibility, change over time. A survey instrument was administered to students initially primarily in their first year, senior year, or graduate studies majoring in mechanical, civil, or environmental engineering at five institutions in September 2012, April 2013, and March 2014. The majority of the students (57 %) did not change significantly in their social responsibility attitudes, but 23 % decreased and 20 % increased. The students who increased, decreased, or remained the same in their social responsibility attitudes over time did not differ significantly in terms of gender, academic rank, or major. Some differences were found between institutions. Students who decreased in social responsibility initially possessed more positive social responsibility attitudes, were less likely to indicate that college courses impacted their views of social responsibility, and were more likely to have decreased in the frequency that they participated in volunteer activities, compared to students who did not change or increased their social responsibility. Although the large percentage of engineering students who decreased their social responsibility during college was disappointing, it is encouraging that courses and participation in volunteer activities may combat this trend.     

Engineering Codes of Ethics and the Duty to Set a Moral Precedent

Each of the major engineering societies has its own code of ethics. Seven “common core” clauses and several code-specific clauses can be identified. The paper articulates objections to and rationales for two clauses that raise controversy: do engineers have a duty (a) to provide pro bono services and/or speak out on major issues, and (b) to associate only with reputable individuals and organizations? This latter “association clause” can be justified by the “proclamative principle,” an alternative to Kant’s universalizability requirement. At the heart of engineering codes of ethics, and implicit in what it is to be a moral agent, the “proclamative principle” asserts that one’s life should proclaim one’s moral stances (one’s values, principles, perceptions, etc.). More specifically, it directs engineers to strive to insure that their actions, thoughts, and relationships be fit to offer to their communities as part of the body of moral precedents for how to be an engineer. Understanding codes of ethics as reflections of this principle casts light both on how to apply the codes and on the distinction between private and professional morality.     

Zur Therapie von ADHS bei komorbiden Autismus-Spektrum-Störungen

Until recently, research on the co-occurrence of ADHD with autism spectrum disorder (ASD) has been limited by the fact that current classification systems did not allow a dual diagnosis of these two neurodevelopmental disorders. Since the DSM-5 permits a double diagnosis of ADHD plus ASD, research on their comorbidity has substantially increased. In addition to shared and distinct etiological factors, studies have revealed a high clinical impact of the combined symptomatology on affected individuals. This article provides a selective overview of evidence-based, mainly pharmacological treatment strategies in ADHD/ASD phenotypes.     

Probabilistic numerical discrimination in mice

Previous studies showed that both human and non-human animals can discriminate between different quantities (i.e., time intervals, numerosities) with a limited level of precision due to their endogenous/representational uncertainty. In addition, other studies have shown that subjects can modulate their temporal categorization responses adaptively by incorporating information gathered regarding probabilistic contingencies into their time-based decisions. Despite the psychophysical similarities between the interval timing and nonverbal counting functions, the sensitivity of count-based decisions to probabilistic information remains an unanswered question. In the current study, we investigated whether exogenous probabilistic information can be integrated into numerosity-based judgments by mice. In the task employed in this study, reward was presented either after few (i.e., 10) or many (i.e., 20) lever presses, the last of which had to be emitted on the lever associated with the corresponding trial type. In order to investigate the effect of probabilistic information on performance in this task, we manipulated the relative frequency of different trial types across different experimental conditions. We evaluated the behavioral performance of the animals under models that differed in terms of their assumptions regarding the cost of responding (e.g., logarithmically increasing vs. no response cost). Our results showed for the first time that mice could adaptively modulate their count-based decisions based on the experienced probabilistic contingencies in directions predicted by optimality.     

Multiple cue use and integration in pigeons (<Emphasis Type="Italic">Columba livia</Emphasis>)

Encoding multiple cues can improve the accuracy and reliability of navigation and goal localization. Problems may arise, however, if one cue is displaced and provides information which conflicts with other cues. Here we investigated how pigeons cope with cue conflict by training them to locate a goal relative to two landmarks and then varying the amount of conflict between the landmarks. When the amount of conflict was small, pigeons tended to integrate both cues in their search patterns. When the amount of conflict was large, however, pigeons used information from both cues independently. This context-dependent strategy for resolving spatial cue conflict agrees with Bayes optimal calculations for using information from multiple sources.     

Memory systems in the rat: effects of reward probability,context, and congruency between working and reference memory

The interaction of working and reference memory was studied in rats on an eight-arm radial maze. In two experiments, rats were trained to perform working memory and reference memory tasks. On working memory trials, they were allowed to enter four randomly chosen arms for reward in a study phase and then had to choose the unentered arms for reward in a test phase. On reference memory trials, they had to learn to visit the same four arms on the maze on every trial for reward. Retention was tested on working memory trials in which the interval between the study and test phase was 15 s, 15 min, or 30 min. At each retention interval, tests were performed in which the correct WM arms were either congruent or incongruent with the correct RM arms. Both experiments showed that congruency interacted with retention interval, yielding more forgetting at 30 min on incongruent trials than on congruent trials. The effect of reference memory strength on the congruency effect was examined in Experiment 1, and the effect of associating different contexts with working and reference memory on the congruency effect was studied in Experiment 2.     

Reversal learning in gonadectomized marmosets with and without hormone replacement: are males more sensitive to punishment?

This study examined sex differences in executive function in middle-aged gonadectomized marmosets (Callithrix jacchus) with or without hormonal replacement. We tested ten castrated male (mean age 5.5 years) marmosets treated with testosterone cypionate (T, n = 5) or vehicle (n = 5) on Reversal Learning, which contributes to cognitive flexibility, and the Delayed Response task, measuring working memory. Their performance was compared to that of 11 ovariectomized females (mean age = 3.7 years) treated with Silastic capsules filled with 17-β estradiol (E2, n = 6) or empty capsules (n = 5), previously tested on the same tasks (Lacreuse et al. in J Neuroendocrinol 26:296–309, 2014. doi: 10.1111/jne.12147). Behavioral observations were conducted daily. Females exhibited more locomotor behaviors than males. Males and females did not differ in the number of trials taken to reach criterion on the reversals, but males had significantly longer response latencies, regardless of hormone replacement. They also had a greater number of refusals than females. Additionally, both control and T-treated males, but not females, had slower responses on incorrect trials, suggesting that males were making errors due to distraction, lack of motivation or uncertainty. Furthermore, although both males and females had slower responding following an incorrect compared to a correct trial, the sex difference in response latencies was disproportionally large following an incorrect trial. No sex difference was found in the Delayed Response task. Overall, slower response latencies in males than females during Reversal Learning, especially during and following an incorrect trial, may reflect greater sensitivity to punishment (omission of reward) and greater performance monitoring in males, compared to females. Because these differences occurred in gonadectomized animals and regardless of hormone replacement, they may be organized early in life.     

Evaluation of third-party reciprocity by squirrel monkeys (<Emphasis Type="Italic">Saimiri sciureus</Emphasis>) and the question of mechanisms

Social evaluation during third-party interactions emerges early in human ontogeny, and it has been shown in adult capuchin monkeys who witness violations of reciprocity in object exchanges: Monkeys were less inclined to accept food from humans who refused to reciprocate with another human. A recent study reporting similar evidence in marmoset monkeys raised the possibility that such evaluations might be based on species’ inherent cooperativeness. We tested a species not renowned for cooperativeness—squirrel monkeys—using the procedure used with marmosets and found a similar result. This finding rules out any crucial role for cooperative tendencies in monkeys’ responses to unfair exchanges. We then tested squirrel monkeys using procedures more similar to those used in the original study with capuchins. Squirrel monkeys again accepted food less frequently from non-reciprocators, but unlike capuchins, they also strongly preferred reciprocators. We conclude that neither squirrel monkeys nor marmoset monkeys engaged in emotional bookkeeping of the type that probably underlies social evaluation in capuchin monkeys; instead, they employed one or more simple behavioral rules. Further comparative studies are required to clarify the mechanisms underlying social evaluation processes across species.