Harbour seals (<Emphasis Type="Italic">Phoca vitulina</Emphasis>) can steer by the stars

Offshore orientation in marine mammals is still a mystery. For visual orientation during night-time foraging and travelling in the open seas, seals cannot rely on distant terrestrial landmarks, and thus might use celestial cues as repeatedly shown for nocturnally migrating birds. Although seals detect enough stars to probably allow for astronavigation, it was unclear whether they can orient by the night sky. The widely accepted cognitive mechanism for bird night-time orientation by celestial cues is a time-independent star compass with learned geometrical star configurations used to pinpoint north as the rotational centre of the starry sky while there is no conclusive evidence for a time-compensated star compass or true star navigation. Here, we present results for two harbour seals orienting in a custom made swimming planetarium. Both seals learned to highly accurately identify a lodestar out of a pseudo-randomly oriented, realistic projection of the northern hemisphere night sky. Providing the first evidence for star orientation capability in a marine mammal, our seals’ outstanding directional precision would allow them to steer by following lodestars of learned star courses, a celestial orientation mechanism that has been known to be used by Polynesian navigators but has not been considered for animals yet.     

Rational Ignorance and Political Morality*

People frequently advance political proposals in the name of a goal while remaining apparently indifferent to the fact that those proposals, if implemented, would frustrate that goal. Theorists of “deliberative democracy” purport to avoid this difficulty by arguing that deliberation is primarily about moral not empirical issues. We reject this view (the moral turn) and propose a method (The Display Test) to check whether a political utterance is best explained by the rational ignorance hypothesis or by the moral turn: the speaker must be prepared to openly acknowledge the bad consequences of his political position. If he is, the position is genuinely moral; if he is not, the position evinces either rational ignorance or posturing. We introduce deontological notions to explain when the moral turn works and when it does not. We discuss and reject possible replies, in particular the view that a moral‐political stance insensitive to consequences relies on a distribution of moral responsibility in evildoing. Finally, we show that even the most plausible candidates for the category of purely moral political proposals are best explained by the rational ignorance/posturing hypothesis, if only because enforcing morality gives rise to complex causal issues.     

Definability and decidability of binary predicates for time granularity

In this paper we study the definability and decidability of binary predicates for time granularity in monadic languages interpreted over finitely and infinitely layered structures. We focus our attention on the equi-level (respectively equi-column) predicate constraining two time points to belong to the same layer (respectively column) and on the horizontal (respectively vertical) successor predicate relating a time point to its successor within a given layer (respectively column). We give a number of positive and negative results by reduction to/from a wide spectrum of decidable/undecidable problems.     

Dysphoria and Mobilization of Mental Effort: Effects on Cardiovascular Reactivity

Two studies examined the influence of dysphoria on motivational intensity in a student sample. Participants worked on a memory task (Study 1) or a mental concentration task (Study 2) without fixed performance standard (“do your best”). Based on their scores on the Center for Epidemiologic Studies – Depression Scale (L. S. Radloff, 1977), dysphoric and nondysphoric students were compared with regard to their effort-related cardiovascular reactivity during task performance. As predicted on the basis of the mood-behavior-model (G. H. E. Gendolla, 2000) and motivational intensity theory (J. W. Brehm & E. A. Self, 1989), dysphoric participants showed stronger cardiovascular reactivity while working on the cognitive tasks than nondysphoric participants. In Study 1, nondysphoric participants performed better on the memory task than dysphoric participants. Theoretical implications are discussed.

Psychometric intelligence dissociates implicit and explicit learning

The hypothesis that performance on implicit learning tasks is unrelated to psychometric intelligence was examined in a sample of 605 German pupils. Performance in artificial grammar learning, process control, and serial learning did not correlate with various measures of intelligence when participants were given standard implicit instructions. Under an explicit rule discovery instruction, however, a significant relationship between performance on the learning tasks and intelligence appeared. This finding provides support for Reber's hypothesis that implicit learning, in contrast to explicit learning, is independent of intelligence, and confirms thereby the distinction between the 2 modes of learning. However, because there were virtually no correlations among the 3 learning tasks, the assumption of a unitary ability of implicit learning was not supported.     

Action monitoring and perfectionism in anorexia nervosa

To study action monitoring in anorexia nervosa, behavioral and EEG measures were obtained in underweight anorexia nervosa patients (n=17) and matched healthy controls (n=19) while performing a speeded choice-reaction task. Our main measures of interest were questionnaire outcomes, reaction times, error rates, and the error-related negativity ERP component. Questionnaire and behavioral results indicated increased perfectionism in patients with anorexia nervosa. In line with their perfectionism and controlled response style patients made significantly less errors than controls. However, when controlling for this difference in error rates, the EEG results demonstrated a reduced error-related negativity in the patient group. These seemingly contradictory outcomes of improved performance and reduced error monitoring are discussed in relation with indications of anterior cingulate cortex hypoactivity in anorexia nervosa patients.     

Drive for thinness, affect regulation and physical activity in eating disorders: a daily life study

Using Ecological Momentary Assessment, the within patient associations between drive for thinness, emotional states, momentary urge to be physically active and physical activity were studied in 32 inpatients with an eating disorder. Participants received an electronic device and had to indicate at nine random times a day during 1 week their momentary drive for thinness, positive and negative emotional states and their urge to be physically active and physical activity. Multilevel analyses indicated that patients with higher mean levels for urge to be physically active were characterized by lower body mass index (BMI) and chronically negative affect whereas patients with higher mean levels for physical activity were characterized by lower BMI and higher dispositions for drive for thinness. In addition, within patient relations between drive for thinness and urge to be physically active were moderated by BMI and chronically negative affect whereas within patient relations between drive for thinness and physical activity were moderated by BMI. Finally, also positive emotional states were significantly associated with physical activity within patients. By using a daily process design, characteristics of physical activity were revealed that have not been identified with assessment methods that have a lower time resolution.     

Motivation gains of inferior group members: a meta-analytical review

In recent years, a growing number of studies have demonstrated that individuals can exert higher motivation when working in a group compared to working individually. This is particularly true for less capable, inferior group members. To aggregate these findings and to examine preconditions as well as moderating influences on motivation gains of inferior group members, the authors conducted a meta-analysis (17 studies, N=2,240). Results indicated that the overall motivation gain effect of inferior group members observed is moderate and significant (g=.60). Moderator analyses revealed substantial influences of task structure, performance information, physical presence, gender, and task type.