Semantics for Analytic Containment

In 1977, R. B. Angell presented a logic for analytic containment, a notion of relevant implication stronger than Anderson and Belnap's entailment. In this paper I provide for the first time the logic of first degree analytic containment, as presented in [2] and [3], with a semantical characterization—leaving higher degree systems for future investigations. The semantical framework I introduce for this purpose involves a special sort of truth-predicates, which apply to pairs of collections of formulas instead of individual formulas, and which behave in some respects like Gentzen's sequents. This semantics captures very general properties of the truth-functional connectives, and for that reason it may be used to model a vast range of logics. I briefly illustrate the point with classical consequence and Anderson and Belnap's tautological entailments.     

Exploring the suffix effect in serial visuospatial short-term memory

The suffix effect—the loss of recency induced by a redundant end-of-list item—was studied in a visuospatial serial recall task involving the memory for the position of dots on a screen. A visuospatial suffix markedly impaired recall of the last to-be-remembered dot. The impact on recall was roughly of equal magnitude whether the suffix shared attributes with the to-be-remembered dots (Experiment 1) or was visually distinct (Experiments 2 and 3). Although the presence of a tone suffix also impaired serial memory for the last items in the sequence, the impact of a visuospatial suffix was more marked, implying a specific as well as a possible general effect of suffix in the visuospatial domain (Experiment 4). The suffix effect seems not to be a phenomenon confined to verbal material but rather a universal phenomenon possibly related to grouping.     

Local temporal distinctiveness does not benefit auditory verbal and spatial serial recall

In the present study, we examined the role of randomly arranged temporal intervals preceding and following items (pre- and postitem intervals, respectively) in auditory verbal and spatial recall tasks. The duration of the pre- and postitem intervals did not affect serial recall performance. This finding calls into question (1) the suggestion that the interval following an item permits the consolidation of information in memory, even in a relatively demanding spatial task, and (2) the prediction that temporal distinctiveness should improve performance. The latter was explored further by showing that in contrast to our empirical data, a relative temporal distinctiveness model produced significant increases in recall performance when pre- and postitem intervals increased. The results are discussed with regard to recent studies revisiting the role of temporal isolation in short-term serial memory.     

Friend versus foe: Neural correlates of prosocial decisions for liked and disliked peers

Although the majority of our social interactions are with people we know, few studies have investigated the neural correlates of sharing valuable resources with familiar others. Using an ecologically valid research paradigm, this functional magnetic resonance imaging study examined the neural correlates of prosocial and selfish behavior in interactions with real-life friends and disliked peers in young adults. Participants (N = 27) distributed coins between themselves and another person, where they could make selfish choices that maximized their own gains or prosocial choices that maximized outcomes of the other. Participants were more prosocial toward friends and more selfish toward disliked peers. Individual prosociality levels toward friends were associated negatively with supplementary motor area and anterior insula activity. Further preliminary analyses showed that prosocial decisions involving friends were associated with heightened activity in the bilateral posterior temporoparietal junction, and selfish decisions involving disliked peers were associated with heightened superior temporal sulcus activity, which are brain regions consistently shown to be involved in mentalizing and perspective taking in prior studies. Further, activation of the putamen was observed during prosocial choices involving friends and selfish choices involving disliked peers. These findings provide insights into the modulation of neural processes that underlie prosocial behavior as a function of a positive or negative relationship with the interaction partner.     

Vertical perceptual span and the processing of visual signals in reading

A previous study by Pollatsek et al. ( 1993 ) claims that the perceptual span in reading is restricted to the fixated line, i.e. readers typically focus their visual attention on the line of text being read. The present study investigated whether readers make use of content structure signals (paragraph indentations and topic headings) present several lines away from the currently fixated line. We reasoned that as these signals are low-resolution visual objects (as opposed to letter and word identity), readers may attend to them even if they are located some distance away from the fixated line. Participants read a hierarchically organized multi-topic expository text containing structure signals in either a normal condition or a window condition, where the text disappeared above and below a vertical 3° gaze-contingent region. After reading, participants were asked to produce a written recall of the text. The results showed that the overall reading rate was not affected by the window. Nevertheless, the headings were reread more in the normal condition than in the window one. In addition, more topics were recalled in the normal than in the window condition. We interpret the results as indicating that the readers visually attend to useful text layout features while considering bigger units than single text lines. The perception of topic headings located away from the fixated line may favour long-range regressions towards them, which in turn may favour text comprehension. This claim is consistent with previous studies that showed that look-back fixations to headings are performed with an integrative intent.     

Competitive conflict regulation and informational dependence in peer learning

The present set of studies investigates the role of competitive conflict regulation and informational dependence in peer learning. Previous studies have shown that peer work on identical information produces not only confrontation of viewpoints but also competitive conflict regulation, the latter of which is detrimental for learning. Conversely, working on complementary information produces positive interactions but also informational dependence, and good quality information transmission is needed to foster learning. The present research shows that discussion aids (note‐taking and access to the study materials during discussion), a variable related to the quality of informational input, moderated the relationship between information interdependence and learning. This moderation was mediated by competitive conflict regulation: Students who worked on identical information with discussion aids reported more competitive conflict regulation than those without discussion aids, which in turn reduced learning, a pattern that did not appear for students working on complementary information. Moreover, when students worked on complementary information, the good quality of information transmission elicited by discussion aids led to high levels of learning for all students. Contributions to research on resource interdependence, socio‐cognitive conflict, and peer learning are discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Horses discriminate between human facial and vocal expressions of sadness and joy

Animal Cognition - Communication of emotions plays a key role in intraspecific social interactions and likely in interspecific interactions. Several studies have shown that animals perceive human...