Different levels of complexity in the play-fighting by muroid rodents appear to result from different levels of intensity of attack and defense

Play-fighting in deer mice, Peromyscus maniculatus bairdii, prairie voles, Microtus ochrogaster, and montane voles, M. Montanus, was compared to that of laboratory rats, Rattus norvegicus. Play in rats appears more complex for two reasons: 1) more of the playful contacts elicit defensive behaviors, and 2) more of these defenses lead to counterattacks, and hence, role reversals between attackers and defenders. Neither high levels of defense, as shown by montane voles, nor high levels of counterattack, as shown by prairie voles, produce rat-like play-fighting. This only occurs when high rates of defense involving turning to face the attacker and counterattack are combined, as in rats. These two components are rarely combined together by deer mice, and so this species rarely exhibits rat-like play-fighting. Furthermore, playful counterattack appears to arise from playful attack, and not from an escalation of defense. These data suggest that the more complex forms of social play, such as play-fighting, have evolved, in part, via the escalation of defense in response to playful attack.     

A tool to act blind? Object-assisted eye-covering as a self-handicapping behavior and social play signal in Balinese long-tailed macaques

Animal Cognition - Self-handicapping behaviors evolved as honest signals that reliably reflect the quality of their performers. In playful activities, self-handicapping is described as...     

Probabilistic inferences,discrimination, and stimulus interference in comparative judgement

Comparative judgements of successive stimuli involve constant errors. Here, two theories of these errors are considered. For the wave theory of discrimination, constant errors directly originate from discrimination operations. For the inferential theory, the same errors are due to probabilistic inferences drawn after discrimination. Previous studies suggest that the second of two successively compared stimuli has more influence on the comparative response. The results of the present experiment, in which successive lines as comparison stimuli were used, confirm this suggestion. The wave theory does not explain these results, while the inferential theory explains them in terms of probabilistic inferences. Analysis of response frequencies and response times indicates that there was a response bias in favour of the longer response. Interfering lines appearing before the first comparison line significantly affected response frequency, response time, and discriminability, whereas interpolated lines significantly affected only response frequency and response time. The inferential theory does not explain these effects on response time, while the wave theory explains them as due to modifications of response bias. These results suggest the possibility that the two theories describe independent sources of constant errors.     

A note on the ω-incompleteness formalization

The paper studies two formal schemes related to -completeness.LetS be a suitable formal theory containing primitive recursive arithmetic and letT be a formal extension ofS. Denoted by (a), (b) and (c), respectively, are the following three propositions (where (x) is a formula with the only free variable x): (a) (for anyn) ( _T (n)), (b) _{T x} Pr _T (^–(x)^–) and (c) _T x(x) (the notational conventions are those of Smoryski [3]). The aim of this paper is to examine the meaning of the schemes which result from the formalizations, over the base theoryS, of the implications (b) (c) and (a) (b), where ranges over all formulae. The analysis yields two results overS : 1. the schema corresponding to (b) (c) is equivalent to ¬Cons _T and 2. the schema corresponding to (a) (b) is not consistent with 1-CON _T. The former result follows from a simple adaptation of the -incompleteness proof; the second is new and is based on a particular application of the diagonalization lemma.Presented byMelvin Fitting     

Group aggregates and individual reliability: The case of verbal short-term memory

Two experiments examined the generalizability of the effects of word length and phonological similarity with visual and auditory presentation in immediate verbal serial ordered recall. In Experiment 1, data were collected from 251 adult volunteers drawn from a broad cross-section of the normal population. Word length and phonological similarity in both presentation modes significantly influenced the group means. However, 43% of the subjects failed to show at least one of the effects, and the likelihood that effects appeared was highly correlated with verbal memory span. In Experiment 2, 40 subjects of the original sample were retested, 20 of whom had failed to show one or more effects in Experiment 1. Whether or not an effect had appeared for individual subjects on the first test session was a poor predictor of whether the effect would appear on retest. Finally, an analysis of subject reports demonstrated that the patterns of experimental data could be accounted for in part by the strategies that subjects reported using, and the effect of strategy was independent of the effect of span. The implications of these findings for theories of verbal short-term memory are discussed.     

Attentional scanning and space errors

Using the method of paired comparisons, pairs of simultaneous horizontal or vertical lines, with one line above and one below or one on the left and one on the right of a fixation point, respectively, were presented tachistoscopically for length comparison. Space errors were found to have a pattern similar to that of time errors. The tendency to guess the comparative response from the absolute magnitude of stimuli is proposed as a basis for time and space errors. Manipulation of attentional scanning, which implies a more frequent usage of this guessing strategy for one of the two lines in a pair, was shown to affect space errors.     

Language Processing Differences Between Blind and Sighted Individuals and the Abstract Versus Concrete Concept Difference

In the property listing task (PLT), participants are asked to list properties for a concept (e.g., for the concept dog, “barks,” and “is a pet” may be produced). In conceptual property norming (CPNs) studies, participants are asked to list properties for large sets of concepts. Here, we use a mathematical model of the property listing process to explore two longstanding issues: characterizing the difference between concrete and abstract concepts, and characterizing semantic knowledge in the blind versus sighted population. When we apply our mathematical model to a large CPN reporting properties listed by sighted and blind participants, the model uncovers significant differences between concrete and abstract concepts. Though we also find that blind individuals show many of the same processing differences between abstract and concrete concepts found in sighted individuals, our model shows that those differences are noticeably less pronounced than in sighted individuals. We discuss our results vis-a-vis theories attempting to characterize abstract concepts.     

Coping strategies in obsessive-compulsive patients during Covid-19 lockdown

Background/ObjectiveThe main aim of this study was to compare coping strategies in obsessive-compulsive disorder (OCD) patients and a healthy control group during COVID-19 lockdown and to analyze the relationship with some variables which may influence results (depression, anxiety, comorbidity, subtype of obsession-compulsion). Method: There were 237 participants, 122 OCD and 115 healthy controls, aged 17-61 years old (M = 33.48, SD = 11.13). Results: Groups showed differences in the use of some adaptive strategies (positive reinterpretation, acceptance, humor) and maladaptive (denial, self-blame). Within obsessive-compulsive group, comorbidity affected the greater use of inappropriate strategies (denial, substance abuse and self-blame) while type of obsession-compulsion did not influence use. Anxiety and depression levels were related to the use of less adaptive strategies. Conclusions: These findings strengthen the need for training in the use of effective and adaptive coping strategies, making it necessary to improve clinical follow-up of these patients. It is relevant to be in contact with healthcare professionals, review medication and observe the anxiety and depression levels.