Algebraic aspects of deduction theorems

The first known statements of the deduction theorems for the first-order predicate calculus and the classical sentential logic are due to Herbrand [8] and Tarski [14], respectively. The present paper contains an analysis of closure spaces associated with those sentential logics which admit various deduction theorems. For purely algebraic reasons it is convenient to view deduction theorems in a more general form: given a sentential logic C (identified with a structural consequence operation) in a sentential language I, a quite arbitrary set P of formulas of I built up with at most two distinct sentential variables p and q is called a uniform deduction theorem scheme for C if it satisfies the following condition: for every set X of formulas of I and for any formulas and , C(X{{a}}) iff P(, ) AC(X). [P(, ) denotes the set of formulas which result by the simultaneous substitution of for p and for q in all formulas in P]. The above definition encompasses many particular formulations of theorems considered in the literature to be deduction theorems. Theorem 1.3 gives necessary and sufficient conditions for a logic to have a uniform deduction theorem scheme. Then, given a sentential logic C with a uniform deduction theorem scheme, the lattices of deductive filters on the algebras A similar to the language of C are investigated. It is shown that the join-semilattice of finitely generated (= compact) deductive filters on each algebra A is dually Brouwerian.A part of this paper was presented in abstracted form in Bulletin of the Section of Logic, Vol. 12, No. 3 (1983), pp. 111–116, and in The Journal of Symbolic Logic.     

Unrealistic Optimism and Positive-Negative Asymmetry: A Conceptual and Cross-cultural Study of Interrelationships between Optimism,Pessimism, and Realism

Using a variant of Weinstein's (1980) technique for the measurement of unrealistic optimism, subjects were classified as optimistic, realistic, or pessimistic about their chances of being confronted in the future with problems such as divorce, nervous breakdown, etc. On the basis of previous theory and research on cognition and affect, it was hypothesized that, across problems, subjects would alternate optimism with realism rather than with pessimism. Cross-cultural data obtained from 19 samples of Belgian, Moroccan, and Polish subjects not only confirmed the hypothesis but also showed high agreement about the nature of the problems that were selectively associated with optimism, realism and pessimism.     

Some theorems on structural entailment relations

The classesMatr( \( \subseteq \) ) of all matrices (models) for structural finitistic entailments \( \subseteq \) are investigated. The purpose of the paper is to prove three theorems: Theorem I.7, being the counterpart of the main theorem from Czelakowski [3], and Theorems II.2 and III.2 being the entailment counterparts of Bloom's results [1]. Theorem I.7 states that if a classK of matrices is adequate for \( \subseteq \) , thenMatr( \( \subseteq \) ) is the least class of matrices containingK and closed under the formation of ultraproducts, submatrices, strict homomorphisms and strict homomorphic pre-images. Theorem II.2 in Section II gives sufficient and necessary conditions for a structural entailment to be finitistic. Section III contains theorems which characterize finitely based entailments.     

Splitting the affective atom: Divergence of valence and approach-avoidance motivation during a dynamic emotional experience

Current Psychology - Valence and approach-avoidance motivation are two distinct but closely related components of affect. However, little is known about how these two processes evolve and covary in...     

Complex effects of NMDA receptor antagonist APV in the basolateral amygdala on acquisition of two-way avoidance reaction and long-term fear memory

Although much has been learned about the role of the amygdala in Pavlovian fear conditioning, relatively little is known about an involvement of this structure in more complex aversive learning, such as acquisition of an active avoidance reaction. In the present study, rats with a pretraining injection of the N-methyl-D-aspartate (NMDA) receptor antagonist, 2-amino-5-phosphonopentanoic acid (APV), into the basolateral amygdala (BLA) were found to be impaired in two-way active avoidance learning. During multitrial training in a shuttle box, the APV-injected rats were not different from the controls in sensitivity to shock or in acquisition of freezing to contextual cues. However, APV injection led to impaired retention of contextual fear when tested 48 h later, along with an attenuation of c-Fos expression in the amygdala. These results are consistent with the role of NMDA receptors of the BLA in long-term memory of fear, previously documented in Pavlovian conditioning paradigms. The APV-induced impairment in the active avoidance learning coincided with deficits in directionality of the escape reaction and in attention to conditioned stimuli. These data indicate that normal functioning of NMDA receptors in the basolateral amygdala is required during acquisition of adaptive instrumental responses in a shuttle box but is not necessary for acquisition of short-term contextual fear in this situation.     

Extension of Luria's Psycholinguistic Studies in Poland

One of Luria's basic interests was the organization of human cognitive processes, and thinking in particular. He believed that language and thought are closely related, and hence the manner in which we speak reflects the way we think. To verify this assumption, he and his collaborators performed a number of interesting psycholinguistic experiments with subjects of various ages and cultural backgrounds. The tasks used made the evaluation of both receptive and expressive language possible. The Narrative Ability Test described here stems from Luria's observations to a considerable degree. The test was administered to preschool children (N = 106), schoolchildren (N = 143), adolescents (N = 89), adults (N = 126), and older persons (N = 175). Findings of the 20-year studies with normal and deviant populations indicate close relationships among thought, language, and self-control. It was found that difficulty in developing narratives corresponds with a disability to process complex information. Correlations between narrative skills and age, sex, and social background were also noted.     

Smile intensity in social networking profile photographs is related to greater scientific achievements

Theory and research indicates that individuals with more frequent positive emotions are better at attaining goals at work and in everyday life. In the current study we examined whether the expression of genuine positive emotions by scientists was positively correlated with work-related accomplishments, defined by bibliometric (e.g. number of citations) and sociometric (number of followers for scholarly updates) indices. Using a sample of 440 scientists from a social networking site for researchers, multiple raters coded smile intensity (full smile, partial smile, or no smile) in publicly available photographs. We found that scientists who presented a full smile had the same quantity of publications yet of higher quality (e.g. citations per paper) and attracted more followers to their updates compared to less positive emotionally expressive peers; results remained after controlling for age and sex. Thin-slicing approaches to the beneficial effects of positive emotionality offer an ecologically valid approach to complement experimental and longitudinal evidence. Evidence linking positive emotional expressions to scientific impact and social influence provides further support for broaden and build models of positive emotions.