Single-Assumption Systems in Proof-Theoretic Semantics

Proof-theoretic semantics is an inferentialist theory of meaning, usually developed in a multiple-assumption and single-conclusion framework. In that framework, this theory seems unable to justify classical logic, so some authors have proposed a multiple-conclusion reformulation to accomplish this goal. In the first part of this paper, the debate originated by this proposal is briefly exposed and used to defend the diverging opinion that proof-theoretic semantics should always endorse a single-assumption and single-conclusion framework. In order to adopt this approach some of its criteria of validity, especially separability, need to be weakened. This choice is evaluated and defended. The main argument in this direction is based on the circular dependences of meaning between multiple assumptions and conjunctions, and between multiple conclusions and disjunctions. In the second part of this paper, some systems that suit the new requirements are proposed for both intuitionistic and classical logic. A proof that they are valid, according to the weakened criteria, is sketched.

     

Introduction to the Special Issue on the Utility of Transdiagnostic Approaches for Developing Novel Interventions for Substance and Behavioural Addictions

Neuropsychology Review -     

Conceptual Change,Crucial Experiments and Auxiliary Hypotheses. A Theoretical Contribution

Theories about conceptual change have been generally related to historical and philosophical analysis of science. Yet, there is still much debate on how ideas coming from the history of science and their implications can be applied in this field. Our study intends to investigate the complex structure of conceptual change, by making use of some particularly representative features of the History and Philosophy of science, while considering the structure of so-called crucial experiments and the specific role of implicit hypotheses. Due to their historical importance and logical reasoning aspects, examining these issues may contribute to understand how conceptual change may take place.     

Extinction partially reverts structural changes associated with remote fear memory

Structural synaptic changes occur in medial prefrontal cortex circuits during remote memory formation. Whether extinction reverts or further reshapes these circuits is, however, unknown. Here we show that the number and the size of spines were enhanced in anterior cingulate (aCC) and infralimbic (ILC) cortices 36 d following contextual fear conditioning. Upon extinction, aCC spine density returned to baseline, but the enhanced proportion of large spines did not. Differently, ILC spine density remained elevated, but the size of spines decreased dramatically. Thus, extinction partially erases the remote memory network, suggesting that the preserved network properties might sustain reactivation of extinguished conditioned fear.     

Visual selective attention and the effects of monetary rewards

Outcomes of actions, in the form of rewards and punishments, are known to shape behavior. For example, an action followed by reward will be more readily elicited on subsequent encounters with the same stimuli and context -- a phenomenon known as the law of effect. These consequences of rewards (and punishments) are important because they reinforce adaptive behaviors at the expense of competing ones, thus increasing fitness of the organism in its environment. However, it is unknown whether similar influences regulate covert mental processes, such as visual selective attention. Visual selective attention allows privileged processing of task-relevant information, while inhibiting distracting contextual elements. Using variable monetary rewards as arbitrary feedback on performance, we tested whether acts of attentional selection, and in particular the resulting aftereffects, can be modulated by their consequences. Results show that the efficacy of visual selective attention can be sensibly adjusted by external feedback. Specifically, although lingering inhibition of distractors is robust after highly rewarded selections, it is eliminated after poorly rewarded selections. This powerful feature of visual selective attention provides attentive processes with both flexibility and self-regulation properties.     

Psychological impact of coronavirus-related social isolation in Colombia after a year of lockdown

Several repercussions of the COVID-19 pandemic and its subsequent isolation period have been reported worldwide. In this paper, we analyze the behavioral and emotional effects of 1 year of coronavirus-related lockdown in Colombia. A cross-sectional correlational design was used on a sample of 1853 participants from different regions, and with different levels of education, income, and employment situations. We applied the fear of coronavirus scale, the use of preventive behaviors scale, and a scale to measure pleasant and unpleasant emotions based on the circumplex model of affect. Our data shows that women, participants who were unemployed during the lockdown, and participants that study or work in legal, computational, or related fields, have been more affected in terms of unpleasant emotions. In addition, we observed a trend towards a relation between higher income and educational levels with lower degrees of fear, higher degrees of pleasant emotions, and a greater use of preventive behaviors related to the pandemic.     

Serial attention mechanisms in visual search: A critical look at the evidence

Until a few years ago, visual search tasks were of exclusive pertinence to psychophysicists and cognitive psychologists trying to understand the operating principles and computational constraints of visual perception and visual selective attention. In recent years, cognitive neuroscience, with its powerful tools, has started to explore more directly the neuronal mechanisms underlying search performance in humans and macaques, aiming at the same general goals. New observations from a number of cognitive neuroscience approaches are promising a near future of great excitement in this field of research. This article offers a critical review of some of these recent contributions and highlights some of the interpretational problems that they pose. Received: 20 January 1998 / Accepted: 25 September 1998