Models for relevant modal logics

Semantics are given for modal extensions of relevant logics based on the kind of frames introduced in [7]. By means of a simple recipe we may obtain from a class FRM (L) of unreduced frames characterising a (non-modal) logic L, frame-classes FRM (L.M) characterising conjunctively regular modal extensions L.M of L. By displaying an incompleteness phenomenon, it is shown how the recipe fails when reduced frames are under consideration.     

Sex differences and bilateral electrodermal activity

The present study was aimed at replicating the results of a previous work on sex differences and electrodermal asymmetry from our laboratory (Román,et al. 1987). Skin conductance was bilaterally recorded in a sample of 44 dextral volunteers (22 males and 22 females) during a stimulus-free period, and the performance of two tasks (verbal and spatial). Subjects were grouped into two groups of right-hand and left-hand dominance in their electrodermal responses (EDRs) in accordance with their laterality coefficient scores at rest. During the tasks subjects appeareed clearly differentiated by their lateralization in the magnitude and frequency of EDRs independently of gender: right-hand responders showed higher electrodermal activity on their right hand, while left-hand responders showed higher electrodermal activity on their left hand. Sex differences were not observed within each responsiveness pattern. The orientation of phasic electrodermal changes remained constant throughout the different conditions.     

A replication of the use of public posting in traffic speed control

In an attempt to replicate several previous studies, a reversal design was used to assess the effects of publicly posted feedback on vehicle speed reduction. The intervention phases consisted of daily posted feedback that supplied drivers with either accurate or inaccurate information regarding the percentage of vehicles exceeding the speed limit on the road. Results from the two feedback conditions indicated no speed reduction in comparison to baseline levels. These results are discussed in light of previous studies that found strong effects for such feedback. Baseline levels of driver compliance and methodological differences may limit the effectiveness of posted feedback in reducing speeding.     

Movement errors and levels of processing in sentence production

From a corpus of 3,530 slips of the tongue in Spanish, a sample of 753 cases of movement errors was analyzed, comprising those tokens that could be unambiguously assigned to the major categories of anticipations, perseverations, exchanges, and shifts. The analysis was performed according to two main criteria: (a) the degree of correspondence between the linguistic elements interacting in an error, and (b) the distance between such elements in terms of the type and number of the intervening linguistic boundaries. The results of this analysis converge with those obtained in English, supporting a model of sentence planning with different levels of representation and processing. Furthermore, Spanish provides a clear case to attest the role of syllabic structure in production processes, the constraints set by word boundaries in sublexical errors, and the contribution of inflectional suffixes to the assignment of grammatical category to the root morphemes.     

On the relationship between Fortier's simultaneous linear prediction and van den Wollenberg's redundancy analysis

The purpose of this note is to show that Van den Wollenberg's method of redundancy analysis is a special case of a simultaneous linear prediction method offered by Fortier.     

The Small Worlds and Floyd's algorithms: a way to study scientific collaboration

Many proposals from the analysis of social networks focused on the study of scientific collaboration have been made recently. The Small Worlds theory seems to be the most efficient to study the inner features of the scientific community. Those researches have demonstrated that small communities are based on some key individuals who connect some groups which, on the contrary, would be disconnected. One of the disadvantages from the perspective of the analysis of networks is the lack of researches of particular nodes. With the implementation of a pseudocode algorithm of Floyd, we try to avoid this. To study how a small community is formed and, as a research of one case, we observe the invisible college which is formed when connecting the fifteen most productive authors of the Journal of Personality and Social Psychology .     

Transthyretin influences spatial reference memory

Transthyretin (TTR) is a plasma and cerebrospinal fluid carrier for thyroxine and retinol, described also to sequester the amyloid beta peptide. TTR levels have been described as decreased in the cerebrospinal fluid of patients with Alzheimer's disease. In order to investigate the role of TTR in learning and memory, we studied young adult and old TTR-null 129/Sv mice for cognitive performance. In the absence of TTR, 5-month-old mice display spatial reference memory impairment when compared to age-matched wild-type mice. Interestingly, while aging in wild-type mice is associated with a worsening reference memory performance, TTR-null mice show no further impairment with increasing age. As a result, no significant differences were found in this spatial reference task in old mice. Our data show that the absence of TTR seems to accelerate the poorer cognitive performance normally associated with aging.     

First came the trees, then the forest: developmental changes during childhood in the processing of visual local-global patterns according to the meaningfulness of the stimuli

This study investigated how global and local perceptual processes evolve during childhood according to the meaningfulness of the stimuli. Children had to decide whether visually presented pairs of items were identical or not. Items consisted of global forms made up of local forms. Both global and local forms could represent either objects or nonobjects. In dissimilar pairs, items differed at one level (target level), while the other level included similar forms on both sides (irrelevant level). The results indicate an evolution from local preference at 4 years of age to adult-like global preference at 9 years of age. Moreover, as previously reported in adults, regardless of age, identification impaired performance when the irrelevant level was made of objects and the target level was made of nonobjects (interference). However, in younger children, this interference existed even when objects were present at all levels, suggesting that the strategy used to perform the comparison task also varied according to age.