Individual differences in the capacity limitations of visuospatial short-term memory: Research on sighted and totally congenitally blind people

The study of visuospatial imagery processes in totally congenitally blind people makes it possible to understand the specific contribution of visual experience for imagery processes. We argue that blind people may have visuospatial imagery processes, but they suffer from some capacity limitations. Similar, although smaller, limitations and individual differences may be found in sighted people. Visuospatial imagery capacity was explored by asking people to follow an imaginary pathway through either two- or three-dimensional matrices of different complexity. The blind appear to use specific visuospatial processes in this task (Experiments 2 and 3), but they have difficulty with three-dimensional matrices; sighted people have no such difficulty with three-dimensional matrices (Experiment 1). On the other hand, when a three-dimensional pattern exceeded sighted capacity, the blind and sighted showed similar patterns of errors. Subsequent analyses suggested that both visuospatial processes and verbal mediation were used.     

The attentional blink effect: influence of negative words in an affective valence categorization task

In this study, we explored the emotional modulation of the Attentional Blink effect. In a Rapid Serial Visual Presentation procedure, a word (Target 1), either positive, negative or neutral, was followed by the word "WATER" (Target 2) in one half of the trials. The task included two conditions. In one of them, participants only had to detect the word "WATER". In double-response trials, participants also categorized Target 1's valence. Results showed that the detection of Target 2 was impaired in the double-response condition, this impairment being greater when negative word appeared as Target 1, as compared to positive and neutral words. However, these effects were independent on the Anxiety-Trait levels of participants. Overall, the pattern of data suggests that cognitive resources are focused on negative stimuli when their negative valence is emotionally salient enough.     

Numerosity judgments for tactile stimuli distributed over the body surface

A large body of research now supports the claim that two different and dissociable processes are involved in making numerosity judgments regarding visual stimuli: subitising (fast and nearly errorless) for up to 4 stimuli, and counting (slow and error-prone) when more than 4 stimuli are presented. We studied tactile numerosity judgments for combinations of 1-7 vibrotactile stimuli presented simultaneously over the body surface. In experiment 1, the stimuli were presented once, while in experiment 2 conditions of single presentation and repeated presentation of the stimulus were compared. Neither experiment provided any evidence for a discontinuity in the slope of either the RT or error data suggesting that subitisation does not occur for tactile stimuli. By systematically varying the intensity of the vibrotactile stimuli in experiment 3, we were able to demonstrate that participants were not simply using the 'global intensity' of the whole tactile display to make their tactile numerosity judgments, but were, instead, using information concerning the number of tactors activated. The results of the three experiments reported here are discussed in relation to current theories of counting and subitising, and potential implications for the design of tactile user interfaces are highlighted.     

Multisensory synesthetic interactions in the speeded classification of visual size

In the present study, we attempted to demonstrate a synesthetic relationship between auditory frequency and visual size. In Experiment 1, participants performed a speeded visual size discrimination task in which they had to judge whether a variable-sized disk was bigger or smaller than a standard reference disk. A task-irrelevant sound that was either synesthetically congruent with the relative size of the disk (e.g., a low-frequency sound presented with a bigger disk) or synesthetically incongruent with it (e.g., a low-frequency sound presented with a smaller disk) was sometimes presented together with the variable disk. Reaction times were shorter in the synesthetically congruent condition than in the incongruent condition. Verbal labeling and semantic mediation interpretations of this interaction were explored in Experiment 2, in which high- and low-frequency sounds were presented in separate blocks of trials, and in Experiment 3, in which the tones were replaced by the spoken words "high" and "low." Response priming/bias explanations were ruled out in Experiment 4, in which a synesthetic congruency effect was still reported even when participants made same-versus-different discrimination responses regarding the relative sizes of the two disks. Taken together, these results provide the first empirical demonstration that the relative frequency of an irrelevant sound can influence the speed with which participants judge the size of visual stimuli when the sound varies on a trial-by-trial basis along a synesthetically compatible dimension. The possible cognitive bases for this synesthetic association are also discussed.     

Modal Deduction in Second-Order Logic and Set Theory - II

In this paper, we generalize the set-theoretic translation method for poly-modal logic introduced in [11] to extended modal logics. Instead of devising an ad-hoc translation for each logic, we develop a general framework within which a number of extended modal logics can be dealt with. We first extend the basic set-theoretic translation method to weak monadic second-order logic through a suitable change in the underlying set theory that connects up in interesting ways with constructibility; then, we show how to tailor such a translation to work with specific cases of extended modal logics.     

Action of structures,structure of actions

This paper was throught of as a form of silent dialogue with my friend Michael Wright. As such, it has the merits, if any, and the defects of a flowing course of thoughts that entersin medias res with less feignings than in standard philosophical literature.     

Axiomatization of ‘Peircean’ branching-time logic

The branching-time logic called Peircean by Arthur Prior is considered and given an infinite axiomatization. The axiomatization uses only the standard deduction rules for tense logic.     

Maternal attachment representations and the development of very low birth weight premature infants at two years of age

There is a consensus that prematurity could increase the risk of attachment impairment. We studied 90 premature children with very low birth weights (<1,500 g) and 96 healthy children born at term with similar age and sociodemographic characteristics. Our objective was to assess maternal stress and attachment representations, and compare development indices on both groups at 2 years of age. Premature infants had a medium‐to‐severe degree of immaturity and biological risk (M gestational age = 29.98 weeks; birth weight = 1,159.76 g), with 57% staying in the ICU ≥1 week. These children born prematurely had lower scores on the development indices within the normal range. Mothers of premature infants (n = 74) reported higher levels of stress during their first year of life (59%) than did controls (41%), but no significant differences were detected in maternal attachment discourse between the two groups. The findings confirm that premature birth has a great influence on maternal emotional responses and the health and development of children in the first years of life, and indicate that stress responses in parents and warning signs for attachment problems should be assessed as early as possible.