Central executive system impairment in traumatic brain injury

The aim of the present study was to identify cognitive functions affected by traumatic brain injury (TBI) and to verify the mechanism underlying cognitive impairment. More precisely, cognitive deficits following TBI can be considered as a consequence of (a) a speed processing deficit, that is a general slowing of perceptual, motor and cognitive subroutines; (b) an impairment of the Central Executive System of working memory (CES).Thirty-seven patients were submitted to a neuropsychological battery, aimed to evaluate different cognitive functions.Results showed severe deficits in speed processing, divided attention,working memory, executive functions and long term memory.Regression analyses, performed to test the two hypotheses, showed that the working memory deficit hypothesis is able to explain divided attention, executive functions and long term memory deficits more than speed processing hypothesis.     

The effect of spatial-frequency filtering on the visual processing of global structure

In three experiments we measured reaction times (RTs) and error rates in identifying the global structure of spatially filtered stimuli whose spatial-frequency content was selected by means of three types of 2-D isotropic filters (Butterworth of order 2, Butterworth of order 10, and a filters with total or partial Gaussian spectral profile). In each experiment, low-pass (LP), bandpass (BP), and high-pass (HP) filtered stimuli, with nine centre or cut-off spatial frequencies, were used. Irrespective of the type of filter, the experimental results showed that: (a) RTs to stimuli with low spatial frequencies were shorter than those to stimuli with medium or high spatial frequencies, (b) RTs to LP filtered stimuli were nearly constant, but they increased in a nonmonotonic way with the filter centre spatial frequency in BP filtered stimuli and with the filter cut-off frequency in HP filtered stimuli, and (c) the identification of the global pattern occurred with all visible stimuli used, including BP and HP images without low spatial frequencies. To remove the possible influence of the energy, a fourth experiment was conducted with Gaussian filtered stimuli of equal contrast power (c(rms) = 0.065). Similar results to those described above were found for stimuli with spatial-frequency content higher than 2 cycles deg(-1). A model of isotropic first-order visual channels collecting the stimulus spectral energy in all orientations explains the RT data. A subsequent second-order nonlinear amplitude demodulation process, applied to the output of the most energetic first-order channel, could explain the perception of global structure of each spatially filtered stimulus, including images lacking low spatial frequencies.     

Dancing shapes: a comparison of luminance-induced distortions

We present an illusory display in which a grid of outlined squares is positioned in front of a moving luminance gradient. Observers perceive a strong, illusory, 'wavelike' motion of the superimposed squares. We compared luminance effects on dynamic and static aspects of this illusion. The dynamic aspect was investigated by means of a temporal gradient, which induced an illusory pulsing of the outlined squares. The static aspect was investigated in two different ways. In one experiment, the outlined squares were positioned on a spatial gradient, which caused the squares to look like trapezoid shapes. In another experiment, the squares were positioned on different luminance fields, which affected their apparent size. In all experiments, luminance settings were the same, and observers were asked to indicate the direction and strength of the induced distortions. The overall results show large agreements between the dynamic distortion and the first-mentioned static distortion, whereas different tendencies emerged for the second static distortion. In a second series of experiments, we examined these distortions for various ranges of the luminance gradient and for border gradients as well. On the basis of these data, we explored how the directions of the perceived distortions of the single-gradient displays examined in this paper could be related to each other.     

Surface assignment modulates object formation for visual short-term memory

Recent results have suggested that the operational units of visual short-term memory (VSTM) are whole objects, rather than features or the total amount of information to be remembered. Here, for the first time, the influence of surface assignment on object formation for VSTM was investigated. The observers had to memorize the features of four briefly presented (300 ms) two-part objects, followed by a mask and a cue indicating which object to report on. The experiments contrasted whether there were any apparent depth differences between the two parts of each object, and whether observers had to report on only one or both features of the post-cued target object. Depth differences induced with stereoscopic disparity, and with a pictorial depth cue (simple interposition of object features), interfered strongly with performance when both features of an object needed to be memorized, but aided performance when only a single feature needed to be remembered. Furthermore, there was considerable within-feature interference consistent with some previous findings, but contradicting others. The potential implications for conceptions of VSTM are discussed in the light of two hypothesized stages: an early feature-based stage, as well as a higher-level object-based stage where the depth manipulations exert their effects. The results argue for a strong modulatory influence of surface assignment on object formation for a VSTM task.     

Qualitative differences between implicit and explicit sequence learning

Four experiments investigate the differences between implicit and explicit sequence learning concerning their resilience to structural and superficial task changes. A superficial change that embedded the SRT task in the context of a selection task, while maintaining the sequence, did selectively hinder the expression of implicit learning. In contrast, a manipulation that maintained the task surface, but decreased the sequence validity, affected the expression of learning specifically when it was explicit. These results are discussed in the context of a dynamic framework (Cleeremans & Jiménez, 2002), which assumes that implicit knowledge is specially affected by contextual factors and that, as knowledge becomes explicit, it allows for the development of relevant metaknowledge that modulates the expression of explicit knowledge.     

Sexual attraction: its dimensionality

The purpose of this research was to develop a new Sexual Attraction Questionnaire (SAQ) [Cuestionario de Atracción Sexual, CAS]. The goal was to determine whether sexual attraction could be represented as two different clusters (Attraction to men and Attraction to women), which would imply two negatively correlated factors or a bipolar one. Three studies were carried out with 182, 118, and 425 participants, respectively. Cluster and exploratory factor analyses were performed. The results obtained show satisfactory psychometric properties for the SAQ, the two clusters, and the two predicted negatively related factors or the bipolar factor. Results are discussed in the context of the different conceptions of sexual attraction and the fourfold typology: attracted to both sexes, to men, to women, or to neither sex.     

Relationship between dispositional optimism/pessimism and stress coping strategies

Recent studies confirm that dispositional pessimism is related with a worse state of physical health, in comparison with dispositional optimism . The efficacy of stress coping strategies has been considered as a mediating mechanism in this relationship. The aim of the present study is to analyze in a sample of university students (n = 200) the association between dispositional optimism/pessimism and different categories of self-reported somatic symptoms , and evaluate the possible mediation of the stress coping strategies in this relationship. The results indicate that: 1) pessimism is positively related with the report of physical symptoms, whereas optimism is negatively associated to somatic complaints; and 2) this relationship can be mainly explained by the differential utilization of the coping strategy denominated self-criticism (characteristic of pessimism).     

Why do people change in therapy? A preliminary study

Why do people change in therapy? A preliminary study. This work represents the beginning of a new way to study the processes that can explain the therapeutic change. The method used is the observation and analysis of therapeutic sessions directly recorded and developed inside a behavioural approach. The category system tries to carry out a functional analysis of the therapist-client interaction which enables the identification of learning processes that work in clinical setting and explain success in therapy. Outcomes are provisional but show the utility of this initial trend of investigation to the comprehension of clinical phenomenon. Conclusions also emphasize the importance of associative learning processes on the therapeutic change.     

Validation of a questionnaire for measuring psychosocial factors associated with pharmaceutical care in Spanish community pharmacists

Pharmacotherapy follow-up (PTF) is the professional practice in which the pharmacist takes charge of the needs of the patients related to their drugs. OBJECTIVE: To validate a questionnaire to measure the ASE psychosocial determinants (attitude, social influence, self-efficacy) of PTF and the Prochaska & DiClemente's stage of change in Spanish community pharmacists. METHOD: Postal survey to 482 Asturian community pharmacists (test and retest). Validity was estimated in 134 pharmacists answering the test. Stability was estimated in 85 pharmacists answering the test and retest. Exploratory factorial analysis was used to investigate construct validity and produced 4 factors and 104 items. Those factors had high reliability (Cronbach's a between 0,87 and 0,96). DISCRIMINANT VALIDITY: Pharmacists in extreme stages of change showed significant differences of attitude, motivation and self-efficacy. Repeatability was good and the questionnaire appears valid and reliable.     

Adaptation to Spanish of the Vividness of Visual Imagery Questionnaire-Revised Version (VVIQRV)

Adaptation to Spanish of the Vividness of Visual Imagery Questionnaire-Revised Version (VVIQRV). The main goal of this paper was to adapt to Spanish language and to examine the psychometric properties of the "Vividness of Visual Imagery Questionnaire-Revised Version" (VVIQRV), an instrument that can be used to assess vividness of visual imagery. The adaptation was carried out starting from the Spanish version of VVIQ and taking into consideration improvement proposals suggested in other studies. The questionnaire was then administered to a sample of 414 Spanish university students and the psychometric characteristics were estimated on the basis of the classic theory and the Rasch rating scale model (RSM). The results were convergent with previous studies and indicated that the Spanish VVIQRV has good internal consistency and can be characterized by a single main factor structure. Also, the RSM analysis showed that the increment in the number of response categories, a proposal to improve the instrument, was not appropriate.