Is the unilateral lesion of the left substantia nigra pars compacta sufficient to induce working memory impairment in rats?

Adult male Wistar rats with a substantia nigra pars compacta (SNc) lesion induced by intranigral administration of 1 micromol 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were used as a model of early phase Parkinson's disease (PD). This lesion caused a partial depletion of striatal dopamine (DA). The animals were submitted to a spatial working memory version of the water maze task in which they had to find a hidden (submersed) platform using online-maintained information that the platform remains in the same place during four consecutive trials, but that it is moved to another place every training day. Left, but not right SNc-lesioned rats were impaired in finding the platform in the second trial. This result suggests that the left SNc plays a key role in spatial working memory. Control experiments ruled out the possibility that motor impairment, sensory neglect, and/or impairment in the mental representation of the contralateral spatial environment had affected performance of the SNc-lesioned rats.     

The Five-factor Personality Inventory as a measure of the Five-factor Model: Belgian, American, and Hungarian comparisons with the NEO-PI-R

The lexically based Five-Factor Personality Inventory (FFPI) was correlated with the factors and facets of the Revised NEO Personality Inventory (NEO-PI-R) in Belgian (N = 265), American (N = 116), and Hungarian (N = 320) samples. Results were similar across the three cultures. Analysis of orthogonalized FFPI factors showed that three of them--emotional stability, extraversion, and agreeableness--showed a direct correspondence to their NEO-PI-R counterparts. Autonomy, however, was not clearly related to openness, and facet analysis suggested that it might be interpreted as a dominance factor Better matches to NEO-PI-R conscientiousness and openness could be obtained by using vectors rotated 30 degrees from the FFPI positions. Raw scale scores showed similar results. Researchers should not assume that all measures of the Five-Factor Model are qualitatively similar     

Something from nothing: exploring dimensions of children's knowing through the repeated reading of favourite books

Witte‐Townsend and DiGiulio explore some of the dimensions of knowing that children, teachers and parents may engage together during story‐time. They reflect on some of their own long‐term relationships with children and children's books, especially Phoebe Gilman's Gilman P 1992 Something from nothing (New York, NY, Scholastic Inc)  [Google Scholar] Something from nothing (published in 1992) and Simms Taback's Taback S 1999 Joseph had a little overcoat (New York, NY, Viking‐Penguin)  [Google Scholar] Joseph had a little overcoat, published in 1999. The authors probe issues such as why children ask to hear a favourite story over and over and why they suddenly abandon all interest and move on to a new book. They explore the meaning of the silences that sometimes arise during story‐time, pooling around the young listeners as the last words of the book are read. Witte‐Townsend and DiGiulio remind us of the value of literature in the lives of children and they affirm that the reading and re‐reading of favourite stories enables the understanding of complex human issues and contributes significantly to social, emotional and spiritual growth.     

Allophonic mode of speech perception in dyslexia

Perceptual discrimination between speech sounds belonging to different phoneme categories is better than that between sounds falling within the same category. This property, known as "categorical perception," is weaker in children affected by dyslexia. Categorical perception develops from the predispositions of newborns for discriminating all potential phoneme categories in the world's languages. Predispositions that are not relevant for phoneme perception in the ambient language are usually deactivated during early childhood. However, the current study shows that dyslexic children maintain a higher sensitivity to phonemic distinctions irrelevant in their linguistic environment. This suggests that dyslexic children use an allophonic mode of speech perception that, although without straightforward consequences for oral communication, has obvious implications for the acquisition of alphabetic writing. Allophonic perception specifically affects the mapping between graphemes and phonemes, contrary to other manifestations of dyslexia, and may be a core deficit.     

Death anxiety and death obsession in Spanish students

This study examined the dimensional structure of Templer's Death Anxiety Scale and Abdel-Khalek's Death Obsession Scale. The responses of 289 Spanish students to the Spanish forms of both scales were evaluated by means of a principal components analysis with varimax rotation. Three significant factors were identified: Death Obsession, Cognitive-Affective, and Death Anxiety. The distribution of the factor loadings for the items of both scales on Factors 1 and 3 supported the discriminant validity of the constructs specific to each of the scales, while Factor 2 showed a common component in both scales characterized by cognitive and affective aspects in relation to the idea of death.     

The planning and execution of sequential eye movements: saccades do not show the one target advantage

The present experiment examined the one-target advantage (OTA) with regard to saccadic eye movements. The OTA, previously found with manual pointing responses, refers to the finding that movements are executed faster when the limb is allowed to stop on the target compared to the situation where it has to proceed and hit a second target. Using an adapted limb movement OTA task, saccades of 5 degrees and 15 degrees were made to (a) a single target (one-target), (b) one target and immediately to another target without a change in direction (two-target-extension), and (c) one target and immediately back to the start location (two-target-reversal). Unlike manual movements, the movement times for the initial saccade in the two-target-extension condition were not prolonged compared to either of the other two conditions. Moreover, this pattern of results was found for both the shorter and longer amplitude saccades. The results indicate that the OTA does not occur in the oculomotor system and therefore is not a general motor control phenomenon.     

Iberian rock lizards (Lacerta monticola) assess short-term changes in predation risk level when deciding refuge use

Prey might assess that risk level estimated in the first encounter with a predator was fixed in subsequent responses, whereas prey using flexible behavior would track short-term changes in risk. The authors examined, in the field, refuge use of Iberian rock lizards (Lacerta monticola) after simulated predator attacks and tested (a) how risk was assessed when multiple sources of risk were present simultaneously, (b) how short-term changes in risk level of successive attacks affected refuge use, and (c) whether the interval between attacks was important, insofar as attacks were considered to be coming from the same or different predators. Results suggest that lizards have a flexible estimate of risk that is based on multiple sources and flexibly dependent on previous estimates.     

Houses built on sand: effects of exemplar stability on susceptibility to attitude change

Attitude representation theory (C. G. Lord & M. R. Lepper, 1999) explains both attitude-behavior consistency and attitude change with the same principles. When individuals respond evaluatively to an attitude object, they activate and combine assumptions about the attitude object with perceptions of the immediate situation. The assumptions activated can vary across time, even without additional information. Previous research has shown that individuals activate exemplars when answering attitude questions, attitude reports vary with the valence of the assumptions activated, and activating differently liked exemplars reduces attitude-behavior consistency. The present research completed study of the theoretical implications of exemplar stability by showing that individuals with temporally unstable exemplars, whether spontaneous (Experiment 1) or manipulated (Experiments 2 and 3), are more susceptible to subsequent attitude change than are individuals with stable exemplars.     

Exploring the structure of Zuckerman's Sensation Seeking Scale, Form V in a Spanish sample

The psychometric properties of the original version of the Sensation Seeking Scale (Form V) were analyzed in a sample of 1,006 Spanish university students. The total sample was randomly split into two halves. Exploratory factor analyses were conducted on the calibration sample (n=504), whereas confirmatory factor analysis procedures were performed on the validation sample (n=502). As previous studies have suggested, exploratory factor structure indicated that several items load on a different factor or have loadings lower than .30. Those problems were surpassed when the best five items per factor were factor analyzed again. The confirmatory factor analyses showed that a 4-factor simple structure model gave a clearly imperfect fit. A model of 20 items (5 items per factor) gave a better fit, although with similar problems regarding the low reliabilities of the Experience Seeking and Boredom Susceptibility subscales. The need for improvement of the four-factor structure is discussed.