Pre-training to find a hidden platform in the Morris water maze can compensate for a deficit to find a cued platform in a rat model of Parkinson's disease

The bilateral intranigral infusion of 1 micromol 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in adult male Wistar rats caused a specific and partial loss of substantia nigra pars compacta (SNc) dopamine neurons, a partial depletion of striatal dopamine, and a deficit to learn the intra-maze cued version of the Morris water maze. Pre-training the SNc rats in the spatial version of the water maze or simply maintaining the animals on the water maze platform reversed this deficit. This improvement was even observed when the order of the extra-maze cues presented to the rats during pre-training of the spatial version was changed during training of the intra-maze cued version. However, this deficit was not reversed either by maintaining the animals on the platform if the spatial cues were surrounded and covered with a curtain or by swimming sessions in the maze without the escape platform and the curtain. These findings suggest that none of the following elements alone, learned during the spatial task pre-training, could help SNc rats learn the intra-maze cued task: improvement of swimming skills or knowledge of the existence of the escape platform; distance between the platform and the border of the pool; location of a particular extra-maze cue; relations among extra-maze cues. However, the simultaneous presence of the escape platform and extra-maze cues (irrespective of their relational configuration) during the pre-training sessions proved to be necessary for this improving effect to occur.     

Scales for perceived egocentric distance in a large open field: comparison of three psychophysical methods

Scales for perceived egocentric distance produced by three psychophysical methods in four ranges of distances were compared. It was found that (a) the exponents produced by ratio and fractionation methods are in good agreement; (b) the exponents of both these methods were larger than those produced by magnitude estimation; (c) an increase in range of distance was associated with a decrease in exponent, but this diminution seems to interact with the method used; (d) for all the psychophysical methods used, there was large variability in the individual exponent; (e) the exponent was smaller than 1.0 for approximately 78% of the pooled sample, with all adult observers (N = 612) considered; and (f) an arithmetic mean exponent equal to 0.90 represents fairly all the results obtained.     

The surreptitious observation design: an experimental paradigm for distinguishing artifact from essence in hypnosis

Administered a hypnotic induction and 5 standard hypnotic suggestions twice via audiotape to a group of high-hypnotizable subjects and a group of low-hypnotizable simulators. During the first administration, subjects were led to believe that they were alone. However, their behavior was surreptitiously recorded on videotape and observed on a video monitor. The second administration occurred in the presence of an experimenter who had not been informed of group assignment. When unaware that they were being observed, simulators were significantly less responsive to suggestions than they were when openly observed. In contrast, the behavior of nonsimulating subjects was not affected by the presence of an experimenter. These data indicate that the responses of highly hypnotizable subjects to standard hypnotic suggestions cannot be accounted for in terms of simple compliance with experimental demand.     

DIMENSIONS AND CORRELATES OF THE PERSONNEL AUDIT AS AN ORGANIZATIONAL ASSESSMENT TOOL

This study analyzes the measurement properties of the personnel audit as an organizational assessment tool and the extent to which audit results relate to important organizational criteria. The findings reported here indicate that nine dimensions can effectively summarize 37 audit measures. The composite factor scores for these dimensions predict executive perceptions of "overall organizational performance" and "overall contribution of Personnel Function," employee "overall satisfaction with personnel services," and to a lesser extent, "profitability per capita." The personnel budget allotted per capita is in turn related to executive perceptions of Personnel's contributions.     

Reduced K+ Channel Inactivation, Spike Broadening, and After-Hyperpolarization in Kvβ1.1-Deficient Mice with Impaired Learning

A-type K⁺ channels are known to regulate neuronal firing, but their role in repetitive firing and learning in mammals is not well characterized. To determine the contribution of the auxiliary K⁺ channel subunit Kvβ1.1 to A-type K⁺ currents and to study the physiological role of A-type K⁺ channels in repetitive firing and learning, we deleted the Kvβ1.1 gene in mice. The loss of Kvβ1.1 resulted in a reduced K⁺ current inactivation in hippocampal CA1 pyramidal neurons. Furthermore, in the mutant neurons, frequency-dependent spike broadening and the slow afterhyperpolarization (sAHP) were reduced. This suggests that Kvβ1.1-dependent A-type K⁺ channels contribute to frequency-dependent spike broadening and may regulate the sAHP by controlling Ca²⁺ influx during action potentials. The Kvβ1.1-deficient mice showed normal synaptic plasticity but were impaired in the learning of a water maze test and in the social transmission of food preference task, indicating that the Kvβ1.1 subunit contributes to certain types of learning and memory.     

Personality correlates of dissociative experiences

This study investigated the prevalence of dissociative experiences in a normal British sample. The Dissociation Experiences Scale of Bernstein and Putnam was used to measure these experiences. The relationship between dissociative experiences and personality variables measured by the Eysenck Personality Questionnaire was a major focus of the study. It was found that the degree of dissociative experiences was related to neuroticism, but not to any other variable.     

The impact of object size and rigidity on infant reaching

Although the changes in kinematics of infant reaching have been studied, few researchers have investigated the improvement of reaching regarding objects of distinct physical properties. The aim of this longitudinal study was to verify the impact of object size and rigidity on the development of reaching in 4-6-month-old infants. Four infants were observed with a motion capture system during trials with four objects of distinct sizes and rigidity. A total of 188 reaches were analyzed by using the 3D movement reconstruction. Our results showed that reaching frequency, mean velocity, and straightness index increased with age. The number of movement units decreased with age and increased for small objects. Rigidity was not shown to affect reaching trajectories. These findings suggest that infants are capable of perceiving the more relevant object properties, thus using their available motor capabilities to modify the essential variables so that they can reach the target more accurately.     

Virtual reality and acrophobia: one-year follow-up and case study.

We present a study with 10 subjects being exposed to three sessions of simulated heights in a virtual reality (VR) system. Among the participants we highlight a 66-year-old man blind in his left eye. The participants show significant progress in anxiety, avoidance, and behavior measurements when confronted with real height circumstances. The results obtained 1 year later at follow-up are statistically significant in the Behavioral Avoidance Test (BAT) and the Attitudes Toward Heights Questionnaire (ATHQ), but not the Acrophobia Questionnaire (AQ).     

The Axioms of Set Theory

In this paper I argue for the view that the axioms of ZF are analytic truths of a particular concept of set. By this I mean that these axioms are true by virtue only of the meaning attached to this concept, and, moreover, can be derived from it. Although I assume that the object of ZF is a concept of set, I refrain from asserting either its independent existence, or its dependence on subjectivity. All I presuppose is that this concept is given to us with a certain sense as the objective focus of a ”phenomenologically reduced“ intentional experience. The concept of set that ZF describes, I claim, is that of a multiplicity of coexisting elements that can, as a consequence, be a member of another multiplicity. A set is conceived as a quantitatively determined collection of objects that is, by necessity, ontologically dependent on its elements, which, on the other hand, must exist independently of it. A close scrutiny of the essential characters of this conception seems to be sufficient to ground the set-theoretic hierarchy and the axioms of ZF. This revised version was published online in August 2006 with corrections to the Cover Date.