The effect of home or novel environment on the facilitation of passive avoidance by post-training ethanol

Passive avoidance behavior of mice is improved when mice are injected with ethanol immediately after footshock training. Further study has shown that avoidance can be affected by ethanol injections given within 1 h, but not at 90 or 180 min, after training. The present study was conducted to investigate the possibility that events which occur in the homecage during this sensitive period may influence the effect of ethanol on subsequent avoidance. Male Swiss-Webster mice were housed either singly in a novel environment for 90 min or returned to their (group) homecage following one-trial, step-through, passive avoidance training (0.1 mA footshock) and intraperitoneal injection of 3.0 g/kg ethanol (15% v/v) or saline. As in previous studies, when ethanol-treated mice were returned to their homecage, avoidance was significantly increased at 24 h compared to the behavior of saline-treated mice. However, when mice were isolated in the novel environment for 90 min immediately following treatment, the memory facilitating effects of ethanol were not observed. The avoidance behavior of mice injected with saline was the same regardless of their post-training environment. Also, the number of mice (6 or 10) housed per homecage did not significantly influence the effects of ethanol or post-training environment on avoidance. These findings indicate that environmental factors may interact with the effects of ethanol to modify avoidance behavior. The possible influence of variables such as aggression, thermoregulation, and behavioral arousal on the effects of ethanol in this paradigm are discussed.     

Role of interstimulus and stimulus-hemisphere compatibility in the process of interhemispheric integration

Normal subjects had to name German compound nouns which were presented tachistoscopically. The compound nouns were displayed either unilaterally to the left or right visual field, or bilaterally with one element to the left and one to the right visual field. A distinction was made between the bilateral conditions as to whether the representation of the elements, printed and/or pictorial, included a high or low interstimulus and a high or low stimulus-hemisphere compatibility. Analysis indicated firstly a superiority of the left hemisphere for the naming of compound nouns in mixed print and pictorial representation. Secondly, the performance in the bilateral conditions was moderated by stimulus-hemisphere compatibility. In the process of interhemispheric integration stimulus-hemisphere compatibility proved more crucial than interstimulus compatibility. Analyses of errors further illustrated hemispheric behaviour.     

Different Mechanisms Underly Shifting Set on External and Internal Cues in Parkinson′s Disease

A set shifting task consisting of the comparison of two digits according to their numerical value or their form guided by an explicit (external cue) or implicit (internal cue) rule was performed by 8 untreated and 19 treated patients suffering from Parkinson′s disease (PD) and 15 control subjects. The subjects could not predict the number of trials for a given target. The treated PD patient group exhibited increased post-shift error rates under the internal cue condition. In the external cue condition, only the untreated patients produced more errors when shifting to a new.response criterion. Reaction times were prolonged in treated PD patients, irrespective of type of cue. Large interindividual variability within the patient groups is considered as meaningful and indicates individual differences in the neuropsychological impairment and/or the neurotransmission deficit. Pathophysiological and neuropsychological impairments underlying these findings are discussed on the basis of the models of Penney and Young (1983/1986) and Norman and Shallice (1980/1986).     

Personality diagnosis of school-age children]

This paper discusses some selected methodical and metric problems of psychological personality diagnosis in both childhood and the period of youth. In additon to discussing a number of important questions concerning psychometric methods, the author deals with problems associated with personality diagnosis, sociometric methods, and fictitious situational tests, analyzing them by reference to data reported in the literature.     

A Predicate Logical Extension of a Subintuitionistic Propositional Logic

We develop a predicate logical extension of a subintuitionistic propositional logic. Therefore a Hilbert type calculus and a Kripke type model are given. The propositional logic is formulated to axiomatize the idea of strategic weakening of Kripke's semantic for intuitionistic logic: dropping the semantical condition of heredity or persistence leads to a nonmonotonic model. On the syntactic side this leads to a certain restriction imposed on the deduction theorem. By means of a Henkin argument strong completeness is proved making use of predicate logical principles, which are only classically acceptable.     

Dogs and wolves do not differ in their inhibitory control abilities in a non-social test battery

Animal Cognition - Being able to inhibit certain behaviours is of clear advantage in various situations. In particular, it has been suggested that inhibitory control plays a role in problem-solving...     

Inferential reasoning by exclusion in pigeons, dogs, and humans

The ability to reason by exclusion (which is defined as the selection of the correct alternative by logically excluding other potential alternatives; Call in Anim Cogn 9:393–403 2006) is well established in humans. Several studies have found it to be present in some nonhuman species as well, whereas it seems to be somewhat limited or even absent in others. As inconsistent methodology might have contributed to the revealed inter-species differences, we examined reasoning by exclusion in pigeons (n = 6), dogs (n = 6), students (n = 6), and children (n = 8) under almost equal experimental conditions. After being trained in a computer-controlled two-choice procedure to discriminate between four positive (S+) and four negative (S−) photographs, the subjects were tested with displays consisting of one S− and one of four novel stimuli (S′). One pigeon, half of the dogs and almost all humans preferred S′ over S−, thereby choosing either by novelty, or by avoiding S− without acquiring any knowledge about S′, or by inferring positive class membership of S′ by excluding S−. To decide among these strategies the subjects that showed a preference for S′ were then tested with displays consisting of one of the S′ and one of four novel stimuli (S′′). Although the pigeon preferentially chose the S′′ and by novelty, dogs and humans maintained their preference for S′, thereby showing evidence of reasoning by exclusion. Taken together, the results of the present study suggest that none of the pigeons, but half of the dogs and almost all humans inferred positive class membership of S′ by logically excluding S−. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

No difference between conscious and nonconscious visuomotor control: evidence from perceptual learning in the masked prime task

Negative compatibility effects (NCEs) in the masked-prime paradigm are usually obtained when primes are masked effectively. With ineffective masks-and primes above the perceptual threshold-positive compatibility effects (PCEs) occur. We investigated whether this pattern reflects a causal relationship between conscious awareness and low-level motor control, or whether it reflects the fact that both are affected in the same way by changes in physical stimulus attributes. In a 5-session perceptual learning task, participants learned to consciously identify masked primes. However, they showed unaltered NCEs that were not different from those produced by participants in a control group without equivalent perceptual learning. A control experiment demonstrated that no NCEs occur when prime identification is made possible by ineffective masking. The results suggest that perceptual awareness and low-level motor control are affected by the same factors, but are fundamentally independent of each other.     

When, what, and whom to watch? Quantifying attention in ravens (Corvus corax) and jackdaws (Corvus monedula)

Complex social life requires monitoring of conspecifics. The amount and focus of attention toward others has been suggested to depend on the social relationships between individuals. Yet there are surprisingly few experiments that have tested these assumptions. This study compared attention patterns toward conspecifics in two corvid species, ravens (Corvus corax) and jackdaws (Corvus monedula). Birds were confronted with affiliated and non-affiliated conspecifics engaged in foraging and object manipulation. Visual access to the model bird was provided through two observation holes, which allowed measurement of exactly how often and for how long observers watched the other. Overall, ravens were more attentive to conspecifics than were jackdaws. Moreover, only ravens showed higher interest toward food-related than object-related behaviors of the model and toward close affiliates than non-affiliates by increasing the duration rather than the frequency of looks. These results are in accordance with predictions derived from the species' foraging biology and suggest that the facultative social, but highly manipulative, ravens use and value information from others differently than do the obligate social jackdaws.