Prior cocaine exposure disrupts extinction of fear conditioning

Psychostimulant exposure has been shown to cause molecular and cellular changes in prefrontal cortex. It has been hypothesized that these drug-induced changes might affect the operation of prefrontal-limbic circuits, disrupting their normal role in controlling behavior and thereby leading to compulsive drug-seeking. To test this hypothesis, we tested cocaine-treated rats in a fear conditioning, inflation, and extinction task, known to depend on medial prefrontal cortex and amygdala. Cocaine-treated rats conditioned and inflated similar to saline controls but displayed slower extinction learning. These results support the hypothesis that control processes in the medial prefrontal cortex are impaired by cocaine exposure.     

Psychobiology of altered states of consciousness

The article reviews the current knowledge regarding altered states of consciousness (ASC) (a) occurring spontaneously, (b) evoked by physical and physiological stimulation, (c) induced by psychological means, and (d) caused by diseases. The emphasis is laid on psychological and neurobiological approaches. The phenomenological analysis of the multiple ASC resulted in 4 dimensions by which they can be characterized: activation, awareness span, self-awareness, and sensory dynamics. The neurophysiological approach revealed that the different states of consciousness are mainly brought about by a compromised brain structure, transient changes in brain dynamics (disconnectivity), and neurochemical and metabolic processes. Besides these severe alterations, environmental stimuli, mental practices, and techniques of self-control can also temporarily alter brain functioning and conscious experience.     

DISSOCIATION OF SPATIAL AND TEMPORAL COUPLING IN THE BIMANUAL MOVEMENTS OF CALLOSOTOMY PATIENTS

Abstract— The neural mechanisms of limb coordination were investigated by Jesting callosotomy patients and normal control subjects on bimanual movements. Normal subjects produced deviations in the trajectories when spatial demands for the two spatial deviations, although their hands moved with normal temporal synchrony. Normal subjects but not callosotomy patients exhibited large increases in planning and execution time for movements with different spatial demands for the two hands relative to movements with identical spatial demands for the two hands. This neural dissociation indicate that spatial interference in movements results from callosal connections whereas temporal synchrony in movement onset does not rely on the corpus callosum.     

Markers’ influence on the duration discrimination of intermodal intervals

The effects of sensory signal characteristics on the duration discrimination of intermodal intervals was investigated in three experiments. Temporal intervals were marked by either the successive presentation of a visual then auditory signal (VA), or by the successive presentation of an auditory then visual signal (AV). The results indicated that (1) VA intervals are generally easier to discriminate than are AV intervals, but this effect depends on the range of duration studied; (2) AV intervals are perceived as longer than VA intervals for durations ranging from 250 to 750 msec; (3) the intensity of the visual markers for both AV and VA intervals does not affect the discrimination; and (4) the perceived duration of an intermodal interval is influenced by the length of the first and second markers. The results are mainly interpreted in terms of (1) a sensory trace left by visual and auditory signals and (2) the detection of these signals.     

GPOWER: A general power analysis program

GPOWER is a completely interactive, menu-driven program for IBM-compatible and Apple Macintosh personal computers. It performs high-precision statistical power analyses for the most common statistical tests in behavioral research, that is,t tests,F tests, andχ ² tests. GPOWER computes (1) power values for given sample sizes, effect sizes andα levels (post hoc power analyses); (2) sample sizes for given effect sizes,α levels, and power values (a priori power analyses); and (3)α andβ values for given sample sizes, effect sizes, andβ/α ratios (compromise power analyses). The program may be used to display graphically the relation between any two of the relevant variables, and it offers the opportunity to compute the effect size measures from basic parameters defining the alternative hypothesis. This article delineates reasons for the development of GPOWER and describes the program’s capabilities and handling.     

A Quantitative Case Study of Longitudinal Changes in Identity, Intimacy, and Generativity

A quantitative case study of one woman's development was conducted in order to explore psychosocial change in early adulthood. A contentanalytic coding system for identity, intimacy, and generativity themes derived from E. H. Erikson's writing was applied to letters and diaries of the British writer Vera Brittain written when she was 20 to 21 and 30 to 31 years old. Over time, Brittain used more intimacy and generativity themes and fewer identity themes. Even though Brittain used fewer total identity themes in her writing in her early 30s, her use of one identity subcategory—occupational role—increased in frequency, and the way in which she expressed her identity concerns indicated greater certainty about her identity.     

Della sostanza

Inedito (Dal lascito, pp. 30604 – 30620) Con unaIntroduzione di Wilhelm BaumgartnerProbabilmente: Palermo, marzo 1900. Per la datazione, cf. la concordanza di contenuto con la lettera a A. Marty del 28 marzo 1900, in appendice.     

Semantics and the computational paradigm in cognitive psychology

There is a prevalent notion among cognitive scientists and philosophers of mind that computers are merely formal symbol manipulators, performing the actions they do solely on the basis of the syntactic properties of the symbols they manipulate. This view of computers has allowed some philosophers to divorce semantics from computational explanations. Semantic content, then, becomes something one adds to computational explanations to get psychological explanations. Other philosophers, such as Stephen Stich, have taken a stronger view, advocating doing away with semantics entirely. This paper argues that a correct account of computation requires us to attribute content to computational processes in order to explain which functions are being computed. This entails that computational psychology must countenance mental representations. Since anti-semantic positions are incompatible with computational psychology thus construed, they ought to be rejected. Lastly, I argue that in an important sense, computers are not formal symbol manipulators.     

Current status of intrathecal antifibrinolytic therapy with p-aminomethylbenzoic acid (PAMBA) in subarachnoid hemorrhages

The blood-brain barrier is barely affected by slight or moderate subarachnoidal bleeding so that the p-aminomethylbenzoic acid (PAMBA) administered systemically for antifibrinolytic therapy does not attain the continuous level necessary in the cerebrospinal fluid. Thus the antifibrinolytic agent should be applied intrathecally because this would totally inhibit fibrinolytic activity in cerebrospinal fluid containing blood and during the wound healing of ruptured aneurysmas. The improvement in wound healing reduces the occurrence of rebleeding, especially during the first 10 days, and improves conditions for successful surgical intervention.