V. P. Branskij: Die philosophische Bedeutung des Anschaulichkeitsproblems in der modernen Physik

Ohne ZusammenfassungDie Originalitiel von Branskijs Buch lauete:Filosofskoe znaenie problemy nagljanost v sovremennoj fizike. Izd. Len. Univ. 1962. 192 Str.     

Can humans perceive their brain states?

Although the brain enables us to perceive the external world and our body, it remains unknown whether brain processes themselves can be perceived. Brain tissue does not have receptors for its own activity. However, the ability of humans to acquire self-control of brain processes indicates that the perception of these processes may also be achieved by learning. In this study patients learned to control low-frequency components of their EEG: the so-called slow cortical potentials (SCPs). In particular "probe" sessions, the patients estimated the quality of the SCP shift they had produced in the preceding trial. The correspondence between the recorded SCP amplitudes and the subjective estimates increased with training. The ability to perceive the SCPs was related to the ability to control them; this perception was not mediated by peripheral variables such as changes in muscle tonus and cannot be reduced to simple vigilance monitoring. These data provide evidence that humans can learn to perceive the neural activity of their brain. Alternative interpretations are discussed.     

The effect of response competition on functional hemispheric asymmetries for global/local processing

It is widely assumed that the cerebral hemispheres differ in their capacity for processing the global and local levels of hierarchical stimuli. However, corresponding visual-field (VF) effects in response time studies did not show up under all circumstances. In the present article the role of response conflict between the levels for the occurrence of these effects is investigated. Three experiments with hierarchical letters are reported, in which the absolute and/or the relative interference between the stimulus levels was varied. It turned out that VF effects occurred only for conflicting stimuli and only when there was at least a certain amount of absolute interference, whereas variations of the relative interference had no effect in this respect. These results suggest that there is a qualitative relationship between interference and VF effects. A possible explanation is provided by the assumption that the hemispheres are functionally equivalent with respect to early stimulus representations, whereas they differ in their efficiency for integrating letter identity and stimulus level.     

Personal names and the human right hemisphere: an illusory link?

Names are thought to be represented in the brain differently from common nouns. Although this idea is supported by both theoretical and empirical arguments, the brain areas that are relevant for the recognition of personal names-and in particular the extent of right hemisphere involvement-remain controversial. We investigated the hypothesis that, unlike common nouns, personal names are represented preferentially by the right hemisphere (D. Van Lancker, 1991; D. Van Lancker et al., 1991; C. Ohnesorge & D. Van Lancker, 1999). Participants performed lexical decisions to common nouns and pseudowords (Experiment 1) or familiarity decisions to personal names (Experiment 2), which were presented briefly to the left or right visual fields. Asymmetries were small or absent for both pseudowords and unfamiliar names. For familiar names, both reaction times and error rates revealed strong advantages for the right visual field/left hemisphere (RVF/LH), which were comparable to the asymmetries for nouns. Familiar personal names may be represented by brain systems that differ from those representing common nouns, but current evidence does not suggest a distinct contribution of the right hemisphere to these brain systems.     

About the relationship between basic numerical processing and arithmetics in early Alzheimer's disease--a follow-up study

We studied the relationship between basic numerical knowledge and arithmetics (facts and procedures) in early Alzheimer's Disease (AD). In most patients, basic numerical knowledge was found to be preserved, as reflected by low error rates, distance effect in number comparison, and subitizing in naming numerosities. However, within arithmetics, AD patients exhibited decreased fact and procedural knowledge. Interestingly, double dissociations were found not only between facts and procedures but also between basic numerical knowledge and arithmetics. Thus, our results suggest that basic numerical knowledge need not be a prerequisite for the maintenance of arithmetics, but rather corroborate calculation models that postulate the functional independence of its components. Further, we found patient specific error types which might serve to identify early AD. The follow-up about one year later indicated significant qualitative, but only marginal quantitative performance changes.     

Unconscious consciousness in Husserl and Freud

A clarification of Husserl's changing conceptions of imaginary consciousness (phantasy) and memory, especially at the level of auto-affective time-consciousness, suggests an interpretation of Freud's concept of the Unconscious. Phenomenology of consciousness can show how it is possible that consciousness can bring to present appearance something unconscious, that is, something foreign or absent to consciousness, without incorporating it into or subordinating it to the conscious present. This phenomenological analysis of Freud's concept of the Unconscious leads to a partial critique of Freud's metapsychological determination of the Unconscious as a simple, internally unperceived representational consciousness. It also suggests an account of how a reproductive inner consciousness can free the subject from the experience of anxiety by allowing for possibilities of self-distanciation and symbolic self-representation that protect the subject from traumatic affection by and through its own instinctual drives.     

Hindsight bias around the world

Hindsight bias refers to the tendency to overestimate in hindsight what one has known in foresight. Recently, two experiments extended the research to include samples from different cultures (Choi & Nisbett, 2000; Heine & Lehman, 1996). Asking their participants what they would have guessed before they knew the outcome ("hypothetical design"), Choi and Nisbett (2000) found that Koreans, in comparison to North Americans, exhibited more hindsight bias. Heine and Lehman (1996), however, reported that Japanese people in comparison to Canadians showed marginally less hindsight bias. In a second study, in which participants were asked to recall what they had estimated before they knew the outcome ("memory design"), the latter authors found no difference in hindsight bias between Japanese people and Canadians. We extended these studies with 225 Internet participants, in a hypothetical design, from four different continents (Asia, Australia, Europe, and North America). Hindsight bias was large and similar for all samples except for German and Dutch participants who showed no hindsight bias at all. While the latter effect may be based on peculiarities of the material and of the participants, the former underscores the worldwide stability of the phenomenon. In addition a follow-up surprise rating (paper and pencil) in China (35 participants) and Germany (20 participants) revealed that only less surprising items led to hindsight bias while more surprising ones did not. We suggest that the basic cognitive processes leading to hindsight bias are by-products of the evolutionary-evolved capacity of adaptive learning. On top of these basic processes, individual meta-cognitions (e.g., elicited by surprise) or motives (e.g., a self-serving motive) may further moderate the amount of bias, thus explaining the diverging results of Choi and Nisbett (2000), Heine and Lehman (1996), and our own study.     

Acquisition and use of mental operators: effects of type of practice

Planning interactions with the physical world requires knowledge about operations; in short, mental operators. Abstractness of content and directionality of access are two important properties to characterize the representational units of this kind of knowledge. Combining these properties allows four classes of knowledge units to be distinguished that can be found in the literature: (a) rules, (b) mental models or schemata, (c) instances, and (d) episodes or chunks. The influence of practicing alphabet-arithmetic operators in a prognostic, diagnostic, or retrognostic way (A + 2 = ?, A? = C, or ? + 2 = C, respectively) on the use of that knowledge in a subsequent test was used to assess the importance of these dimensions. At the beginning, the retrognostic use of knowledge was worse than the prognostic use, although identical operations were involved (A + 2 = ? vs. ? - 2 = A). This disadvantage was reduced with increased practice. Test performance was best if the task and the letter pairs were the same as in the acquisition phase. Overall, the findings support theories proposing multiple representational units of mental operators. The disadvantage for the retrognosis task was recovered in the test phase, and may be evidence for the importance of the order of events independent of the order of experience.