The logic of viewpoints

In this paper a propositional logic of viewpoints is presented. The language of this logic consists of the usual modal operatorsL (of necessity) andM (of possibility) as well as of two new operatorsA andR. The intuitive interpretations ofA andR are “from all viewpoints” and “from some viewpoint”, respectively. Semantically the language is interpreted by using Kripke models augmented with sets of “viewpoints” and with a new alternativeness relation for the operatorA. Truth values of formulas are evaluated with respect to a world and a viewpoint. Various axiomatizations of the logic of viewpoints are presented and proved complete. Finally, some applications are given.     

Paranormal and Religious Believers Are More Prone to Illusory Face Perception than Skeptics and Non‐believers

Illusory face perception, a tendency to find human‐like faces where none are actually present in, for example, artifacts or scenery, is a common phenomenon that occasionally enters the public eye. We used two tests (N = 47) to analyze the relationship between paranormal and religious beliefs and illusory face perception. In a detection task, the participants detected face‐like features from pictures of scenery and landscapes with and without face‐like areas and, in a rating task, evaluated the face‐likeness and emotionality of these areas. Believer groups were better at identifying the previously defined face‐like regions in the images but were also prone to false alarms. Signal detection analysis revealed that believers had more liberal answering criteria than skeptics, but the actual detection sensitivity did not differ. The paranormal believers also evaluated the artifact faces as more face‐like and emotional than the skeptics, and a similar trend was found between religious and non‐religious people. Copyright © 2012 John Wiley & Sons, Ltd.     

PSYCHOMOTOR EXPRESSION AND PERSONALITY STUDY

The main purpose was to examine whether ratings of the 'natural speed of behaviour' are related to factors of 'personal tempo' found by common types of tempo tests. Psychomotor performance of varying levels of complexity was studied. In addition to standard tempo tasks, tests of maximum tempo were used. There were significant positive correlations between the ratings of the 'natural speed' and the tests of personal tempo, especially in ideomotor and drawing tasks, in subjects aged 13 to 14 years. In younger age groups the correlations were low. An attempt is made to interpret the results in terms of 'working habits'.     

The earliest electrophysiological correlate of visual awareness?

To examine the neural correlates and timing of human visual awareness, we recorded event-related potentials (ERPs) in two experiments while the observers were detecting a grey dot that was presented near subjective threshold. ERPs were averaged for conscious detections of the stimulus (hits) and nondetections (misses) separately. Our results revealed that hits, as compared to misses, showed a negativity around 180-350 ms at occipital and posterior temporal sites. It was followed by a positive wave after 400-500 ms, peaking at parietal sites. These correlates were not affected by a manipulation of attention. The early negativity, called 'visual awareness negativity' (VAN), may be a general, primary electrophysiological correlate of visual awareness. The present data show that it can be observed in response to appearance of a stimulus in visual awareness and that it generalizes across different manipulations of stimulus visibility.     

Brain activation and deactivation during location and color working memory tasks in 11-13-year-old children

Using functional magnetic resonance imaging (fMRI) and n-back tasks we investigated whether, in 11-13-year-old children, spatial (location) and nonspatial (color) information is differentially processed during visual attention (0-back) and working memory (WM) (2-back) tasks and whether such cognitive task performance, compared to a resting state, results in regional deactivation. The location 0-back task, compared to the color 0-back task, activated segregated areas in the frontal, parietal and occipital cortices whereas no differentially activated voxels were obtained when location and color 2-back tasks were directly contrasted. Several midline cortical areas were less active during 0- and 2-back task performance than resting state. The task-induced deactivation increased with task difficulty as demonstrated by larger deactivation during 2-back than 0-back tasks. The results suggest that, in 11-13-year-old children, the visual attentional network is differently recruited by spatial and nonspatial information processing, but the functional organization of cortical activation in WM in this age group is not based on the type of information processed. Furthermore, 11-13-year-old children exhibited a similar pattern of cortical deactivation that has been reported in adults during cognitive task performance compared to a resting state.     

Location vs. frequency of pure tones as a basis of fast discrimination

There are ample data suggesting that a spatial difference between two competing auditory messages provides a better basis for selective attention and listening than other differences. The present experiments show that the spatial difference (left vs. right ear) between two auditory inputs leads to their faster discrimination than even large differences in frequency (in the same ear). These results might explain the afore-mentioned privileged status of the spatial dimension as a basis of selective attention: spatial differences lead in faster identification of relevant or attended input than differences in other dimensions.     

Tracking the processes behind conscious perception: a review of event-related potential correlates of visual consciousness

Event-related potential (ERP) studies have attempted to discover the processes that underlie conscious visual perception by contrasting ERPs produced by stimuli that are consciously perceived with those that are not. Variability of the proposed ERP correlates of consciousness is considerable: the earliest proposed ERP correlate of consciousness (P1) coincides with sensory processes and the last one (P3) marks postperceptual processes. A negative difference wave called visual awareness negativity (VAN), typically observed around 200 ms after stimulus onset in occipitotemporal sites, gains strong support for reflecting the processes that correlate with, and possibly enable, aware visual perception. Research suggests that the early parts of conscious processing can proceed independently of top-down attention, although top-down attention may modulate visual processing even before consciousness. Evidence implies that the contents of consciousness are provided by interactions in the ventral stream, but indispensable contributions from dorsal regions influence already low-level visual responses.