Moon illusion simulated in complete darkness: planetarium experiment reexamined

In 1962, Kaufman and Rock reported that the moon illusion did not occur in the darkness of a planetarium or in a completely dark room. The present study reexamined their findings. Two pairs of light points, separated by 3.5 degrees, were presented on the dome screen of a planetarium. Subjects compared the distance between the two light points presented in the horizontal direction with the distance between the two light points at the zenith. Three illumination conditions were used: The inside of the planetarium was completely dark, was lighted, or was projected with the silhouette of a city under a starry sky. The effect of eye elevation on the illusion was also examined. Contrary to Kaufman and Rock's results, a size discrepancy comparable to the moon illusion was obtained in the horizon-and-stars condition and even in the complete-darkness condition. Little or no illusion was obtained in the lighted-room condition. The results also showed that eye elevation affected the magnitude of the illusion.     

Human and institutional transformations: Catholic hospitals becoming 'a light in the the darkness.

Catholic health care institutions in the United States and Canada face internal and external challenges to their continued existence. Confronted by these external and internal challenges, Catholic hospitals in the United States and Canada have been pressed to identify what is distinctive about the Catholic contribution to health care and to consider whether existing institutional structures and partnerships foster what is distinctive. The author looks at the essays in this volume by Dennis Brodeur, Clarke E. Cochran, and Christopher J. Kauffman, and suggests that there is little agreement, even among Catholics, on such fundamental issues. The aim of this article is to highlight three important and often overlooked ideas raised by the authors, to relate them to the Canadian context by means of a story, and to pose questions for further discussion.     

Transcendental pride and Luciferism: On being bearers of light and powers of darkness

Continental Philosophy Review - The ancient theme of the metaphysical-theological extremes of being-human is revisited by asking about the condition for the readiness to engage in the form of...     

Golden hamsters on the eight-arm maze in light and darkness: The role of dead reckoning

This paper examines whether golden hamsters can rely on dead reckoning (getting positional information from updated signals generated during locomotion) on an eight-arm maze. Two groups of hamsters were tested: Group L under ordinary room light, Group D in darkness. To enhance the role of dead reckoning, each subject could climb from its own home cage onto the central platform of the maze. In a first experimental phase (15 trials), the L subjects learned to master the maze through developing a locomotor rule (arm chaining) after three to four trials. The D subjects developed arm chaining less readily and fluctuated more in their performance than did the L subjects. In a second experimental phase (15 trials), four arms were blocked at the beginning of each trial. In both experimental groups the performance decreased, yet remained well above chance level. Success and arm chaining were positively correlated in Phase 1 and negatively correlated with success in Phase 2. We assume that in Phase 2 the L subjects switched to the predominant use of visual cues, and the D subjects to dead reckoning.     

Resting gamma power is linked to reading ability in adolescents

Infants who have more power within the gamma frequency range at rest develop better language and cognitive abilities over their first 3 years of life (Benasich et al., 2008). This positive trend may reflect the gradual increase in resting gamma power that peaks at about 4 years (Takano & Ogawa, 1998): infants further along the maturational curve may exhibit both increased resting gamma power and more advanced language and cognitive function. Similar to other neural characteristics such as synaptic density, resting gamma power subsequently decreases with further development into adulthood (Tierney, Strait, O'Connell & Kraus, 2013). If previously reported relationships between resting gamma power and behavioral performance reflect variance in maturation, at least in part, negative correlations between resting gamma and behavior may predominate in later developmental stages, during which resting gamma activity is decreasing. We tested this prediction by examining resting gamma activity and language‐dependent behavioral performance, reflected by a variety of reading‐related tests, in adolescents between the ages of 14 and 15 years. Consistent with our predictions, resting gamma power inversely related to every aspect of reading assessed (i.e. reading fluency, rapid naming, and basic reading proficiency). Our results suggest that resting gamma power acts as an index of maturational progress in adolescents.     

In vitro hippocampal gamma oscillation power as an index of in vivo CA3 gamma oscillation strength and spatial reference memory

Neuronal synchronisation at gamma frequencies (30-100 Hz) has been implicated in cognition and memory. Gamma oscillations can be studied in various in vitro models, but their in vivo validity and their relationship with reference memory remains to be proven. By using the natural variation of wild type C57bl/6J mice, we assessed the relationships between reference memory and gamma oscillations recorded in hippocampal area CA3 in vivo and in vitro. Local field potentials (LFPs) were recorded from area CA3 in behaviourally-characterised freely moving mice, after which hippocampal slices were prepared for recordings in vitro of spontaneous gamma oscillations and kainate-induced gamma oscillations in CA3. The gamma-band power of spontaneous oscillations in vitro correlated with that of CA3 LFP oscillations during inactive behavioural states. The gamma-band power of kainate-induced oscillations correlated with the activity-dependent increase in CA3 LFP gamma-band power in vivo. Kainate-induced gamma-band power correlated with Barnes circular platform performance and object location recognition, but not with object novelty recognition. Kainate-induced gamma-band power was larger in mice that recognised the aversive context, but did not correlate with passive avoidance delay. The correlations between behavioural and electrophysiological measures obtained from the same animals show that the gamma-generating capacity of the CA3 network in vitro is a useful index of in vivo gamma strength and supports an important role of CA3 gamma oscillations in spatial reference memory.     

The effect of light color on muscular strength and power

The purpose of this study was to assess the effect of the color of light in a room on muscular strength and power. A convenience sample of 18 men (M age = 20.4 yr., SD = 1.2) performed a modified Wingate Anaerobic Cycle Test for muscular power and a hand grip strength test in each of the following conditions: red, blue, and white (neutral) ambient light. A repeated-measures multivariate analysis of variance indicated that average muscular power was significantly higher when performing the test in the room with red light compared to rooms lit with blue light or white light. The results also indicated that grip strength was significantly higher in the room lit with white light as compared to the room lit with blue light.     

Oculomotor adjustments in darkness and the specific distance tendency

Two experiments were performed to investigate the relationship between the oculomotor adjustments assumed in total darkness and perceived distance under reduced visual conditions. Experiment I compared the dark focus of accommodation with the perceived distance of a monocular light point presented in a dark environment. Experiment II compared the convergence angle assumed in darkness (dark convergence) with the perceived distance of the light point. Both accommodation and convergence were found to assume intermediate values in darkness. Perceived distance of the monocular light point was significantly correlated with dark convergence and unrelated to the dark focus of accommodation. It was suggested that ocular vergence is a major determinant of perceived distance under reduced visual conditions, and thus provides a possible mechanism for the specific distance tendency.     

Eye position affects audio-visual fusion in darkness

We investigated the frame of reference involved in audio-visual (AV) fusion over space. This multisensory phenomenon refers to the perception of unity resulting from visual and auditory stimuli despite their potential spatial disparity. The extent of this illusion depends on the eccentricity in azimuth of the bimodal stimulus (Godfroy et al, 2003 Perception 32 1233-1245). In a previous study, conducted in a luminous environment, Roumes et al 2004 (Perception 33 Supplement, 142) have shown that variation of AV fusion is gaze-dependent. Here we examine the contribution of ego- or allocentric visual cues by conducting the experiment in total darkness. Auditory and visual stimuli were displayed in synchrony with various spatial disparities. Subjects had to judge their unity ('fusion' or 'no fusion'). Results showed that AV fusion in darkness remains gaze-dependent despite the lack of any allocentric cues and confirmed the hypothesis that the reference frame of the bimodal space is neither head-centred nor eye-centred.     

Daylight and darkness: Images of Christians in mixed marriages

Marriage between Christians and non-Christians has generally been regarded with suspicion by the churches, and has at times been severely punished. However, mixed marriage has also sometimes been seen as a means by which the non-Christian partner may be drawn into the faith. In this article I review some of the underlying reasons for these attitudes and the theological concepts of marriage which informed those responsible for its regulation. I focus particularly on the issues and images surrounding religious intermarriage in the early Church and during the medieval period, with special reference to legends and literature.     

Play desensitization of fear of darkness in preschool children.

Systematic desensitization therapy (SDT) is considered to be a technique of established effectiveness in reducing monosymptomatic fears (Paul, 1969a, 1969b), yet little systematic research has been done to investigate the merit of desensitization procedures in modifying children's behavior. The few available controlled studies (Miller et al., 1972; Obler and Terwilliger, 1970; Oliver, 1971) on desensitization with children have produced equivocal results. Although imagery and relaxation have been reported of benefit when used separately (Graziano and Kean, 1971; Lazarus and Abramovitz, 1962), evidence suggests that the usual combination of imagery and relaxation is not effective in reducing children's fears (Miller et al., 1972). Investigators in this area have often modified traditional SDT to include alternatives to imagery such as pictures, drawings, play (Cassell, 1965; Lazarus, 1960; Obler and Terwilliger, 1970; Patterson, 1965), or in vivo exposure to the feared stimulus (Obler and Terwilliger, 1970). Relaxation has often been replaced with other responses thought to be incompatible with anxiety such as eating (Jones, 1924). Another deviation from traditional SDT has been the delivery of positive reinforcement (food, praise, or toys) contingent upon the child's approaching the feared object (Obler and Terwilliger, 1970; Patterson, 1965). On the basis of such varied techniques, it is impossible to determine which of these procedures constitutes an effective treatment method for children. In the following study, three desensitization procedures involving graded exposure to the feared stimulus (darkness) through symbolic play, were compared to no-treatment and placebo control groups under differing instructional sets. Treatments were designed to determine the therapeutic efficacy of play as a method of stimulus presentation with children, and to determine whether reciprocal inhibition, extinction, operant reinforcement, or instructional set contribute to fear reduction in desensitization with children.     

Temporal brightness and darkness enhancement; further evidence for asymmetry

Abstract.— Previous studies by the authors on brightness and darkness enhancement during flicker indicate a sizeable and consistent difference in magnitude between the two effects, as defined in terms of log matching luminance. To explore whether this difference is an artifact of the logluminance representation of the perceptual effects, a psychophysical scaling experiment was performed and results from present and former flicker experiments were replotted in terms of subjective units. When the depth of luminance modulation of the flicker stimulus exceeded 50%, the difference in magnitude of temporal brightness and darkness enhancement was somewhat smaller expressed in subjective units compared to a log-luminance representation. On the whole, however, the two plots gave essentially similar results. The results are discussed with reference to the neurophysiological theory of the B- and D-systems.