Effect of contiguity and figure-ground organization on the area rule of lightness

Cataloged from PDF version of article.In a simple two-dimensional (2D) display composed of two uniform surfaces with different luminances, the lightness of the darker surface varies as a function of its relative area while its luminance is held constant (Gilchrist & Radonjić, 2009; Li & Gilchrist, 1999). This phenomenon is known as the area rule of lightness, and although it is extensively studied in the literature, the underlying principles are still largely unknown. Here, using computer-generated stimuli, we investigated the effects of contiguity and figure-ground organization on the area rule of lightness. Stimuli were 2D disks composed of radial sectors with high (25 cd/ m2) or low (8 cd/m2 ) luminance. On each trial, observers judged the lightness of the sectors by adjusting the luminance of a matching patch. Four conditions were tested. In the contiguous condition, there were one dark and one light sector, in the noncontiguous condition, both the light and dark surfaces were split into four equal radial sectors. Figure and ground conditions were generated by adding small contextual elements to the stimulus. We found that the area rule applied under all conditions; however, the functional form of the effect showed marked differences across conditions. Taken together, our results show that both high-level (e.g., perceptual grouping, figure-ground organization) and low-level (e.g., spatial-summation) mechanisms play a role in the area rule of lightness. © 2014 ARVO

Measuring the Cosmic Ray Muon-Induced Fast Neutron Spectrum by (n,p) Isotope Production Reactions in Underground Detectors

While cosmic ray muons themselves are relatively easy to veto in underground detectors, their interactions with nuclei create more insidious backgrounds via: (i) the decays of long-lived isotopes produced by muon-induced spallation reactions inside the detector, (ii) spallation reactions initiated by fast muon-induced neutrons entering from outside the detector, and (iii) nuclear recoils initiated by fast muon-induced neutrons entering from outside the detector. These backgrounds, which are difficult to veto or shield against, are very important for solar, reactor, dark matter, and other underground experiments, especially as increased sensitivity is pursued. We used fluka to calculate the production rates and spectra of all prominent secondaries produced by cosmic ray muons, in particular focusing on secondary neutrons, due to their importance. Since the neutron spectrum is steeply falling, the total neutron production rate is sensitive just to the relatively soft neutrons, and not to the fast-neutron component. We show that the neutron spectrum in the range between 10 and 100 MeV can instead be probed by the (n, p)-induced isotope production rates 12C(n, p)12B and 16O(n, p)16N in oil- and water-based detectors. The result for 12B is in good agreement with the recent KamLAND measurement. Besides testing the calculation of muon secondaries, these results are also of practical importance, since 12B (T1/2 = 20.2 ms, Q = 13.4 MeV) and 16N (T1/2 = 7.13 s, Q = 10.4 MeV) are among the dominant spallation backgrounds in these detectors

Chemistry in Second Life

This review will focus on the current level on chemistry research, education, and visualization possible within the multi-user virtual environment of Second Life. We discuss how Second Life has been used as a platform for the interactive and collaborative visualization of data from molecules and proteins to spectra and experimental data. We then review how these visualizations can be scripted for immersive educational activities and real-life collaborative research. We also discuss the benefits of the social networking affordances of Second Life for both chemists and chemistry students

Quantum Fluctuation Theorems

Recent advances in experimental techniques allow one to measure and control systems at the level of single molecules and atoms. Here gaining information about fluctuating thermodynamic quantities is crucial for understanding nonequilibrium thermodynamic behavior of small systems. To achieve this aim, stochastic thermodynamics offers a theoretical framework, and nonequilibrium equalities such as Jarzynski equality and fluctuation theorems provide key information about the fluctuating thermodynamic quantities. We review the recent progress in quantum fluctuation theorems, including the studies of Maxwell's demon which plays a crucial role in connecting thermodynamics with information.Comment: As a chapter of: F. Binder, L. A. Correa, C. Gogolin, J. Anders, and G. Adesso (eds.), "Thermodynamics in the quantum regime - Fundamental Aspects and New Directions", (Springer International Publishing, 2018

Street Earnings Activation Delay

Street earnings are non-GAAP earnings, adjusted for consistency with the analyst majority basis and disseminated by forecast data providers (FDPs). We find that the time it takes an FDP to incorporate street earnings in its products (activation delay, hereafter) reflects variation in the difficulty of constructing street earnings, investor demand for timely street earnings, and FDPs' limited attention and resources. Furthermore, the market reaction to reported earnings is more timely when activation delay is shorter, and price discovery is highly concentrated during the hour after street earnings are activated. Finally, activation delay increases the delay with which street earnings are incorporated in analyst forecasts. We conclude that frictions in information processing prevent market participants from instantaneously constructing and incorporating street earnings in their decisions, and that FDPs play a key role in alleviating these frictions

The links between health-related behaviors and life satisfaction in elderly individuals who prefer institutional living

BACKGROUND: Life satisfaction among residents of institutions is becoming an important issue in a rapidly aging population. The aim of this cross-sectional study was to investigate the links between life satisfaction and health-related behaviors amongst functionally independent elderly people who prefer institutional living in İstanbul, Turkey. METHODS: The socio-demographic characteristics, health-related behaviors, leisure-time activities and fall histories of 133 residents of an institution in Istanbul were assessed by a structured questionnaire during face-to-face interviews. A validated life-satisfaction index questionnaire (LSI-A) was completed. RESULTS: The mean age of the study group was 73.9 ± 8.0 (range 60–90 years). Within the group, 22.6% had never married and 14.3% had university degrees. The majority (71.4%) were in the low income bracket. The overall mean LSI-A score was 20.3 ± 5.9. Participants who declared moderate/high income levels had a significantly higher mean LSI-A score than those in the low-income bracket (p = 0.009). Multivariate analysis of the data suggested that leisure-time activities and participation in regular physical activities are significant predictors of LSI-A scores (R(2): 0.112; p = 0.005 and p = 0.02, respectively). CONCLUSION: The findings imply that regular physical activity and leisure-time activities are significantly related to life satisfaction among residents in institutions. Participation in physical activity and leisure-time activity programs may help to improve the life satisfaction of elderly people living in institutions

Affective recognition from EEG signals: an integrated data-mining approach

Emotions play an important role in human communication, interaction, and decision making processes. Therefore, considerable efforts have been made towards the automatic identification of human emotions, in particular electroencephalogram (EEG) signals and Data Mining (DM) techniques have been then used to create models recognizing the affective states of users. However, most previous works have used clinical grade EEG systems with at least 32 electrodes. These systems are expensive and cumbersome, and therefore unsuitable for usage during normal daily activities. Smaller EEG headsets such as the Emotiv are now available and can be used during daily activities. This paper investigates the accuracy and applicability of previous affective recognition methods on data collected with an Emotiv headset while participants used a personal computer to fulfill several tasks. Several features were extracted from four channels only (AF3, AF4, F3 and F4 in accordance with the 10–20 system). Both Support Vector Machine and Naïve Bayes were used for emotion classification. Results demonstrate that such methods can be used to accurately detect emotions using a small EEG headset during a normal daily activity

Evidence for sparse synergies in grasping actions

Converging evidence shows that hand-actions are controlled at the level of synergies and not single muscles. One intriguing aspect of synergy-based action-representation is that it may be intrinsically sparse and the same synergies can be shared across several distinct types of hand-actions. Here, adopting a normative angle, we consider three hypotheses for hand-action optimal-control: sparse-combination hypothesis (SC) – sparsity in the mapping between synergies and actions - i.e., actions implemented using a sparse combination of synergies; sparse-elements hypothesis (SE) – sparsity in synergy representation – i.e., the mapping between degrees-of-freedom (DoF) and synergies is sparse; double-sparsity hypothesis (DS) – a novel view combining both SC and SE – i.e., both the mapping between DoF and synergies and between synergies and actions are sparse, each action implementing a sparse combination of synergies (as in SC), each using a limited set of DoFs (as in SE). We evaluate these hypotheses using hand kinematic data from six human subjects performing nine different types of reach-to-grasp actions. Our results support DS, suggesting that the best action representation is based on a relatively large set of synergies, each involving a reduced number of degrees-of-freedom, and that distinct sets of synergies may be involved in distinct tasks

Analysis of action oriented effects on perceptual process of object recognition using physiological responses

Action on any objects provides perceptual information about the environment. There is a significant evidence that human visual system responds to action possibilities in an image as perceiving any ones action stimulates human motor system. However very limited studies have been done to analyze the effect of object affordance during action perception and execution. To study the effect of object affordance on human perception, in this paper we have analyzed the human brain signals using EEG based oscillatory activity of brain. EEG responses corresponding to images of objects shown with correct, incorrect and without grips are examined. Exploration of different gripping effects has been done by extracting Alpha and Beta frequency bands using Discrete Wavelet Transform based band extraction method, then baseline normalized power of Alpha and Beta frequency bands at 24 positions of motor area of left and right side of brain are examined. The result shows that 12 pooled electrodes at central and central parietal region provides a clear discrimination among the three gripping cases in terms of calculated power. The presented research explores new applicabilities of object affordance to develop a variety of Brain Computer Interface (BCI) based devices and to improve motor imagery ability among motor disorder related patients