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The Mona Lisa (1503–6) is probably the most celebrated example of ambiguous expression in art. Soranzo and Newberry (2015) demonstrated that a similar ambiguity can be perceived also in La Bella Principessa (1495–6), another portrait credited to Leonardo da Vinci (1452–1519) by many. The paper aims to show that an ambiguous expression can be perceived in a further painting attributed (although not unanimously) to Leonardo: The Lady with Dishevelled Hair, or La Scapigliata. An experiment was conducted whereby participants rated on a 7-point Likert scale the perceived level of contentment of La Scapigliata and that of a comparable painting created by Andrea di Cione, alias Il Verrocchio. The two artworks were presented in random order to two groups of participants. One group could see the artworks from Close (0.6m) whilst the other group from Far (6m) from a Close (0.6 m) or Far (6 m) condition. Results show that the change of distance affected the perceived level of contentment of Leonardo’s figure but not that of Verrocchio’s. Specifically, whilst both artworks received similar ratings of contentment from the close-up condition, La Scapigliata was perceived to be more content from afar. It is concluded that La Scapigliata exhibits an ambiguous expression, and that this ambiguity is similar to the one observed in the Mona Lisa and La Bella Principessa. This result can be only partially interpreted within the spatial frequency hypothesis advanced by Livingstone (2000) and shows that a phenomenological account of Leonardo’s work might be more suited to capture the full extent of the phenomenon. Specifically, it is suggested that the principles of perceptual belongingness (Wertheimer, 1923) may need to be considered to fully capture the extent of the ambiguity depicted by Leonardo.

In 1993, Agostini and Proffitt showed that perceptual belongingness (the subsumption of some sets of elements into a perceived whole) causes simultaneous lightness contrast to be seen in configurations in which the inducing elements are not adjacent to the target. The aim of the present research was to measure the strength of belongingness in determining the contrast phenomenon when the numbers of the inducing and induced elements and their relative positions are manipulated in Agostini-and-Proffitt-type configurations. In the first experiment, by using a forced choice paradigm, naïve observers indicated which gray disks arranged to form the letter T in two rows (organized with black/white inducers) appeared lighter/darker. In the second experiment, expert observers performed two nulling tasks: 1) the lightness of gray disk(s) was adjusted until it was perceived equal to that of gray target(s) aligned with white/black inducers; 2) the lightness of target(s) organized with white/black inducers was adjusted to match the target(s) organized with black/ white inducers. We found that also when there are few inducers, perceptual belongingness causes the contrast effect to propagate spatially on all the induced elements. Spatial position does not influence the induction effect. Low-level theories cannot account for these phenomena, but higher-level processes must be factored in to explain them.

A large number of studies have focused on the aesthetic value of smoothly curved objects. By contrast, angular shapes tend to be associated with tertiary qualities such as threat, hardness, loudness, nervousness, etc. The present study focuses on the effect of curvilinearity vs angularity on the aesthetic experience of design artefacts. We used the drawings of everyday objects with novel shapes created by 56 designers (IUAV image dataset). Each drawing had two versions: a smooth and an angular version. To test new tertiary associations, beyond aesthetic value, we obtained ratings for seven characteristics (‘soft/hard, sad/cheerful, male/female, bad/good, aggressive/peaceful, agitated/serene, useless/useful’) from 174 naïve observers. Importantly, each naïve rater saw only one of the two versions of an object. The results confirmed a significant relation between smoothness and hardness as well as other (tertiary) associations. The link between smoothness and usefulness confirms that perceptual utility is significantly influenced by the shape of the object. This finding suggests that tertiary qualities convey both static and functional information about design objects. The role of perceptual constraints in drawing design artefacts is also discussed.

People’s attention cannot help being affected by what others are looking at. The dot-perspective task has been often employed to investigate this visual attentional shift. In this task, participants are presented with virtual scenes with a cue facing some targets and must judge how many targets are visible from their own or the cue perspective. Typically, this task shows an interference pattern: Participants record slower reaction times (RTs) and more errors when the cue is facing away from the targets. Interestingly, this occurs also when participants take their own perspective. Two accounts contend the explanation of this interference. The mentalising account focuses on the social relevance of the cue, while the domain-general account focuses on the directional features of the cue. To investigate the relative contribution of the two accounts, we developed a Social_Only cue, a cue having only social features and compared its effects with a Social+Directional cue, which had both social and directional features. Results show that while the Social+Directional cue generates the typical interference pattern, the Social_Only cue does not generate interference in the RTs, only in the error rate. We advance an integration between the mentalising and the domain-general accounts. We suggest that the dot-perspective task requires two processes: an orienting process, elicited by the directional features of the cue and measured by the RTs, and a decisional process elicited by the social features of the cue and measured also by the error rate.

This paper investigates the performance of a class of irregular low-density parity-check (LDPC) codes through a recently published low complexity upper bound on their belief propagation decoding thresholds. Moreover, their performance analysis is carried out through a recently published algorithmic method, presented in Babich et al. 2017 paper. In particular, the class considered is characterized by variable node degree distributions (lambda(x)) of minimum degree (i_1 gt 2): being, in this case, (lambda^{'} (0)=lambda_2=0), this is useful to design LDPC codes presenting a linear minimum distance growth with the block length with probability 1, as shown in Di et al.’s 2006 paper. These codes unfortunately cannot reach capacity under iterative decoding, since the achievement of capacity requires (lambda_2 neq 0). However, in this latter case, the block error probability might converge to a constant, as shown in the aforementioned paper.

Government restrictions to the movement of people due to the COVID-19 pandemic have had a wide range of effects on scientific activity. Here, we show that during the pandemic there has been a reduction in the number of registered non-COVID-19 clinical trials. Furthermore, using the Oxford COVID-19 Government Response Tracker Stringency Index (SI) as an indicator of COVID-19–related workplace adjustment (e.g., restrictions on gatherings, workplace closures, and stay-at-home orders), we demonstrate that this drop in clinical trial registration has been greater in countries with a higher SI. This could have significant consequences for the discovery of treatments that are required to reduce the global burden of disease.

The approximations of the Gaussian Q-function found in the literature have been often developed with the goal of obtaining high estimation accuracies in deriving the error probability for digital modulation schemes. Unfortunately, the obtained mathematical expressions are often too complex, even difficultly tractable. A new approximation for the Gaussian Q-function is presented in the form of the standard normal density multiplied by a rational function. The rational function is simply a linear combination of the first 5 integer negative powers of the same term, linear in x, using only 4 decimal constants. In this paper we make some considerations about the significant interval where to consider the Q-function in telecommunication theory. The relative error in absolute value of the given approximation is less than 0.06% in the considered significant interval.

Low Density Parity Check (LDPC) codes are currently being deeply analyzed through algorithms that require the capability of addressing their iterative decoding convergence performance. Since it has been observed that the probability distribution function of the decoder’s log-likelihood ratio messages is roughly Gaussian, a multiplicity of moderate entanglement strategies to this analysis has been suggested. The first of them was proposed in Chung et al.’s 2001 paper, where the recurrent sequence, characterizing the passage of messages between variable and check nodes, concerns the function ϕ(x), therein specified, and its inverse. In this paper, we review this old approximation to the function ϕ(x), one variant on it obtained in the same period (proposed in Ha et al.’s 2004 paper), and some new ones, recently published in two 2019 papers by Vatta et al. The objective of this review is to analyze the differences among them and their characteristics in terms of accuracy and computational complexity. In particular, the explicitly invertible, not piecewise defined approximation of the function ϕ(x), published in the second of the two abovementioned 2019 papers, is shown to have less relative error in any x than most of the other approximations. Moreover, its use conducts to an important complexity reduction, and allows better Gaussian approximated thresholds to be obtained.

Lightness contrast and assimilation are opposite phenomena: in contrast grey targets appear\ud darker when bordering bright rather than dark surfaces; in assimilation grey targets appear\ud lighter when bordering bright rather than dark surfaces. The underlying neurophysiological\ud mechanisms of these phenomena are not known. The aim of this study was to investigate the\ud relationship between contrast and assimilation, and the timing and levels of perceptual and\ud cognitive processing using combined behavioural and electrophysiological methods. Thirty\ud undergraduate students (23 female, age range 18-48 years old) participated in a forced-choice\ud (grey target is lighter/darker than a comparison square) task, using stimuli designed such that the\ud inducers were in two configurations (small and large) and two shades (white and black). The\ud behavioural data (more consistent and faster responses) corroborated previous findings of\ud stronger contrast effects with white inducers and stronger assimilation effects with black\ud inducers. According to the Event Related Potentials (ERP) results the mean amplitude was larger\ud in conditions with less consistent and slower behavioural responses. Thus, with contrast\ud responses P1 amplitude was larger with black than white inducers, and N1 amplitude was larger\ud to assimilation than contrast when the configuration of the stimulus was held constant. These\ud results suggest contrast may occur as early as P1 (~110 ms) and assimilation may occur later in\ud N2 (~220 ms), whereas in some conditions, differences in ERPs associated with contrast versus\ud assimilation may happen as early as in N1 (~170m), in occipital and parietal cortical sites.

This article serves as a step-by-step guide of a new application of Q-methodology to investigate people’s preferences for multivariate stimuli. Q-methodology has been widely applied in fields such as sociology, education and political sciences but, despite its numerous advantages, it has not yet gained much attention from experimental psychologists. This may be due to the fact that psychologists examining preferences, often adopt stimuli resulting from a combination of characteristics from multiple variables, and in repeated measure designs. At present, Q methodology has not been adapted to accommodate. We therefore developed a novel analysis procedure allowing Q-methodology to handle these conditions. We propose a protocol requiring five analyses of a decision process to estimate: (1) the preference of stimuli, (2) the dominance of variables, (3) the individual differences, (4) the interaction between individual differences and preference, and (5) the interaction between individual differences and dominance. The guide comes with a script developed in R (R Core Team, 2020) to run the five analyses; furthermore, we provide a case study with a detailed description of the procedure and corresponding results. This guide is particularly beneficial to conduct and analyze experiments in any research on people’s preferences, such as experimental aesthetics, prototype testing, visual perception (e.g., judgments of similarity/dissimilarity to a model), etc.

This paper investigates about the usefulness of a recently published low complexity upper bound on beliefpropagation decoding thresholds for a class of irregular lowdensity parity-check (LDPC) codes. In particular, the class considered is characterized by variable node degree distributions λ(x) of minimum degree ${i_1}$ >2: being, in this case, $\lambda^{\prime}$(0)=$\lambda_{2}=0$, this is useful to design LDPC codes presenting a linear minimum distance growth with the block length with probability 1, as shown in Di et al.’s 2006 paper. These codes unfortunately cannot reach capacity under iterative decoding, since the achievement of capacity requires $\lambda_{2}\neq0$. However, in this latter case, the block error probability might converge to a constant, as shown in the aforementioned paper.

BackgroundSelfies are a novel social phenomenon that is gradually beginning to receive attention within the cognitive sciences. Several studies have documented biases that may be related to nonverbal communicative intentions. For instance, in selfies posted on the dating platform Tinder males but not females prefer camera views from below (Sedgewick, Flath & Elias, 2017). We re-examined this study to assess whether this bias is confined to dating selection contexts and to compare variability between individuals and between genders.MethodsThree raters evaluated vertical camera position in 2000 selfies- 1000 by males and 1000 by females-posted in Instagram.ResultsWe found that the choices of camera angle do seem to vary depending on the context under which the selfies were uploaded. On Tinder, females appear more likely to choose neutral, frontal presentations than they do on Instagram, whereas males on Tinder appear more likely to opt for camera angles from below than on Instagram.ConclusionsThis result confirms that the composition of selfies is constrained by factors affecting nonverbal communicative intentions.

Lightness contrast and assimilation are two opposite phenomena: contrast occurs when a grey target perceptually acquires a complementary colour than the bordering, inducing, surfaces; assimilation is when a grey target perceptually acquires the same colour component as the inducers. Previous research has shown that both phenomena are affected by the manipulation of depth between the inducers and target. However, different results have been reported; it is not clear whether contrast persists when inducers are non-coplanar with the target. Previous studies differ for the spatial configuration of the stimuli and the technique adopted to manipulate depth. The aim of this research was to measure the effects of manipulating the depth between inducers and target in comparable conditions. Results show that contrast persists, but largely reduces, after depth manipulation whilst assimilation reverses to contrast. Furthermore, interesting asymmetries between white and black inducers emerged with white inducers favouring contrast and black inducers favouring assimilation. These results provide further evidence that high-level processes of visual processing are involved in both phenomena; with important consequences for lightness theories.

This paper investigates the efficacy of a tactile and haptic human robot interface developed and trialled to aid navigation in poor visibility and audibility conditions, which occur, for example, in search and rescue. The new developed interface generates haptic directional information that will support human navigation when other senses are not or only partially accessible. The central question of this paper was whether humans are able to interpret haptic signals as denoting different spatial directions. The effectiveness of the haptic signals was measured in a novel experimental set up. Participants were given a stick (replicating the robot interface) and asked to reproduce the specific spatial information denoted by each of the haptic signals. The task performance was examined quantitatively and results show that the haptic signals can denote distinguishable spatial directions, supporting the hypothesis that tactile and haptic information can be effectively used to aid human navigation.

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Both numerical and non-numerical magnitudes elicit similar Spatial-Numerical Association of Response Codes (SNARC) effects, with small magnitudes associated with left hand responses and large magnitudes associated with right hand responses (Dehaene, Bossini, Giraux, 1993). In the present study, we investigated whether the phenomenal size of visual illusions elicits the same SNARC-like effect revealed for the physical size of pictorial surfaces. Four experiments were conducted by using the Delboeuf illusion (Experiment 1) and the Kanizsa triangle illusion (Experiments 2, 3 & 4). Experiment 1 suggests the presence of a SNARC-like compatibility effect for the physical size of the inducers, while this effect was not revealed for the phenomenal size of the induced elements, possibly masked by a stronger effect of the inducers. A SNARC-like effect for the phenomenal size of the Kanizsa triangle was revealed when participants directly compared the size of the triangles (Experiment 4). Conversely, when participants performed an indirect task (orientation judgment), the SNARC-like effect was present neither for the illusory nor for the physical displays (Experiments 2 & 3). The effect revealed for the size of illusory triangles was comparable to that of real triangles with physical contours, suggesting that both phenomenal and physical magnitudes similarly elicit SNARC-like effects.

Beauty plays an important role in everyday life. When we shop, for example, our preferences often rely on aesthetic evaluations. This decision-making process is rooted in our brain and is often based on the stimulation of multiple senses at once. To investigate how each of our senses contributes to the overall aesthetic experience Soranzo et al. (2018) studied the aesthetics of the Interactive Objects (IOs); which are objects supplied with electronics that react when handled; e.g. by vibrating, sounding or lightning-up. It emerged that people prefer objects exhibiting a “behaviour” over quiescent objects. Furthermore, interesting different aesthetics “mindsets” emerged: Some people based their aesthetic judgments on the IOs’ behaviour only and other also considered a combination of IOs’ texture and shape. These individual differences are important as the aesthetic response is a subjective and a whimsical experience. To further explore the individual differences in multiple stimulations, in this project we used the Q-methodology (Stephenson, 1953) together with behavioural methods. The results suggest that people can be clustered into different groups based on their aesthetic mindset. These clustered preference groups have shed more light on individual differences in aesthetics, which paves the foundation for future research.

In this paper we survey, complete and refine some recent results concerning the Dirichlet problem for the prescribed anisotropic mean curvature equation \begin{document}$\begin{equation*}{\rm{ -div}}\left({\nabla u}/{\sqrt{1 + |\nabla u|^2}}\right) = -au + {b}/{\sqrt{1 + |\nabla u|^2}},\end{equation*}$ \end{document} in a bounded Lipschitz domain \begin{document} $Ω \subset \mathbb{R}^N$ \end{document} , with \begin{document} $a,b>0$ \end{document} parameters. This equation appears in the description of the geometry of the human cornea, as well as in the modeling theory of capillarity phenomena for compressible fluids. Here we show how various techniques of nonlinear functional analysis can successfully be applied to derive a complete picture of the solvability patterns of the problem.

Animal studies have demonstrated that catecholamines regulate several aspects of fear conditioning. In humans, however, pharmacological manipulations of the catecholaminergic system have been scarce, and their primary focus has been to interfering with catecholaminergic activity after fear acquisition or expression had taken place, using L-Dopa, primarily, as catecholaminergic precursor. Here, we sought to determine if putative increases in presynaptic dopamine and norepinephrine by tyrosine administered before conditioning could affect fear expression. Electrodermal activity (EDA) of 46 healthy participants (24 placebo, 22 tyrosine) was measured in an instructed fear task. Results showed that tyrosine abolished fear expression compared to placebo. Importantly, tyrosine did not affect EDA responses to the aversive stimulus (UCS) or alter participants’ mood. Therefore, the effect of tyrosine on fear expression cannot be attributed to these factors. Taken together, these findings provide evidence that the catecholaminergic system influences fear expression in humans.

The aim of the current project was to investigate aesthetics in multi-sensorial stimulation and to explore individual differences in the process. We measured the aesthetics of interactive objects (IOs) which are three-dimensional objects with electronic components that exhibit an autonomous behaviour when handled, e.g., vibrating, playing a sound, or lighting-up. The Q-sorting procedure of Q-methodology was applied. Data were analysed by following the Qmulti protocol. The results suggested that overall participants preferred IOs that (i) vibrate, (ii) have rough surface texture, and (iii) are round. No particular preference emerged about the size of the IOs. When making an aesthetic judgment, participants paid more attention to the behaviour variable of the IOs than the size, contour or surface texture. In addition, three clusters of participants were identified, suggesting that individual differences existed in the aesthetics of IOs. Without proper consideration of potential individual differences, aesthetic scholars may face the risk of having significant effects masked by individual differences. Only by paying attention to this issue can more meaningful findings be generated to contribute to the field of aesthetics.

Surface reflectance and illumination level, which are confounded in the\ud retinal image, must be disentangled by the visual system and a theory of\ud lightness must explain how. Thus, a theory of surface lightness should also be\ud a theory of perceived illumination and describe the relationship between\ud them. Perceived illumination and perceived grey values have been measured\ud using a new technique. Looking into a vision tunnel, observers saw two square\ud apertures in the far wall, each revealing a patch of wall composed of two\ud shades of grey. They adjusted the illumination level in one aperture to match\ud that in the other. The stimuli placed in the apertures varied in luminance\ud range, spatial frequency, and relative area. Results show that 1) illumination is\ud matched for highest luminance (with no effect of spatial frequency).\ud Combined with earlier findings that lightness is anchored by highest\ud luminance, this supports Koffka’s suggestion that lightness and perceived\ud illumination are coupled in an invariant way. 2) Changes in the relative area of\ud the light and dark shades produced complementary influences on perceived\ud illumination and surface lightness. That is, when stimulus conditions evoke a\ud conflict between anchoring the highest luminance at white and anchoring the\ud largest area at white, enlarging the darker shade causes its lightness to\ud increase and the perceived illumination to decrease by the same amount,\ud 3\ud further supporting Koffka. 3) These findings allow perceived illumination\ud level to now be systematically incorporated into anchoring theory, which until\ud this point has been solely a theory of surface lightness.

Lightness (the perceived dimension running from black to white) represents a problem for vision science because the light\ud coming to the eye from an object totally fails to specify the shade of gray of the object, due to the confounding of surface gray and\ud illumination intensity. The two leading approaches, decomposition theories and anchoring theories, split the retinal image into\ud overlapping layers and adjacent frameworks, respectively. Because each approach has important strengths and some weaknesses,\ud an integration of them would mark an important step forward for the lightness theory. But the problem remains how this\ud integration can actually be realized.

Low density parity check (LDPC) codes are still intensively studied investigating their iterative decoding convergence performance. Since the probability distribution function of the decoder's log-likelihood ratio messages was observed to be approximately Gaussian, a variety of low-complexity approaches to this investigation were proposed. One of them was presented in Chung et al.'s 2001 paper, involving the function ϕ ( x ) , therein specified, and its inverse. In this Letter, a new approximation of the function ϕ ( x ) is given, such that, unlike the other approximations found in the literature, it is defined by a single expression (i.e. it is not piecewise defined), it is explicitly invertible, and it has less relative error in any x than the other approximations.

Technological advances are increasing the range of applications for artificial intelligence, especially through its\ud embodiment within humanoid robotics platforms. This promotes the development of novel systems for automated screening of neurological conditions to assist the clinical practitioners in the detection of early signs\ud of mild cognitive impairments. This article presents the implementation and the experimental validation of\ud the first robotic system for cognitive assessment, based on one of the most popular platforms for social robotics, Softbank "Pepper", which administers and records a set of multi-modal interactive tasks to engage the\ud user cognitive abilities. The robot intelligence is programmed using the state-of-the-art IBM Watson AI Cloud\ud services, which provide the necessary capabilities for improving the social interaction and scoring the tests.\ud The system has been tested by healthy adults (N = 35) and we found a significant correlation between the\ud automated scoring and the MoCA, one of the most widely used paper-and-pencil tests. We conclude that the\ud system can be considered as a screening instrument for cognitive assessment.

This letter presents a more accurate mathematical analysis, with respect to the one performed in Chung et al. ’s 2001 paper, of belief-propagation decoding for low-density parity-check (LDPC) codes on memoryless binary input—additive white Gaussian noise channels, when considering a Gaussian approximation (GA) for message densities under density evolution. The recurrent sequence, defined in Chung et al. ’s 2001 paper, describing the message passing between variable and check nodes follows from the GA approach and involves the function $\boldsymbol {\phi (x)}$ , therein defined, and its inverse. The analysis of this function is here resumed and studied in depth to obtain tighter upper and lower bounds on it. Moreover, unlike the upper bound given in the above cited paper, the tighter upper bound on $\boldsymbol {\phi (x)}$ is invertible. This allows a more accurate evaluation of the asymptotical performance of sum-product decoding of LDPC codes when a GA is assumed.

This paper investigates about the usefulness of some recently published low complexity upper bounds on belief-propagation decoding thresholds for irregular low-density parity-check (LDPC) codes to analyze their performance on memoryless binary input - additive white Gaussian noise (BI-AWGN) channels, with sum-product decoding. Irregular LDPC codes are known to perform better than regular ones, and to exhibit, like them, the so called “threshold phenomenon”, being the threshold defined as the maximum noise level such that an arbitrarily small bit-error probability can be achieved as the block length tends to infinity. We use a simplified analysis of the belief-propagation decoding algorithm, i.e., consider a Gaussian approximation for message densities under density evolution, and a simple algorithmic method, defined recently, to estimate the decoding thresholds for regular and irregular LDPC codes on BI-AWGN channels.

Thanks to recent developments in artificial intelligence and social robotics, Hu-man-Robot Interaction (HRI) can be used as a non-invasive screening tool for the assessment of cognitive decline. In this scenario, the robot manages the assess-ment by providing the instructions to the patient, registering his/her answers and objectively calculating the final score. This service can help to save time and reach a wider population. From the technical point of view, a challenge is to achieve a highly reliable speech and visual recognition as required for a valid scor-ing of performance. \ud In this article, we evaluate a system for cognitive assessment that makes use of the IBM AI Cloud services embodied in one of the most popular platforms for social robotics: the SoftBank Pepper. Results of a pilot study with 16 human par-ticipants shows that IBM Cloud services for speech and visual recognition can improve the system performance in comparison with standard interfaces. Im-portantly, the improvement allows achieving a significant correlation with one of the most used paper-and-pencil tests and, therefore, the study demonstrates the validity of the robotic approach for cognitive assessment

Human observers make errors when predicting what is visible in a mirror. This is true for perception with real mirrors as well as for reasoning about mirrors shown in diagrams. We created an illustration of a room, a top-down view, with a mirror on a wall and objects (nails) on the opposite wall. The task was to select which nails were visible in the mirror from a given position (viewpoint). To study the importance of the social nature of the viewpoint, we divided the sample ( N = 108) in two groups. One group ( n = 54) were tested with a scene in which there was the image of a person. The other group ( n = 54) were tested with the same scene but with a camera replacing the person. Participants were instructed to think about what would be captured by a camera on a tripod. This manipulation tests the effect of social perspective-taking in reasoning about mirrors. As predicted, performance on the task shows an overestimation of what can be seen in a mirror and a bias to underestimate the role of the different viewpoints, that is, a tendency to treat the mirror as if it captures information independently of viewpoint. In terms of the comparison between person and camera, there were more errors for the camera, suggesting an advantage for evaluating a human viewpoint as opposed to an artificial viewpoint. We suggest that social mechanisms may be involved in perspective-taking in reasoning rather than in automatic attention allocation.

Since irregular low-density parity-check (LDPC) codes are known to perform better than regular ones, and to exhibit, like them, the so-called ‘threshold phenomenon’, this Letter investigates a low-complexity upper bound on belief-propagation decoding thresholds for this class of codes on memoryless binary input additive white Gaussian noise channels, with sum-product decoding. A simplified analysis of the belief-propagation decoding algorithm is used, i.e. consider a Gaussian approximation for message densities under density evolution, and a simple algorithmic method, defined recently, to estimate the decoding thresholds for regular and irregular LDPC codes.

Spatial cueing of attention occurs when attention is oriented by the onset of a stimulus or by other information that creates a bias towards a particular location. The presence of a cue that orients attention can also interfere with participants' reporting of what they see. It has been suggested that this type of interference is stronger in the presence of socially-relevant cues, such as human faces or avatars, and is therefore indicative of a specialised role for perspective calculation within the social domain. However, there is also evidence that the effect is a domain-general form of processing that is elicited equally with non-social directional cues. The current paper comprises four experiments that systematically manipulated the social factors believed necessary to elicit the effect. The results show that interference persists when all social components are removed, and that visual processes are sufficient to explain this type of interference, thus supporting a domain-general perceptual interpretation of interference.