How universal is preference for visual curvature? A systematic review and meta-analysis

Evidence dating back a century shows that humans are sensitive to and exhibit a preference for visual curvature. This effect has been observed in different age groups, human cultures, and primate species, suggesting that a preference for curvature could be universal. At the same time, several studies have found that preference for curvature is modulated by contextual and individual factors, casting doubt on this hypothesis. To resolve these conflicting findings, we conducted a systematic meta-analysis of studies that have investigated the preference for visual curvature. Our meta-analysis included 61 studies which provided 106 independent samples and 309 effect sizes. The results of a three-level random effects model revealed a Hedges' g of 0.39-consistent with a medium effect size. Further analyses revealed that preference for curvature is moderated by four factors: presentation time, stimulus type, expertise, and task. Together, our results suggest that preference for visual curvature is a reliable but not universal phenomenon and is influenced by factors other than perceptual information.

Shape familiarity modulates preference for curvature in drawings of common-use objects

Drawing is a way to represent common-use objects. The contour of an object is a salient feature that defines its identity. Preference for a contour (curved or angular) may depend on how familiar the resulting shape looks for that given object. In this research, we examined the influence of shape familiarity on preference for curved or sharp-angled drawings of common-use objects. We also examined the possibility that some individual differences modulated this preference. Preference for curvature was assessed with a liking rating task (Experiment 1) and with a two-alternative forced-choice task simulating approach/avoidance responses (Experiment 2). Shape familiarity was assessed with a familiarity selection task where participants selected the most familiar shape between the curved and the angular version for each object, or whether both shapes were equally familiar for the object. We found a consistent preference for curvature in both experiments. This preference increased when the objects with a curved shape were selected as the most familiar ones. We also found preference for curvature when participants selected the shape of objects as equally familiar. However, there was no preference for curvature or preference for angularity when participants selected the sharp-angled shapes as the most familiar ones. In Experiment 2, holistic and affective types of intuition predicted higher preference for curvature. Conversely, participants with higher scores in the unconventionality facet showed less preference for the curved drawings. We conclude that shape familiarity and individual characteristics modulate preference for curvature.

When symmetric and curved visual contour meet intentional instructions: Hedonic value and preference

Symmetry and contour take part in shaping visual preference. However, less is known about their combined contribution to preference. We examined the hedonic tone and preference triggered by the interaction of symmetry and contour. Symmetric/curved, symmetric/sharp-angled, asymmetric/curved, and asymmetric/sharp-angled stimuli were presented in an implicit and explicit task. The implicit task consisted of an affective stimulus-response compatibility task where participants matched the stimuli with positive and negative valence response cues. The explicit task recorded liking ratings from the same stimuli. We used instructed mindset to induce participants to focus on symmetry or contour in different parts of the experimental session. We found an implicit compatibility of symmetry and curvature with positive hedonic tone. Explicit results showed preference for symmetry and curvature. In both tasks, symmetry and curvature showed a cumulative interaction, with a larger contribution of symmetry to the overall effect. While symmetric and asymmetric stimuli contributed to the implicit positive valence of symmetry, the effect of curvature was mainly caused by inclination towards curved contours rather than rejection of sharp-angled contours. We did not find any correlation between implicit and explicit measures, suggesting that they may involve different cognitive processing.

Implicit Attitudes Toward Violence in a Sample of Adolescent Offenders With Conduct Disorder

Few studies have addressed attitudes toward violence in offender populations using implicit measures. The aim of this study is to test whether implicit attitudes toward two types of violence (physical and relational) differ between two groups of adolescent offenders: one group with conduct disorder (CD; n = 36) and the other group without this condition (No-CD; n = 26). We found that adolescent offenders with CD evidenced less negative implicit attitudes toward physical violence than the No-CD group. No differences between groups were observed in the case of relational violence. Our results suggest that CD modulates implicit attitudes toward violence in adolescent offenders and that the influence of CD is stronger in the case of physical rather than relational acts of violence.

Circles Are Detected Faster Than Downward-Pointing Triangles in a Speeded Response Task

Simple geometric shapes are associated with facial emotional expressions. According to previous research, a downward-pointing triangle conveys the threatening perception of an angry facial expression, and a circle conveys the pleasant perception of a happy facial expression. Some studies showed that downward-pointing triangles have the advantage to capture attention faster than circles. Other studies proposed that curvature enhances visual detection and guides attention. We tested a downward-pointing triangle and a circle as target stimuli for a speeded response task. The distractors were two stimuli that resulted from the mixture of both targets to control for low-level features' balanced presentation. We used 3 × 3, 4 × 4, and 5 × 5 matrices to test whether these shapes led attention to an efficient response. In Experiment 1, participants responded faster to the circle than to the downward-pointing triangle. They also responded slower to both targets as the number of distractors increased. In Experiment 2, we replicated the main findings of Experiment 1. Overall, the circle was detected faster than the downward-pointing triangle with small matrices, but this difference decreased as the matrix size increased. We suggest that circles capture attention faster because of the influence of low-level features, that is, curvature in this case.

Does mindfulness improve inhibitory control in psychotic disorders? A randomized controlled clinical trial

Background/Objective: Impaired Inhibitory Control (IC) is a core feature of psychotic disorders and is related with impaired social functioning in people experiencing psychosis. Despite research showing the benefits of mindfulness over IC in the general population, no study has assessed its effects on IC in psychoses. The aim of our study was to assess the effectiveness of a mindfulness-based intervention combined with integrated rehabilitation treatment in a sample of people diagnosed of psychotic disorders. Method: Fifty-six patients diagnosed with psychotic disorder were recruited and randomly allocated either to integrated rehabilitation treatment or integrated rehabilitation treatment enhanced with 26 mindfulness group sessions. Measures comprised PANSS interview, MAAS scale, and Stroop Color Word Test (SCWT). The primary outcome variable was the performance in the non-congruent trials of the SCWT. Results: There were no differences between groups at baseline. At post-treatment patients allocated to mindfulness group increased their scores in non-congruent trials of SCWT and in MAAS. At post-treatment mindfulness group scored higher than integrated rehabilitation treatment in MAAS. Conclusions: Data suggest that mindfulness added to integrated rehabilitation treatment may improve IC in psychosis. Results are convergent with prior works about the effect of mindfulness over cognitive performance in general population.

The effects of presentation time on preference for curvature of real objects and meaningless novel patterns

Objects with curved contours are generally preferred to sharp-angled ones. In this study, we aim to determine whether different presentation times influence this preference. We used images of real objects (experiment 1) and meaningless novel patterns (experiment 2). Participants had to select one of two images from a contour pair, curved and sharp-angled versions of the same object/pattern. With real objects, the preference for curved versions was greatest when presented for 84 ms, and it faded when participants were given unlimited viewing time. Curved meaningless patterns were preferred when presented for 84 and 150 ms. However, in contrast to real objects, preference for meaningless patterns increased significantly in the unlimited viewing time condition. Participants discriminated poorly between the two versions (curved and sharp-angled) of the meaningless patterns in the 84- and 150-ms presentations (experiment 3). Therefore, in short times with meaningless patterns, participants selected mostly the curved version without being aware of the difference. In conclusion, presentation time, type of stimulus, and their interaction influence preference for curvature.

Trust-based altruism facing new contexts: The Vyegwa-Gika pygmies from Burundi

The community of Pygmies settled in Vyegwa-Gika provides an exceptional case study to test the role of trust in the evolution of altruism. The Vyegwa-Gika Pygmies were forced to migrate from rainforests to the savanna, changing quickly their environment, culture, and socio-economic situation. Despite the high level of poverty they suffer in this new settlement, we found evidence of strong altruistic attitudes toward trustees when playing an economic game. In addition, Vyegwa-Gika Pygmies keep small personal trust networks despite the fact they share frequent social interactions within the community. These results indicate the great effectiveness of personal trust in fostering altruism, even if the circumstances make it difficult to establish such kind of affective bonds. A theory of the evolution of altruism should therefore also account for the evolution of psychology of trust, as a key element in the process.

Psychotic symptoms and quality of life: A mediation analysis of daily-life coping

Prior studies suggest the relationship between psychotic symptoms and Quality of Life (QoL) may be mediated by diverse constructs. QoL in schizophrenia-related disorders has been related with coping with daily stressors. Based on previous studies, our hypothesis was that coping mediates the relationship between psychotic symptoms and QoL. Therefore, the aim of the study was to test the hypothesis in a sample of people with schizophrenia-related disorders from a community rehabilitation center. Sixty-six patients were assessed using PANSS, WHOQOL-BREF questionnaire, and COPE Inventory. Regression analyses were performed for each WHOQOL-BREF dimension using PANSS and COPE factors as predictors. Mediation analysis was performed for each WHOQOL-BREF dimension using significant PANSS scales as predictors and significant COPE factors as mediators. Sobel test showed that Self-Sufficient (Problem-focused) coping mediates the relationship between PANSS Positive and WHOQOL-BREF Psychological and WHOQOL-BREF Environmental scores. Results suggest that coping style based on personal abilities and oriented to the stressors mediates the relationship between positive symptoms and QoL associated to well-being and environmental features. However, in our study no coping style mediated the relationship between negative symptoms and QoL. Depressive symptoms predicted each QoL dimension and were not mediated by any coping style.

Preference for Curvature: A Historical and Conceptual Framework

That people find curved contours and lines more pleasurable than straight ones is a recurrent observation in the aesthetic literature. Although such observation has been tested sporadically throughout the history of scientific psychology, only during the last decade has it been the object of systematic research. Recent studies lend support to the idea that human preference for curved contours is biologically determined. However, it has also been argued that this preference is a cultural phenomenon. In this article, we review the available evidence, together with different attempts to explain the nature of preference for curvature: sensoriomotor-based and valuation-based approaches. We also argue that the lack of a unifying framework and clearly defined concepts might be undermining our efforts towards a better understanding of the nature of preference for curvature. Finally, we point to a series of unresolved matters as the starting point to further develop a consistent research program.

Mindfulness improves psychological quality of life in community-based patients with severe mental health problems: A pilot randomized clinical trial

OBJECTIVE

To examine the effectiveness of group mindfulness-based intervention (MBI) in patients diagnosed with severe mental illness. The primary outcome was health-related psychological quality of life. Secondary measures were environmental, social and physical health related quality of life, frequency and intensity of psychotic symptoms and daily-life mindfulness.

METHOD

Forty-four patients from a public community rehabilitation center for people with severe mental illness were recruited, and randomly allocated to Integrated Rehabilitation Treatment (IRT) or IRT plus MBI. Measures included PANSS interview, WHOQOL-BREF, and Mindfulness Attention Awareness Scale. MBI comprised 26 one-hour weekly sessions. Intention-to-treat analysis was used.

RESULTS

One patient did not complete IRT+MBI and two did not complete IRT. At baseline there were no statistical group differences in demographic characteristics or primary and secondary outcomes. At post-treatment interaction between treatment and time in health-related psychological quality of life was statistically significant, and simple effect analysis showed significant differences for between and within subject factor in favor of MBI. Interaction was also significant in PANSS negative symptoms, simple effects showed a statistical trend in within subject factor. Time factor was significant in environmental and physical quality of life.

CONCLUSIONS

Data suggest mindfulness added to IRT may enhance psychological quality of life in people with severe mental illness from a public community center. Results also suggest that mindfulness may impact frequency and intensity of negative symptoms.

Cognitive control and unusual decisions about beauty: an fMRI study

Studies of visual esthetic preference have shown that people without art training generally prefer representational paintings to abstract paintings. This, however, is not always the case: preferences can sometimes go against this usual tendency. We aimed to explore this issue, investigating the relationship between "unusual responses" and reaction time in an esthetic appreciation task. Results of a behavioral experiment confirmed the trend for laypeople to consider as beautiful mostly representational stimuli and as not beautiful mostly abstract ones ("usual response"). Furthermore, when participants gave unusual responses, they needed longer time, especially when considering abstract stimuli as beautiful. We interpreted this longer time as greater involvement of cognitive mastering and evaluation processes during the unusual responses. Results of an fMRI experiment indicated that the anterior cingulate (ACC), orbitofrontal cortex (OFC) and insula were the main structures involved in this effect. We discuss the possible role of these areas in an esthetic appreciation task.

Affective priming using facial expressions modulates liking for abstract art

We examined the influence of affective priming on the appreciation of abstract artworks using an evaluative priming task. Facial primes (showing happiness, disgust or no emotion) were presented under brief (Stimulus Onset Asynchrony, SOA = 20ms) and extended (SOA = 300ms) conditions. Differences in aesthetic liking for abstract paintings depending on the emotion expressed in the preceding primes provided a measure of the priming effect. The results showed that, for the extended SOA, artworks were liked more when preceded by happiness primes and less when preceded by disgust primes. Facial expressions of happiness, though not of disgust, exerted similar effects in the brief SOA condition. Subjective measures and a forced-choice task revealed no evidence of prime awareness in the suboptimal condition. Our results are congruent with findings showing that the affective transfer elicited by priming biases evaluative judgments, extending previous research to the domain of aesthetic appreciation.

The world can look better: enhancing beauty experience with brain stimulation

Aesthetic appreciation is part of our everyday life: it is a subjective judgment we make when looking at a painting, a landscape, or--in fact--at another person. Neuroimaging and electrophysiological evidence suggests that the left dorsolateral prefrontal cortex (DLPFC) plays a critical role in aesthetic judgments. Here, we show that the experience of beauty can be artificially enhanced with brain stimulation. Specifically, we show that aesthetic appreciation of representational paintings and photographs can be increased by applying anodal (excitatory) transcranial direct current stimulation on the left DLPFC. Our results thus show that beauty is in the brain of the beholder, and offer a novel view on the neural networks underlying aesthetic appreciation.

Roman Catholic beliefs produce characteristic neural responses to moral dilemmas

This study provides exploratory evidence about how behavioral and neural responses to standard moral dilemmas are influenced by religious belief. Eleven Catholics and 13 Atheists (all female) judged 48 moral dilemmas. Differential neural activity between the two groups was found in precuneus and in prefrontal, frontal and temporal regions. Furthermore, a double dissociation showed that Catholics recruited different areas for deontological (precuneus; temporoparietal junction) and utilitarian moral judgments [dorsolateral prefrontal cortex (DLPFC); temporal poles], whereas Atheists did not (superior parietal gyrus for both types of judgment). Finally, we tested how both groups responded to personal and impersonal moral dilemmas: Catholics showed enhanced activity in DLPFC and posterior cingulate cortex during utilitarian moral judgments to impersonal moral dilemmas and enhanced responses in anterior cingulate cortex and superior temporal sulcus during deontological moral judgments to personal moral dilemmas. Our results indicate that moral judgment can be influenced by an acquired set of norms and conventions transmitted through religious indoctrination and practice. Catholic individuals may hold enhanced awareness of the incommensurability between two unequivocal doctrines of the Catholic belief set, triggered explicitly in a moral dilemma: help and care in all circumstances-but thou shalt not kill.

Aesthetic appreciation: event-related field and time-frequency analyses

Improvements in neuroimaging methods have afforded significant advances in our knowledge of the cognitive and neural foundations of aesthetic appreciation. We used magnetoencephalography (MEG) to register brain activity while participants decided about the beauty of visual stimuli. The data were analyzed with event-related field (ERF) and Time-Frequency (TF) procedures. ERFs revealed no significant differences between brain activity related with stimuli rated as “beautiful” and “not beautiful.” TF analysis showed clear differences between both conditions 400 ms after stimulus onset. Oscillatory power was greater for stimuli rated as “beautiful” than those regarded as “not beautiful” in the four frequency bands (theta, alpha, beta, and gamma). These results are interpreted in the frame of synchronization studies.

Towards a framework for the study of the neural correlates of aesthetic preference

Aiming to provide a tentative framework for the study of the neural correlates of aesthetic preference, we review three recent neuroimaging studies carried out with the purpose of locating brain activity associated with decisions about the beauty of visual stimuli (Cela-Conde et al., 2004; Kawabata and Zeki, 2004; Vartanian and Goel, 2004). We find that the results of the three studies are not in line with previous neuropsychological data. Moreover, there are no coincidences among their results. However, when they are mapped on to Chatterjee's (2003) neuropsychological model of aesthetic preference it becomes clear that neuroimaging data are not contradictory, but complementary, and their interpretation is enriched. The results of these studies suggest that affective processes have an important role in aesthetic preference, and that they are integrated with cognitive processes to reach a decision regarding the beauty of visual stimuli. Future studies must aim to clarify whether certain methodological procedures are better suited to study any of the particular cognitive operations involved in aesthetic preference, and ascertain the extent to which the proposed framework is compatible with the aesthetic appreciation of musical stimuli.

Activation of the prefrontal cortex in the human visual aesthetic perception

Visual aesthetic perception ("aesthetics") or the capacity to visually perceive a particular attribute added to other features of objects, such as form, color, and movement, was fixed during human evolutionary lineage as a trait not shared with any great ape. Although prefrontal brain expansion is mentioned as responsible for the appearance of such human trait, no current knowledge exists on the role of prefrontal areas in the aesthetic perception. The visual brain consists of "several parallel multistage processing systems, each specialized in a given task such as, color or motion" [Bartels, A. & Zeki, S. (1999) Proc. R. Soc. London Ser. B 265, 2327-2332]. Here we report the results of an experiment carried out with magnetoencephalography which shows that the prefrontal area is selectively activated in humans during the perception of objects qualified as "beautiful" by the participants. Therefore, aesthetics can be hypothetically considered as an attribute perceived by means of a particular brain processing system, in which the prefrontal cortex seems to play a key role.

The "style scheme" grounds perception of paintings

We studied the formation of style scheme (identification of the style that characterizes an artist) presenting 100 participants aesthetic visual stimuli. Participants were Spanish university students who volunteered: 72 women, 28 men of mean age 22.8 yr. Among those 50 were enrolled in History of Art and 50 students in Psychology. Stimuli belonged to different categories--High Art (pictures of well-known artists, like Van Gogh)/Popular Art (decorative pictures like Christmas postcards) and Representational (pictures with explicit meaning content, like a landscape)/Abstract (pictures without explicit meaning content, like Pollock's colored stains). Analysis using Signal Detection Theory techniques focused on how participants discriminate representational and abstract pictures. With High Art stimuli, participants can better discriminate representational paintings than abstract ones. However, the difference in discrimination between representational and abstract pictures diminishes among participants studying History of Art. It seems that prior education in art favors forming style schemes and to some extent enables the participant to detect the "meaning" in High Art abstract paintings.

Mitogen-activated protein kinase kinase activity is required for the G(2)/M transition of the cell cycle in mammalian fibroblasts

The mitogen-activated protein kinase (MAPK) cascade is required for mitogenesis in somatic mammalian cells and is activated by a wide variety of oncogenic stimuli. Specific roles for this signaling module in growth were dissected by inhibiting MAPK kinase 1 (MAPKK1) activity in highly synchronized NIH 3T3 cells. In addition to the known role of this kinase in cell-cycle entry from G(0), the level of MAPKK activity was observed to affect the kinetics of progression through both the G(1) and G(2) phases of the cell cycle in NIH 3T3 cells. Ectopic expression of dominant-negative forms of MAPKK1, which was previously shown to inhibit G(0)/G(1) progression, was found to also delay progression of cells through G(2). In addition, treatment of cells with the specific MAPKK inhibitor PD 98059 during a synchronous S phase arrested the cells in the following G(2) phase. These data demonstrate a novel role for the MAPK cascade in progression from G(2) into mitosis in NIH 3T3 cells.

Inhibition of cellular differentiation by phospholipase C. I. Effects of the enzyme on myogenesis and chondrogenesis in vitro

In cell culture, a partially purified commercial preparation of phospholipase C (PLC) from Clostridium welchii inhibited fusion of myoblasts at concentrations of 12-50 microg per ml. At lower concentrations, PLC-treated cultures were indistinguishable from controls, and at concentrations above 100 microg per ml, PLC-treated cells detached from their substrates. The effect was reversible and fusion resumed approximately one cell cycle time after removal of the enzyme. Neither the percent of cells in the mitotic cycle nor the duration of the different phases of the cycle were altered by PLC at concentrations which inhibited fusion. Cell motility was not reduced by the enzyme. Unfused, PLC-treated myoblasts were virtually indistinguishable in ultrastructure from untreated cells just before fusion. In the presence of PLC, mononucleated myogenic cells did not synthesize thick (150 A) filaments. Treatment of culture medium with insolubilized commercial PLC did not abolish the capacity of the medium to support myogenesis. Chondrocytes treated with PLC divided repeatedly but failed to synthesize metachromatic matrix and failed to incorporate labeled sulfate into chondroitin sulfate. PLC was further purified by chromatography on Sephadex G-100. The resulting preparation was free of detectable protease, yielded one band on SDS-acrylamide gel electrophoresis, and displayed all of the biological activities of the less pure material.