Perception is subjective. Even basic judgments, like those of visual object size, vary substantially between observers and also across the visual field within the same observer. The way in which the visual system determines the size of objects remains unclear, however. We hypothesize that object size is inferred from neuronal population activity in V1 and predict that idiosyncrasies in cortical functional architecture should therefore explain individual differences in size judgments. Here we show results from novel behavioural methods and functional magnetic resonance imaging (fMRI) demonstrating that biases in size perception are correlated with the spatial tuning of neuronal populations in healthy volunteers. To explain this relationship, we formulate a population read-out model that directly links the spatial distribution of V1 representations to our perceptual experience of visual size. Taken together, our results suggest that the individual perception of simple stimuli is warped by idiosyncrasies in visual cortical organization.

Abstract:The cardiac extracellular matrix (ECM) is a complex architectural network consisting of structural and nonstructural proteins, creating strength and plasticity. The nonstructural compartment of the ECM houses a variety of proteins, which are vital for ECM plasticity, and can be divided into 3 major groups: glycoproteins, proteoglycans, and glycosaminoglycans. The common denominator for these groups is glycosylation, which refers to the decoration of proteins or lipids with sugars. This review will discuss the fundamental role of the matrix in cardiac development, homeostasis, and remodeling, from a glycobiology point of view. Glycoproteins (eg, thrombospondins, secreted protein acidic and rich in cysteine, tenascins), proteoglycans (eg, versican, syndecans, biglycan), and glycosaminoglycans (eg, hyaluronan, heparan sulfate) are upregulated on cardiac injury and regulate key processes in the remodeling myocardium such as inflammation, fibrosis, and angiogenesis. Albeit some parallels can be made regarding the processes these proteins are involved in, their specific functions are extremely diverse. In fact, under varying conditions, individual proteins can even have opposing functions, making spatiotemporal contribution of these proteins in the rearrangement of multifaceted ECM very hard to grasp. Alterations of protein characteristics by the addition of sugars may explain the immense, yet tightly regulated, variability of the remodeling cardiac matrix. Understanding the role of glycosylation in altering the ultimate function of glycoproteins, proteoglycans, and glycosaminoglycans in the myocardium may lead to the development of new biochemical structures or compounds with great therapeutic potential for patients with heart disease. (Circ Res. 2014;114:872-888.)

14 Perception is subjective. Even basic judgments, like those of visual object size, vary substantiallyHow do we perceive the size of an object? A range of recent observations have lent support to the 26 hypothesis that the visual system generates the perceived size of an object from its cortical 27 representation in early visual cortex 1 . In particular, the spatial spread of neural activity in visual 28 cortex has been related to apparent size under a range of contextual modulations [2][3][4][5][6][7] . The strength of 29 contextual size illusions has further been linked to the cortical territory in V1 that represents the 30 central visual field 8,9 . These findings suggest that lateral connections in V1 may play a central role in 31 size judgments because these interactions are reduced when V1 surface area is larger. Indeed, 32 similar interactions have been argued to underlie the strength of the tilt illusion 10,11 , perceptual 33 alternations in binocular rivalry 12 , the influence of distractors in visual search tasks 13 , and visual 34 working memory capacity 14 . Even the precision of mental imagery co-varies with V1 area 15 35 suggesting V1 may be used as a 'workspace' for storing mental images whose resolution is better 36 when surface area is larger. 37. CC-BY-NC 4.0 International license not peer-reviewed) is the author/funder. It is made available under a The copyright holder for this preprint (which was . http://dx.doi.org/10.1101/026989 doi: bioRxiv preprint first posted online Sep. 16, 2015; 2 However, these previous findings do not demonstrate that V1 representations per se are relevant for 38 size judgments, and in particular for subjective judgments of object size. If V1 signals were indeed 39 the basis for these judgments then variations in the functional architecture of V1 should explain 40 idiosyncratic biases in basic size perception (i.e. size judgements that occur in the absence of any 41 contextual/illusory effects). To date this prediction remains untested. Previous neuroimaging 42 experiments have focused on modulations of apparent size that must involve additional processing, 43 either due to local interactions between adjacent stimuli in V1 or by a context that likely involves 44 processing in higher visual areas. Others have shown that the objective ability to discriminate subtle 45 differences between stimuli is related to cortical magnification and spatial tuning in early visual 46 cortex 11,16,17 . However, no experiment to date has shown a relationship between V1 and subjective 47 perceptual biases in the absence of any contextual interaction, even though there are considerable 48 individual differences in perceptual biases. 49It is well established that subjective size judgments for simple, small stimuli can vary substantially 50 between observers and even across the visual field within the same observer. Previous behavioral 51 research has shown that small visual stimuli appear smaller when they are presented in the 52 periphery [18][19][20] . A ...

Between-group variability in socioeconomic status (SES) has been identified as a potentially important contributory factor in studies reporting cognitive advantages in bilinguals over monolinguals (the so called “bilingual advantage”). The present study addresses the potential importance of this alternative explanatory variable in a study of low and high SES bilingual and monolingual performance on the Simon task and the Tower of London (TOL) task. Results indicated an overall bilingual response time advantage on the Simon task, despite equivalent error rates. Socioeconomic status was an important modulator in this effect, with evidence that bilingualism may be particularly important in promoting speed of processing advantages in low status individuals but have little impact in high status individuals. However, there was a monolingual advantage on the TOL test of executive planning ability. Together, our findings run counter to the central assertion of the bilingual advantage account, that the process of multi-language acquisition confers a broad cognitive advantage in executive function. We discuss these findings in the context of SES as an important modulator in published studies advocating a bilingual cognitive advantage.

Optimal healing after myocardial infarction requires not only the induction of inflammation, but also its timely resolution. In patients, 30 days post myocardial infarction, circulating monocytes have increased expression of Semaphorin3A (Sema3A) as compared to directly after admission. This increased expression coincides with increased expression of Cx3CR1—a marker of non-classical monocytes that are important for immune resolution hence proper wound healing. In mice, the expression of Sema3A also increases in response to myocardial ischemia being expressed by infiltrating leukocytes. Comparing Sema3A heterozygote (HZ) and wild type (WT) mice post myocardial infarction, revealed increased presence of leukocytes in the cardiac tissues of HZ mice as compared to WT, with no differences in capillary density, collagen deposition, cardiomyocyte surface area, chemokine—or adhesion molecules expression. Whilst infarct sizes were similar 14 days after myocardial infarction in both genotypes, Sema3A HZ mice had thinner infarcts and reduced cardiac function as compared to their WT littermates. In vitro experiments were conducted to study the role of Sema3A in inflammation and resolution of inflammation as a potential explanation for the differences in leukocyte recruitment and cardiac function observed in our in vivo experiments. Here, recombinant Sema3A protein was able to affect the pro-inflammatory state of cultured bone marrow derived macrophages. First, the pro-inflammatory state was altered by the induced apoptosis of classical macrophages in the presence of Sema3A. Second, Sema3A promoted the polarization of classical macrophages to resolution-phase macrophages and enhanced their efferocytotic ability, findings that were reflected in the infarcted cardiac tissue of the Sema3A HZ mice. Finally, we demonstrated that besides promoting resolution of inflammation, Sema3A was also able to retard the migration of monocytes to the myocardium. Collectively our data demonstrate that Sema3A reduces cardiac inflammation and improves cardiac function after myocardial infarction by promoting the resolution of inflammation.Electronic supplementary materialThe online version of this article (doi:10.1007/s00395-017-0630-5) contains supplementary material, which is available to authorized users.