The Influence of Directionality on the Giovanelli Illusion

In the Giovanelli illusion, some collinear dots appear misaligned, when each dot lies within a circle and the circles are not collinear. In this illusion, the role of the frame of reference, determined by the circles, is considered a crucial factor. Three experiments were carried out to study the influence of directionality of the circles on the misalignment. The adjustment method was used. Participants changed the orthogonal position of each dot, from the left to the right of the sequence, until a collinear sequence of dots was achieved. The first experiment verified the illusory effect of the misalignment. In the second experiment, the influence of two different directionalities of the circles (-0.58\ub0 and +0.58\ub0) on the misalignment was tested. The results show an over-normalization on the sequences of the dots. The third experiment tested the misalignment of the dots without any inclination of the sequence of circles (0\ub0). Only a local illusory effect was found. These results demonstrate that the directionality of the circles, as a global factor, can increase the misalignment. The findings also indicate that directionality and the frame of reference are independent factors in explaining the Giovanelli illusion

Perceptual Organization within Temporal Displacement

The psychological present has an actual extension. When a sequence of instantaneous stimuli falls in this short interval of time, observers perceive a compresence of events in succession and the temporal order depends on the qualitative relationships between the perceptual properties of the events. Two experiments were carried out to study the influence of perceptual grouping, with and without temporal displacement, on the duration of auditory sequences. The psychophysical method of adjustment was adopted. The first experiment investigated the effect of temporal displacement of a white noise on sequence duration. The second experiment investigated the effect of temporal displacement, along the pitch dimension, on temporal shortening of sequence. The results suggest that the temporal order of sounds, in the case of temporal displacement, is organized along the pitch dimension

Il design dei caratteri tipografici centrato sui segni e sulle qualità espressive

Le proprietà formali dei caratteri tipografici veicolano signi- ficati che impattano sui lettori oltre la funzione di leggibilità. Lo studio del processo di espressione di significati implica variabili cognitive e percettive. Nel testo si tratta la differenza tra significati mediati dai segni o mediati da qualità espres- sive, allo scopo di individuare una base intersoggettiva per la progettazione. Sono analizzati tre presupposti epistemo- logici: la mediazione cognitiva, l’universalità, il ruolo delle conoscenze pregresse nella comunicazione basata sui segni rispetto a quella basata sulle qualità espressive. Infine si propone uno schema sperimentale per dissociare le due modalità, per consentire al designer di progettare un ca- rattere distinguendo operativamente il piano segnico dalle qualità espressive.---The formal properties of typeface make it possible to convey meanings that have an impact on readers that goes far beyond the function of readability and legibility. The study of the process of expression of meanings involves cognitive and perceptual variables. This paper deals with the difference between meanings mediated by signs or mediated by expressive qualities, in order to identify an intersubjective basis for design. Three epistemological presuppositions are then analyzed: cognitive mediation, universality, the role of past knowledge in communication based on signs compared to communication based on expressive qualities. Finally, an experimental scheme is proposed to dissociate the two communication modalities, in order to allow the designer to design a typeface distinguishing the sign level from the level of expressive qualities

to communicate without signs through expressive qualities

Summary The present paper introduces the theoretical conceptualization of perceptual communication through expressive qualities. Initially, the difference with respect to the modality of perceptual communication mediated by signs is analyzed. Conversely, the theory of expressive qualities reflects the psychological conception of direct perception: any assumption of a cognitive stage of representation is excluded. Perceptual communication immediately expresses the specific character of the structural essence of the object. The structural essence is well studied by the perceptual paradigms of Experimental Phenomenology. Plurivocity, the case in which the same objects can share many expressive characters, is also considered

why experimentum crucis is possible in psychology of perception

Summary This paper examines the experimentum crucis under the light of the Duhem's holistic thesis. This methodological instrument is not usable in physics, because physical theories are always logically connected to many assumptions. On the contrary, it is usable in psychological research oriented to perceptual laws, when these laws are, without any hypothetical term, isolated systems. An application of experimentum crucis in Experimental Phenomenology of perception is presented. In conclusion, the role of perceptual knowledge as an essential assumption in other scientific disciplines that have a high degree of theoricity is also underlined

Boosting antigen-specific T cell activation with lipid-stabilized protein nanoaggregates

Vaccines based on protein antigens have numerous advantages over inactivated pathogens, including easier manufacturing and improved safety. However, purified antigens are weakly immunogenic, as they lack the spatial organization and the associated 'danger signals' of the pathogen. Formulating vaccines as nanoparticles enhances the recognition by antigen presenting cells, boosting the cell-mediated immune response. This study describes a nano-precipitation method to obtain stable protein nanoaggregates with uniform size distribution without using covalent cross-linkers. Nanoaggregates were formed via microfluidic mixing of ovalbumin (OVA) and lipids in the presence of high methanol concentrations. A purification protocol was set up to separate the nanoaggregates from OVA and liposomes, obtained as byproducts of the mixing. The nanoaggregates were characterized in terms of morphology, zeta-potential and protein content, and their interaction with immune cells was assessed in vitro. Antigen-specific T cell activation was over 6-fold higher for nanoaggregates compared to OVA, due in part to the enhanced uptake by immune cells. Lastly, a two-dose immunization with nanoaggregates in mice induced a significant increase in OVA-specific CD8+ T splenocytes compared to soluble OVA. Overall, this work presents for the first time the microfluidic production of lipid-stabilized protein nanoaggregates and provides a proof-of-concept of their potential for vaccination

Visual preference for abstract curvature and for interior spaces: beyond undergraduate student samples

Smoothly curved objects elicit feelings of pleasantness, and tend to be preferred over angular objects. Furthermore, individual differences (i.e., art expertise, openness to experience, holistic thinking), and the complexity of the stimuli are known to moderate the effect. We extended the study of individual differences to two theoretically-relevant groups. Study 1 compared liking for curvature in individuals with autism and a matched neurotypical control group (for age, gender and IQ). Because preference for curvature depends on both sensory (visuospatial) and affective input, for which individuals with autism exhibit anomalies, we hypothesized a difference in preference for curved stimuli between the two groups. Study 2 examined preference for curvature in a group of quasi-expert students of design. Because working architects and designers tend to regard curved interior spaces as beautiful, we hypothesized to replicate this effect within quasi-experts as well, thereby extending the effect across levels of expertise. Using an identical methodology across both studies, we administered abstract stimuli consisting of irregular polygons (angular vs. curved) and patterns of coloured lines (angular vs. curved), as well as concrete stimuli consisting of images of interior spaces. Preference for curvature was confirmed with abstract stimuli in all three groups. For interior design, the curvature effect diminished in magnitude, and this was especially evident in individuals with autism. Interestingly, quasi-experts preferred rectilinear over curvilinear interiors. We discuss the results in relation to the impact of individual differences and expertise on preference for curvature, and their implication for design studies in ecologically valid settings

Production of liposomes by microfluidics: The impact of post-manufacturing dilution on drug encapsulation and lipid loss

Microfluidic mixing is recognized as a convenient method to produce liposomes for its scalability and reproducibility. Numerous studies have described the effect of process parameters such as flow rate ratios and total flow rate on size and size distribution of vesicles. In this work, we focused our attention on the effect of flow rate ratios on the encapsulation efficiency of liposomes, as we hypothesized that different amount of residual organic solvent could affect the retention of lipophilic drug molecules within the bilayer. In a further step, we investigated how the liposomes integrity and loading were impacted by different methods of solvent removal: direct dialysis and dilution & dialysis. Liposomes were prepared by rapidly mixing an ethanolic solution of lipids and a model drug with buffer in a herringbone micromixer, employing four different flow rate ratios (FRR, 4:1, 7:3, 3:2, 1:1). Quercetin, resveratrol and ascorbyl palmitate were used as model antioxidant drugs with different lipophilicity. Data showed that liposomes produced using lower flow rate ratios (i.e., with more residual ethanol) had lower encapsulation efficiencies as well as a more prominent loss of lipids from the bilayer following purification with direct dialysis. If the amount of residual ethanol was reduced to 5% (dilution & dialysis method), the lipids and drug leakage was prevented. Such effect was correlated with the drug aggregation propensity in different ethanol/water mixtures measured by molecular dynamics simulations. Overall, these results highlight the need to tailor the purification method basing on the molecular properties of the loaded drug to ensure high encapsulation and limit the waste of material