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Keywords = sustained posterior negativity

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10 pages, 4087 KiB  
Case Report
Tricuspid Valve Infective Endocarditis in a Chronic Haemodialysis Patient with a Hickman Catheter: A Case Report
by Dalila Šačić, Saddam Shawamri, Ivana Jovanović, Marija Boričić-Kostić, Boris Jegorović, Miloš Mijalković, Kristina Filić, Stefan Juričić, Vidna Karadžić-Ristanović, Danka Bjelić, Selena Gajić and Marko Baralić
Pathogens 2025, 14(6), 539; https://doi.org/10.3390/pathogens14060539 - 28 May 2025
Viewed by 156
Abstract
Infective endocarditis (IE) of the tricuspid and pulmonary valve accounts for 5 to 10% of all IE cases and, compared with left-sided IE, is often associated with intravenous (i.v.) drug use, presence of intracardiac devices, and central venous catheters (CVCs), including permanent—Hickman catheter [...] Read more.
Infective endocarditis (IE) of the tricuspid and pulmonary valve accounts for 5 to 10% of all IE cases and, compared with left-sided IE, is often associated with intravenous (i.v.) drug use, presence of intracardiac devices, and central venous catheters (CVCs), including permanent—Hickman catheter (HC). We report a case of a 71-year-old female patient on a chronic hemodialysis (HD) program who had developed IE. Her first symptoms were fever and malaise. Transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) examinations were performed, revealing vegetations on the tip of HC and the anterior and posterior leaflets of the tricuspid valve (TV). Three blood culture bottles were positive for Enterococcus spp. The HC was replaced with a new CVC to continue HD. After a six-week antibiotic treatment, most clinical symptoms were resolved, and there was a decrease in vegetation size with normalization of inflammatory markers and negative follow-up blood cultures. After this initial improvement in the patient’s condition, the clinical course was complicated by the development of Citrobacter koseri bacteremia and sepsis. Despite adequate antibiotic therapy, the condition progressed to septic shock, which was soon followed by a fatal outcome. IE treatment in HD patients requires long-term broad-spectrum antibiotic therapy, and also, in patients without arteriovenous fistula (AVF), the CVC should be replaced after each HD during IE and sepsis treatment to minimize the patient’s exposure to a foreign body that is susceptible to bacterial colonization. A colonized foreign body is a focus for sustained and spreading infection, and its presence prevents adequate antibiotic treatment until the focus of infection is removed. Full article
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19 pages, 5448 KiB  
Article
Characterization and Phylogenetic Analysis of the Complete Mitogenomes of Valsa mali and Valsa pyri
by Guoqing Xing, Shunpei Xie, Zhanxiang Qiao, Qingzhou Ma, Chao Xu, Yuehua Geng, Yashuang Guo, Rui Zang and Meng Zhang
J. Fungi 2025, 11(5), 348; https://doi.org/10.3390/jof11050348 - 30 Apr 2025
Viewed by 349
Abstract
Apple Valsa canker, caused by Valsa mali and Valsa pyri, is a devastating disease of apple trees and poses a severe threat to the sustainable development of apple production. Although the two species’ whole genomes have been sequenced, their mitochondrial genomes are [...] Read more.
Apple Valsa canker, caused by Valsa mali and Valsa pyri, is a devastating disease of apple trees and poses a severe threat to the sustainable development of apple production. Although the two species’ whole genomes have been sequenced, their mitochondrial genomes are still uncharacterized. In this study, the complete mitochondrial genomes of V. mali and V. pyri were assembled, annotated, and compared by bioinformatic methods. The results indicate that the mitogenomes are both circular DNA molecules with sizes of 213,406 bp and 128,022 bp, respectively. The AT skew values of the two Valsa species’ mitogenomes were positive, while the GC skew values were negative. Comparative mitogenome analysis revealed that the length and base composition of protein-coding genes (PCGs), rRNA genes, and tRNA genes differed between the two Valsa species. It was found that the expansion of V. mali was primarily attributable to the intronic regions. There are large numbers of interspersed repetitive sequences (IRS) in both Valsa mitogenomes; however, the proportion of IRS in V. mali (43.56%) was much higher than that in V. pyri (2.41%). The alignment of large fragments between the mitochondrial and nuclear genomes of both V. mali (1.73 kb) and V. pyri (5.17 kb) indicates that gene transfer between mitochondrial and nuclear genomes occurred during evolution. The ka/ks ratios for 15 core PCGs were below one, suggesting that these genes were subjected to purifying selection pressure. Comparative mitogenomics revealed that the two fungi had significant mitogenomic collinearity and large-scale gene rearrangements. The results of phylogenetic analysis based on Bayesian inference (BI) and maximum likelihood (ML) using a combined mitochondrial gene set confirmed that V. mali and V. pyri were fully independent taxa with a high bootstrap value of 100 (ML) and a high posterior probability of 1.0 (BI). This is the first report on the mitogenomes within the genus Valsa. These results will pave the way to understanding the evolution and differentiation of mitogenomes in the genus Valsa. Full article
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11 pages, 2967 KiB  
Article
Does Presentation Duration Modulate the Effect of Task on Perceptual Organization?
by Ned Buckley and Alexis D. J. Makin
Symmetry 2024, 16(11), 1486; https://doi.org/10.3390/sym16111486 - 7 Nov 2024
Viewed by 676
Abstract
Visual symmetry activates the extrastriate cortex. This symmetry activation generates an Event Related Potential (ERP) named the Sustained Posterior Negativity (SPN). The SPN is larger when participants engage in regularity discrimination tasks than luminance discrimination tasks. Two recent studies suggest that the type [...] Read more.
Visual symmetry activates the extrastriate cortex. This symmetry activation generates an Event Related Potential (ERP) named the Sustained Posterior Negativity (SPN). The SPN is larger when participants engage in regularity discrimination tasks than luminance discrimination tasks. Two recent studies suggest that the type of task matters more when the stimulus is presented briefly. We tested this claim with a new sample of 52 participants in a within-subjects design. As predicted, the SPNs were larger in Regularity tasks than Luminance tasks. However, contrary to predictions, the effect of the task was very similar in long and short presentation duration blocks. It remains unclear what factors modulate the task effect. However, presentation duration is not as important as previous results suggest. Full article
(This article belongs to the Section Life Sciences)
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31 pages, 5754 KiB  
Review
Symmetry Perception and Psychedelic Experience
by Alexis D. J. Makin, Marco Roccato, Elena Karakashevska, John Tyson-Carr and Marco Bertamini
Symmetry 2023, 15(7), 1340; https://doi.org/10.3390/sym15071340 - 30 Jun 2023
Cited by 8 | Viewed by 5835
Abstract
This review of symmetry perception has six parts. Psychophysical studies have investigated symmetry perception for over 100 years (part 1). Neuroscientific studies on symmetry perception have accumulated in the last 20 years. Functional MRI and EEG experiments have conclusively shown that regular visual [...] Read more.
This review of symmetry perception has six parts. Psychophysical studies have investigated symmetry perception for over 100 years (part 1). Neuroscientific studies on symmetry perception have accumulated in the last 20 years. Functional MRI and EEG experiments have conclusively shown that regular visual arrangements, such as reflectional symmetry, Glass patterns, and the 17 wallpaper groups all activate the extrastriate visual cortex. This activation generates an event-related potential (ERP) called sustained posterior negativity (SPN). SPN amplitude scales with the degree of regularity in the display, and the SPN is generated whether participants attend to symmetry or not (part 2). It is likely that some forms of symmetry are detected automatically, unconsciously, and pre-attentively (part 3). It might be that the brain is hardwired to detect reflectional symmetry (part 4), and this could contribute to its aesthetic appeal (part 5). Visual symmetry and fractal geometry are prominent in hallucinations induced by the psychedelic drug N,N-dimethyltryptamine (DMT), and visual flicker (part 6). Integrating what we know about symmetry processing with features of induced hallucinations is a new frontier in neuroscience. We propose that the extrastriate cortex can generate aesthetically fascinating symmetrical representations spontaneously, in the absence of external symmetrical stimuli. Full article
(This article belongs to the Special Issue Symmetry/Asymmetry: Feature Review Papers)
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17 pages, 731 KiB  
Article
Influence of Hermetia illucens Larvae Meal Dietary Inclusion on Growth Performance, Gut Histological Traits and Stress Parameters in Sparus aurata
by Ambra Rita Di Rosa, Letteria Caccamo, Lidia Pansera, Marianna Oteri, Biagina Chiofalo and Giulia Maricchiolo
Animals 2023, 13(3), 339; https://doi.org/10.3390/ani13030339 - 18 Jan 2023
Cited by 12 | Viewed by 2589
Abstract
This study provided new data and knowledge on the potential use of Hermetia illucens meal (HIM) as a new sustainable ingredient for Sparus aurata diet. The effect of HIM dietary inclusion on fish growth performance, stress indicators and gut histology was studied. For [...] Read more.
This study provided new data and knowledge on the potential use of Hermetia illucens meal (HIM) as a new sustainable ingredient for Sparus aurata diet. The effect of HIM dietary inclusion on fish growth performance, stress indicators and gut histology was studied. For 131 days, 312 fish were fed a basal diet containing fishmeal as animal protein source, and three diets containing 25%, 35% and 50% HIM as a partial replacement for fishmeal. The main findings indicated that fishmeal can be replaced by HIM up to 110 g/kg of substitution (35% of inclusion in diet) without negative effects on growth performance, stress parameters or histological traits of the posterior gut tract, and with positive effects (p < 0.05) on the histological and morphometric characteristics of the anterior gut tract. At the same time, the results showed that the effect of Hermetia illucens meal at 50% inclusion level caused morphometric and histopathological alterations in the anterior gut tract of seabream. In conclusion, this preliminary study suggested that the dietary inclusion level of HIM35 was the most tolerated by fish showing the best gut morphometric parameters and histological conditions, with fewer signs of inflammation, as well as good nutritional and health status. Full article
(This article belongs to the Special Issue Nutritional Management to Promote Responsible Aquaculture)
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9 pages, 2391 KiB  
Article
Overlapping Neural Responses to Reflectional Symmetry and Glass Patterns Revealed by an ERP Priming Paradigm
by John Tyson-Carr, Giulia Rampone, Elena Karakashevska, Yiovanna Derpsch, Marco Bertamini and Alexis D. J. Makin
Symmetry 2022, 14(7), 1329; https://doi.org/10.3390/sym14071329 - 27 Jun 2022
Cited by 1 | Viewed by 2046
Abstract
The extrastriate visual cortex is activated by visual regularity and generates an ERP known as the sustained posterior negativity (SPN). Spatial filter models offer a biologically plausible account of regularity detection based on the spectral properties of an image. These models are specific [...] Read more.
The extrastriate visual cortex is activated by visual regularity and generates an ERP known as the sustained posterior negativity (SPN). Spatial filter models offer a biologically plausible account of regularity detection based on the spectral properties of an image. These models are specific to reflection and therefore imply that reflectional symmetry and Glass patterns are coded by different neural populations. We utilised the SPN priming effect to probe representational overlap between reflection and Glass patterns. For each trial, participants were presented with a rapid succession of three patterns. In the Repeated condition, three reflections or three Glass patterns were presented. In the Changing condition, patterns alternated between reflection and Glass patterns. An increase in SPN amplitude (priming) was observed in both the Repeated and Changing conditions. Results indicate a greater representational overlap in the brain between reflection and Glass patterns than predicted by spatial filter models. Full article
(This article belongs to the Special Issue Visual Processing of Symmetry)
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17 pages, 1504 KiB  
Article
Haemodynamic Signatures of Temporal Integration of Visual Mirror Symmetry
by Cayla A. Bellagarda, J. Edwin Dickinson, Jason Bell and David R. Badcock
Symmetry 2022, 14(5), 901; https://doi.org/10.3390/sym14050901 - 28 Apr 2022
Cited by 1 | Viewed by 2834
Abstract
EEG, fMRI and TMS studies have implicated the extra-striate cortex, including the Lateral Occipital Cortex (LOC), in the processing of visual mirror symmetries. Recent research has found that the sustained posterior negativity (SPN), a symmetry specific electrophysiological response identified in the region of [...] Read more.
EEG, fMRI and TMS studies have implicated the extra-striate cortex, including the Lateral Occipital Cortex (LOC), in the processing of visual mirror symmetries. Recent research has found that the sustained posterior negativity (SPN), a symmetry specific electrophysiological response identified in the region of the LOC, is generated when temporally displaced asymmetric components are integrated into a symmetric whole. We aim to expand on this finding using dynamic dot-patterns with systematically increased intra-pair temporal delay to map the limits of temporal integration of visual mirror symmetry. To achieve this, we used functional near-infrared spectroscopy (fNIRS) which measures the changes in the haemodynamic response to stimulation using near infrared light. We show that a symmetry specific haemodynamic response can be identified following temporal integration of otherwise meaningless dot-patterns, and the magnitude of this response scales with the duration of temporal delay. These results contribute to our understanding of when and where mirror symmetry is processed in the visual system. Furthermore, we highlight fNIRS as a promising but so far underutilised method of studying the haemodynamics of mid-level visual processes in the brain. Full article
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11 pages, 705 KiB  
Review
Electrophysiological Correlates of Romantic Love: A Review of EEG and ERP Studies with Beloved-Related Stimuli
by Sandra J. E. Langeslag
Brain Sci. 2022, 12(5), 551; https://doi.org/10.3390/brainsci12050551 - 26 Apr 2022
Cited by 6 | Viewed by 4665
Abstract
Science is starting to unravel the neural basis of romantic love. The goal of this literature review was to identify and interpret the electrophysiological correlates of romantic love. Electroencephalography (EEG) and event-related potential (ERP) studies with a design that elicits romantic love feelings [...] Read more.
Science is starting to unravel the neural basis of romantic love. The goal of this literature review was to identify and interpret the electrophysiological correlates of romantic love. Electroencephalography (EEG) and event-related potential (ERP) studies with a design that elicits romantic love feelings were included. The methods of previous EEG studies are too heterogeneous to draw conclusions. Multiple ERP studies, however, have shown that beloved stimuli elicit an enhanced late positive potential (LPP/P3/P300), which is not due to familiarity, positive valence, or objective beauty. This effect occurs in Western and Eastern cultures and for pictorial and verbal information, and results from bottom-up rather than top-down factors. Studies have also shown that beloved stimuli elicit an early posterior negativity (EPN), which also does not seem to be due to familiarity or positive valence. Data on earlier ERP components (P1, N1, P2, N170/VPP, N2) is scarce and mixed. Of course, the enhanced LPP and EPN are not specific to romantic love. Instead, they suggest that the beloved captures early attention, within 200–300 ms after stimulus onset that is relatively resource-independent, and subsequently receives sustained motivated attention. Future research would benefit from employing cognitive tasks and testing participants who are in love regardless of relationship status. Full article
(This article belongs to the Section Cognitive, Social and Affective Neuroscience)
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19 pages, 10663 KiB  
Article
Is the Sharing Economy Green? Evidence from Cross-Country Data
by Wei Yin, Berna Kirkulak-Uludag and Ziling Chen
Sustainability 2021, 13(21), 12023; https://doi.org/10.3390/su132112023 - 30 Oct 2021
Cited by 9 | Viewed by 3800
Abstract
Using cross-sectional data from 165 countries, this study takes a fresh look at whether or not the sharing economy is a green solution for countries. This study relies on the Timbro sharing economy index and uses both carbon emission and environmental performance index [...] Read more.
Using cross-sectional data from 165 countries, this study takes a fresh look at whether or not the sharing economy is a green solution for countries. This study relies on the Timbro sharing economy index and uses both carbon emission and environmental performance index as proxies for the greenhouse gas effect and overall environment, respectively. Due to limited sample size and non-normal distribution of the sample, this paper applies the Bayesian regression model, which is based on posterior distribution. The findings suggest the following: (1) a high sharing economy level has a negative relationship to carbon emissions but a positive relationship to overall environmental performance; (2) the joint variables show that a high sharing economy level together with high broadband access, urbanization, and high education level reduces carbon emissions; and (3) for manufacturing countries, a high sharing economy level together with high urbanization is associated with comparatively low carbon emissions and high environmental performance. In general, these findings allow us to conclude in favor of the contribution made by a high sharing economy level to sustainability. Full article
(This article belongs to the Section Economic and Business Aspects of Sustainability)
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7 pages, 401 KiB  
Article
Imbalance between Emotionally Negative and Positive Life Events Retrieval and the Associated Asymmetry of Brain Activity
by Olga Razumnikova and Ekaterina Khoroshavtseva
Behav. Sci. 2020, 10(1), 18; https://doi.org/10.3390/bs10010018 - 30 Dec 2019
Cited by 3 | Viewed by 4475
Abstract
Sustained focusing on a negative assessment of life events can create negative background and changes in the emotional feedback to new information. In this regard, it is important to assess the balance between self-assessment of emotional memories and their reflection in brain activity. [...] Read more.
Sustained focusing on a negative assessment of life events can create negative background and changes in the emotional feedback to new information. In this regard, it is important to assess the balance between self-assessment of emotional memories and their reflection in brain activity. The study was aimed at exploring the brain activity using electroencephalographic (EEG) analysis in six frequency ranges from delta to beta2 during the retrieval of positive or negative emotional memory compared with the resting state. According to ANOVA results, the most informative for differentiation of emotions were the alpha2 and beta2 rhythms with greater synchronization effect for positive than for negative emotions. The memory retrieval, regardless of the valence of emotions, was accompanied by alpha1 desynchronization at the posterior cortex. Self-assessment of the memory intensity was not significantly different due to emotion valences. However, the scores of positive emotions were related positively with beta2 oscillations at the left anterior temporal site, whereas for negative emotions, at the right one. Thus, the emotional autobiographical memory is reflected by activation processes in the visual cortex and areas associated with multimodal information processing, whereas differentiation of the valence of emotions is presented by the high-frequency oscillations at the temporal cortex areas. Full article
(This article belongs to the Special Issue XVI European Congress of Psychology)
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9 pages, 876 KiB  
Communication
Genetic Variation and Trait Correlations for Fruit Weight, Firmness and Color Parameters in Wild Accessions of Fragaria chiloensis
by Freddy Mora, Paz E. Zúñiga and Carlos R. Figueroa
Agronomy 2019, 9(9), 506; https://doi.org/10.3390/agronomy9090506 - 2 Sep 2019
Cited by 10 | Viewed by 9905
Abstract
Fragaria chiloensis is an herbaceous perennial undomesticated species with a high potential for sustainable fruit production in areas where drought and salinity represent a constraint on crop growth and productivity. The present study aimed to examine the genetic variability of fruit weight, firmness [...] Read more.
Fragaria chiloensis is an herbaceous perennial undomesticated species with a high potential for sustainable fruit production in areas where drought and salinity represent a constraint on crop growth and productivity. The present study aimed to examine the genetic variability of fruit weight, firmness and color parameters (L*, a*, b*, Hue angle and Chroma) in wild-collected accessions from south-central Chile. A Bayesian analysis of genetic parameters showed that the traits under study were found to be moderately to highly heritable with estimates from the marginal posterior distributions ranging between 0.26 (firmness) and 0.67 (L*). Interestingly, Hue and Chroma had relatively high values of broad-sense heritability, with the Bayesian credible set: H2 = 0.53–0.76 and H2 = 0.42–0.66, respectively. A Bayesian bi-trait analysis showed a positive genetic correlation ( ˆrg = 0.65, probability of the posterior samples <0.05) between fruit weight and Hue, which agreed with the existence of two pleiotropic loci [from simple sequence repeats (SSR) markers FvH4045 and CFACT084 on linkage groups FG3A and FG2A/2B/2C] with probabilities of the posterior estimates of 0.022 and <0.001, respectively. According to the Bayesian credible region, 5 (of 12) correlation estimates were significantly different from zero. Hue and Chroma showed a high and negative genetic correlation ( ˆrg = −0.762), but no significant pleotropic locus. The results are promising and suggest that the genetic variation found among wild populations of F. chiloensis supports the idea of domesticating this crop for sustainable fruit production systems. Full article
(This article belongs to the Special Issue Crop Domestication and Evolution)
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17 pages, 12252 KiB  
Article
Hollow Microcapsules as Periocular Drug Depot for Sustained Release of Anti-VEGF Protein
by Krishna Radhakrishnan, Anita Vincent, Rini Rachel Joseph, Miguel Moreno, Andreas Dickescheid, Rupesh Agrawal and Subbu Venkatraman
Pharmaceutics 2019, 11(7), 330; https://doi.org/10.3390/pharmaceutics11070330 - 11 Jul 2019
Cited by 15 | Viewed by 4082
Abstract
Diseases affecting the posterior segment of the eye such as age-related macular degeneration and diabetic retinopathy are leading causes of blindness all over the world. The current treatment regimen for such diseases involves repeated intravitreal injections of anti- Vascular Endothelial Growth Factor (VEGF) [...] Read more.
Diseases affecting the posterior segment of the eye such as age-related macular degeneration and diabetic retinopathy are leading causes of blindness all over the world. The current treatment regimen for such diseases involves repeated intravitreal injections of anti- Vascular Endothelial Growth Factor (VEGF) proteins. This method is highly invasive and can lead to severe complications. In an attempt to develop less invasive alternatives, we propose the use of a controlled release system consisting of anti-VEGF loaded hollow microcapsules that can be administered periocularly to form drug eluting depots on the episcleral surface. The microcapsules with either positive or negative surface charge were prepared by a layer by layer approach and showed pH responsive permeability switching. An ex vivo experiment using porcine sclera indicated positively charged microcapsules remained on the episcleral surface over four days while the negatively charged microcapsules were washed away. These positively charged microcapsules were then loaded with anti-VEGF protein ranibizumab using pH dependent permeability switching and protein release from the microcapsules were studied using an in vitro setup. An ex vivo experiment utilizing porcine sclera demonstrated sustained release of ranibizumab over seven days with zero-order kinetics. Full article
(This article belongs to the Special Issue Nanotechnology-Based Approaches for Chronic Diseases)
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8 pages, 1461 KiB  
Article
The Posterior Sustained Negativity Revisited—An SPN Reanalysis of Jacobsen and Höfel (2003)
by Thomas Jacobsen, Stina Klein and Andreas Löw
Symmetry 2018, 10(1), 27; https://doi.org/10.3390/sym10010027 - 12 Jan 2018
Cited by 10 | Viewed by 5396
Abstract
Symmetry is an important cue for the aesthetic judgment of beauty. Using a binary forced-choice format in a cued mixed design, Jacobsen and Höfel (2003) compared aesthetic judgments of beauty and symmetry judgments of novel graphic patterns. A late posterior sustained negativity elicited [...] Read more.
Symmetry is an important cue for the aesthetic judgment of beauty. Using a binary forced-choice format in a cued mixed design, Jacobsen and Höfel (2003) compared aesthetic judgments of beauty and symmetry judgments of novel graphic patterns. A late posterior sustained negativity elicited by symmetric patterns was observed in the symmetry judgment condition, but not in the beauty judgement condition. Therefore, this negativity appeared to be mainly driven by the task.In a series of studies, Bertamini, Makin, and colleagues observed a comparable sustained posterior negativity (SPN) to symmetric stimuli, mainly taken to reflect obligatory symmetry processing independent of task requirements. We reanalyzed the data by Jacobsen and Höfel (2003) using similar parameters for data analysis as Bertamini, Makin, and colleagues to examine these apparent differences. The reanalysis confirmed both a task-driven effect on the posterior sustained negativity/SPN to symmetric patterns in the symmetry judgment condition and a strong symmetry-driven SPN to symmetric patterns. Differences between the references used for analyses of the electroencephalogram (EEG) had an effect. Based on the reanalysis, the Jacobsen and Höfel (2003) data also fit well with Bertamini’s, Makin’s, and colleagues’ account of obligatory symmetry processing. Full article
(This article belongs to the Special Issue Symmetry-Related Activity in Mid-Level Vision)
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22 pages, 25941 KiB  
Review
Brain Activity in Response to Visual Symmetry
by Marco Bertamini and Alexis D.J. Makin
Symmetry 2014, 6(4), 975-996; https://doi.org/10.3390/sym6040975 - 2 Dec 2014
Cited by 100 | Viewed by 18596
Abstract
A number of studies have explored visual symmetry processing by measuring event related potentials and neural oscillatory activity. There is a sustained posterior negativity (SPN) related to the presence of symmetry. There is also functional magnetic resonance imaging (MRI) activity in extrastriate visual [...] Read more.
A number of studies have explored visual symmetry processing by measuring event related potentials and neural oscillatory activity. There is a sustained posterior negativity (SPN) related to the presence of symmetry. There is also functional magnetic resonance imaging (MRI) activity in extrastriate visual areas and in the lateral occipital complex. We summarise the evidence by answering six questions. (1) Is there an automatic and sustained response to symmetry in visual areas? Answer: Yes, and this suggests automatic processing of symmetry. (2) Which brain areas are involved in symmetry perception? Answer: There is an extended network from extrastriate areas to higher areas. (3) Is reflection special? Answer: Reflection is the optimal stimulus for a more general regularity-sensitive network. (4) Is the response to symmetry independent of view angle? Answer: When people classify patterns as symmetrical or random, the response to symmetry is view-invariant. When people attend to other dimensions, the network responds to residual regularity in the image. (5) How are brain rhythms in the two hemispheres altered during symmetry perception? Answer: Symmetry processing (rather than presence) produces more alpha desynchronization in the right posterior regions. Finally, (6) does symmetry processing produce positive affect? Answer: Not in the strongest sense, but behavioural measures reveal implicit positive evaluation of abstract symmetry. Full article
(This article belongs to the Special Issue Visual Symmetry)
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