Search results for "Percept"
showing 10 items of 3839 documents
On the analysis of the cat's pattern recognition system
1983
The objective of the paper is to determine in abstract terms the algorithms used by the cat detecting simple patterns and to quantify the contributions of the visual areas 17, 18, 19 for this task. The data incorporated in the algorithm are collected from behavioral experiments where the animals had to distinguish between two patterns. The patterns were superimposed with gaussian noise and the detection probability was measured. The resulting model describes pattern recognition in two steps: first extraction of features and second classification. The test of the validity of the model system was to predict the outcome of similar experiments but with different patterns. With the help of the m…
On the function of cell systems in area 18. Part I
1981
In addition to the asymmetry of the spatial coupling and of the specific temporal combination of excitation and inhibition, the non-linearity is very pronounced in area 18. Taking the sequence of a linear operation and a stationary nonlinear characteristic as a model, the experimental findings can be systematized and a cell classification specified which departs from the customary ones. The hypercomplex cell system probably originates in recurrent inhibition and leads to differentiation of the patterns along their contour line. Problems of cell classification and of the type of parallelism in the visual cortex are discussed.
Internal limiting membrane peeling versus no peeling during primary vitrectomy for rhegmatogenous retinal detachment: A systematic review and meta-an…
2018
Background Internal limiting membrane (ILM) peeling during primary vitrectomy for rhegmatogenous retinal detachment (RRD) prevents the formation of postoperative macular epiretinal membrane (ERM). However, studies that compared vitrectomy with and without ILM peeling for RRD, have reported controversial outcomes. Objective To assess the efficacy of ILM peeling versus non-ILM peeling during vitrectomy for RRD by a systematic review and meta-analysis of published studies. Methods PubMed, Medline, Web of Science, Embase databases, and the Cochrane Library were searched up to April 2018 to identify studies that compared primary vitrectomy with and without ILM peeling for RRD with at least six m…
Conduct disorder and ADHD: evaluation of conduct problems as a categorical and quantitative trait in the international multicentre ADHD genetics stud…
2008
Contains fulltext : 71374.pdf (Publisher’s version ) (Closed access) Attention-deficit/hyperactivity disorder (ADHD) is typically characterized by inattention, excessive motor activity, impulsivity, and distractibility. Individuals with ADHD have significant impairment in family and peer relations, academic functioning, and show high co-morbidity with a wide range of psychiatric disorders including oppositional defiant disorder (ODD), conduct disorder (CD), anxiety disorder, depression, substance abuse, and pervasive developmental disorder (PDD). Family studies suggest that ADHD + CD represents a specific subtype of the ADHD disorder with familial risk factors only partly overlapping with t…
Meta-analysis of genome-wide linkage scans of attention deficit hyperactivity disorder
2008
Contains fulltext : 69243.pdf (Publisher’s version ) (Closed access) Genetic contribution to the development of attention deficit hyperactivity disorder (ADHD) is well established. Seven independent genome-wide linkage scans have been performed to map loci that increase the risk for ADHD. Although significant linkage signals were identified in some of the studies, there has been limited replications between the various independent datasets. The current study gathered the results from all seven of the ADHD linkage scans and performed a Genome Scan Meta Analysis (GSMA) to identify the genomic region with most consistent linkage evidence across the studies. Genome-wide significant linkage (P(S…
No association between two polymorphisms of the serotonin transporter gene and combined type attention deficit hyperactivity disorder.
2008
Contains fulltext : 71091.pdf (Publisher’s version ) (Closed access) Several independent studies have reported association between serotonin transporter gene (SLC6A4) polymorphisms and attention deficit hyperactivity disorder (ADHD). Five studies found evidence for association between the long-allele of a 44-bp insertion/deletion polymorphism (5-HTTLPR) and ADHD. Another two studies corroborated this finding while a further six studies did not find such an association. For a second polymorphism within the gene, a variable number tandem repeat (VNTR) within intron 2, one study demonstrated that the 12/12 genotype was significantly less frequent in ADHD cases compared to controls, while a sec…
Participation, geography and social media. Discussing method
2022
The chapter, from a cultural geographical perspective, offers a reflection on the research methodology used to study some social media. More particularly, starting from the case of the Facebook group “Palermo di una volta” (“Palermo of the past”), subject of a previous study, the results achieved through the analysis of the research process are retraced. The group, in fact, for the many members (hundreds of thousands) who are part of it, is an opportunity to reconstruct the geography of places in the city, both in their contemporaneity and in their historical context, in an intertwining of individual and collective narratives. Regardless of the formal correctness of the information the grou…
Air pollution perception in ten countries during the COVID-19 pandemic.
2021
As largely documented in the literature, the stark restrictions enforced worldwide in 2020 to curb the COVID-19 pandemic also curtailed the production of air pollutants to some extent. This study investigates the perception of the air pollution as assessed by individuals located in ten countries: Australia, Brazil, China, Ghana, India, Iran, Italy, Norway, South Africa and the USA. The perceptions towards air quality were evaluated by employing an online survey administered in May 2020. Participants (N = 9394) in the ten countries expressed their opinions according to a Likert-scale response. A reduction in pollutant concentration was clearly perceived, albeit to a different extent, by all …
Limited perceptual range and presence of conspecifics both affect the ability of pit-building wormlions to choose favorable microhabitats
2020
Abstract When choosing among several potential habitats, animals should strive to choose the habitat that provides the highest fitness. When animals choose habitats that do not provide the best possible fitness, there is a mismatch between habitat preference and performance. A common reason is that of limited information or perceptual range. Sit-and-wait predators are particularly deficient in information, due to spending most of their time in ambushing prey and, when they do travel, they cover only short distances. Here, we studied the effect of placing pit-building wormlions at a short distance from their preferred microhabitats, on the likelihood of them choosing it. When placed on the b…
Validación de cuestionario sobre percepciones y creencias de epidemia. Una estrategia para aprendizaje en el aula - [Validation of a questionnaire on…
2017
El presente trabajo ofrece una validez de constructo de un cuestionario sobre percepciones y creencias de epidemia. El instrumento a utilizar se apoya con el uso del cine para favorecer aprendizaje significativo y fomentar aprendizaje a lo largo de la vida. Se aprecian dificultades en aspectos de comunicación y ética frente a una epidemia. Los resultados obtenidos en este piloto permiten afirmar que esta experiencia sirve para crear y desarrollar competencias profesionales de tipo comunicativa y pensamiento crítico. Se identificaron situaciones éticas en sucesos complejos que afectan el desempeño de su actividad profesional [The present work offers a construct validity of a questionnaire ab…