Search results for "categorization"

Electrophysiological signatures of masked transposition priming in a same-different task: Evidence with strings of letters vs. pseudoletters

2012

Research on masked transposed-letter priming (i.e., jugde-JUDGE triggers a faster response than jupte-JUDGE) has become a key phenomenon to reveal how the brain encodes letter position. Recent behavioural evidence suggests that the mechanism responsible for position coding in a masked priming procedure works with familiar "object" identities (e.g., letters, digits, symbols) but not with unfamiliar object identities (e.g., pseudoletters). Here we used event-related potentials (ERPs) to explore the time course of masked transposition priming of letters vs. pseudoletters in a cue-target same-different matching task. Target stimuli were preceded by a masked prime that could be: (i) identical to…

Brain responses of dysphoric and control participants during a self-esteem implicit association test.

2021

Previous studies have reported lowered implicit self-esteem at the behavioral level among depressed individuals. However, brain responses related to the lowered implicit self-esteem have not been investigated in people with depression. Here, event-related potentials were measured in 28 dysphoric participants (individuals with elevated amounts of depressive symptoms) and 30 control participants during performance of an implicit association task (IAT) suggested to reflect implicit self-esteem. Despite equivalent behavioral performance, differences in brain responses were observed between the dysphoric and the control groups in late positive component (LPC) within 400-1,000 ms poststimulus lat…

Distribution and categorization of left ventricular measurements in the general population: results from the population-based Gutenberg Heart Study.

2010

Background— Echocardiography, the dominant imaging modality for quantification of left ventricular metrics, has undergone continuing development in the past few decades. However, given the lack of population-based data, current guidelines are still based on restricted and small data sets analyzed with methods including expert opinion. This work presents empirically derived reference values from a large-scale, epidemiologic study conducted with state-of-the-art imaging technology and methods. Methods and Results— The distribution of echocardiographic measurements of the left ventricle was analyzed in a population-based sample of 5000 mid-Europeans from the Gutenberg Heart Study in Germany. …

Towards an international language for incontinence-associated dermatitis (IAD): design and evaluation of psychometric properties of the Ghent Global …

2018

Background Incontinence-associated dermatitis (IAD) is a specific type of irritant contact dermatitis with different levels of severity. An internationally accepted instrument to assess the severity of IAD in adults with established diagnostic accuracy, agreement, and reliability is needed to support clinical practice and research.Objectives To design and psychometrically evaluate the Ghent Global IAD Categorisation Tool (GLOBIAD).Methods The design was based on expert consultation using a three-round Delphi procedure with 34 experts from 13 countries. The instrument was tested using IAD photographs reflecting different severity levels in a sample of 823 health professionals in 30 countries…

Hypoesthesia of the malleolus as a soft sign in depression

2014

Background: Physical signs often are present in many psychiatric conditions, making up a fundamental part of them and accompanying the psychiatric manifestations themselves. Identifying minor neurological signs is especially of interest due to they are easily accessible through simple neurological examination and could be a useful if underused tool for the diagnostic process and patient therapy. Method: A group of depressed patients (a =85) and group of healthy individuals (n=101) that served as control were examined using the Wartenberg wheel, a medical device for neurological use, in order to determine the presence of hypoesthesia on both sides of their ankles. Results.: The data revealed…

Towards reactive navigation and attention skills for 3D intelligent characters

2003

This paper presents a neural design which is able to provide the necessary reactive navigation and attention skills for 3D embodied agents (virtual humanoids or characters). Based on Grossberg's neural model of conditioning [6], as recently implemented by Chang and Gaudiando [7], and according to the Adaptative Resonance Theory (ART) and the neuroscientific concepts associated, the neural design introduced has been divided in two main phases. Firstly, an environmentcategorization phase, where an on-line pattern recognition and categorization of the current agent sensory input data is carried out by a self organizing neural network, which will finally provide the agent's short term memory la…

Connectionist models of face processing: A survey

1994

Abstract Connectionist models of face recognition, identification, and categorization have appeared recently in several disciplines, including psychology, computer science, and engineering. We present a review of these models with the goal of complementing a recent survey by Samal and Iyengar [Pattern Recognition25, 65–77 (1992)] of nonconnectionist approaches to the problem of the automatic face recognition. We concentrate on models that use linear autoassociative networks, nonlinear autoassociative (or compression) and/or heteroassociative backpropagation networks. One advantage of these models over some nonconnectionist approaches is that analyzable features emerge naturally from image-b…

Categorization of Extremely Brief Auditory Stimuli: Domain-Specific or Domain-General Processes?

2011

The present study investigated the minimum amount of auditory stimulation that allows differentiation of spoken voices, instrumental music, and environmental sounds. Three new findings were reported. 1) All stimuli were categorized above chance level with 50 ms-segments. 2) When a peak-level normalization was applied, music and voices started to be accurately categorized with 20 ms-segments. When the root-mean-square (RMS) energy of the stimuli was equalized, voice stimuli were better recognized than music and environmental sounds. 3) Further psychoacoustical analyses suggest that the categorization of extremely brief auditory stimuli depends on the variability of their spectral envelope in…

Visual category representations in the infant brain

2021

SUMMARYVisual categorization is a human core cognitive capacity1,2that depends on the development of visual category representations in the infant brain3–7. However, the exact nature of infant visual category representations and their relationship to the corresponding adult form remains unknown8. Our results clarify the nature of visual category representations from electroencephalography (EEG) data in 6- to 8-month-old infants and their developmental trajectory towards adult maturity in the key characteristics of temporal dynamics2,9, representational format10–12, and spectral properties13,14. Temporal dynamics change from slowly emerging, developing representations in infants to quickly e…

2017

In continuous flash suppression (CFS), a dynamic noise masker, presented to one eye, suppresses conscious perception of a test stimulus, presented to the other eye, until the suppressed stimulus comes to awareness after few seconds. But what do we see breaking the dominance of the masker in the transition period? We addressed this question with a dual-task in which observers indicated (i) whether the test object was left or right of the fixation mark (localization) and (ii) whether it was a face or a house (categorization). As done recently (Stein et al., 2011), we used two experimental varieties to rule out confounds with decisional strategy. In the terminated mode, stimulus and masker wer…