Search results for "Photic stimulation"
showing 10 items of 307 documents
Irrelevant task suppresses the N170 of automatic attention allocation to fearful faces
2021
AbstractRecent researches have provided evidence that stimulus-driven attentional bias for threats can be modulated by top-down goals. However, it is highlight essential to indicate whether and to what extent the top-down goals can affect the early stage of attention processing and its early neural mechanism. In this study, we collected electroencephalographic data from 28 healthy volunteers with a modified spatial cueing task. The results revealed that in the irrelevant task, there was no significant difference between the reaction time (RT) of the fearful and neutral faces. In the relevant task, we found that RT of fearful faces was faster than that of neutral faces in the valid cue condi…
Dependence of Perceived Purity of a Chromatic Stimulus on Saturation Adaptation
2012
Background and Objective. The purpose of sensory adaptation of the visual system is to adjust sensitivity of the photoreceptors to optimize the dynamic range of response of the visual system. It has been shown in numerous research papers that chromatic adaptation influences both color appearance and color discrimination. However, there are almost no studies in which the influence of chromatic adaptation on perceived purity has been investigated. Therefore, the aim of this study was to investigate how chromatic adaptation to stimuli with certain saturation influences perceived purity of test stimuli with the same hue but different saturation. Material and Methods. As the stimuli were modulat…
Visual Attention Patterns Differ in Gynephilic and Androphilic Men and Women Depending on Age and Gender of Targets
2017
Visual attention patterns measured with eye-tracking techniques provide indirect clues about sexual response. This study aimed to test the category specificity of sexual responses to stimuli varying in gender and age by evaluating both early and late attention of gynephilic and androphilic men and women. We simultaneously presented sexually preferred and nonpreferred stimuli and measured time to first fixation and total duration of fixation on four areas of interest: entire body, then face, chest, and pelvis. Androphilic women's early attention patterns were nonspecific, whereas gynephilic women and both groups of men showed a category-specific pattern for the entire body. In contrast, all …
Brand Discrimination: An Implicit Measure of the Strength of Mental Brand Representations
2015
While mental associations between a brand and its marketing elements are an important part of brand equity, previous research has yet to provide a sound methodology to measure the strength of these links. The following studies present the development and validation of an implicit measure to assess the strength of mental representations of brand elements in the mind of the consumer. The measure described in this paper, which we call the Brand Discrimination task, requires participants to identify whether images of brand elements (e.g. color, logo, packaging) belong to a target brand or not. Signal detection theory (SDT) is used to calculate a Brand Discrimination index which gives a measure …
Contour integration with corners.
2016
Contour integration refers to the ability of the visual system to bind disjoint local elements into coherent global shapes. In cluttered images containing randomly oriented elements a contour becomes salient when its elements are coaligned with a smooth global trajectory, as described by the Gestalt law of good continuation. Abrupt changes of curvature strongly diminish contour salience. Here we show that by inserting local corner elements at points of angular discontinuity, a jagged contour becomes as salient as a straight one. We report results from detection experiments for contours with and without corner elements which indicate their psychophysical equivalence. This presents a challeng…
Conceptual proposition selection and the LIFG: neuropsychological evidence from a focal frontal group.
2010
Much debate surrounds the role of the left inferior frontal gyrus (LIFG). Evidence from lesion and neuroimaging studies suggests the LIFG supports a selection mechanism used in single word generation. Single case studies of dynamic aphasic patients with LIFG damage concur with this and extend the finding to selection of sentences at the conceptual preparation stage of language generation. A neuropsychological group with unselected focal frontal and non-frontal lesions is assessed on a sentence generation task that varied the number of possible conceptual propositions available for selection. Frontal patients with LIFG damage when compared to Frontal patients without LIFG damage and Posterio…
Two Distinct Auditory-Motor Circuits for Monitoring Speech Production as Revealed by Content-Specific Suppression of Auditory Cortex
2015
Speech production, both overt and covert, down-regulates the activation of auditory cortex. This is thought to be due to forward prediction of the sensory consequences of speech, contributing to a feedback control mechanism for speech production. Critically, however, these regulatory effects should be specific to speech content to enable accurate speech monitoring. To determine the extent to which such forward prediction is content-specific, we recorded the brain's neuromagnetic responses to heard multisyllabic pseudowords during covert rehearsal in working memory, contrasted with a control task. The cortical auditory processing of target syllables was significantly suppressed during rehear…
Wall patterns influence the perception of interior space
2019
The texture of an object’s surface influences its perceived spatial extent. For example, Hermann von Helmholtz reported that a square patch with black and white stripes appears elongated perpendicular to the stripes’ orientation. This time-honoured finding stands in contrast with more recent recommendations by interior-design experts who suggest that stripe wall patterns make rooms appear elongated in the direction parallel to the stripes’ orientation. In a series of four experiments, we presented stripe wall patterns and varied the orientation of the stripes (horizontal vs. vertical) and their density (number of stripes per degree of visual angle). Subjects estimated the width and height …
Time course of emotion-related responding during distraction and reappraisal
2014
Theoretical accounts of emotion regulation (ER) discriminate various cognitive strategies to voluntarily modify emotional states. Amongst these, attentional deployment (i.e. distraction) and cognitive change (i.e. reappraisal), have been shown to successfully down-regulate emotions. Neuroimaging studies found that both strategies differentially engage neural structures associated with selective attention, working memory and cognitive control. The aim of this study was to further delineate similarities and differences between the ER strategies reappraisal and distraction by investigating their temporal brain dynamics using event-related potentials (ERPs) and their patterns of facial expressi…
The time course of idiom processing.
2007
Recent neuropsychological and neurophysiological studies have suggested that the neural correlates of idiom processing are predominantly located in the left Brodmann's area (BA) 22 and, to some extent, in the prefrontal cortex. The present study explores the temporal dynamics of left prefrontal and temporal cortex in idiom processing by using repetitive transcranial magnetic stimulation (rTMS) in normal subjects. Forty-five opaque highly familiar idioms and 45 literal sentences were used. Forty-three subjects completed 5 blocks of 18 trials (9 idioms, 9 literal sentences) corresponding to 4 stimulation conditions (left prefrontal, left temporal, vertex, no-stimulation baseline). Each subjec…