Search results for "Percept"

2015

Previewing distracters enhances the efficiency of visual search. Watson and Humphreys (1997) proposed that the preview benefit rests on visual marking, a mechanism which actively encodes distracter locations at preview and inhibits them afterwards at search. As Watson and Humphreys did, we used a letter-color search task to study constraints of visual marking in conjunction search and near-efficient single-feature search with single-colored and homogeneous distracter letters. Search performance was measured for fixed target and distracter features (block design) and for randomly changed features across trials (random design). In single-feature search there was a full preview benefit for bot…

Visual grouping under isoluminant condition: impact of mental fatigue

2016

Instead of selecting arbitrary elements our visual perception prefers only certain grouping of information. There is ample evidence that the visual attention and perception is substantially impaired in the presence of mental fatigue. The question is how visual grouping, which can be considered a bottom-up controlled neuronal gain mechanism, is influenced. The main purpose of our study is to determine the influence of mental fatigue on visual grouping of definite information – color and configuration of stimuli in the psychophysical experiment. Individuals provided subjective data by filling in the questionnaire about their health and general feeling. The objective evidence was obtained in t…

Machinery Failure Approach and Spectral Analysis to Study the Reaction Time Dynamics over Consecutive Visual Stimuli: An Entropy-Based Model.

2020

[EN] The reaction times of individuals over consecutive visual stimuli have been studied using an entropy-based model and a failure machinery approach. The used tools include the fast Fourier transform and a spectral entropy analysis. The results indicate that the reaction times produced by the independently responding individuals to visual stimuli appear to be correlated. The spectral analysis and the entropy of the spectrum yield that there are features of similarity in the response times of each participant and among them. Furthermore, the analysis of the mistakes made by the participants during the reaction time experiments concluded that they follow a behavior which is consistent with …

Do young readers have fast access to abstract lexical representations? Evidence from masked priming

2014

Although there is consensus that adult readers have fast access to abstract letter/word representations, the developmental trajectory of such access has not been mapped out yet. To examine whether developmental readers have rapid access to abstract representations during the early stages of word processing, we conducted a masked priming lexical decision experiment with two groups of young readers (third and fifth graders) and a group of young adults. We selected two types of words: (a) words composed of cross-case letters that are visually dissimilar (DIS words; e.g., arte/ARTE [Spanish for art]) and (b) words composed of cross-case letters that are visually similar (SIM words; e.g., vivo/V…

Does Kaniso activate CASINO?: input coding schemes and phonology in visual-word recognition.

2010

Most recent input coding schemes in visual-word recognition assume that letter position coding is orthographic rather than phonological in nature (e.g., SOLAR, open-bigram, SERIOL, and overlap). This assumption has been drawn – in part – by the fact that the transposed-letter effect (e.g., caniso activates CASINO) seems to be (mostly) insensitive to phonological manipulations (e.g., Perea & Carreiras, 2006 , 2008 ; Perea & Pérez, 2009 ). However, one could argue that the lack of a phonological effect in prior research was due to the fact that the manipulation always occurred in internal letter positions – note that phonological effects tend to be stronger for the initial syllable (…

Perceptual uncertainty is a property of the cognitive system

2012

AbstractWe qualify Frost's proposals regarding letter-position coding in visual word recognition and the universal model of reading. First, we show that perceptual uncertainty regarding letter position is not tied to European languages – instead it is a general property of the cognitive system. Second, we argue that a universal model of reading should incorporate a developmental view of the reading process.

Eye movements when reading words with $YMβOL$ and NUM83R5: There is a cost

2009

Recent evidence from masked priming experiments has revealed that readers regularize letter-like symbols and letter-like numbers into their corresponding base letters with minimal processing cost. However, one open question is whether the same pattern occurs when these items are presented during normal silent reading. In the present study, we respond to this question in an eye-movement experiment that included sentences with words that had symbols and numbers as letters, as in “YESTERDAY I SAW THE SECRE74RY WORKING VERY HARD”. Results revealed that there is a greater reading cost associated with letter-by-number replacements than with letter-by-symbol replacements, especially when the repla…

Unveiling the boost in the sandwich priming technique.

2021

The masked priming technique (which compares #####-house-HOUSE vs. #####-fight-HOUSE) is the gold-standard tool to examine the initial moments of word processing. Lupker and Davis showed that adding a pre-prime identical to the target produced greater priming effects in the sandwich technique (which compares #####-HOUSE-house-HOUSE vs #####-HOUSE-fight-HOUSE). While there is consensus that the sandwich technique magnifies the size of priming effects relative to the standard procedure, the mechanisms underlying this boost are not well understood (i.e., does it reflect quantitative or qualitative changes?). To fully characterise the sandwich technique, we compared the sandwich and standard t…

Studying brain visuo-tactile integration through cross-spectral analysis of human MEG recordings

2010

An important aim in cognitive neuroscience is to identify the networks connecting different brain areas and their role in executing complex tasks. In this study, visuo-tactile tasks were employed to assess the functional correlation underlying the cooperation process between visual and tactile regions. MEG data were recorded from eight healthy subjects while performing a visual, a tactile, and a visuo-tactile task. To define regions of interest (ROIs), event-related fields (ERFs) were estimated from MEG data related to visual and tactile areas. The ten channels with the highest increase in ERF variance, moving from rest to task, were selected. Cross-spectral analysis was then performed to a…

Relationship Between Patient-Reported Outcomes and Clinical Outcomes in Patients With Morquio A Syndrome

2019

Abstract This cross-sectional analysis assessed the correlation between patient-reported outcomes (PROs) and clinical outcomes in 24 German patients with Morquio A. Clinical outcomes included 6-minute walk test (6MWT), 3-minute stair climb (3MSC) test, and joint range of motion as measures for endurance/mobility, forced vital capacity (FVC) and maximum voluntary ventilation (MVV) as measures for respiratory function, and height as an important manifestation. The PROs included the EuroQoL (EQ) 5D-5L (EQ5D-5L), to measure health-related QoL (HRQoL), and patients’ rating of their ability to walk, climb, or breathe. In adults, endurance and pulmonary function measures and height showed strong a…