scholarly journals Effects of endogenous attention on early visual processing: The role of stimulus synchrony

2008 ◽  
Vol 2 ◽  
Author(s):  
Schwartz S S.
Keyword(s):  
Visual Processing ◽  
Endogenous Attention ◽  
Early Visual Processing

The Role of Familiarity in a Face Classification Task Using Thatcherized Faces

2005 ◽  
Vol 58 (6) ◽  
pp. 1103-1118 ◽  
Author(s):  
Sarah V. Stevenage ◽  
Elizabeth A. Lee ◽  
Nick Donnelly
Keyword(s):  
Visual Processing ◽  
Target Face ◽  
Classification Task ◽  
Space Model ◽  
Face Space ◽  
Face Classification ◽  
Early Visual Processing ◽  
The Face ◽  
Theoretical Developments

Two experiments are reported to test the proposition that facial familiarity influences processing on a face classification task. Thatcherization was used to generate distorted versions of familiar and unfamiliar individuals. Using both a 2AFC (which is “odd”?) task to pairs of images (Experiment 1) and an “odd/normal” task to single images (Experiment 2), results were consistent and indicated that familiarity with the target face facilitated the face classification decision. These results accord with the proposal that familiarity influences the early visual processing of faces. Results are evaluated with respect to four theoretical developments of Valentine's (1991) face-space model, and can be accommodated with the two models that assume familiarity to be encoded within a region of face space.

scholarly journals Letter chunk frequency does not explain morphological masked priming

2021 ◽  
Author(s):  
Mara De Rosa ◽  
Davide Crepaldi
Keyword(s):  
Visual Processing ◽  
Word Identification ◽  
Masked Priming ◽  
Visual Word ◽  
System Sensitivity ◽  
Early Visual Processing ◽  
Morphological Status ◽  
Visual Word Identification ◽  
Rule Out

Research on visual word identification has extensively investigated the role of morphemes, recurrent letter chunks that convey a fairly regular meaning (e.g.,lead-er-ship). Masked priming studies highlighted morpheme identification in complex (e.g., sing-er) and pseudo-complex (corn-er) words, as well as in nonwords (e.g., basket-y). The present study investigated whether such sensitivity to morphemes could be rooted in the visual system sensitivity to statistics of letter (co)occurrence. To this aim, we assessed masked priming as induced by nonword primes obtained by combining a stem (e.g.,bulb) with (i) naturally frequent, derivational suffixes (e.g.,-ment), (ii) non-morphological, equally frequent word endings (e.g.,-idge), and (iii) non-morphological, infrequent word endings (e.g.,-kle). In two additional tasks, we collected interpretability and word-likeness measures for morphologically-structured nonwords, to assess whether priming is modulated by such factors. Results indicate that masked priming is not affected by either the frequency or the morphological status of word endings. Our findings are in line with models of early visual processing based on automatic stem/word extraction, and rule out letter chunk frequency as a main player in the early stages of visual word identification. Nonword interpretability and word-likeness do not affect this pattern.

scholarly journals Letter chunk frequency does not explain morphological masked priming

2021 ◽  
Author(s):  
Mara De Rosa ◽  
Davide Crepaldi
Keyword(s):  
Visual Processing ◽  
Word Identification ◽  
Masked Priming ◽  
Visual Word ◽  
System Sensitivity ◽  
Early Visual Processing ◽  
Morphological Status ◽  
Visual Word Identification ◽  
Rule Out

AbstractResearch on visual word identification has extensively investigated the role of morphemes, recurrent letter chunks that convey a fairly regular meaning (e.g., lead-er-ship). Masked priming studies highlighted morpheme identification in complex (e.g., sing-er) and pseudo-complex (corn-er) words, as well as in nonwords (e.g., basket-y). The present study investigated whether such sensitivity to morphemes could be rooted in the visual system sensitivity to statistics of letter (co)occurrence. To this aim, we assessed masked priming as induced by nonword primes obtained by combining a stem (e.g., bulb) with (i) naturally frequent, derivational suffixes (e.g., -ment), (ii) non-morphological, equally frequent word-endings (e.g., -idge), and (iii) non-morphological, infrequent word-endings (e.g., -kle). In two additional tasks, we collected interpretability and word-likeness measures for morphologically-structured nonwords, to assess whether priming is modulated by such factors. Results indicate that masked priming is not affected by either the frequency or the morphological status of word-endings, a pattern that was replicated in a second experiment including also lexical primes. Our findings are in line with models of early visual processing based on automatic stem/word extraction, and rule out letter chunk frequency as a main player in the early stages of visual word identification. Nonword interpretability and word-likeness do not affect this pattern.

Is early visual processing attention impenetrable?

1999 ◽  
Vol 22 (3) ◽  
pp. 400-400 ◽  
Author(s):  
Su-Ling Yeh ◽  
I-Ping Chen
Keyword(s):  
Visual Processing ◽  
Vision System ◽  
Early Vision ◽  
Focal Attention ◽  
Early Visual Processing ◽  
Multiple Stages

Pylyshyn's effort in establishing the cognitive impenetrability of early vision is welcome. However, his view about the role of attention in early vision seems to be oversimplified. The allocation of focal attention manifests its effect among multiple stages in the early vision system, it is not just confined to the input and the output levels.

Top-Down Processing and Visual Reorientation Illusions in a Virtual Reality Environment

2004 ◽  
Vol 63 (3) ◽  
pp. 143-149 ◽  
Author(s):  
Fred W. Mast ◽  
Charles M. Oman
Keyword(s):  
Virtual Reality ◽  
Visual Processing ◽  
Line Length ◽  
Perceptual Cues ◽  
Virtual Reality Environment ◽  
Top Down ◽  
Test Conditions ◽  
The Subject ◽  
Processing Mechanisms

The role of top-down processing on the horizontal-vertical line length illusion was examined by means of an ambiguous room with dual visual verticals. In one of the test conditions, the subjects were cued to one of the two verticals and were instructed to cognitively reassign the apparent vertical to the cued orientation. When they have mentally adjusted their perception, two lines in a plus sign configuration appeared and the subjects had to evaluate which line was longer. The results showed that the line length appeared longer when it was aligned with the direction of the vertical currently perceived by the subject. This study provides a demonstration that top-down processing influences lower level visual processing mechanisms. In another test condition, the subjects had all perceptual cues available and the influence was even stronger.

scholarly journals Directional selectivity and its use in early visual processing

1981 ◽  
Vol 211 (1183) ◽  
pp. 151-180 ◽  
Keyword(s):  
Visual Processing ◽  
Visual Motion ◽  
Time Derivative ◽  
Receptive Fields ◽  
Specific Model ◽  
Zero Crossings ◽  
Second Stage ◽  
Early Visual Processing ◽  
Local Direction ◽  
Zero Values

The construction of directionally selective units, and their use in the processing of visual motion, are considered. The zero crossings of ∇ 2 G(x, y) ∗ I(x, y) are located, as in Marr & Hildreth (1980). That is, the image is filtered through centre-surround receptive fields, and the zero values in the output are found. In addition, the time derivative ∂[∇ 2 G(x, y) ∗ l(x, y) ]/∂ t is measured at the zero crossings, and serves to constrain the local direction of motion to within 180°. The direction of motion can be determined in a second stage, for example by combining the local constraints. The second part of the paper suggests a specific model of the information processing by the X and Y cells of the retina and lateral geniculate nucleus, and certain classes of cortical simple cells. A number of psychophysical and neurophysiological predictions are derived from the theory.

Repetition Suppression of Induced Gamma Activity Predicts Enhanced Orienting toward a Novel Stimulus in 6-month-old Infants

2008 ◽  
Vol 20 (12) ◽  
pp. 2137-2152 ◽  
Author(s):  
Kelly A. Snyder ◽  
Andreas Keil
Keyword(s):  
Visual Processing ◽  
Novelty Detection ◽  
Neural Mechanisms ◽  
Human Infant ◽  
Gamma Activity ◽  
Repeated Stimulus ◽  
Repetition Suppression ◽  
The Face ◽  
Over 40 Years

Habituation refers to a decline in orienting or responding to a repeated stimulus, and can be inferred to reflect learning about the properties of the repeated stimulus when followed by increased orienting to a novel stimulus (i.e., novelty detection). Habituation and novelty detection paradigms have been used for over 40 years to study perceptual and mnemonic processes in the human infant, yet important questions remain about the nature of these processes in infants. The aim of the present study was to examine the neural mechanisms underlying habituation and novelty detection in infants. Specifically, we investigated changes in induced alpha, beta, and gamma activity in 6-month-old infants during repeated presentations of either a face or an object, and examined whether these changes predicted behavioral responses to novelty at test. We found that induced gamma activity over occipital scalp regions decreased with stimulus repetition in the face condition but not in the toy condition, and that greater decreases in the gamma band were associated with enhanced orienting to a novel face at test. The pattern and topography of these findings are consistent with observations of repetition suppression in the occipital–temporal visual processing pathway, and suggest that encoding in infant habituation paradigms may reflect a form of perceptual learning. Implications for the role of repetition suppression in infant habituation and novelty detection are discussed with respect to a biased competition model of visual attention.

Sign in / Sign up

Export Citation Format

Share Document