scholarly journals Estimating Critical Stimulus Features from Psychophysical Data: The Decision-Image Technique Applied to Human Faces

2010 ◽  
Vol 9 (8) ◽  
pp. 31-31 ◽  
Author(s):  
J. H. Macke ◽  
F. A. Wichmann
Keyword(s):  
Critical Stimulus ◽  
Psychophysical Data ◽  
Image Technique ◽  
Stimulus Features ◽  
Human Faces

FACE RECOGNITION UNDER GENERIC ILLUMINATION BASED ON HARMONIC RELIGHTING

2005 ◽  
Vol 19 (04) ◽  
pp. 513-531 ◽  
Author(s):  
LAIYUN QING ◽  
SHIGUANG SHAN ◽  
WEN GAO ◽  
BO DU
Keyword(s):  
Face Recognition ◽  
Low Frequency ◽  
Recognition System ◽  
Face Database ◽  
Facial Image ◽  
Ratio Image ◽  
The Face ◽  
Frequency Components ◽  
Image Technique ◽  
Human Faces

The performances of the current face recognition systems suffer heavily from the variations in lighting. To deal with this problem, this paper presents an illumination normalization approach by relighting face images to a canonical illumination based on the harmonic images model. Benefiting from the observations that human faces share similar shape, and the albedos of the face surfaces are quasi-constant, we first estimate the nine low-frequency components of the illumination from the input facial image. The facial image is then normalized to the canonical illumination by re-rendering it using the illumination ratio image technique. For the purpose of face recognition, two kinds of canonical illuminations, the uniform illumination and a frontal flash with the ambient lights, are considered, among which the former encodes merely the texture information, while the latter encodes both the texture and shading information. Our experiments on the CMU-PIE face database and the Yale B face database have shown that the proposed relighting normalization can significantly improve the performance of a face recognition system when the probes are collected under varying lighting conditions.

Differences in Onset Latency of Macaque Inferotemporal Neural Responses to Primate and Non-Primate Faces

2005 ◽  
Vol 94 (2) ◽  
pp. 1587-1596 ◽  
Author(s):  
Roozbeh Kiani ◽  
Hossein Esteky ◽  
Keiji Tanaka
Keyword(s):  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Complex Object ◽  
Neural Responses ◽  
Onset Latency ◽  
Single Cell Responses ◽  
Response Onset ◽  
Stimulus Features ◽  
Animal Faces ◽  
Human Faces

Neurons in the visual system respond to different visual stimuli with different onset latencies. However, it has remained unknown which stimulus features, aside from stimulus contrast, determine the onset latencies of responses. To examine the possibility that response onset latencies carry information about complex object images, we recorded single-cell responses in the inferior temporal cortex of alert monkeys, while they viewed >1,000 object stimuli. Many cells responded to human and non-primate animal faces with comparable magnitudes but responded significantly more quickly to human faces than to non-primate animal faces. Differences in onset latency may be used to increase the coding capacity or enhance or suppress information about particular object groups by time-dependent modulation.

Response Interference as a Mechanism Underlying Implicit Measures

2008 ◽  
Vol 24 (4) ◽  
pp. 218-225 ◽  
Author(s):  
Bertram Gawronski ◽  
Roland Deutsch ◽  
Etienne P. LeBel ◽  
Kurt R. Peters
Keyword(s):  
Task Performance ◽  
Psychological Research ◽  
Implicit Measures ◽  
Mediation Model ◽  
Response Interference ◽  
Relevant Evidence ◽  
Moderated Mediation Model ◽  
Stimulus Features ◽  
Underlying Mechanisms

Over the last decade, implicit measures of mental associations (e.g., Implicit Association Test, sequential priming) have become increasingly popular in many areas of psychological research. Even though successful applications provide preliminary support for the validity of these measures, their underlying mechanisms are still controversial. The present article addresses the role of a particular mechanism that is hypothesized to mediate the influence of activated associations on task performance in many implicit measures: response interference (RI). Based on a review of relevant evidence, we argue that RI effects in implicit measures depend on participants’ attention to association-relevant stimulus features, which in turn can influence the reliability and the construct validity of these measures. Drawing on a moderated-mediation model (MMM) of task performance in RI paradigms, we provide several suggestions on how to address these problems in research using implicit measures.

Self-Prioritization Beyond Perception

2015 ◽  
Vol 62 (6) ◽  
pp. 415-425 ◽  
Author(s):  
Sarah Schäfer ◽  
Dirk Wentura ◽  
Christian Frings
Keyword(s):  
The Self ◽  
Stimulus Category ◽  
Abstract Concept ◽  
Conceptual Level ◽  
New Paradigm ◽  
Stimulus Features ◽  
Relevant Word ◽  
Word Shape

Abstract. Recently, Sui, He, and Humphreys (2012) introduced a new paradigm to measure perceptual self-prioritization processes. It seems that arbitrarily tagging shapes to self-relevant words (I, my, me, and so on) leads to speeded verification times when matching self-relevant word shape pairings (e.g., me – triangle) as compared to non-self-relevant word shape pairings (e.g., stranger – circle). In order to analyze the level at which self-prioritization takes place we analyzed whether the self-prioritization effect is due to a tagging of the self-relevant label and the particular associated shape or due to a tagging of the self with an abstract concept. In two experiments participants showed standard self-prioritization effects with varying stimulus features or different exemplars of a particular stimulus-category suggesting that self-prioritization also works at a conceptual level.

The Sorting Paired Features Task

2009 ◽  
Vol 56 (5) ◽  
pp. 329-343 ◽  
Author(s):  
Yoav Bar-Anan ◽  
Brian A. Nosek ◽  
Michelangelo Vianello
Keyword(s):  
Discriminant Validity ◽  
Association Measures ◽  
Response Options ◽  
Convergent And Discriminant Validity ◽  
Attitude Measures ◽  
Stimulus Features ◽  
Single Response

The sorting paired features (SPF) task measures four associations in a single response block. Using four response options (e.g., good-Republicans, bad-Republicans, good-Democrats, and bad-Democrats), each trial requires participants to categorize two stimuli at once to a category pair (e.g., wonderful-Clinton to good-Democrats). Unlike other association measures, the SPF requires simultaneous categorization of both components of the association in the same trial. Providing measurement flexibility, it is sensitive to both focal, attended concepts and nonfocal, unattended stimulus features (e.g., gender of individuals in a politics SPF). Three studies measure race, gender, and political evaluations, differentiate automatic evaluations between known groups, provide evidence of convergent and discriminant validity with other attitude measures, and illustrate the SPF’s unique measurement qualities.

The Two Sides of Temporal Orienting

2010 ◽  
Vol 57 (2) ◽  
pp. 142-148 ◽  
Author(s):  
Ángel Correa ◽  
Paola Cappucci ◽  
Anna C. Nobre ◽  
Juan Lupiáñez
Keyword(s):  
Executive Control ◽  
Stroop Effect ◽  
Traffic Situation ◽  
Target Onset ◽  
Stimulus Features ◽  
Two Sides ◽  
Spatial Stroop Effect ◽  
Probable Interval ◽  
Spatial Stroop ◽  
Temporal Orienting

Would it be helpful to inform a driver about when a conflicting traffic situation is going to occur? We tested whether temporal orienting of attention could enhance executive control to select among conflicting stimuli and responses. Temporal orienting was induced by presenting explicit cues predicting the most probable interval for target onset, which could be short (400 ms) or long (1,300 ms). Executive control was measured both by flanker and Simon tasks involving conflict between incompatible responses and by the spatial Stroop task involving conflict between perceptual stimulus features. The results showed that temporal orienting facilitated the resolution of perceptual conflict by reducing the spatial Stroop effect, whereas it interfered with the resolution of response conflict by increasing flanker and Simon effects. Such opposite effects suggest that temporal orienting of attention modulates executive control through dissociable mechanisms, depending on whether the competition between conflicting representations is located at perceptual or response levels.

The identification of the critical haptic stimulus features in a clinical dental task

2004 ◽  
Author(s):  
Li Liu ◽  
Geb Thomas ◽  
Clark Stanford ◽  
Lynn Johnson
Keyword(s):  
Haptic Stimulus ◽  
Stimulus Features
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