Spatial Interactions Modulate Stereoscopic Processing of Horizontal and Vertical Disparities

Mark W Pettet

doi:10.1068/p260693

Spatial Interactions Modulate Stereoscopic Processing of Horizontal and Vertical Disparities

Perception ◽

10.1068/p260693 ◽

1997 ◽

Vol 26 (6) ◽

pp. 693-706

Author(s):

Mark W Pettet

Keyword(s):

Size Effect ◽

Weighted Average ◽

Vertical Axis ◽

Spatial Interactions ◽

Depth Contrast ◽

Direction Opposite ◽

Lines Of Evidence

Stereoscopic processing of horizontal and vertical disparities was assessed by measuring how the stereoscopic appearance of test dots near the fixation point was influenced by inducing stimuli in the near periphery. The inducing stimuli were differentially magnified in the two eyes and varied in horizontal eccentricity. As expected, when the inducers were horizontally magnified, the test dots exhibited depth contrast, slanting in depth in a direction opposite the slant of the inducing dots. When the inducers were vertically magnified, the test dots slanted in depth around a vertical axis toward the eye with the larger vertical image (the induced-size effect). However, two lines of evidence suggested that an eccentricity-dependent weighted average of horizontal and vertical components of inducer-dot magnification determined the slant of the test dots. First, as the horizontal eccentricity of the inducing dots was varied, the trend of test-dot slants measured with vertical inducer magnifications was predicted by the trend of test-dot slants measured with horizontal inducer magnifications. Second, test-dot slants measured with a combination of both horizontal and vertical inducer magnification could be predicted by simply adding test-dot slants measured with either horizontal or vertical inducer magnification alone.

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Types of Size Disparity and the Perception of Surface Slant

Perception ◽

10.1068/p261503 ◽

1997 ◽

Vol 26 (12) ◽

pp. 1503-1517 ◽

Cited By ~ 14

Author(s):

Byron J Pierce ◽

Ian P Howard

Keyword(s):

Vertical Axis ◽

Textured Surface ◽

Curved Boundary ◽

Surface Slant ◽

Size Disparity ◽

Horizontal Size ◽

Depth Contrast ◽

Depth Enhancement ◽

Vertical Size

We examined (i) perceived slant of a textured surface about a vertical axis as a function of disparity magnitude for horizontal-size disparity, vertical-size disparity, and overall-size disparity; and (ii) interactions between patterns with various types and magnitudes of size disparity and superimposed or adjacent zero-disparity stimuli. Horizontal-size disparity produced slant which increased with increasing disparity, was enhanced by superimposed zero-disparity stimuli, and induced contrasting slant in superimposed or adjacent zero-disparity stimuli. Vertical-size disparity produced opposite slant (induced effect) which was reduced to near zero by a superimposed zero-disparity pattern and both patterns appeared as one surface. Adjacent vertical-size-disparity and zero-disparity patterns appeared as separate surfaces with a wide curved boundary. Overall-size disparity produced slant which was enhanced by a superimposed zero-disparity pattern and less so by a zero-disparity line, and induced more slant in a zero-disparity line than in a zero-disparity pattern. The results are discussed in terms of depth underestimation of isolated surfaces, depth enhancement, depth contrast, and the processing of deformation disparity.

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Effect of Semicircular Canal Stimulation on the Perception of the Visual Vertical

Journal of Neurophysiology ◽

10.1152/jn.00960.2002 ◽

2003 ◽

Vol 90 (2) ◽

pp. 622-630 ◽

Cited By ~ 63

Author(s):

Marousa Pavlou ◽

Nicole Wijnberg ◽

Mary E. Faldon ◽

Adolfo M. Bronstein

Keyword(s):

Semicircular Canal ◽

Three Dimensional ◽

Vertical Axis ◽

Normal Subjects ◽

Slow Phase ◽

Visual Vertical ◽

Axis Rotation ◽

Highly Correlated ◽

Head Positions ◽

Direction Opposite

The subjective visual vertical (SVV) is usually considered a measure of otolith function. Herewith we investigate the influence of semicircular canal (SCC) stimulation on the SVV by rotating normal subjects in yaw about an earth-vertical axis, with velocity steps of ± 90°/s, for 60 s. SVV was assessed by setting an illuminated line to perceived earth vertical in darkness, during a per- and postrotary period. Four head positions were tested: upright, 30° backward (chin up) or forward, and ∼40° forward from upright. During head upright/backward conditions, a significant SVV tilt ( P < 0.01) in the direction opposite to rotation was found that reversed during postrotary responses. The rotationally induced SVV tilt had a time constant of decay of ∼30 s. Rotation with the head 30° forward did not affect SVV, whereas the 40° forward tilt caused a direction reversal of SVV responses compared with head upright/backward. Spearman correlation values (Rho) between individual SCC efficiencies in different head positions and mean SVV tilts were 0.79 for posterior, 0.34 for anterior, and – 0.80 for horizontal SCCs. Three-dimensional video-oculography showed that SVV and torsional eye position measurements were highly correlated (0.83) and in the direction opposite to the slow phase torsional vestibuloocular reflex. In conclusion: 1) during yaw axis rotation without reorientation of the head with respect to gravity, the SVV is influenced by SCC stimulation; 2) this effect is mediated by the vertical SCCs, particularly the posterior SCCs; 3) rotationally induced SVV changes are due to torsional ocular tilt; 4) SVV and ocular tilts occur in the “anticompensatory,” fast phase direction of the torsional nystagmus; and 5) clinically, abnormal SVV tilts cannot be considered a specific indication of otolith system dysfunction.

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Fluency: A trigger of familiarity for relational representations?

Behavioral and Brain Sciences ◽

10.1017/s0140525x1900178x ◽

2019 ◽

Vol 42 ◽

Author(s):

Talya Sadeh

Keyword(s):

Memory Model ◽

Lines Of Evidence

Abstract According to Bastin et al.’s integrative memory model, familiarity may be attributed to both entity representations and relational representations. However, the model does not specify what triggers familiarity for relational representations. I argue that fluency is a key player in the attribution of familiarity regardless of the type of representation. Two lines of evidence are reviewed in support of my claim.

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Size Effect Aspects of Measurement of Fracture Characteristics of Quasibrittle Material

Advanced Cement Based Materials ◽

10.1016/s1065-7355(96)00037-5 ◽

1996 ◽

Vol 4 (3-4) ◽

pp. 128-137 ◽

Cited By ~ 13

Author(s):

Z Bazant

Keyword(s):

Size Effect ◽

Fracture Characteristics ◽

Quasibrittle Material

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Spatial Representations as an Emergent Feature of Perceptual Processing

Journal of Psychophysiology ◽

10.1027/0269-8803/a000007 ◽

2010 ◽

Vol 24 (3) ◽

pp. 161-172 ◽

Cited By ~ 14

Author(s):

Edmund Wascher ◽

C. Beste

Keyword(s):

Common Ground ◽

Event Related Potentials ◽

Vertical Axis ◽

Relevant Information ◽

Sources Of Information ◽

Integrated Network ◽

Perceptual Maps ◽

Emergent Feature ◽

Related Potentials ◽

Selection Of

Spatial selection of relevant information has been proposed to reflect an emergent feature of stimulus processing within an integrated network of perceptual areas. Stimulus-based and intention-based sources of information might converge in a common stage when spatial maps are generated. This approach appears to be inconsistent with the assumption of distinct mechanisms for stimulus-driven and top-down controlled attention. In two experiments, the common ground of stimulus-driven and intention-based attention was tested by means of event-related potentials (ERPs) in the human EEG. In both experiments, the processing of a single transient was compared to the selection of a physically comparable stimulus among distractors. While single transients evoked a spatially sensitive N1, the extraction of relevant information out of a more complex display was reflected in an N2pc. The high similarity of the spatial portion of these two components (Experiment 1), and the replication of this finding for the vertical axis (Experiment 2) indicate that these two ERP components might both reflect the spatial representation of relevant information as derived from the organization of perceptual maps, just at different points in time.

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