Apparent Depth with Motion Aftereffect and Head Movement

Perception ◽  
1994 ◽  
Vol 23 (10) ◽  
pp. 1241-1248 ◽  
Author(s):  
Hiroshi Ono ◽  
Hiroyasu Ujike
Keyword(s):  
Decay Time ◽  
Head Movement ◽  
Motion Aftereffect ◽  
Apparent Depth ◽  
Shearing Motion ◽  
Lateral Head ◽  
Do So

Coupling a motion aftereffect (MAE) produced by horizontal shearing motion with a lateral head movement yields apparent depth. In experiments 1 and 2, respectively, the magnitude and the decay time of this apparent depth were measured. In experiment 3, it was found that the stimulus that produced an MAE in experiments 1 and 2 failed to do so when it was viewed while the head moved leftward and rightward and depth was seen.

Head Movement Changes Apparent Depth Order in a Motion-Parallax Display

Perception ◽  
1993 ◽  
Vol 22 (6) ◽  
pp. 643-652 ◽  
Author(s):  
Keikichi Hayashibe
Keyword(s):  
Head Movement ◽  
Horizontal Plane ◽  
Motion Parallax ◽  
Apparent Depth ◽  
Visual Depth ◽  
Depth Order ◽  
Direction Of Movement ◽  
Random Dot Pattern ◽  
Lateral Head

The hypothesis that the apparent visual depth is determined by the proximal velocity relative to the position of the head was examined in three experiments. Apparent protrusion/recession changed when subjects observed a moving random-dot pattern with their heads tilted sideways or rotated in the horizontal plane. This is ascribed to lateral head movement, which increases the proximal velocity when the dots and the subjects' heads are moving in opposite directions, and decreases the proximal velocity when both are moving in the same direction. Changes in the direction of movement of the stimulus caused a reversal of the apparent protrusion/recession. The resultant proximal velocity of the stimulus determined the order of depth of surfaces when the movement of the stimulus was linked to the subject's head movement.

scholarly journals The Perceived Direction of Textured Gratings and Their Motion Aftereffects

Perception ◽  
1995 ◽  
Vol 24 (12) ◽  
pp. 1383-1396 ◽  
Author(s):  
David Alais ◽  
Maarten J van der Smagt ◽  
Frans A J Verstraten ◽  
Wim A van de Grind
Keyword(s):  
Motion Aftereffect ◽  
Sine Wave ◽  
Circular Aperture ◽  
High Luminance ◽  
One Dimensional ◽  
Square Wave ◽  
Aperture Problem ◽  
Motion Energy ◽  
Motion Aftereffects ◽  
Do So

The stimuli in these experiments are square-wave luminance gratings with an array of small random dots covering the high-luminance regions. Owing to the texture, the direction of these gratings, when seen through a circular aperture, is disambiguated because the visual system is provided with an unambiguous motion energy. Thus, the direction of textured gratings can be varied independently of grating orientation. When subjects are required to judge the direction of textured gratings moving obliquely relative to their orientation, they can do so accurately (experiment 1). This is of interest because most studies of one-dimensional motion perception have involved (textureless) luminance-defined sine-wave or square-wave gratings, and the perceived direction of these gratings is constrained by the aperture problem to be orthogonal to their orientation. Thus, direction and orientation have often been confounded. Interestingly, when subjects are required to judge the direction of an obliquely moving textured grating during a period of adaptation and then the direction of the motion aftereffect (MAE) immediately following adaptation (experiments 2 and 3), these directions are not directly opposite each other. MAE directions were always more orthogonal to the orientation of the adapting grating than the corresponding direction judgments during adaptation (by as much as 25°). These results are not readily explained by conventional MAE models and possible accounts are considered.

scholarly journals Comparison between Lateral Head Movement and To-and-Fro Head Movement on Depth Perception from Motion Parallax

i-Perception ◽  
10.1068/ic393 ◽  
2011 ◽  
Vol 2 (4) ◽  
pp. 393-393
Author(s):  
Masahiro Ishii ◽  
Masashi Fujita ◽  
Masayuki Sato
Keyword(s):  
Depth Perception ◽  
Head Movement ◽  
Motion Parallax ◽  
Lateral Head

Apparent Motion of a Wallpaper Illusion with Lateral Head Movement

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 281-281
Author(s):  
S Nakamizo ◽  
M Kondo
Keyword(s):  
Apparent Motion ◽  
Head Movement ◽  
Egocentric Distance ◽  
Independent Variable ◽  
Lateral Head

We measured the magnitude and direction of apparent motion of the wallpaper illusion produced by a lateral head movement. The wallpaper illusion was produced by converging on a grating stimulus located between a far and a near grating stimuli placed, respectively, higher and lower than the fixated middle stimulus. The proximal size of the stimuli was held constant. Observers were asked to move their head laterally on a sliding chinrest and to report the magnitude and direction of the apparent motion of each stimulus. The independent variable was the extent (2.5, 5.0, and 7.5 cm) of the head movement. The results for five observers showed that: (a) the larger mean magnitude of apparent motion was associated with larger extent of head movement, and (b) the direction of apparent motion for the far stimulus was the same as that of the head movement, and that for the near stimulus was opposite to that of the head movement. These results are consistent with Gogel's hypothesis of an apparent concomitant motion of the object with head movement when the egocentric distance of the object is misperceived.

Head Movement in Linguistic Theory

2006 ◽  
Vol 37 (1) ◽  
pp. 69-109 ◽  
Author(s):  
Ora Matushansky
Keyword(s):  
Head Movement ◽  
Linguistic Theory ◽  
Do So ◽  
New View

In this article, I address the issue of head movement in current linguistic theory. I propose a new view of the nature of heads and head movement that reveals that head movement is totally compliant with the standardly suggested properties of grammar. To do so, I suggest that head movement is not a single syntactic operation, but a combination of two operations: a syntactic one (movement) and a morphological one (m-merger). I then provide independent motivation for m-merger, arguing that it can be attested in environments where no head movement took place

scholarly journals Effects of damping head movement and facial expression in dyadic conversation using real–time facial expression tracking and synthesized avatars

2009 ◽  
Vol 364 (1535) ◽  
pp. 3485-3495 ◽  
Author(s):  
Steven M. Boker ◽  
Jeffrey F. Cohn ◽  
Barry-John Theobald ◽  
Iain Matthews ◽  
Timothy R. Brick ◽  
...  
Keyword(s):  
Experimental Design ◽  
Facial Expression ◽  
Real Time ◽  
Facial Expressions ◽  
Head Movement ◽  
Head Movements ◽  
Head Nodding ◽  
Lateral Head

When people speak with one another, they tend to adapt their head movements and facial expressions in response to each others' head movements and facial expressions. We present an experiment in which confederates' head movements and facial expressions were motion tracked during videoconference conversations, an avatar face was reconstructed in real time, and naive participants spoke with the avatar face. No naive participant guessed that the computer generated face was not video. Confederates' facial expressions, vocal inflections and head movements were attenuated at 1 min intervals in a fully crossed experimental design. Attenuated head movements led to increased head nods and lateral head turns, and attenuated facial expressions led to increased head nodding in both naive participants and confederates. Together, these results are consistent with a hypothesis that the dynamics of head movements in dyadicconversation include a shared equilibrium. Although both conversational partners were blind to the manipulation, when apparent head movement of one conversant was attenuated, both partners responded by increasing the velocity of their head movements.

Holding replication studies to mainstream standards of evidence

2018 ◽  
Vol 41 ◽  
Author(s):  
Duane T. Wegener ◽  
Leandre R. Fabrigar
Keyword(s):  
Replication Studies ◽  
Replication Research ◽  
Standards Of Evidence ◽  
Do So

AbstractReplications can make theoretical contributions, but are unlikely to do so if their findings are open to multiple interpretations (especially violations of psychometric invariance). Thus, just as studies demonstrating novel effects are often expected to empirically evaluate competing explanations, replications should be held to similar standards. Unfortunately, this is rarely done, thereby undermining the value of replication research.

Electron Microscopy of a Herpesvirus Isolated from Marek's Disease in Duck and Chicken Embryo Fibroblast Cultures

1968 ◽  
Vol 26 ◽  
pp. 222-223 ◽  
Author(s):  
Keyvan Nazerian
Keyword(s):  
Inclusion Bodies ◽  
Chicken Embryo Fibroblast ◽  
Marek's Disease ◽  
Marek’S Disease ◽  
Duck Embryo Fibroblast ◽  
Multinucleated Cells ◽  
Viral Particles ◽  
Infected Cells ◽  
And Control ◽  
Do So

A herpes-like virus has been isolated from duck embryo fibroblast (DEF) cultures inoculated with blood from Marek's disease (MD) infected birds. Cultures which contained this virus produced MD in susceptible chickens while virus negative cultures and control cultures failed to do so. This and other circumstantial evidence including similarities in properties of the virus and the MD agent implicate this virus in the etiology of MD.Histochemical studies demonstrated the presence of DNA-staining intranuclear inclusion bodies in polykarocytes in infected cultures. Distinct nucleo-plasmic aggregates were also seen in sections of similar multinucleated cells examined with the electron microscope. These aggregates are probably the same as the inclusion bodies seen with the light microscope. Naked viral particles were observed in the nucleus of infected cells within or on the edges of the nucleoplasmic aggregates. These particles measured 95-100mμ, in diameter and rarely escaped into the cytoplasm or nuclear vesicles by budding through the nuclear membrane (Fig. 1). The enveloped particles (Fig. 2) formed in this manner measured 150-170mμ in diameter and always had a densely stained nucleoid. The virus in supernatant fluids consisted of naked capsids with 162 hollow, cylindrical capsomeres (Fig. 3). Enveloped particles were not seen in such preparations.

Debates in Dysphagia Management: How Do You Use Evidence-Based Practice in Your Dysphagia Patient Care?

2011 ◽  
Vol 20 (4) ◽  
pp. 121-123
Author(s):  
Jeri A. Logemann
Keyword(s):  
Decision Making ◽  
Patient Care ◽  
Clinical Outcomes ◽  
Clinical Judgment ◽  
Clinical Decision Making ◽  
Evidence Based Practice ◽  
Clinical Decision ◽  
Evidence Based ◽  
Clinical Method ◽  
Do So

Evidence-based practice requires astute clinicians to blend our best clinical judgment with the best available external evidence and the patient's own values and expectations. Sometimes, we value one more than another during clinical decision-making, though it is never wise to do so, and sometimes other factors that we are unaware of produce unanticipated clinical outcomes. Sometimes, we feel very strongly about one clinical method or another, and hopefully that belief is founded in evidence. Some beliefs, however, are not founded in evidence. The sound use of evidence is the best way to navigate the debates within our field of practice.

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