Velocity Threshold for Relative and Uniform Motion

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 353-353
Author(s):  
S Shioiri ◽  
S Ito ◽  
H Yaguchi
Keyword(s):  
Spatial Frequency ◽  
Relative Motion ◽  
Threshold Function ◽  
Uniform Motion ◽  
Measured Velocity ◽  
Velocity Threshold ◽  
Spatial Frequencies ◽  
Motion Condition ◽  
The Difference ◽  
The Right

We measured velocity thresholds for relative and uniform motion as functions of spatial frequency and contrast. Stimuli were two horizontal bands on top of each other, both filled with vertical sinusoidal gratings. The gratings drifted either to the right or to the left, in opposite directions in the relative-motion condition but in the same direction in the uniform-motion condition. Observers had to report the direction of motion, and the velocity was varied until a velocity threshold was obtained. The results showed that the shapes of the threshold function plotted against spatial frequency are quite different for uniform and relative motion. The threshold for relative motion had a minimum at around 5 cycles deg−1, whereas the threshold for uniform motion had no such minimum, at least at higher contrasts (10% or higher). The difference was unclear for lower-contrast stimuli, however. The threshold profile as a function of contrast was also different between relative and uniform motion. Although the threshold decreased with increasing contrast in both cases, this dependence saturated at around 10% contrast for uniform motion, while it continued up to the highest contrast (85%) for relative motion. This difference held for all the spatial frequencies examined (from 0.75 to 12.1 cycles deg−1). The results suggest that the detection mechanisms for relative motion and uniform motion are different.

Hemispheric Processing of Categorical and Coordinate Spatial Relations in the Absence of Low Spatial Frequencies

2002 ◽  
Vol 14 (2) ◽  
pp. 291-297 ◽  
Author(s):  
Matia Okubo ◽  
Chikashi Michimata
Keyword(s):  
Visual Field ◽  
Spatial Frequency ◽  
Right Hemisphere ◽  
Spatial Relation ◽  
Spatial Relations ◽  
Right Visual Field ◽  
Spatial Frequencies ◽  
Categorical Task ◽  
The Right ◽  
Coordinate Spatial Relations

Right-handed participants performed the categorical and coordinate spatial relation judgments on stimuli presented to either the left visual field—right hemisphere (LVF-RH) or the right visual field—left hemisphere (RVF-LH). The stimulus patterns were formulated either by bright dots or by contrast-balanced dots. When the stimuli were bright, an RVF-LH advantage was observed for the categorical task, whereas an LVF-RH advantage was observed for the coordinate task. When the stimuli were contrast balanced, the RVF-LH advantage was observed for the categorical task, but the LVF-RH advantage was eliminated for the coordinate task. Because the contrast-balanced dots are largely devoid of low spatial frequency content, these results suggest that processing of low spatial frequency is responsible for the right hemisphere advantage for the coordinate spatial processing.

Right-Hemisphere Superiority in the Discrimination of Spatial Phase

Perception ◽  
1984 ◽  
Vol 13 (6) ◽  
pp. 695-708 ◽  
Author(s):  
Adriana Fiorentini ◽  
Nicoletta Berardi
Keyword(s):  
Spatial Frequency ◽  
Right Hemisphere ◽  
Frequency Discrimination ◽  
High Contrast ◽  
Spatial Phase ◽  
Phase Discrimination ◽  
Visual Hemifield ◽  
Spatial Frequencies ◽  
Sinusoidal Gratings ◽  
The Right

Visual field differences have been investigated in various detection and discrimination tasks for simple sinusoidal gratings or for complex gratings composed of two sinusoids of spatial frequencies f and 3 f. Sinusoidal gratings were employed to evaluate contrast sensitivity, subthreshold summation effects, aftereffects of adaptation to a high-contrast grating, and spatial-frequency discrimination. The tasks with complex gratings were detection of the 3 f component in the presence of a high-contrast f component and spatial-phase discrimination. The stimuli were presented either in the left or in the right visual hemifield. The results indicate a lack of lateralization for detection and spatial-frequency discrimination of sinusoidal gratings, and for the bandwidth of subthreshold summation effects and adaptation aftereffects, whereas the detection of the 3 f component in the presence of a high-contrast f component, as well as spatial-phase discrimination of f + 3 f gratings, show a left-field advantage. This suggests a right-hemisphere superiority in the processing of spatial phase.

The Perceived Duration of Gratings

Perception ◽  
1992 ◽  
Vol 21 (2) ◽  
pp. 161-166 ◽  
Author(s):  
John A Baro ◽  
Lynda J Brzezicki ◽  
Stephen Lehmkuhle ◽  
Howard C Hughes
Keyword(s):  
Spatial Frequency ◽  
Reaction Times ◽  
Visible Persistence ◽  
Subjective Duration ◽  
Spatial Frequencies ◽  
The Difference ◽  
Perceived Duration

Since visible persistence of grating patterns increases with spatial frequency, it is often inferred that the perceived duration of a grating is also longer at higher spatial frequencies. However, other work has demonstrated that the perceived onset of a grating is also delayed at higher spatial frequencies. Thus it is impossible to infer the subjective duration from the results of visible persistence studies alone. In order to estimate perceived duration in the present study, reaction times (RTs) to grating onsets and offsets were measured for a range of spatial frequencies. The results indicate that although the perceived duration (ie the difference between offset and onset RTs) was consistently longer than the physical duration, the estimates of perceived duration did not vary with changes in spatial frequency. Differences between the present results and earlier findings are interpreted in the context of the different methods used to measure perceived offset.

scholarly journals Glyph guessing for ‘oo’ and ‘ee’: spatial frequency information in sound symbolic matching for ancient and unfamiliar scripts

2017 ◽  
Vol 4 (9) ◽  
pp. 170882 ◽  
Author(s):  
Nora Turoman ◽  
Suzy J. Styles
Keyword(s):  
Spatial Frequency ◽  
Historical Time ◽  
Adult Readers ◽  
Visual Spatial ◽  
Internet Users ◽  
Spatial Frequencies ◽  
The Difference ◽  
Diverse Groups ◽  
Geographical Space ◽  
Larger Sample

In three experiments, we asked whether diverse scripts contain interpretable information about the speech sounds they represent. When presented with a pair of unfamiliar letters, adult readers correctly guess which is /i/ (the ‘ee’ sound in ‘feet’), and which is /u/ (the ‘oo’ sound in ‘shoe’) at rates higher than expected by chance, as shown in a large sample of Singaporean university students (Experiment 1) and replicated in a larger sample of international Internet users (Experiment 2). To uncover what properties of the letters contribute to different scripts' ‘guessability,’ we analysed the visual spatial frequencies in each letter (Experiment 3). We predicted that the lower spectral frequencies in the formants of the vowel /u/ would pattern with lower spatial frequencies in the corresponding letters. Instead, we found that across all spatial frequencies, the letter with more black/white cycles (i.e. more ink) was more likely to be guessed as /u/, and the larger the difference between the glyphs in a pair, the higher the script's guessability. We propose that diverse groups of humans across historical time and geographical space tend to employ similar iconic strategies for representing speech in visual form, and provide norms for letter pairs from 56 diverse scripts.

scholarly journals Persistent Hemispheric Differences in the Perceptual Selection of Spatial Frequencies

2014 ◽  
Vol 26 (9) ◽  
pp. 2021-2027 ◽  
Author(s):  
Elise A. Piazza ◽  
Michael A. Silver
Keyword(s):  
Spatial Frequency ◽  
Left Hemisphere ◽  
Hemispheric Asymmetry ◽  
Time Course ◽  
Right Hemisphere ◽  
High Spatial Frequency ◽  
Hemispheric Differences ◽  
Spatial Frequencies ◽  
The Right ◽  
Perceptual Selection

Previous research has shown that the right hemisphere processes low spatial frequencies more efficiently than the left hemisphere, which preferentially processes high spatial frequencies. These studies have typically measured RTs to single, briefly flashed gratings and/or have directed observers to attend to a particular spatial frequency immediately before making a judgment about a subsequently presented stimulus. Thus, it is unclear whether the hemispheres differ in perceptual selection from multiple spatial frequencies that are simultaneously present in the environment, without bias from selective attention. Moreover, the time course of hemispheric asymmetry in spatial frequency processing is unknown. We addressed both of these questions with binocular rivalry, a measure of perceptual selection from competing alternatives over time. Participants viewed a pair of rivalrous orthogonal gratings with different spatial frequencies, presented either to the left or right of central fixation, and continuously reported which grating they perceived. At the beginning of a trial, the low spatial frequency grating was perceptually selected more often when presented in the left hemifield (right hemisphere) than in the right hemifield (left hemisphere), whereas the high spatial frequency grating showed the opposite pattern of results. This hemispheric asymmetry in perceptual selection persisted for the entire 30-sec stimulus presentation, continuing long after stimulus onset. These results indicate stable differences in the resolution of ambiguity across spatial locations and demonstrate the importance of considering sustained differences in perceptual selection across space when characterizing conscious representations of complex scenes.

Legal Update: North Dakota Supreme Court: Third Edition of Guides is “Most Current”

1999 ◽  
Vol 4 (1) ◽  
pp. 6-7
Author(s):  
James J. Mangraviti
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Measurement Techniques ◽  
Fourth Edition ◽  
Hip Motion ◽  
The Difference ◽  
The Right ◽  
Hip Flexion ◽  
Hip Rotation ◽  
Hip Extension

Abstract The accurate measurement of hip motion is critical when one rates impairments of this joint, makes an initial diagnosis, assesses progression over time, and evaluates treatment outcome. The hip permits all motions typical of a ball-and-socket joint. The hip sacrifices some motion but gains stability and strength. Figures 52 to 54 in AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fourth Edition, illustrate techniques for measuring hip flexion, loss of extension, abduction, adduction, and external and internal rotation. Figure 53 in the AMA Guides, Fourth Edition, illustrates neutral, abducted, and adducted positions of the hip and proper alignment of the goniometer arms, and Figure 52 illustrates use of a goniometer to measure flexion of the right hip. In terms of impairment rating, hip extension (at least any beyond neutral) is irrelevant, and the AMA Guides contains no figures describing its measurement. Figure 54, Measuring Internal and External Hip Rotation, demonstrates proper positioning and measurement techniques for rotary movements of this joint. The difference between measured and actual hip rotation probably is minimal and is irrelevant for impairment rating. The normal internal rotation varies from 30° to 40°, and the external rotation ranges from 40° to 60°.

Right-Hemisphere Specialization for Contour Grouping

2014 ◽  
Vol 61 (5) ◽  
pp. 331-339 ◽  
Author(s):  
Gregor Volberg
Keyword(s):  
Right Hemisphere ◽  
Contour Detection ◽  
Global Processing ◽  
Detection Accuracy ◽  
Frequency Spectra ◽  
Visual Hemifield ◽  
Spatial Frequencies ◽  
A Chain ◽  
The Right ◽  
Hemisphere Specialization

Previous studies often revealed a right-hemisphere specialization for processing the global level of compound visual stimuli. Here we explore whether a similar specialization exists for the detection of intersected contours defined by a chain of local elements. Subjects were presented with arrays of randomly oriented Gabor patches that could contain a global path of collinearly arranged elements in the left or in the right visual hemifield. As expected, the detection accuracy was higher for contours presented to the left visual field/right hemisphere. This difference was absent in two control conditions where the smoothness of the contour was decreased. The results demonstrate that the contour detection, often considered to be driven by lateral coactivation in primary visual cortex, relies on higher-level visual representations that differ between the hemispheres. Furthermore, because contour and non-contour stimuli had the same spatial frequency spectra, the results challenge the view that the right-hemisphere advantage in global processing depends on a specialization for processing low spatial frequencies.

Implementasi Sistem Informasi Monitoring Pengolahan Data Inventory Gudang Pada PT.Talaga Mulya Indah

2020 ◽  
Vol 6 (2) ◽  
pp. 187-197
Author(s):  
Nurlaila Suci Rahayu Rais ◽  
Dedeh Apriyani ◽  
Gito Gardjito
Keyword(s):  
Data Processing ◽  
Integrated Control ◽  
Unified Modeling Language ◽  
Review Literature ◽  
Analysis Method ◽  
Inventory Data ◽  
Literature Study ◽  
Unified Modeling ◽  
The Difference ◽  
The Right

Monitoring of warehouse inventory data processing is an important thing for companies. PT Talaga mulya indah is still manual using paper media, causing problems that have an effect on existing information, namely: problems with data processing of incoming and outgoing goods. And the difference between data on the amount of stock of goods available with physical data, often occurs inputting data more than once for the same item, searching for available data, and making reports so that it impedes companies in monitoring inventory of existing stock of goods. Which aims to create a system that can provide updated information to facilitate the warehouse admin in making inventory reports, and reduce errors in input by means of integrated control. In this study, the authors used the data collection method used in this analysis using the method of observation, interviews, and literature review (literature study). For analysis using the PIECES analysis method. Furthermore, the system design used is UML (Unified Modeling Language). The results of this study are expected to produce the right data in the process of monitoring inventory data processing, also can provide the right information and make it easier to control the overall availability of goods.

Konsep Pemerintahan Religius dan Demokrasi Menurut Abdul Karim Soroush dan Ayatullah Khomeini

2013 ◽  
Vol 3 (2) ◽  
pp. 438-473
Author(s):  
M. Heri Fadoil
Keyword(s):  
Religious System ◽  
Islamic Jurisprudence ◽  
Ayatollah Khomeini ◽  
The Difference ◽  
The Government ◽  
The Right

Abstract: Abdul Karim Soroush judges that religious rule is incorrect assessment of the application of Islamic jurisprudence. In a religious society, Islamic jurisprudence obtains the right to govern. It is, of course, necessary to establish a kind of Islamic jurisprudence-based religious rule. Soroush firmly rejects it because such interpretation is too narrow. As for democracy, Soroush argues that the system used is not necessarily equal to that of the Western. On the contrary, Ayatollah Khomeini’s thoughts on religious rule are reflected in the so called wilayat al-faqih. It is a religious scholar-based government. Democracy, according to him, is the values of Islam itself, which is able to represent the level of a system to bring to the country’s progress. Principally, there are some similarities between the ideas of Ayatollah Khomeini and those of Abdul Karim Soroush in term of religiosity. They assume that it is able to sustain the religious system of government. The difference between both lies on the application of religiosity itself. Ayatollah Khomeini applies the concept of a religious scholar-based government, while Abdul Karim Soroush rejects the institutionalization of religion in the government or state.Keywords: Governance, democracy, Abdul Karim Soroush, Ayatollah Khomeini

Our Bodies, Whose Property?

2013 ◽  
Author(s):  
Anne Phillips
Keyword(s):  
Labor Markets ◽  
Personal Autonomy ◽  
The Body ◽  
Body Parts ◽  
Complex Issue ◽  
Human Organs ◽  
Property Owners ◽  
The Common ◽  
The Difference ◽  
The Right

No one wants to be treated like an object, regarded as an item of property, or put up for sale. Yet many people frame personal autonomy in terms of self-ownership, representing themselves as property owners with the right to do as they wish with their bodies. Others do not use the language of property, but are similarly insistent on the rights of free individuals to decide for themselves whether to engage in commercial transactions for sex, reproduction, or organ sales. Drawing on analyses of rape, surrogacy, and markets in human organs, this book challenges notions of freedom based on ownership of our bodies and argues against the normalization of markets in bodily services and parts. The book explores the risks associated with metaphors of property and the reasons why the commodification of the body remains problematic. The book asks what is wrong with thinking of oneself as the owner of one's body? What is wrong with making our bodies available for rent or sale? What, if anything, is the difference between markets in sex, reproduction, or human body parts, and the other markets we commonly applaud? The book contends that body markets occupy the outer edges of a continuum that is, in some way, a feature of all labor markets. But it also emphasizes that we all have bodies, and considers the implications of this otherwise banal fact for equality. Bodies remind us of shared vulnerability, alerting us to the common experience of living as embodied beings in the same world. Examining the complex issue of body exceptionalism, the book demonstrates that treating the body as property makes human equality harder to comprehend.

Sign in / Sign up

Export Citation Format

Share Document