Examining Gaze Cone Shape and Size

Perception ◽  
2021 ◽  
pp. 030100662110599
Author(s):  
Gernot Horstmann ◽  
Linda Linke
Keyword(s):  
Present Experiment ◽  
Cone Angle ◽  
Important Task ◽  
Gaze Direction ◽  
Direct Gaze ◽  
The Gaze ◽  
Extended Range ◽  
The Mean ◽  
Fixation Points ◽  
Shape And Size

Another person's looking behavior is used by observers to judge gaze direction and fixation points. An important task in this context is the judgement of direct gaze, that is, the perception of being looked at. The cone of gaze can be defined as the range of fixation points that support direct gaze. The cone concept implies that this range lawfully increases with distance, but that the cone angle is constant. The present experiment tested the concept with a larger number and a more extended range of distances than previously done, and took care of possible directional errors. The gaze cone was found to be roughly linear, and stable between 1.6 m and 7.9 m – an almost perfect cone. The mean cone size subtended 5.2° in diameter when averaged over ascending and descending series. Measures differed, however, in ascending and descending series, consistent with a conservative bias. Also, the variability of judgements increased slightly with distance. Results are discussed considering whether cone size is actually smaller than often reported in the literature.

Relational property between head and eye regions is the primary determinant of the efficiency in search for a deviant gaze

2009 ◽  
Vol 62 (9) ◽  
pp. 1723-1737 ◽  
Author(s):  
Hirokazu Doi ◽  
Kazuhiro Ueda ◽  
Kazuyuki Shinohara
Keyword(s):  
Visual System ◽  
Human Visual System ◽  
Gaze Direction ◽  
Relational Property ◽  
Direct Gaze ◽  
The Gaze ◽  
Primary Determinant ◽  
Feature Information ◽  
Types Of Information ◽  
Eye Region

The human visual system is extremely sensitive to the directions of the gazes of others. However, the mechanism underlying gaze direction perception has yet to be clarified. The primary aim of the present study is to investigate whether the relational property between the local eye region and other facial regions serves as the primary visual system cue in detecting a direct gaze. Our results showed that search efficiency was determined primarily by the gaze direction indicated by the relational property regardless of the direction indicated by the local feature information of the eye region; this was true even when the gaze directions indicated by these two types of information were conflicting. These results bolster the hypothesis that the human visual system primarily accesses socially meaningful information in searching for a deviant gaze.

scholarly journals How wide is the cone of direct gaze?

2018 ◽  
Vol 5 (8) ◽  
pp. 180249 ◽  
Author(s):  
Tarryn Balsdon ◽  
Colin W. G. Clifford
Keyword(s):  
Gaze Direction ◽  
Considerable Evidence ◽  
Direct Gaze ◽  
The Gaze ◽  
Insight Into ◽  
Clinical Populations

The cone of direct gaze refers to the range of gaze deviations an observer accepts as looking directly at them. Previous experiments have calculated the width of the cone of direct gaze using the gaze deviations actually presented to the observer, however, there is considerable evidence that observers actually perceive gaze to be systematically more deviated than actually presented. Here, we examine the width of the cone of direct gaze in units of perceived gaze deviation. In doing so, we are able to disambiguate differences in width both within and between observers that are due to differences in their perception of gaze and due to differences in what observers consider to be looking at them. We suggest that this line of inquiry can offer further insight into the perception of gaze direction, and how this perception may differ in clinical populations.

The analysis of the results of a rotation experiment on the use of straw and fertilizers

1953 ◽  
Vol 43 (1) ◽  
pp. 77-88 ◽  
Author(s):  
H. D. Patterson
Keyword(s):  
Present Experiment ◽  
Treatment Effects ◽  
Standard Errors ◽  
Methods Of Analysis ◽  
Seasonal Factors ◽  
Long Term Experiments ◽  
The Mean ◽  
Linear Regressions

An experiment, designed to test different ways of using straw with fertilizers, and involving a three course rotation of crops, was carried out at Rothamsted between 1933 and 1951. The methods of analysis developed for this experiment are described in the present paper and demonstrated using yields of potatoes.Treatment effects of interest are given by the mean yields over all years and the linear regressions of yield on time. These estimates are straightforward but the evaluation of their errors is complicated by the existence of correlations due to the recurrence of treatments on the same plots. Further complications are introduced when, as frequently happens in long-term experiments, treatment effects show real variation from year to year. A method is given for estimating standard errors which include a contribution from this variation.The various relationships between yields and the uncontrolled seasonal factors can also be examined; in the present experiment there is some indication that the effects of treatments on yields of potatoes are influenced by the dates of planting.In other circumstances the analysis requires modifications, some of which are briefly considered.

scholarly journals Dynamic Response of Fuel Nozzles for Liquid-Fueled Gas Turbine Combustors

1996 ◽  
Author(s):  
Mounir Ibrahim ◽  
Terry Sanders ◽  
Douglas Darling ◽  
Michelle Zaller
Keyword(s):  
Gas Turbine ◽  
Cone Angle ◽  
Outer Region ◽  
Test Fluid ◽  
Mean Flow ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Gas Turbine Combustors ◽  
The Mean ◽  
Piezoelectric Drive

To imitate resonances that might occur in the fuel delivery system of gas turbine combustors, the incoming liquid streams of two pressure swirl nozzles were perturbed using a piezoelectric driver. Frequencies of perturbations examined were from 3 to 20 kHz, and water was used as the test fluid. A video camera and a Phase Doppler Particle Analyzer (PDPA) were used to study the effect of perturbations on the mean flow quantities of the sprays. Various lighting arrangements were used for the video photography: back lighting, front lighting, a strobe synchronized with the input to the piezoelectric, and a laser sheet oriented along the midplane of the sprays. The study showed that the piezoelectric drive had an effect an the spray system at discrete frequencies. At these particular frequencies, by increasing the input voltage, it was found that the piezoelectric drive affected the atomization in the following ways: (1) the mean flow rate decreased, (2) the spray cone angle decreased, (3) the break up length decreased, (4) the peak of the spatial distribution of the mean droplet size decreased, and (5) the mean droplet sizes and velocities increased near the spray center line and decreased in the outer region of the spray. A hysteresis effect of the drive frequency on the spray cone angle was observed. The results indicated that more fundamental research is needed to gain an in-depth understanding of the physical processes induced in the spray by the piezoelectric drive.

scholarly journals Fear-specific leftward bias in gaze direction judgment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yue Zhang ◽  
Qiqi Hu ◽  
Xinwei Lai ◽  
Zhonghua Hu ◽  
Shan Gao
Keyword(s):  
Judgment Task ◽  
Gaze Direction ◽  
Emotional Information ◽  
Cerebral Lateralization ◽  
Low Level ◽  
The Gaze ◽  
Fearful Faces ◽  
Perception Bias ◽  
Behavioural Experiments ◽  
Direction Judgment

AbstractPrevious studies have shown that humans have a left spatial attention bias in cognition and behaviour. However, whether there exists a leftward perception bias of gaze direction has not been investigated. To address this gap, we conducted three behavioural experiments using a forced-choice gaze direction judgment task. The point of subjective equality (PSE) was employed to measure whether there was a leftward perception bias of gaze direction, and if there was, whether this bias was modulated by face emotion. The results of experiment 1 showed that the PSE of fearful faces was significantly positive as compared to zero and this effect was not found in angry, happy, and neutral faces, indicating that participants were more likely to judge the gaze direction of fearful faces as directed to their left-side space, namely a leftward perception bias. With the response keys counterbalanced between participants, experiment 2a replicated the findings in experiment 1. To further investigate whether the gaze direction perception variation was contributed by emotional or low-level features of faces, experiment 2b and 3 used inverted faces and inverted eyes, respectively. The results revealed similar leftward perception biases of gaze direction in all types of faces, indicating that gaze direction perception was biased by emotional information in faces rather than low-level facial features. Overall, our study demonstrates that there a fear-specific leftward perception bias in processing gaze direction. These findings shed new light on the cerebral lateralization in humans.

scholarly journals What is unique about the human eye? Comparative image analysis on the external eye morphology of human and nonhuman great apes

2021 ◽  
Author(s):  
Fumihiro Kano ◽  
Takeshi Furuichi ◽  
Chie Hashimoto ◽  
Christopher Krupenye ◽  
Jesse G Leinwand ◽  
...  
Keyword(s):  
Image Analysis ◽  
Eye Gaze ◽  
Great Apes ◽  
Gaze Direction ◽  
Human Eye ◽  
The Gaze ◽  
Eye Morphology ◽  
New Findings ◽  
Heated Debate ◽  
Signaling Hypothesis

The gaze-signaling hypothesis and the related cooperative-eye hypothesis posit that humans have evolved special external eye morphology, including exposed white sclera (the white of the eye), to enhance the visibility of eye-gaze direction and thereby facilitate conspecific communication through joint-attentional interaction and ostensive communication. However, recent quantitative studies questioned these hypotheses based on new findings that humans are not necessarily unique in certain eye features compared to other great ape species. Therefore, there is currently a heated debate on whether external eye features of humans are distinguished from those of other apes and how such distinguished features contribute to the visibility of eye-gaze direction. This study leveraged updated image analysis techniques to test the uniqueness of human eye features in facial images of great apes. Although many eye features were similar between humans and other species, a key difference was that humans have uniformly white sclera which creates clear visibility of both eye outline and iris; the two essential features contributing to the visibility of eye-gaze direction. We then tested the robustness of the visibility of these features against visual noises such as darkening and distancing and found that both eye features remain detectable in the human eye, while eye outline becomes barely detectable in other species under these visually challenging conditions. Overall, we identified that humans have distinguished external eye morphology among other great apes, which ensures robustness of eye-gaze signal against various visual conditions. Our results support and also critically update the central premises of the gaze-signaling hypothesis.

Growth and Carcass Composition of Implanted and Non-Implanted Heifers and Steers Reared Together

1986 ◽  
Vol 1986 ◽  
pp. 23-23
Author(s):  
M. G. Keane ◽  
M. J. Drennan
Keyword(s):  
Present Experiment ◽  
Live Weight ◽  
Beef Cows ◽  
Carcass Composition ◽  
Birth Date ◽  
Milk Replacer ◽  
Beef Production ◽  
Treatment Groups ◽  
Sex Type ◽  
The Mean

The national cow herd consists of 1.64m dairy and 0.43m beef cows. They produce a total of 1.76m reared calves annually. Of these 0.42m heifers go as herd replacements, leaving 0.46m heifers and 0.88m males available for beef production. There is a 2:l ratio of males to femaies in the population of calves available for beef production. Also, there are few straightbred dairy heifer calves available and the mean birth date of heifer calves for beef production is later than that cf males. The objectives of the present experiment were (i) to compare the performance and carcass composition of non-implanted and implanted heifers and steers and (ii) to compare the carcass composition of serially slaughtered non-implanted and implanted heifers.Sixty tour (48 female and 16 male) Spring born Hereford x Friesian calves (initial live-weight 45 kg) were purchased and reared on milk replacer and concentrates. After 81 days they were blocked on weight and assigned from within sex type to 8 treatment groups.

Sign in / Sign up

Export Citation Format

Share Document