scholarly journals Direct Response of the Crab Carcinus to the Movement of the Sun

1966 ◽  
Vol 44 (2) ◽  
pp. 275-283
Author(s):  
G. A. HORRIDGE

1. The eyes of the crab follow the movement of the sun if stationary landmarks, which would arrest the eye movement, are obscured. 2. Therefore, even if the eyes do not move when the crab is in a normal environment, the sun's movement is certainly seen by the crab. 3. The eye movements in response to tilting the whole animal only partially compensate for the body tilt. Therefore an obvious contrasting object such as the sun is not absolutely stabilized on the retina in tilting. 4. This sensory ability of the crab could form the basis of a compass response with a minimum latency of 10 sec.

2019 ◽  
Vol 12 (2) ◽  
Author(s):  
Hoo Keat Wong ◽  
Ian D. Stephen

Human behaviour is not only influenced by the physical presence of others, but also implied social presence. According to Risko and Kingstone (2011), an eye tracker can represent an implied social presence which could influence individuals’ gaze behaviour. This study examines the impact of awareness of being eye-tracked on eye movement behaviour in a laboratory setting.  During a classic yes/no face recognition task, participants were made to believe that their eye movements were recorded (or not recorded) by eye trackers. Their looking patterns with and without the awareness of being eye-tracked were compared while perceiving social (faces, faces-and-bodies) and non-social (inanimate objects) video stimuli. Area-of-interest (AOI) analysis revealed that misinformed participants (who were not aware that their eye movements were being recorded) looked more at the body (chest and waist) compared to informed participants (who believed they were being eye-tracked), whereas informed participants fixated longer on the mouth and shorter on the eyes of female models than misinformed participants did. These findings highlight the potential impact of an awareness of being eye tracked on one’s eye movement pattern when perceiving a social stimulus. We therefore suggest that even within laboratory settings an eye tracker may function as an implied social presence that leads individuals to modify their eye movement behaviour according to socially-derived inhibitory norms.


1964 ◽  
Vol 9 (4) ◽  
pp. 336-344 ◽  
Author(s):  
E. Llewellyn Thomas ◽  
Eugene Stasiak

The eye-movement patterns of nine hospitalized psychiatric patients were compared with those of ten non-patients when looking at pictures of themselves and others. There were highly significant differences between both the mean fixation times of the two groups and also between the area of the body to which they paid the most attention. The mean fixation times of all the non-patients grouped closely around 0.61 seconds whereas the patients varied between 0.12 seconds and 0.47 seconds and 0.72 seconds and 1.04 seconds. Non-patients looked at all body levels, but spent much more time looking at the face. Patients on the other hand paid much more visual attention to the body and tended to avoid the face. It is suggested that the variability in the fixation times and the tendency to avoid the face reflects a mechanism in the patient which is tending to avoid receiving information about certain aspects of the external world.


2012 ◽  
Vol 605-607 ◽  
pp. 2434-2437
Author(s):  
Chang Yuan Wang ◽  
Bing Yao ◽  
Hong Zhe Bi ◽  
Hong Bo Jia

Head and eye movement is eye movement response to head movements ,the eyes are the signals generated by the vestibular system is movement.The vestibular system is important to feel the organs and tissues of the body movement,Can be said that the vestibular system response to head movement, eye movement associated with the vestibule.We can use eye movements comparing with normal eye movements to detect whether the dizziness,in this process the modeling of the vestibular system is very important.Paper summarizes the response of head and eye movement system, vestibular system in the head and eye movement systems vestibular system exercise and Research at home and abroad, raised modeling method of the head and eye movement system when turn the head.


2019 ◽  
Vol 24 (4) ◽  
pp. 297-311
Author(s):  
José David Moreno ◽  
José A. León ◽  
Lorena A. M. Arnal ◽  
Juan Botella

Abstract. We report the results of a meta-analysis of 22 experiments comparing the eye movement data obtained from young ( Mage = 21 years) and old ( Mage = 73 years) readers. The data included six eye movement measures (mean gaze duration, mean fixation duration, total sentence reading time, mean number of fixations, mean number of regressions, and mean length of progressive saccade eye movements). Estimates were obtained of the typified mean difference, d, between the age groups in all six measures. The results showed positive combined effect size estimates in favor of the young adult group (between 0.54 and 3.66 in all measures), although the difference for the mean number of fixations was not significant. Young adults make in a systematic way, shorter gazes, fewer regressions, and shorter saccadic movements during reading than older adults, and they also read faster. The meta-analysis results confirm statistically the most common patterns observed in previous research; therefore, eye movements seem to be a useful tool to measure behavioral changes due to the aging process. Moreover, these results do not allow us to discard either of the two main hypotheses assessed for explaining the observed aging effects, namely neural degenerative problems and the adoption of compensatory strategies.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Rizki Andalia ◽  
Mulia Aria Suzanni ◽  
Rini Rini

Lipstick or lip dye is a cosmetic dose that serves to coloring, decorative the lips, as a moisturizing material and protect the lips from exposure the sun to provide optimum results. Lipstick should not contain chemicals such as lead (Pb) because the Pb is a heavy metal that is very dangerous when continuously used on the skin, because it will be absorbed into the blood and attack the body organ causing the onset of disease. According to BPOM that the lead rate on the lipstick does not exceed the permissible limit of 20 mg/kg or 20 ppm.This research aims to know the levels contained in the samples are 4 brands of matte lipstick that are sold in the Aceh market in Banda Aceh City with the method of atomic absorption spectrophotometry (AAS). The results showed that on the 4 brands of lipstick matte contain heavy metal lead (Pb) with a rate still qualified allowed by BPOM  is samples A, B, C, and D, respectively at 0.24 ppm; 0.10 ppm; 2.87 ppm and 1.32 ppm, so that the 4 brands of lipstick matte are still used.


2020 ◽  
Vol 10 (5) ◽  
pp. 92
Author(s):  
Ramtin Zargari Marandi ◽  
Camilla Ann Fjelsted ◽  
Iris Hrustanovic ◽  
Rikke Dan Olesen ◽  
Parisa Gazerani

The affective dimension of pain contributes to pain perception. Cognitive load may influence pain-related feelings. Eye tracking has proven useful for detecting cognitive load effects objectively by using relevant eye movement characteristics. In this study, we investigated whether eye movement characteristics differ in response to pain-related feelings in the presence of low and high cognitive loads. A set of validated, control, and pain-related sounds were applied to provoke pain-related feelings. Twelve healthy young participants (six females) performed a cognitive task at two load levels, once with the control and once with pain-related sounds in a randomized order. During the tasks, eye movements and task performance were recorded. Afterwards, the participants were asked to fill out questionnaires on their pain perception in response to the applied cognitive loads. Our findings indicate that an increased cognitive load was associated with a decreased saccade peak velocity, saccade frequency, and fixation frequency, as well as an increased fixation duration and pupil dilation range. Among the oculometrics, pain-related feelings were reflected only in the pupillary responses to a low cognitive load. The performance and perceived cognitive load decreased and increased, respectively, with the task load level and were not influenced by the pain-related sounds. Pain-related feelings were lower when performing the task compared with when no task was being performed in an independent group of participants. This might be due to the cognitive engagement during the task. This study demonstrated that cognitive processing could moderate the feelings associated with pain perception.


2009 ◽  
Vol 101 (2) ◽  
pp. 934-947 ◽  
Author(s):  
Masafumi Ohki ◽  
Hiromasa Kitazawa ◽  
Takahito Hiramatsu ◽  
Kimitake Kaga ◽  
Taiko Kitamura ◽  
...  

The anatomical connection between the frontal eye field and the cerebellar hemispheric lobule VII (H-VII) suggests a potential role of the hemisphere in voluntary eye movement control. To reveal the involvement of the hemisphere in smooth pursuit and saccade control, we made a unilateral lesion around H-VII and examined its effects in three Macaca fuscata that were trained to pursue visually a small target. To the step (3°)-ramp (5–20°/s) target motion, the monkeys usually showed an initial pursuit eye movement at a latency of 80–140 ms and a small catch-up saccade at 140–220 ms that was followed by a postsaccadic pursuit eye movement that roughly matched the ramp target velocity. After unilateral cerebellar hemispheric lesioning, the initial pursuit eye movements were impaired, and the velocities of the postsaccadic pursuit eye movements decreased. The onsets of 5° visually guided saccades to the stationary target were delayed, and their amplitudes showed a tendency of increased trial-to-trial variability but never became hypo- or hypermetric. Similar tendencies were observed in the onsets and amplitudes of catch-up saccades. The adaptation of open-loop smooth pursuit velocity, tested by a step increase in target velocity for a brief period, was impaired. These lesion effects were recognized in all directions, particularly in the ipsiversive direction. A recovery was observed at 4 wk postlesion for some of these lesion effects. These results suggest that the cerebellar hemispheric region around lobule VII is involved in the control of smooth pursuit and saccadic eye movements.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Talora L. Martin ◽  
Jordan Murray ◽  
Kiran Garg ◽  
Charles Gallagher ◽  
Aasef G. Shaikh ◽  
...  

AbstractWe evaluated the effects of strabismus repair on fixational eye movements (FEMs) and stereopsis recovery in patients with fusion maldevelopment nystagmus (FMN) and patients without nystagmus. Twenty-one patients with strabismus, twelve with FMN and nine without nystagmus, were tested before and after strabismus repair. Eye-movements were recorded during a gaze-holding task under monocular viewing conditions. Fast (fixational saccades and quick phases of nystagmus) and slow (inter-saccadic drifts and slow phases of nystagmus) FEMs and bivariate contour ellipse area (BCEA) were analyzed in the viewing and non-viewing eye. Strabismus repair improved the angle of strabismus in subjects with and without FMN, however patients without nystagmus were more likely to have improvement in stereoacuity. The fixational saccade amplitudes and intersaccadic drift velocities in both eyes decreased after strabismus repair in subjects without nystagmus. The slow phase velocities were higher in patients with FMN compared to inter-saccadic drifts in patients without nystagmus. There was no change in the BCEA after surgery in either group. In patients without nystagmus, the improvement of the binocular function (stereopsis), as well as decreased fixational saccade amplitude and intersaccadic drift velocity, could be due, at least partially, to central adaptive mechanisms rendered possible by surgical realignment of the eyes. The absence of improvement in patients with FMN post strabismus repair likely suggests the lack of such adaptive mechanisms in patients with early onset infantile strabismus. Assessment of fixation eye movement characteristics can be a useful tool to predict functional improvement post strabismus repair.


1980 ◽  
Vol 50 (2) ◽  
pp. 631-636
Author(s):  
Evans Mandes

Post-exposural eye movements were studied in 32 adults and 24 7-yr.-old children. Stimuli were binary figures exposed tachistoscopically in both visual fields simultaneously. The data showed significant correlations between direction of eye movement and locus of recognition for both children and adults. No significant differences were found in frequencies of eye movements of children and adults. The data are interpreted in terms of the facilitative effects of post-exposural eye movements upon perception for both groups.


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