scholarly journals Amygdala lesions eliminate viewing preferences for faces in rhesus monkeys

2018 ◽  
Vol 115 (31) ◽  
pp. 8043-8048 ◽  
Author(s):  
Jessica Taubert ◽  
Molly Flessert ◽  
Susan G. Wardle ◽  
Benjamin M. Basile ◽  
Aidan P. Murphy ◽  
...  
Keyword(s):  
Eye Movements ◽  
Social Communication ◽  
Rhesus Monkeys ◽  
Natural Images ◽  
Facial Features ◽  
Neural Basis ◽  
Everyday Objects ◽  
Free Viewing ◽  
Amygdala Lesions ◽  
Socially Relevant

In free-viewing experiments, primates orient preferentially toward faces and face-like stimuli. To investigate the neural basis of this behavior, we measured the spontaneous viewing preferences of monkeys with selective bilateral amygdala lesions. The results revealed that when faces and nonface objects were presented simultaneously, monkeys with amygdala lesions had no viewing preference for either conspecific faces or illusory facial features in everyday objects. Instead of directing eye movements toward socially relevant features in natural images, we found that, after amygdala loss, monkeys are biased toward features with increased low-level salience. We conclude that the amygdala has a role in our earliest specialized response to faces, a behavior thought to be a precursor for efficient social communication and essential for the development of face-selective cortex.

Image Structure at the Center of Gaze during Free Viewing

2006 ◽  
Vol 18 (5) ◽  
pp. 737-748 ◽  
Author(s):  
Valentin Dragoi ◽  
Mriganka Sur
Keyword(s):  
Eye Movements ◽  
Rhesus Monkeys ◽  
Discrimination Performance ◽  
Natural Scenes ◽  
Image Patch ◽  
Image Scanning ◽  
Retinal Stimulation ◽  
Free Viewing ◽  
Precise Knowledge ◽  
Orientation Structure

It is generally believed that the visual system is adapted to the statistics of the visual world. Measuring and understanding these statistics require precise knowledge of the structure of the signals reaching fovea during image scanning. However, despite the fact that eye movements cause retinal stimulation to change several times in a second, it is implicitly assumed that images are sampled uniformly during natural viewing. By analyzing the eye movements of three rhesus monkeys freely viewing natural scenes, we report here significant anisotropy in stimulus statistics at the center of gaze. We find that fixation on an image patch is more likely to be followed by a saccade to a nearby patch of similar orientation structure or by a saccade to a more distant patch of largely dissimilar orientation structure. Furthermore, we show that orientation-selective neurons in the primary visual cortex (V1) can take advantage of eye movement statistics to selectively improve their discrimination performance.

scholarly journals Atomoxetine modulates the contribution of low-level signals during free viewing of natural images in rhesus monkeys

2021 ◽  
Vol 182 ◽  
pp. 108377
Author(s):  
Amélie J. Reynaud ◽  
Elvio Blini ◽  
Eric Koun ◽  
Emiliano Macaluso ◽  
Martine Meunier ◽  
...  
Keyword(s):  
Rhesus Monkeys ◽  
Natural Images ◽  
Low Level ◽  
Free Viewing

scholarly journals Predicting eye movements of rhesus monkeys searching for pedestrians in natural images

2014 ◽  
Vol 14 (10) ◽  
pp. 766-766
Author(s):  
M. Segraves ◽  
S. Caddigan ◽  
R.-S. Kuo ◽  
K. Kording
Keyword(s):  
Eye Movements ◽  
Rhesus Monkeys ◽  
Natural Images

scholarly journals Neural Basis of Visually Guided Head Movements Studied With fMRI

2003 ◽  
Vol 89 (5) ◽  
pp. 2516-2527 ◽  
Author(s):  
Laurent Petit ◽  
Michael S. Beauchamp
Keyword(s):  
Eye Movements ◽  
Head Movement ◽  
Brain Activity ◽  
Posterior Part ◽  
Vestibular Stimulation ◽  
Head Movements ◽  
Oculomotor Control ◽  
Imaging Studies ◽  
Neural Basis ◽  
Temporoparietal Junction

We used event-related fMRI to measure brain activity while subjects performed saccadic eye, head, and gaze movements to visually presented targets. Two distinct patterns of response were observed. One set of areas was equally active during eye, head, and gaze movements and consisted of the superior and inferior subdivisions of the frontal eye fields, the supplementary eye field, the intraparietal sulcus, the precuneus, area MT in the lateral occipital sulcus and subcortically in basal ganglia, thalamus, and the superior colliculus. These areas have been previously observed in functional imaging studies of human eye movements, suggesting that a common set of brain areas subserves both oculomotor and head movement control in humans, consistent with data from single-unit recording and microstimulation studies in nonhuman primates that have described overlapping eye- and head-movement representations in oculomotor control areas. A second set of areas was active during head and gaze movements but not during eye movements. This set of areas included the posterior part of the planum temporale and the cortex at the temporoparietal junction, known as the parieto-insular vestibular cortex (PIVC). Activity in PIVC has been observed during imaging studies of invasive vestibular stimulation, and we confirm its role in processing the vestibular cues accompanying natural head movements. Our findings demonstrate that fMRI can be used to study the neural basis of head movements and show that areas that control eye movements also control head movements. In addition, we provide the first evidence for brain activity associated with vestibular input produced by natural head movements as opposed to invasive caloric or galvanic vestibular stimulation.

Peripheral Facial Features Guiding Eye Movements and Reducing Fixational Variability

2021 ◽  
Author(s):  
Nicole X Han ◽  
Puneeth N. Chakravarthula ◽  
Miguel P. Eckstein
Keyword(s):  
Eye Movements ◽  
Spatial Configuration ◽  
Oculomotor System ◽  
Facial Features ◽  
Robust Solution ◽  
The Face ◽  
And Gender ◽  
Social Importance ◽  
Fixation Variability

Face processing is a fast and efficient process due to its evolutionary and social importance. A majority of people direct their first eye movement to a featureless point just below the eyes that maximizes accuracy in recognizing a person's identity and gender. Yet, the exact properties or features of the face that guide the first eye movements and reduce fixational variability are unknown. Here, we manipulated the presence of the facial features and the spatial configuration of features to investigate their effect on the location and variability of first and second fixations to peripherally presented faces. Results showed that observers can utilize the face outline, individual facial features, and feature spatial configuration to guide the first eye movements to their preferred point of fixation. The eyes have a preferential role in guiding the first eye movements and reducing fixation variability. Eliminating the eyes or altering their position had the greatest influence on the location and variability of fixations and resulted in the largest detriment to face identification performance. The other internal features (nose and mouth) also contribute to reducing fixation variability. A subsequent experiment measuring detection of single features showed that the eyes have the highest detectability (relative to other features) in the visual periphery providing a strong sensory signal to guide the oculomotor system. Together, the results suggest a flexible multiple-cue approach that might be a robust solution to cope with how the varying eccentricities in the real world influence the ability to resolve individual feature properties and the preferential role of the eyes.

Effects of cerebellar lesions on saccadic eye movements

1976 ◽  
Vol 39 (6) ◽  
pp. 1246-1256 ◽  
Author(s):  
L. Ritchie
Keyword(s):  
Eye Movements ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Saccadic Eye Movements ◽  
Motor Systems ◽  
Antagonist Muscle ◽  
Restoring Forces ◽  
System 2 ◽  
Cerebellar Lesions ◽  
Cerebellar Symptoms

1. Areas of cerebellar cortex related to saccadic eye movements were ablated in three Macaca mulatta monkeys trained to fixate visual targets. There followed a postoperative dysmetria of saccadic eye movements which appeared to be the result of an impairment specifically within the saccadic system. 2. Convergent evidence from two experimental paradigms indicated that the saccadic deficit was a function of the position of the eye in the orbit and did not involve retinal error processing. 3. The pattern of this position-dependent dysmetria suggests that the eye was no longer fully compensating for the elastic restoring forces imposed by the orbital medium and antagonist muscle(s). 4. The similarity of these data to saccadic eye movements of human cerebellar patients and arm movements of rhesus monkeys with cerebellar lesions indicates that the inability to compensate for the differential loads placed on motor systems by the mechanics of those systems may explain several cerebellar symptoms.

scholarly journals Unrestricted eye movements strengthen causal connectivity from hippocampal to oculomotor regions during scene construction

2021 ◽  
Author(s):  
Natalia Ladyka-Wojcik ◽  
Zhong-Xu Liu ◽  
Jennifer D. Ryan
Keyword(s):  
Eye Movements ◽  
Visual Processing ◽  
Oculomotor System ◽  
Visual Input ◽  
Causal Modeling ◽  
Oculomotor Control ◽  
Visual Stream ◽  
Functional Connections ◽  
Free Viewing ◽  
Scene Construction

Scene construction is a key component of memory recall, navigation, and future imagining, and relies on the medial temporal lobes (MTL). A parallel body of work suggests that eye movements may enable the imagination and construction of scenes, even in the absence of external visual input. There are vast structural and functional connections between regions of the MTL and those of the oculomotor system. However, the directionality of connections between the MTL and oculomotor control regions, and how it relates to scene construction, has not been studied directly in human neuroimaging. In the current study, we used dynamic causal modeling (DCM) to investigate this relationship at a mechanistic level using a scene construction task in which participants' eye movements were either restricted (fixed-viewing) or unrestricted (free-viewing). By omitting external visual input, and by contrasting free- versus fixed- viewing, the directionality of neural connectivity during scene construction could be determined. As opposed to when eye movements were restricted, allowing free viewing during construction of scenes strengthened top-down connections from the MTL to the frontal eye fields, and to lower-level cortical visual processing regions, suppressed bottom-up connections along the visual stream, and enhanced vividness of the constructed scenes. Taken together, these findings provide novel, non-invasive evidence for the causal architecture between the MTL memory system and oculomotor system associated with constructing vivid mental representations of scenes.

scholarly journals Perspective influences eye movements during real-life conversation: Mentalising about self vs. others in autism

2019 ◽  
Author(s):  
Mahsa Barzy ◽  
Heather Jane Ferguson ◽  
David Williams
Keyword(s):  
Eye Movements ◽  
Real Life ◽  
Social Background ◽  
Relevant Information ◽  
Mental States ◽  
Social Attention ◽  
Typically Developing ◽  
Cognitive Mechanisms ◽  
Verbal Responses ◽  
Socially Relevant

Socio-communication is profoundly impaired among autistic individuals. Difficulties representing others’ mental states have been linked to modulations of gaze and speech, which have also been shown to be impaired in autism. Despite these observed impairments in ‘real-world’ communicative settings, research has mostly focused on lab-based experiments, where the language is highly structured. In a pre-registered experiment, we recorded eye movements and verbal responses while adults (N=50) engaged in a real-life conversation. Conversation topic either related to the self, a familiar other, or an unfamiliar other (e.g. "Tell me who is your/your mother’s/Marina’s favourite celebrity and why?”). Results replicated previous work, showing reduced attention to socially-relevant information among autistic participants (i.e. less time looking at the experimenter’s face, and more time looking around the background), compared to typically-developing controls. Importantly, perspective modulated social attention in both groups; talking about an unfamiliar other reduced attention to potentially distracting or resource demanding social information, and increased looks to non-social background. Social attention did not differ between self and familiar other contexts- reflecting greater shared knowledge for familiar/similar others. Autistic participants spent more time looking at the background when talking about an unfamiliar other vs. themselvesFuture research should investigate the cognitive mechanisms underlying this effect.

scholarly journals Infants' eye movements during free-viewing as a window into the development of attention

2010 ◽  
Vol 7 (9) ◽  
pp. 998-998
Author(s):  
M. C. Frank ◽  
E. Vul ◽  
S. P. Johnson
Keyword(s):  
Eye Movements ◽  
Free Viewing

scholarly journals Normal correspondence of tectal maps for saccadic eye movements in strabismus

2016 ◽  
Vol 116 (6) ◽  
pp. 2541-2549 ◽  
Author(s):  
John R. Economides ◽  
Daniel L. Adams ◽  
Jonathan C. Horton
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Superior Colliculus ◽  
Saccadic Eye Movements ◽  
Systematic Change ◽  
Free Viewing ◽  
Pattern Deviation ◽  
Ocular Deviation ◽  
The Right ◽  
Stem Structure

The superior colliculus is a major brain stem structure for the production of saccadic eye movements. Electrical stimulation at any given point in the motor map generates saccades of defined amplitude and direction. It is unknown how this saccade map is affected by strabismus. Three macaques were raised with exotropia, an outwards ocular deviation, by detaching the medial rectus tendon in each eye at age 1 mo. The animals were able to make saccades to targets with either eye and appeared to alternate fixation freely. To probe the organization of the superior colliculus, microstimulation was applied at multiple sites, with the animals either free-viewing or fixating a target. On average, microstimulation drove nearly conjugate saccades, similar in both amplitude and direction but separated by the ocular deviation. Two monkeys showed a pattern deviation, characterized by a systematic change in the relative position of the two eyes with certain changes in gaze angle. These animals' saccades were slightly different for the right eye and left eye in their amplitude or direction. The differences were consistent with the animals' underlying pattern deviation, measured during static fixation and smooth pursuit. The tectal map for saccade generation appears to be normal in strabismus, but saccades may be affected by changes in the strabismic deviation that occur with different gaze angles.

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