Simple reaction time to visual and auditory stimulation in glaucoma.

Background/objectives: Glaucoma can impact the ability to perform daily life activities such as driving. In such tasks, reaction time is critical to detect hazards. Understanding the modalities that affect response times is thus essential for clinical care.

Visual Functions in Patients With Leber Hereditary Optic Neuropathy (LHON).

Background: Most of the data on visual functions in Leber hereditary optic neuropathy (LHON) is based on patient questionnaires. Our study assessed the impact of LHON on visual function by testing facial recognition and execution of purposeful actions.

Methods: Twelve participants with LHON with central scotoma ranging from 5° to 20° and 12 unaffected age-matched controls were involved in our study.

Age Difference on the Spatial Scale of Object Categorization.

Background: As the elderly population is growing worldwide and communication is increasingly relayed by visual interfaces, identifying age-related changes in the visual perception of complex stimuli is critical. We examined the effect of spatial frequency filtering on object categorization in young (mean 25 years) and older (mean 65 years) participants.

Method: The stimuli used were low spatial frequency (LSF, cutoff 8 cpi) or high spatial frequency (HSF, cutoff 24 cpi) images of objects of various categories, and hybrid images composed of a LSF object superimposed on a HSF object from a different semantic category.

Method to Quickly Map Multifocal Pupillary Response Fields (mPRF) Using Frequency Tagging.

We present a method for mapping multifocal Pupillary Response Fields in a short amount of time using a visual stimulus covering 40° of the visual angle divided into nine contiguous sectors simultaneously modulated in luminance at specific, incommensurate, temporal frequencies. We test this multifocal Pupillary Frequency Tagging (mPFT) approach with young healthy participants (N = 36) and show that the spectral power of the sustained pupillary response elicited by 45 s of fixation of this multipartite stimulus reflects the relative contribution of each sector/frequency to the overall pupillary response. We further analyze the phase lag for each temporal frequency as well as several global features related to pupil state.

Impact of glaucoma on the spatial frequency processing of scenes in central vision.

Glaucoma is an eye disease characterized by a progressive vision loss usually starting in peripheral vision. However, a deficit for scene categorization is observed even in the preserved central vision of patients with glaucoma. We assessed the processing and integration of spatial frequencies in the central vision of patients with glaucoma during scene categorization, considering the severity of the disease, in comparison to age-matched controls.

Higher susceptibility to central crowding in glaucoma.

Clinical Relevance: Crowding limits many daily life activities, such as reading and the visual search for objects in cluttered environments. Excessive sensitivity to crowding, especially in central vision, may amplify the difficulties of patients with ocular pathologies. It is thus important to investigate what limits visual activities and how to improve it.

Impact of neovascular age-related macular degeneration on eye-movement control during scene viewing: Viewing biases and guidance by visual salience.

Human vision requires us to analyze the visual periphery to decide where to fixate next. In the present study, we investigated this process in people with age-related macular degeneration (AMD). In particular, we examined viewing biases and the extent to which visual salience guides fixation selection during free-viewing of naturalistic scenes.

Reduced peripheral vision in glaucoma and boundary extension.

Clinical Relevance: Peripheral vision is known to be critical for spatial navigation. However, visual cognition, which impacts peripheral vision, has not been studied extensively in glaucoma.

Background: Spatial memory was assessed with a known to induce a robust memory distortion called "boundary extension" in which participants erroneously remember seeing more of a scene than was present in the sensory input.

Semantic and Physical Properties of Peripheral Vision Are Used for Scene Categorization in Central Vision.

Theories of visual recognition postulate that our ability to understand our visual environment at a glance is based on the extraction of the gist of the visual scene, a first global and rudimentary visual representation. Gist perception would be based on the rapid analysis of low spatial frequencies in the visual signal and would allow a coarse categorization of the scene. We aimed to study whether the low spatial resolution information available in peripheral vision could modulate the processing of visual information presented in central vision.

Sensitivity to Central Crowding for Faces in Patients With Glaucoma.

Precis: Some patients with glaucoma report difficulties to recognize faces when they are far away. We show that this deficit could result from a higher sensitivity to crowding in central vision.

Purpose: The aim of the study is to investigate whether face recognition difficulties reported by some patients with glaucoma result from a greater sensitivity to inner crowding in central vision.

A Saccadic Choice Task for Target Face Detection at Large Visual Eccentricities in Patients with Glaucoma.

Significance: Little is known about the perception of glaucomatous patients at large visual eccentricities. We show that the patients' performance drops beyond 40° eccentricity even for large images of scenes, suggesting that clinical tests should assess the patients' vision at larger eccentricities than 24 or 30°.

Purpose: Daily activities such as visual search, spatial navigation, and hazard detection require rapid scene recognition on a wide field of view.

Perception of Gaze Direction in Glaucoma: A Study on Social Cognition.

Significance: Discriminating quickly where another person's gaze is directed is a key component of social interaction, as gaze direction conveys information about others' intentions (approach or avoidance) and shift in gaze is used in group conversation. This study shows that patients with glaucoma are delayed in their discrimination of gaze direction.

Purpose: The purpose of this study was to investigate whether glaucoma affects the perception of gaze direction.

Rapid scene categorization: From coarse peripheral vision to fine central vision.

Studies on scene perception have shown that the rapid extraction of low spatial frequencies (LSF) allows a coarse parsing of the scene, prior to the analysis of high spatial frequencies (HSF) containing details. Many studies suggest that scene gist recognition can be achieved with only the low resolution of peripheral vision. Our study investigated the advantage of peripheral vision on central vision during a scene categorization task (indoor vs.

Object search in neovascular age-related macular degeneration: the crowding effect.

Background: Visual search, an activity that relies on central vision, is frequent in daily life. This study investigates the effect of spacing between items in an object search task in participants with central vision loss.

Methods: Patients with neovascular age-related macular degeneration (AMD), age-matched controls, and young controls were included.

The contributions of central and peripheral vision to scene-gist recognition with a 180° visual field.

We investigated the relative contributions of central versus peripheral vision in scene-gist recognition with panoramic 180° scenes. Experiment 1 used the window/scotoma paradigm of Larson and Loschky (2009). We replicated their findings that peripheral vision was more important for rapid scene categorization, while central vision was more efficient, but those effects were greatly magnified.

Glaucoma Affects Viewing Distance for Recognition of Sex and Facial Expression.

Purpose: To measure the distance for sex and facial expression recognition in patients with glaucoma.

Methods: Sixteen patients with open-angle glaucoma, 16 age-matched controls, and 12 young controls participated. During each trial, a face covering 0.

Attentional capture by incongruent object/background scenes in patients with Alzheimer disease.

Aim: Object/background association is critical to understand the context of visual scenes but also in daily life tasks like object search. Patients with Alzheimer disease (AD) exhibit impairment in scene processing at different levels: perception, recognition, memory and spatial navigation. We explored whether patients with AD make use of contextual information in congruent and incongruent target/background conditions in three different saccadic choice tasks.

Scene and human face recognition in the central vision of patients with glaucoma.

Primary open-angle glaucoma (POAG) firstly mainly affects peripheral vision. Current behavioral studies support the idea that visual defects of patients with POAG extend into parts of the central visual field classified as normal by static automated perimetry analysis. This is particularly true for visual tasks involving processes of a higher level than mere detection.

What Is the Nature of the Reach and Grasp Deficit in Wet Age-related Macular Degeneration?

Significance: Vision is paramount for motor actions directed toward objects. Vision allows not only the identification of objects and their shape and spatial location, but also the adaptation of our movement when it arrives on the object. These findings show that vision deficits, as in age-related macular degeneration (AMD), can lead to reaching and grasping deficits.

Impact of age-related macular degeneration on object searches in realistic panoramic scenes.

Background: This study investigated whether realistic immersive conditions with dynamic indoor scenes presented on a large, hemispheric panoramic screen covering 180° of the visual field improved the visual search abilities of participants with age-related macular degeneration (AMD).

Method: Twenty-one participants with AMD, 16 age-matched controls and 16 young observers were included. Realistic indoor scenes were presented on a panoramic five metre diameter screen.

Do low spatial frequencies explain the extremely fast saccades towards human faces?

The visual perception of human faces by man is fast and efficient compared to that of other categories of objects. Using a saccadic choice task, recent studies showed that participants were able to initiate fast reliable saccades in just 100-110ms toward an image of a human face, when this was presented alongside another image without a face. This extremely fast saccadic reaction time is barely predicted using classical models of visual perception.

Eye movement during retrieval of emotional autobiographical memories.

This study assessed whether specific eye movement patterns are observed during emotional autobiographical retrieval. Participants were asked to retrieve positive, negative and neutral memories while their scan path was recorded by an eye-tracker. Results showed that positive and negative emotional memories triggered more fixations and saccades but shorter fixation duration than neutral memories.

Impact of Peripheral Field Loss on the Execution of Natural Actions: A Study With Glaucomatous Patients and Normally Sighted People.

Purpose: We investigated the visuomotor behavior of people with reduced peripheral field due to glaucoma while they accomplished natural actions.

Methods: Twelve participants with glaucoma and 13 normally sighted controls were included. Participants were asked to accomplish a familiar sandwich-making task and a less familiar model-building task with a children's construction set while their eye movements were recorded.