Simplification of Visual Rendering in Simulated Prosthetic Vision Facilitates Navigation.

Visual neuroprostheses are still limited and simulated prosthetic vision (SPV) is used to evaluate potential and forthcoming functionality of these implants. SPV has been used to evaluate the minimum requirement on visual neuroprosthetic characteristics to restore various functions such as reading, objects and face recognition, object grasping, etc. Some of these studies focused on obstacle avoidance but only a few investigated orientation or navigation abilities with prosthetic vision.

The Role of Cognitive and Perceptual Loads in Inattentional Deafness.

The current study examines the role of cognitive and perceptual loads in inattentional deafness (the failure to perceive an auditory stimulus) and the possibility to predict this phenomenon with ocular measurements. Twenty participants performed Air Traffic Control (ATC) scenarios-in the Laby ATC-like microworld-guiding one (low cognitive load) or two (high cognitive load) aircraft while responding to visual notifications related to 7 (low perceptual load) or 21 (high perceptual load) peripheral aircraft. At the same time, participants were played standard tones which they had to ignore (probability = 0.

Simulated Prosthetic Vision: The Benefits of Computer-Based Object Recognition and Localization.

Clinical trials with blind patients implanted with a visual neuroprosthesis showed that even the simplest tasks were difficult to perform with the limited vision restored with current implants. Simulated prosthetic vision (SPV) is a powerful tool to investigate the putative functions of the upcoming generations of visual neuroprostheses. Recent studies based on SPV showed that several generations of implants will be required before usable vision is restored.

Wayfinding with simulated prosthetic vision: performance comparison with regular and structure-enhanced renderings.

In this study, we used a simulation of upcoming low-resolution visual neuroprostheses to evaluate the benefit of embedded computer vision techniques in a wayfinding task. We showed that augmenting the classical phosphene rendering with the basic structure of the environment - displaying the ground plane with a different level of brightness - increased both wayfinding performance and cognitive mapping. In spite of the low resolution of current and upcoming visual implants, the improvement of these cognitive functions may already be possible with embedded artificial vision algorithms.

Simulated prosthetic vision: improving text accessibility with retinal prostheses.

Image processing can improve significantly the every-day life of blind people wearing current and upcoming retinal prostheses relying on an external camera. We propose to use a real-time text localization algorithm to improve text accessibility. An augmented text-specific rendering based on automatic text localization has been developed.

Reaching nearby sources: comparison between real and virtual sound and visual targets.

Sound localization studies over the past century have predominantly been concerned with directional accuracy for far-field sources. Few studies have examined the condition of near-field sources and distance perception. The current study concerns localization and pointing accuracy by examining source positions in the peripersonal space, specifically those associated with a typical tabletop surface.

Haptic identification of raised-line drawings: high visuospatial imagers outperform low visuospatial imagers.

It has been assumed (Lederman et al. 1990, Perception & psychophysics) that a visual imagery process is involved in the haptic identification of raised-line drawings of common objects. The finding of significant correlations between visual imagery ability and performance on picture-naming tasks was taken as experimental evidence in support of this assumption.

Haptic recognition of two-dimensional raised-line patterns by early-blind, late-blind, and blindfolded sighted adults.

We investigated the role of visual experience and visual imagery in the processing of two-dimensional (2-D) tactile patterns. The performance of early-blind (EB), late-blind (LB), and blindfolded sighted (S) adults in the recognition of 2-D raised-line patterns was compared. We also examined whether recognition of 2-D tactile patterns depends on the type of memory strategy (eg spatial, visuo-spatial, verbal, and kinesthetic) used by EB, LB, and S participants to perform the task.

A case of polymicrogyria in macaque monkey: impact on anatomy and function of the motor system.

Background: Polymicrogyria is a malformation of the cerebral cortex often resulting in epilepsy or mental retardation. It remains unclear whether this pathology affects the structure and function of the corticospinal (CS) system. The anatomy and histology of the brain of one macaque monkey exhibiting a spontaneous polymicrogyria (PMG monkey) were examined and compared to the brain of normal monkeys.

Coding of shape from shading in area V4 of the macaque monkey.

Background: The shading of an object provides an important cue for recognition, especially for determining its 3D shape. However, neuronal mechanisms that allow the recovery of 3D shape from shading are poorly understood. The aim of our study was to determine the neuronal basis of 3D shape from shading coding in area V4 of the awake macaque monkey.

Single-unit responses in the auditory cortex of monkeys performing a conditional acousticomotor task.

The general goal of the present study was to assess the response properties to tones of single neurons in the auditory cortex (primary auditory area, A1, and middle lateral auditory belt, ML) of two macaque monkeys while performing an acousticomotor discrimination task requiring a controlled level of attention and motivation. For each neuron, an approximation of the frequency receptive field (FRF) was first established. Second, based on the FRF, sets of paired tone frequencies were defined in which two different tone frequencies had to be associated by the monkey, following a trial and error strategy, to a left or a right key-press with the left arm.