Time-to-contact perception in the brain.

Time-to-contact (TTC) perception refers to the ability of an observer to estimate the remaining time before an object reaches a point in the environment, and is of crucial importance in daily life. Noninvasive correlational approaches have identified several brain areas sensitive to TTC information. Here we report the results of two studies, including one during an awake brain surgery, that aimed to identify the specific areas causally engaged in the TTC estimation process.

Key periods of cognitive decline in a nonhuman primate model of cognitive aging, the common marmoset (Callithrix jacchus).

It is well established that human life expectancy increases considerably with an ever-growing number of people suffering from age-related cognitive decline and degenerative brain diseases. This necessitates the development of animal models to counteract or stop the progression of the decline early enough. Presently, primate models are few, and many studies argue for the marmoset as an interesting primate model presenting a short life span and being easily available in research laboratories.

The detrimental influence of attention on time-to-contact perception.

To which extent is attention necessary to estimate the time-to-contact (TTC) of a moving object, that is, determining when the object will reach a specific point? While numerous studies have aimed at determining the visual cues and gaze strategy that allow this estimation, little is known about if and how attention is involved or required in this process. To answer this question, we carried out an experiment in which the participants estimated the TTC of a moving ball, either alone (single-task condition) or concurrently with a Rapid Serial Visual Presentation task embedded within the ball (dual-task condition). The results showed that participants had a better estimation when attention was driven away from the TTC task.

Parkinson's patients can rely on perspective cues to perceive 3D space.

3D perception, which is necessary for an optimal navigation in our environment, relies on 2 complementary kinds of cues; binocular cues allowing precise depth localization near the point of visual interest and monocular ones that are necessary for correct global perception of visual space. Recent studies described deficient binocular 3D vision in PD patients; here we tested 3D vision in PD patients when based on monocular cues (m3D). Sixteen PD patients and 16 controls had to categorize visual stimuli as perceived in 2D (flat) or 3D (with depth).

Effect of audiovisual training on monaural spatial hearing in horizontal plane.

The article aims to test the hypothesis that audiovisual integration can improve spatial hearing in monaural conditions when interaural difference cues are not available. We trained one group of subjects with an audiovisual task, where a flash was presented in parallel with the sound and another group in an auditory task, where only sound from different spatial locations was presented. To check whether the observed audiovisual effect was similar to feedback, the third group was trained using the visual feedback paradigm.