The vast majority of these visual fixation signs are linked to dysfunctions of the central nervous system, in the absence of inaccurate vision, ophthalmologic diseases, or eye muscle affections.
PSP patients also present with disrupted visual fixation when they attempt to fix their eyes upon stationary targets.
(duration per minute for each phase) on the infant's feet (for the three reinforcement groups) and on the visual target (for the visual reinforcement group) were also analyzed to determine their relative contribution in the establishment of the free operant conditioning of kicks.
How these late transitions occur is unknown, but the usual progression begins with the appearance of nonreflexive signs such as visual fixation
(noted at the time of the imaging studies) and visual tracking (observed six months later).
Attention is linked to visual fixation
(Daffner et al., 1992), and visual fixation
is linked to cognitive processing (Just and Carpenter, 1980; Rayner, 1978).
It is characterized by optic ataxia (lack of co-ordination of hand and eye movement), oculomotor apraxia (the inability to voluntarily guide eye movements/change to a new location of visual fixation
), and simultanagnosia (the inability to perceive more than one object at a time, even when in the same place).
The researchers isolated areas involved in the two musical tasks by removing PET data on blood-flow activity generated during control trials involving visual fixation
on a blank screen, manual responses to dots shown on the screen, and listening to and playing musical scales.
Both signals are registered through its DVCR recording unit and merged by the computer system, producing a compound image of the environment observed together with the participant's visual fixations
. The Mobile Eye system was calibrated using the Eye Vision 2.2.5 software, and the videos rendered during the study were analysed using the ASL Result Plus Gaze Map software.
Barba, "Predicting visual fixations
on video based on low-level visual features," Vision Research, vol.
As pioneering work by the Russian psychologist Yarbus (1967) demonstrated over three decades ago, for example, a person pictured in a scene usually will compel the viewer's attention to a much greater degree than will most other objects pictured in that scene, and that is especially so of the image of a human face, which attracts a disproportionately large number of visual fixations
that specifically target the eyes, mouth, nose, and broad contours that describe the boundaries of the face (see Figure 1).
Taylor found that most kindergarteners demonstrated left-to-right directionality patterns in their visual fixations
. Nodine and colleagues also conducted several important studies of visual processing patterns in kindergarteners (Nodine & Lang, 1971; Nodine & Simmons, 1974).