Further analysis shows two types of the fixation point
One such point, obviously, is the intersection of the visual axes, that is, the fixation point
The participants were instructed to keep their eyes on the fixation point
and to avoid eye movements during the intervention, although this was not monitored in every training session.
Going back to the design, after the words were presented, a fixation point
was presented for 300 msec that signaled the Distractor phase, in which the participants would make the same-different decision.
A trial started with the presentation of a target stimulus, after which a fixation point
was presented for 2 s, followed by the presentation of one of the four types of display The participant was required to indicate as quickly and accurately as possible whether or not the display contained a target.
For both humans and monkeys, if a letter or other stimulus appears to the left of a fixation point
for a period faster than the one-fifth of a second needed for the eyes to focus on the stimulus, it enters only the left visual field and gets processed only by the right hemisphere.
Fixation stability (P1 and P2) was measured by calculating the percentage of fixation points
(%) located within a distance of 1[degrees] and 2[degrees], respectively.
The eye-tracking instrument (SMI iViewX HED) was employed for recording fixation points
of drivers as test time goes on (Figures 3(c) and 3(d)).
The pupillometer is a tool that can be used to measure both the NPD and the ID, in which the measurement is based on the assessment of the corneal reflex in both eyes while the patient observes a fixation point
. This method provides a more accurate measurement than a metric ruler, since when the patient observes the fixation point
, the corneal reflection denotes the point known as visual axis or vision line, and without the errors of parallelism of the lanterns or other systems .
The response-key mapping was counterbalanced across participants, who were encouraged not to move the eyes from the fixation point
In a recent study (Canto-Pereira, David, Machado-Pinheiro, & Ranvaud, 2007), for instance, volunteers had to respond (by pressing a key-manual reaction time, RT) to luminous points appearing at different positions on the screen while they kept staring at the fixation point
in the center of the screen.
When scenes were presented to the parafovea (2.5 away from a fixation point
), Calvo and Lang (2005) found that semantic content of pleasant and unpleasant rather than neutral scenes was especially likely to be recognized.