INVESTIGADORES
MARTIN Andres
congresos y reuniones científicas
Título:
Reaction times dependence on luminance spatial noise for a pseudo-isochromatic stimuli
Autor/es:
CORMENZANA MÉNDEZ, IÑAKI; O'DONELL, BEATRIZ; MARTÍN, ANDRÉS; SOUZA, GIVAGO S
Reunión:
Conferencia; 43 ECVP; 2014
Institución organizadora:
ECVP
Resumen:
The objective is to analyze the role of amplitude and mean luminance
noise for color reaction time -RT- task using pseudoisochromatic
stimuli. The stimuli were composed by a Landolt-C surrounded by a
background that differed only in chromaticity. Target chromaticity
varied along chromatic vectors (0, 90, 180 and 270 deg). Subjects had to
find the orientation of the C-Landolt gap while the chromatic vector
was decreased. The RT task was performed against luminance noise at
three noise mean luminance (13, 19, and 25 cd/m2). The luminance noise
modulation was composed by patches with luminance ranging between 7
cd/m2 above and below stimulus mean luminance (constant delta protocol)
or by luminance ranging between 70% above and below stimulus mean
luminance (constant proportion protocol). The results showed that RT
decreased with luminance with constant delta protocol while in the case
of constant proportion protocol there is no dependence with luminance
within the luminance range analyzed, being longer - ≈100 ms - in the
later case. Gomes et al, 2012, showed similar results but measuring
color discrimination vector length. On the other hand, the number of
wrong answer depends on the protocol, bigger for constant proportion
protocol than for constant delta protocol.