Effects of intensity and positional predictability of a visual stimulus on simple reaction time.
The influence of visual stimuli intensity on manual reaction time (RT) was investigated under two different attentional settings: high (Experiment 1) and low (Experiment 2) stimulus location predictability. These two experiments were also run under both binocular and monocular viewing conditions. We observed that RT decreased as stimulus intensity increased. It also decreased as the viewing condition was changed from monocular to binocular as well as the location predictability shifted from low to high. A significant interaction was found between stimulus intensity and viewing condition, but no interaction was observed between neither of these factors and location predictability. These findings support the idea that the stimulus intensity effect arises from purely sensory, pre-attentive mechanisms rather than deriving from more efficient attentional capture.
Developmental Disorders Program, Center for Health and Biological Sciences, Mackenzie Presbyterian University, Rua da Consolação, 896, Prédio 38/Térreo, Centro, 01302-907 São Paulo, SP, Brazil. renato.carreiro@gmail.com
Luiz Renato Rodrigues
LR
Carreiro
Hamilton
H
Haddad
Marcus Vinicius Chrysóstomo
MV
Baldo
D000328:Adult; D001288:Attention / Q000502:physiology*; D006801:Humans; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology*; D015348:Vision, Binocular / Q000502:physiology; D015349:Vision, Monocular / Q000502:physiology; D055815:Young Adult