The effects of time-on-task and concurrent cognitive load on normal visuospatial bias.
Research suggests that the severity of left spatial neglect can be modulated by changes in general alertness. Analogous effects in healthy volunteers now suggest that this may reflect an amplified form of a normal pattern. Recent neuropsychological studies also suggest that concurrent cognitive load may exacerbate rightward bias. In this study, for the first time, the authors examined the effect of both factors on spatial bias in healthy volunteers. Participants performed a task in which as many letters as possible needed to be reported from a briefly presented visual array under three conditions (alone, with a syllable-discrimination secondary task and with a pitch-discrimination secondary task). The results confirmed a significant rightward shift associated with time-on-task across all conditions--the first demonstration of such an effect within a fixation controlled, brief presentation task. While the secondary tasks influenced overall visual performance, there was no discernable effect on bias.
Dodds
Christopher M
CM
UK Medical Research Council Cognition and Brain Sciences Unit, Cambridge, United kingdom.
van Belle
Janna
J
Peers
Polly V
PV
Dove
Anja
A
Cusack
Rhodri
R
Duncan
John
J
Manly
Tom
T
D000161:Acoustic Stimulation; D000328:Adult; D015982:Bias; D003071:Cognition / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000503:physiopathology*; D010775:Photic Stimulation / Q000379:methods; D010897:Pitch Discrimination / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D013997:Time Factors; D014705:Verbal Behavior; D014796:Visual Perception / Q000502:physiology*