Page No 168-180
Anil Kumar Yadav, Shalini Dubey, Trayambak Tiwari, Shreshtha Yadav,
Indramani L. Singh
Banaras Hindu University, Varanasi.
Anju L. Singh
Vasanta Kanya Mahavidyalaya, Varanasi
Two experiments were conducted to examine the effects of exogenous and endogenous
modes of covert orienting and different SOAs (stimulus onset asynchrony) on vigilance
task performance. In experiment one endogenous and exogenous orienting were
compared to know which mode of orienting was more influential on vigilance task
performance. The most influential and effective mode of orienting then were examined
at three Stimulus onset asynchrony (SOA) levels in experiment two. Results revealed
that exogenous cue elicited faster detection of target and produced more cue validity
effect in comparison to endogenous cue. However, both the types of cues were able to
prevent the decrement functions as performance decrement was not seen across the
time period. The SOAs were tested with exogenous cue in experiment two. The inhibition
of return (IOR) was not seen in exogenous orienting but cue validity effect decreased
with increasing SOAs during vigilance task. This suggested that exogenous cue was
beneficial for vigilance however the benefit was limited to the shorter SOA