Inhibition of return in pro- and anti-localization tasks with mixed and blocked designs
Eng, V and Gan, SR and Kwon, SM and Lim, SE and Lim, CKA and Satel, J, Inhibition of return in pro- and anti-localization tasks with mixed and blocked designs, Malaysian International Psychology Conference (MIPC'15), Bangi, Selangor, Malaysia (2015) [Conference Extract]
There are thought to be two forms of inhibition of return (IOR) depending on whether the oculomotor
system is activated or suppressed. When saccades are allowed, output-based IOR is generated, whereas
input-based IOR arises when saccades are forbidden. In a series of six experiments, we mixed or blocked
pro- and anti-localization trials in order to investigate whether cueing effects would follow the same
pattern as those observed with more traditional peripheral onsets and central arrows. In all experiments,
an uninformative cue was displayed, followed by a cue-back stimulus that was either red or green. Green
cue-backs indicated that pro-localization responses were to be made to the upcoming targets, whereas red
called for anti-localization (respond opposite the targets). In the first experiment, subjects did not make
any saccades, whereas saccades were made to cues in Experiment 2, and to targets in Experiment 3.
Experiments 1 to 3 used a mixed design, with intermixed pro- and anti-localization responses, whereas
Experiments 4 to 6 repeated the same experiments with a blocked design. We predicted that prolocalization
trials would show the same pattern of effects as previously observed (IOR in all experiments),
whereas anti-localization trials would result in IOR when the oculomotor system was activated and no
effect when suppressed. However, our results showed that for pro-localization, IOR was only observed
when saccades were made to the targets in a mixed design, although IOR was elicited in all three blocked
experiments. For the anti-localization condition, IOR was only observed with saccadic responses in the
mixed design, whereas facilitation was observed with manual responses in the blocked design.
Challenging the influential two forms theory of IOR, this suggests a dissociation in cueing effects
depending on response modality when a complex, mixed design is used.