Inhibitory Effect

Inhibition of return is an attentional effect and relates to eye movement
An Inhibitory effect to slow the reaction time (RT) of responses to previous cued location was first discovered by Michael Posner and Giovanni Berlucchi in 1981 (Cohen, 1981 cited in Klein and Hilchey, 2011). It is a phenomenon that a delay of RT presents when a person responds to the previous cued location (Posner and Cohen, 1984). It is thought to facilitate foraging behaviour by inhibiting the return to the attended regions and named as inhibition of return in 1985 (Posner et al, 1985).
IOR was first suggested as an attentional effect that serves to reduce the efficiency of target detection (Posner and Cohen, 1984). Posner and Cohen (1984) found that an inhibition

In Back-and-Forth experiment, participants were asked to fixate at the central box and then read the digit (the cue) from one of the two peripheral boxes. When participants returned their eyes to the brightening central box, the target was given. A strong inhibitory effect showed for at least 1.5 sec at the cued location. It was found that inhibition occurred when the cue was in the same retinal and environmental location as the target. Right-Angle experiment showed an inhibition presented when a cued location is environmentally coordinated but without retinal stimulation to the participants. Participants were required to have three eye movements. There were one central box and four peripheral boxes, two were next to the central box and the other two were below the top peripheral boxes. The first eye movement required moving from the central box to one of peripheral boxes with a digit at the bottom (EM1). The second movement made from the box with digit to the box with a different digit (EM2). Participants had to read the digit one by one and back to the brightening central box at the end. The result showed a strong inhibition when the retinal stimulation was not as the same as environmental stimulation between cues and targets. This suggests that inhibition occurs in environmental but not retinal location. Also, inhibition occurs not only in fixated eyes, but also in moving eyes. IOR also suggested to be closely associated with eye