A Model of JOR in Neural and Cognitive ControlYin Tian

School of Life Science and Technology,University ofElectronic Science and

Technology of China,ChengDu, 610054, China

College of Bio-information, ChongQingUniversity of Posts and Telecommunications,

ChongQing, 400065, ChinaE-mail: tiany20032003@163.com

AbstracL-Inhibition of return (IOR) refers to a performancedecrement for stimuli appearing at recently cued location. Bothattentional and motor processes have been implicated in theIOR effect. This paper first reviewed the role of IOR in bothbehavioral and neural levels, and then a model of IOR inneural and cognitive control was proposed. Finally, wediscussed this model and concluded it's valid that theattention-based component of IOR was presented in the cortexand the oculomotor component of IOR was presented in thecolliculus.

L. INTRODUCTION

When attention is drawn to a location in spatial location,the detection of targets appearing there is initially facilitated,then impaired, relative to other locations. The laterimpairment at the recently attended location was firstdemonstrated by Posner and Cohen in 1984[1] and has cometo be known as inhibition of return (IOR), meaning the ideathat attention is biased away from a location it has recentlyinspected. But the mechanism ofIOR is still unveiled today.Two main viewpoints were put forward by researchers andsupported respectively by behavioral experiments: one ofthem suggested that the mechanism of IOR is attentionalbias, but the others support that the mechanism of IOR ismotor bias or oculomotor bias. And the currently held viewof IOR is that these two seemingly contradictory accountsmay both be correct, with both attentional and motorcomponents contributing to IOR (see review of Klein,2000[2])

Recently, researchers used new methods and technologyto study activation in the brain by IOR. For example, Dorriset al.[3] found that the activity cells in the superiorcolliculus reflect IOR by using single-cell recordingtechnology. Pollen et al.[4] found activation relative withIOR in the SEF and the FEF by making use of fMRI,Whereas Ro et al. [5] discovered that the FEF played acrucial role in the generation of IOR, using single-pulsetranscranial magnetic stimulation (TMS). Above all theactivity areas are related to oculomotor on IOR, so theysupport the mechanism ofIOR was the motor bias. However,other researchers[6][7], using event-related potential (ERP),

Dezhong YaoSchool of Life Science and Technology,University of Electronic Science and

Technology of China,ChengDu, 610054, China

E-mail: dyao@uestc.edu.cn

found that P1 or/and NI components of ERP enhanced byeliciting IOR, and both components of ERP is related toextrastriate cortex, which can modulate attention shift. AndSumner, P. et al. [8] studies IOR effects by using atechnique that employs stimuli visible only toshort-wave-sensitive (S) cones, and these stimuli, to whichthe SC is blinded, only received by the pathway to cortex.So they suggested that IOR was related with attention.

All to accounts, two mechanisms ofthe generation ofIORwere supported by habitual and neuroelectro- physiologicalexperiments. According to previous studies, a model ofIORin neural and cognitive control was proposed and explainedthe following text in detail.

II. MODEL OF IOR

When these behavioral and neural findings of IOR areintegrated, a network of three separate systems appearsnecessary to accommodate both inhibitory effects, and themodel of IOR was proposed by us based on previous studiesshown on figure 1.

This model included both components of IOR, and theywere composed of three systems, respectively. Inoculomotor-based IOR, three neural and cognitive systemswere the (superior colliculus, SC) saccade map, theinhibitory control system including both the dorsolateralprefrontal cortex (dIPFC) and the frontal eye fields (FEFs),and the oculomotor programming map (presumably thelateral intraparietal area, LIP) as well. Whereas in theattention-based IOR, there still were three systems, the(lateral geniculate nucleus, LGN) attentional map, the(extrastriate, ES) inhibitory control system, and the (lateralintratemporal) attentional programming map as well.When an irrelevant stimulus is presented in the periphery,

it typically captures attention in an exogenous way. Thisso-called "capture of attention" implies that there isexogenous activation within the oculomotor programmingor attentional programming map. This in turn generatesoculomotor/attentional activation within thesaccade/attention map corresponding to the location invisual space where the stimulus was presented. However, as

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long as no eye movement or no attention shift has to bemade and the observer remains fixated, this oculomotor orattention activation within the saccade/attention map has noconsequences other than the generation of an inhibitory tagcorresponding to the location of activation within thesaccade/attention map. This inhibitory tag is delivered to theinhibitory control system. By inhibiting theocculomotor/attentional programming map, the inhibitorycontrol system inhibits activation at the location at whichthe initial stimulus was presented. This mechanism ofinhibitory control is what is typically referred to as IOR.After attention is reflexively shifted to the location of theinitially presented stimulus, there is delayed responding tostimuli subsequently displayed at that location. Thisinterpretation fits with the presumed role of IOR as aninhibitory mechanism that would encourage the sapling ofnew information in the visual search.

Inibitory control syst(cortex)

[1] M. I. Posner, Y. Cohet, "Components ofvisual orienting," In H. Bouma& D. G. Bouwhuis (Eds.), Attention and performance X. Control oflanguage processes, pp.531-556. Hillsale, NJ: Erlbaum. 1984.

[2] R. M. Klein, "Inhibition of retutr," Trends in Cognitive Sciences, vol. 4,pp.138-147, 2000.

[3] M. C. Dorris, R. M. Klein, "Contribution of the primate superiorcolliculus to inhibition of retuir," Journal of Cognitive Neuroscience,vol.14, pp.1256-1263, 2002.

[4] J. Lepsien, S. Pollmann, "Covert reotienting and inhibition of retun: anevent-related IMIRI study," Journal of Cognitive Neuroscience, vol.14,pp.l27-144, 2002.

[5] T. Ro, A. Fame, E. Chang, "Inhibition of return and the human frontaleye fields," Exp Brain Res, vol.150, pp.290-296, 2003.

[6] F. Di Russo, A. Mart'nez, M.tSereno, S. Pitzalis, & S.A.Hillyard,"Cortical sources of the early components of the visual evokedpotential.", Human Brain Mapping, vol.1S, pp.95-111, 2001.

[7]F.Di Russo, A.Marft'nez, S.A.Hillyad, "'Source analysis ofevent-related cortical activity during visuo-spatial attention.", CerebralCortex, vol.13, pp.486499, 2003.

[8] P. Sumner, et al., "Distinct cortical and collicular mechanism ofinhibition of return revealed with S cone stimuli," Current biology,vol.14, pp.2259-2263, 2004.

Signal input

Fig. 1. A model ofIOR in neural and cognitive control, activation wasshown by solid-line, and inhibition was shown by dashed-line

I1. CONCLUSIONS

In this paper, we proposed the model ofIOR in neural andcognitive control, combined the occulomotor-basedcomponent of IOR and the attention-based component ofIOR. This model discovered the nature of the generation ofIOR in advance.

ACKNOWLEDGMENT

This work was supported by NSFC#90208003 and#30200059, TRAPOYT, the 973 Project # 2003CB71610.

REFERENCES

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