Shape effects on reflexive spatial selective attention and a plausible neurophysiological model

نویسندگان

  • Saumil S. Patel
  • Xinmiao Peng
  • Anne B. Sereno
چکیده

If a peripheral, behaviorally irrelevant cue is followed by a target at the same position, response time for the target is either facilitated or inhibited relative to the response at an uncued position, depending on the delay between target and cue (Posner, 1980; Posner & Cohen, 1984). A few studies have suggested that this spatial cueing effect (termed reflexive spatial attention) is affected by non-spatial cue and target attributes such as orientation or shape. We measured the dependence of the spatial cueing effect on the shapes of the cue and the target for a range of cue onset to target onset asynchronies (CTOAs). When cue and target shapes were different, the spatial cueing effect was facilitatory for short CTOAs and inhibitory for longer CTOAs. The facilitatory spatial effect at short CTOAs was substantially reduced when cue and target shapes were the same. We present a simple neural network to explain our data, providing a unified explanation for the spatial cueing effect and its dependence on shape similarities between the cue and the target. Our modeling suggests that one does not need independent mechanisms to explain both facilitatory and inhibitory spatial cueing effects. Because the neuronal properties (repetition suppression) and the network connectivity (mutual inhibition) of the model are present throughout many visual brain regions, it is possible that reflexive attentional effects may be distributed throughout the brain with different regions expressing different types of reflexive attention depending on their sensitivities to various aspects of visual stimuli.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Single Canonical Model of Reflexive Memory and Spatial Attention

Many neurons in the dorsal and ventral visual stream have the property that after a brief visual stimulus presentation in their receptive field, the spiking activity in these neurons persists above their baseline levels for several seconds. This maintained activity is not always correlated with the monkey's task and its origin is unknown. We have previously proposed a simple neural network mode...

متن کامل

Shape effects on reflexive spatial attention are driven by the dorsal stream

In a modified reflexive spatial attention paradigm, when the cue and the target are at the same spatial location, processing of the target is faster when the cue and the target have different shapes compared to same (shape effect). Recent physiological findings suggest distinct population level encoding of shape in ventral versus dorsal cortical visual streams in monkeys. In human observers, we...

متن کامل

Neurophysiological Correlates of the Reflexive Orienting of Spatial Attention

There are two reflexive biases in orienting attention that assist in the exploration of the visual scene. A distinct object will draw, or capture, spatial attention to its locus. After this object has been inspected (and deemed irrelevant), inhibition of return prevents its repeated inspection. Here, we describe the neurophysiological correlates of these biases in orienting attention. In the su...

متن کامل

Voluntary spatial attention has different effects on voluntary and reflexive saccades.

Although numerous studies have investigated the relationship between saccadic eye movements and spatial attention, one fundamental issue remains controversial. Some studies have suggested that spatial attention facilitates saccades, whereas others have claimed that eye movements are actually inhibited when spatial attention is engaged. However, these discrepancies may be because previous resear...

متن کامل

Modeling the Effects of Perceptual Load: Saliency, Competitive Interactions, and Top-Down Biases

A computational model of visual selective attention has been implemented to account for experimental findings on the Perceptual Load Theory (PLT) of attention. The model was designed based on existing neurophysiological findings on attentional processes with the objective to offer an explicit and biologically plausible formulation of PLT. Simulation results verified that the proposed model is c...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Vision Research

دوره 50  شماره 

صفحات  -

تاریخ انتشار 2010