Visual Attention

Lucretius and Bayes: Above a schematic of a Bayesian Ideal Observer for a Yes/No Posner Cueing task
(see: Shimozaki et al., 2003; Eckstein et al., 2002)

"Even if things are plainly visible you can note that if you do not direct the mind (advertas animum), the things are so to speak, far removed and remote for the whole time" 
Lucretius,  1st century B.C.

How does covert attention change visual processing?  Does it change the quality of processing or does it simply allow the observer to ignore irrelevant information?  Is attention required to bind feature information in visual search? Our work has focused in showing that many classic results in the visual attention literature can be accounted for without assuming a limited capacity mechanism (e.g., serial processing, attentional enhancement). In particular we have worked on formalizing previous modeling efforts using a signal detection approach within the framework of an ideal Bayesian observer model. We have been able to explain these human search performance with the ideal observer or approximations of such model for these phenomena::

• Feature vs. Conjunction
• Cueing effects
• Target/Distractor discriminability
• Oddity Search
• Contextual cueing
  

We have also tried to develop neuron-based models that allow us to evaluate what neural measures from neurophysiology/neuroimaging can differential across psychological theories/models.

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 Here is what we have found:

In many instances we have studied attentional benefits with predictive cues and lower performance with number of distractors can be explained (quantiatively predicted) in terms of the selection and/or weighted combination of  relevant task-information without resorting to a quantiative/qualitative change in the quality of processing at/of each location/item.

Two classical paradigms that have been the main thrust behind the idea that visual attention fundmentally changes either the quality of processing or the type of processing in simple tasks are the feature/conjunction dichotomy in visual search and the Posner cueing paradigm. 

The lower efficiency for conjunctions is due to noise and not serial visual attention

The valid/invalid cue advantage in the Posner paradigm explained by ideal combination of information and without a change in quality of processing at the two locations.
 

Publications:

Eckstein, MP, Peterson MF, Pham BT, Droll JA, Statistical decision theory to relate neurons to behavior in the study of covert visual attention, Vision Research, Special Issue on Visual Attention, 49(10):1097-128 (2009)

Schoonveld, W., Shimozaki, S. S., & Eckstein, M. P. (2007). Optimal observer model of single-fixation oddity search predicts a shallow set-size function. Journal of Vision, 7(10):1, 1-16, http://journalofvision.org/7/10/1/, doi:10.1167/7.10.1.

Shimozaki SS, Chen K, Abbey CK, Eckstein MP, The temporal dynamics of selective attention of the visual periphery as measured by classification images, Journal of Vision, 7(12):10, 1-20, (2007)

Eckstein, M.P., Drescher B., Shimozaki, S.S., Attentional cues in real scenes, saccadic targeting and Bayesian priors, Psychological Science, 17, 973-80 (2006)

Shimozaki, S. S., Kingstone, A., Olk, B., Stowe, R., & Eckstein, M. P., Classification images of two right hemisphere patients: A window into the attentional mechanisms of spatial neglect, Brain Research, 1080, 26-52, (2006)

Eckstein, M.P., Pham B.T., Shimozaki, S.S., The footprints of visual attention during search with 100% valid and 100% invalid cues, Vision Research, 40, 1193-207 (2004)

Shimozaki, S. S., Eckstein, M. P., & Abbey, C. K. (2003). Comparison of two weighted integration models for the cueing task: linear and likelihood. Journal of Vision, 3(3), 209-229, http://journalofvision.org/3/3/3/, DOI 10.1167/3.3.3.

Eckstein, M.P., Shimozaki, S.S., Abbey, C.K., The footprints of visual attention in the Posner paradigm revealed by classification images. Journal of Vision, 2(1), 25-45, http://journalofvision.org/2/1/3 (2002)

Eckstein, M. P, Thomas, Palmer, J.,J.P, Shimozaki,S.S., A signal detection model predicts effects of set size on visual search accuracy for feature, conjunction and disjunction displays, Perception & Psychophysics,  62,425-451, (2000) 

Eckstein, M.P., Beutter B.R., Stone L.S., Analytic Guided-Search Model of human performance accuracy in target localization search tasks, NASA/TM 209-594 (2000)

Eckstein, M.P., The lower efficiency for conjunctions is due to noise and not serial attentional processing, Psychological Science, 9, 111-118, (1998)