Ayelet Sapir PhD

I am interested in understanding the cognitive strategies and the neural mechanisms that allow us to explore the environment efficiently.

I began as a graduate student in the lab by examining the effects of focal brain dysfunction on inhibition of return (IOR), a phenomenon that is postulated to enhance efficiency of visual search.

We found that a lesion in the superior colliculus, a subcortical structure known to be involved in reflexive eye movements, diminished IOR in the contralesional visual field.

This finding suggests that IOR is an automatic process that relies on lower level structures. We also showed that lesions in the parietal lobe impair the ability to remap the retinal location of inhibitory signals across saccades. We concluded that IOR is generated in the colliculus while it is stored and spatially updated in parietal and possibly other cortical structures.

email: a.sapir@bangor.ac.uk

Recent Publications

  • Sapir, A., Soroker, N., Berger, A., & Henik, A. (1999). Inhibition of Return in spatial attention: Direct evidence for collicular generation. Nature Neuroscience, 2, 1053-1054.
  • Meiran, N., Chorev, Z., & Sapir, A. (2000). Components of the Task-Shift Cost. Cognitive Psychology, 41, 211-253.
  • Sapir, A., Henik, A., Dobrusin, M., & Hochman, E. Y. (2001). Attentional asymmetry in schizophrenia: Disengagement and inhibition of return deficits. Neuropsychology, 15, 361-370.
  • Sapir, A., Rafal, R. D., & Henik, A. (2002). Attending to the thalamus: inhibition of return and nasal-temporal asymmetry in the pulvinar. NeuroReport, 13(5), 693-697.
  • Sapir, A., Hayes, A., Henik, A., Danziger, S., & Rafal, R. D., (2004). Parietal lobe lesions disrupt saccadic remapping of the visual environment: a study of inhibitory location tagging. Journal of Cognitive Neuroscience, 16(4), 503-509.
  • Sacher, Y., Serfaty, C., Deouell, L., Sapir, A., Henik, A., & Soroker, N. (2004). Role of disengagement failure and attentional gradient in unilateral spatial neglect - a longitudinal study. Disability and Rehabilitation, 26(12), 746-755.
  • Corbetta, M., Kincade, M.J., Lewis, C., Snyder, A.Z., & Sapir A. (2005). Neural basis and recovery of spatial attention deficits in spatial neglect. Nature Neuroscience,8, 1603-1610.
  • Sapir, A. *, d'Avossa, G. *, McAvoy, M., Shulman, G. L., & Corbetta, M. (2005). Brain signals for spatial attention predict performance on a motion discrimination task. Proceedings of the National Academy of Sciences, 102, 17810-17815. *contributed equally
  • Sapir, A., Kaplan, J.B., He, B.J., & Corbetta, M (2007). Neuroanatomical correlates of directional hypokinesia in patients with hemispatial neglect. Journal of Neuroscience, 27, 4045-4051.
  • Sapir, A., Dobrusin, M., Henik, A., & Ben-Bashat, G. (2007). Neuroleptics reverse attentional asymmetry in schizophrenia but do not influence inhibition of return. Neuropsychologia, 45, 3263-3271.
  • Okon-Singer, H., Schwartz, D., Berger, A., Sapir, A., Shani, E., Ben-Mair, E., & Henik, A. (submitted). Efficient Spatial Orienting of Attention and Early IOR in Pilots.
  • Kahan, S., Henik, A., & Sapir, A. (submitted). Gaze direction does produce Inhibition of Return.
  • Corbetta, M., He, B.J., Struna, J., Sapir, A. (submitted). A Behavioral-Anatomical Analysis of Spatial Neglect and its Recovery after Stroke.
  • Sapir, A., d'Avossa, G., McAvoy, M., & Corbetta, M. (in preparation). Spatial attention signals in the cerebellum predict subsequent performance but not motor response.
  • Struna, J., Sapir, A., d'Avossa, G., Shulman, G. L., & Corbetta, M. (in preparation). Assessment of unilateral neglect: sensitivity and specificity of behavioral battery.
  • Goldberg, X., Sapir, A., Shulman, G. L., & Corbetta, M. (in preparation). Anosognosia for activities of daily living.
  • d'Avossa, G., Sapir, A., McAvoy, M., Shulman, G. L., & Corbetta, M. (in preparation). Task dependent BOLD fluctuations in cortical networks.
  • Sapir, A., Abrams, R. (in preparation). Inhibition of return is a perceptual, and not motor, phenomenon.