Abstract
Contextual cueing is regarded as an implicit form of spatial learning which occurs in repeated search displays, typically in the absence of explicit recognition. However, recently, there have been behavioral studies suggesting that the search facilitation observed in repeated displays depends on visuospatial working memory resources. Working memory appears to support the expression of learning rather than the learning itself (Manginelli et al., 2011; Vickery et al., 2010). Here, we used fMRI to investigate the neural basis of these processes. To this end, we first looked for brain areas in which the BOLD response in a visual working memory task reflects working memory capacity (Todd & Marois, 2004). Using these areas as a mask, we looked for activation that is correlated with the individual size of the contextual cueing effect in visual search. Such a correlation was observed along the banks of the descending segment of the left intraparietal sulcus. Furthermore, increased activation for repeated versus novel search displays was observed in ventral occipitotemporal cortex.Thus, the cortex along the left posterior intraparietal sulcus became less involved in visual search the better the repeated displays were learned, whereas ventral occipitotemporal areas showed a consistent increased response to repeated displays. The latter may reflect the increased demands on visuospatial working memory that is required for successful expression of visuospatial context learning, whereas the former appears to reflect the more efficient search in learnt displays. References: Manginelli, A. A., Geringswald, F. & Pollmann, S. (2011). Visual search facilitation in repeated displays depends on visuospatial working memory. ExpPsychol, Jul 18:1-8. [Epub ahead of print] Todd, J.J., Marois, R. (2004). Capacity limit of visual short-term memory in human posterior parietal cortex. Nature 428(6984):751-754. Vickery, T.J., Sussman, R.S., Jiang, Y.V. (2010). Spatial context learning survives interference from working memory load.J Exp Psychol Hum Percept Perform 36(6): 1358-1371.
Meeting abstract presented at VSS 2012