Top-down and bottom-up competition in visual stimuli processing

Event-Related Potentials of Bottom-Up and Top-Down Processing of Emotional Faces

Introduction: Emotional stimulus is processed automatically in a bottom-up way or can be processed voluntarily in a top-down way. Imaging studies have indicated that bottom-up and top-down processing are mediated through different neural systems. However, temporal differentiation of top-down versus bottom-up processing of facial emotional expressions has remained to be clarified. The present st...

Visual Attention: Bottom-Up Versus Top-Down

Visual attention is attracted by salient stimuli that 'pop out' from their surroundings. Attention can also be voluntarily directed to objects of current importance to the observer. What happens in the brain when these two processes interact?

Visual search: bottom-up or top-down?

The aim of the experiments in this paper was to explore the relationship between top-down and bottom-up processes in visual search. Employing behavioral techniques, we first consider the possible role of the magnocellular visual pathway in visual search, and find that visual search does not necessarily depend on processing by this visual sub-system. We next use functional imaging (positron emis...

Bottom-up, top-down

Bottom-up and top-down dynamics in visual cortex.

A key emergent property of the primary visual cortex (V1) is the orientation selectivity of its neurons. Recent experiments demonstrate remarkable bottom-up and top-down plasticity in orientation networks of the adult cortex. The basis for such dynamics is the mechanism by which orientation tuning is created and maintained, by integration of thalamocortical and intracortical inputs. Intracellul...