Ristikkäissuuntautumiseen

Ristikkäissuuntautumiseen, known in English as cross-orientation, refers to a phenomenon in visual processing where stimuli presented in a different orientation than the adapting stimulus elicit a stronger neural response. This concept is primarily studied in the context of orientation-selective neurons in the visual cortex. When a neuron is exposed to a stimulus of a particular orientation, it becomes adapted to that orientation, meaning its firing rate decreases. If, after adaptation, a new stimulus is presented with a different orientation, the neuron's response is often enhanced compared to its response to a stimulus of the original orientation or to a stimulus with a completely novel orientation. This enhancement is particularly pronounced for orientations that are orthogonal to the adapting stimulus.

The underlying mechanisms of cross-orientation suppression and enhancement are complex and are thought to involve interactions between excitatory and inhibitory neural circuits within the visual cortex. Adaptation leads to a depression of excitatory input and/or a release of inhibition, while stimuli with orthogonal orientations may effectively disinhibit the neurons or activate different, less adapted pathways. Research into cross-orientation suggests it plays a role in perceptual tasks such as texture discrimination and visual attention, potentially by enhancing the detection of features that deviate from the prevailing visual input. It is a key finding in understanding how the brain processes and interprets spatial information.