Overt orienting is the act of selectively attending to an item or location over others by moving the eyes to point in that direction.  Overt orienting can be directly observed in the form of eye movements. Although overt eye movements are quite common, there is a distinction that can be made between two types of eye movements; reflexive and controlled. Reflexive movements are commanded by the superior colliculus of the midbrain . These movements are fast and are activated by the sudden appearance of stimuli. In contrast, controlled eye movements are commanded by areas in the frontal lobe . These movements are slow and voluntary.
Philosophical logic also addresses extensions and alternatives to traditional, "classical" logic known as "non-classical" logics . These receive more attention in texts such as John P. Burgess 's Philosophical Logic ,  the Blackwell Companion to Philosophical Logic ,  or the multi-volume Handbook of Philosophical Logic  edited by Dov M. Gabbay and Franz Guenthner .
Both the more and the less radical approaches share the central claim that the correct account of knowledge is in terms of reliable processes of belief-acquisition that are themselves explicated in empirical, and mainly causal, terms. The true beliefs of cognitive subjects, we might say, are one type of phenomenon that occurs in the natural world. We need not leave the latter in order to explain the former. There is no stand-alone problem of epistemic justification, requiring its own distinctive vocabulary and evidential considerations. Epistemic value, we might say, can be interpreted in terms of naturalistic facts and properties.