The study of saccade control using functional neuroimaging began with EEG studies in the 1960s (e.g.

Functional neuroimaging is defined here to include techniques used for their excellent spatial resolution, such as positron emission tomography (PET) (see glossary) and functional magnetic resonance imaging (fMRI) (see glossary and text box 1), and techniques used for their excellent time resolution, such as multichannel electroencephalography (EEG) (see glossary and text box 2) and magnetoencephalography (MEG) (see glossary).

Multiple tools exist for studying the neural bases of saccade control, including human functional neuroimaging techniques. Future research on saccade control could usefully (i) delineate important anatomical subdivisions that underlie functional differences, (ii) evaluate functional connectivity of anatomical regions supporting saccade generation using methods such as ICA and structural equation modeling, (iii) investigate how context affects behavior and brain activity, and (iv) use multi-modal neuroimaging to maximize spatial and temporal resolution. Neuroimaging studies suggest two foci of activation within FEF - medial and lateral - which may correspond to volitional and reflexive demands, respectively. Activity in visual cortex is modulated as a function of task demands and may predict the type of saccade to be generated, perhaps via top-down control mechanisms. These additional requirements are supported by changes in neural activity in basic saccade circuitry and by recruitment of additional neural regions (such as prefrontal and anterior cingulate cortices).

antisaccades, ocular motor delayed response or memory saccades, predictive tracking tasks and anticipatory saccades, and saccade sequencing), all of which require complex cognitive processes like inhibition and working memory. Activation in these regions is also observed during endogenously-driven voluntary saccades (e.g. The network involved in prosaccade generation (by definition exogenously-driven) includes subcortical (striatum, thalamus, superior colliculus, and cerebellar vermis) and cortical structures (primary visual, extrastriate, and parietal cortices, and frontal and supplementary eye fields). Considerable knowledge of this system’s functional neuroanatomy makes it useful for investigating models of cognitive control. The saccadic system has been studied extensively in non-human primates (e.g. The generation of simple visually-guided saccades (redirections of gaze to a visual stimulus or prosaccades) and more complex volitional saccades require similar basic neural circuitry with additional neural regions supporting requisite higher level processes. This review provides a summary of the contributions made by human functional neuroimaging studies to the understanding of neural correlates of saccadic control.

Reflexive activation code generator