Editing Saccade (section)

==Types==
Saccades can be categorized by intended goal in four ways:<ref name=Rommelse>{{cite journal |doi=10.1016/j.bandc.2008.08.025 |title=A review on eye movement studies in childhood and adolescent psychiatry |year=2008 |last1=Rommelse |first1=Nanda N.J. |last2=Van Der Stigchel |first2=Stefan |last3=Sergeant |first3=Joseph A. |journal=Brain and Cognition |volume=68 |issue=3 |pages=391–414 |pmid=18835079|s2cid=4658518 }}</ref>

# In a ''visually guided saccade'', the eyes move toward a visual transient, or stimulus. The parameters of visually guided saccades (amplitude, latency, peak velocity, and duration) are frequently measured as a baseline when measuring other types of saccades. Visually guided saccades can be further subcategorized:
#:* A ''reflexive saccade'' is triggered exogenously by the appearance of a peripheral stimulus, or by the disappearance of a fixation stimulus.
#:* A ''scanning saccade'' is triggered endogenously for the purpose of exploring the visual environment.
# In an [[Antisaccade task|''antisaccade'']], the eyes move away from the visual onset. They are more delayed than visually guided saccades, and observers often make erroneous saccades in the wrong direction. A successful antisaccade requires inhibiting a reflexive saccade to the onset location, and voluntarily moving the eye in the other direction.
# In a ''memory guided saccade'', the eyes move toward a remembered point, with no visual stimulus.
# In a sequence of ''predictive saccades'', the eyes are kept on an object moving in a temporally and/or spatially predictive manner. In this instance, saccades often coincide with (or anticipate) the predictable movement of an object.

As referenced to above, it is also useful to categorize saccades by latency (time between go-signal and movement onset). In this case the categorization is binary: Either a given saccade is an ''express saccade'' or it is not. The latency cut-off is approximately ~200&nbsp;ms; any longer than this is outside the express saccade range.<ref name="FischerBoch1983"/><ref name="FischerRamsperger1984"/>

[[Microsaccade]]s are a related type of [[Fixation (visual)|fixational eye movement]] that are small, jerk-like, involuntary [[Eye movement (sensory)|eye movements]], similar to miniature versions of voluntary saccades. They typically occur during visual [[Fixation (visual)|fixation]], not only in humans, but also in animals with [[Fovea centralis|foveal]] vision (primates, cats, etc.). Microsaccade amplitudes vary from 2 to 120 [[arcminute]]s.