A competitive integration model of exogenous and endogenous eye movements

Abstract

We present a model of the eye movement system in which the programming of an eye movement is the result of the competitive integration of information in the superior colliculi (SC). This brain area receives input from occipital cortex, the frontal eye fields, and the dorsolateral prefrontal cortex, on the basis of which it computes the location of the next saccadic target. Two critical assumptions in the model are that cortical inputs are not only excitatory, but can also inhibit saccades to specific locations, and that the SC continue to influence the trajectory of a saccade while it is being executed. With these assumptions, we account for many neurophysiological and behavioral findings from eye movement research. Interactions within the saccade map are shown to account for effects of distractors on saccadic reaction time (SRT) and saccade trajectory, including the global effect and oculomotor capture. In addition, the model accounts for express saccades, the gap effect, saccadic reaction times for antisaccades, and recorded responses from neurons in the SC and frontal eye fields in these tasks.

Visual priming through a boost of the target signal: Evidence from saccadic landing positions

“…The fastest saccades occurred at 130 ms. At this latency, in the range of express saccades (Hamm, Dyckman, Ethridge, McDowell, & Clementz, 2010), a saccade may result from the visual pulse provided by a sudden onset, without any intervening cognitive mechanisms (see also Meeter, Van der Stigchel, & Theeuwes, 2010). This suggests that the effects causing priming are rapid and can occur independent of postselection processes.…”

The effect of sampling rate and lowpass filters on saccades – A modeling approach

“…The proposed model should not be understood as an alternative to elaborated neuronal models for saccades (e.g., Meeter, Van der Stigchel, & Theeuwes, 2010). Rather, it is intended as a simple method for the generation of saccade-like profiles during the examination of processing procedures.…”

Saccadic Inhibition Reveals the Timing of Automatic and Voluntary Signals in the Human Brain

“…These timings are consistent with those envisaged in the discussion of Reingold and Stampe (2002) but are significantly shorter than the values generally chosen in neural field models. For example, Trappenberg et al (2001), Cutsuridis et al (2007), and Meeter et al (2010) all used ␦ exo ϭ 70 ms.…”

“…A more recent generation of models aim at representing the behavior of specific neuronal maps in more detail (Kopecz, 1995;Trappenberg et al, 2001;Wilimzig et al, 2006;Cutsuridis et al, 2007;Lo et al, 2009;Meeter et al, 2010), can capture a wider range of behavioral paradigm, and potentially promise a more sophisticated understanding of saccadic planning. However, for complex models to provide diagnostic and predictive power in clinical or research applications, it is essential that their numerous parameters are meaningful behaviorally, can be constrained in humans, and help disentangle individual differences.…”