Figure 6.

Directional specificity of temporal and spatial IOR. (a, b) Saccade latency as a function of direction relative to preceding eye movement (Δθ), for saccades matched in amplitude (|Δr| < 25%), recorded in free-viewing (a) and search tasks (b). Shaded region indicates ±1 SE. Dashed horizontal lines indicate median latency of all saccades. ‘R' indicates saccades in return direction (180°), i.e., those resulting in refixations. Note that fixation durations are prolonged prior to return saccades (temporal IOR). (c, d) Discrepancy between actual and simulated (memoryless) saccade frequencies as a function of direction relative to preceding eye movement (Δθ), for saccades matched in amplitude (|Δr| < 25%), in free-viewing (c) and in search (d). ‘R' indicates refixations. Dotted horizontal line indicates equality. Negative values indicate that saccades are inhibited relative to memoryless selection (spatial IOR).