TY  - JOUR
A1  - Laubrock, Jochen
A1  - Cajar, Anke
A1  - Engbert, Ralf
T1  - Control of fixation duration during scene viewing by interaction of foveal and peripheral processing
JF  - Journal of vision
N2  - Processing in our visual system is functionally segregated, with the fovea specialized in processing fine detail (high spatial frequencies) for object identification, and the periphery in processing coarse information (low frequencies) for spatial orienting and saccade target selection. Here we investigate the consequences of this functional segregation for the control of fixation durations during scene viewing. Using gaze-contingent displays, we applied high-pass or low-pass filters to either the central or the peripheral visual field and compared eye-movement patterns with an unfiltered control condition. In contrast with predictions from functional segregation, fixation durations were unaffected when the critical information for vision was strongly attenuated (foveal low-pass and peripheral high-pass filtering); fixation durations increased, however, when useful information was left mostly intact by the filter (foveal high-pass and peripheral low-pass filtering). These patterns of results are difficult to explain under the assumption that fixation durations are controlled by foveal processing difficulty. As an alternative explanation, we developed the hypothesis that the interaction of foveal and peripheral processing controls fixation duration. To investigate the viability of this explanation, we implemented a computational model with two compartments, approximating spatial aspects of processing by foveal and peripheral activations that change according to a small set of dynamical rules. The model reproduced distributions of fixation durations from all experimental conditions by variation of few parameters that were affected by specific filtering conditions.
KW  - scene perception
KW  - spatial frequencies
KW  - fixation durations
KW  - computational modeling
Y1  - 2013
U6  - https://doi.org/10.1167/13.12.11
SN  - 1534-7362
VL  - 13
IS  - 12
PB  - Association for Research in Vision and Opthalmology
CY  - Rockville
ER  - 
TY  - JOUR
A1  - Dambacher, Michael
A1  - Slattery, Timothy J.
A1  - Yang, Jinmian
A1  - Kliegl, Reinhold
A1  - Rayner, Keith
T1  - Evidence for direct control of eye movements during reading
JF  - Journal of experimental psychology : Human perception and performance
N2  - It is well established that fixation durations during reading vary with processing difficulty, but there are different views on how oculomotor control, visual perception, shifts of attention, and lexical (and higher cognitive) processing are coordinated. Evidence for a one-to-one translation of input delay into saccadic latency would provide a much needed constraint for current theoretical proposals. Here, we tested predictions of such a direct-control perspective using the stimulus-onset delay (SOD) paradigm. Words in sentences were initially masked and, on fixation, were individually unmasked with a delay (0-, 33-, 66-, 99-ms SODs). In Experiment 1, SODs were constant for all words in a sentence; in Experiment 2, SODs were manipulated on target words, while nontargets were unmasked without delay. In accordance with predictions of direct control, nonzero SODs entailed equivalent increases in fixation durations in both experiments. Yet, a population of short fixations pointed to rapid saccades as a consequence of low-level information at nonoptimal viewing positions rather than of lexical processing. Implications of these results for theoretical accounts of oculomotor control are discussed.
KW  - stimulus-onset delay
KW  - oculomotor control
KW  - fixation durations
KW  - sentence reading
Y1  - 2013
U6  - https://doi.org/10.1037/a0031647
SN  - 0096-1523
VL  - 39
IS  - 5
SP  - 1468
EP  - 1484
PB  - American Psychological Association
CY  - Washington
ER  -