A comparison of the temporal and spatial properties of trans-saccadic perceptual recalibration and saccadic adaptation

Abstract

Repeated exposure to a consistent trans-saccadic step in the position of the saccadic target reliably produces a change of saccadic gain, a well-established trans-saccadic motor learning phenomenon known as saccadic adaptation. Trans-saccadic changes can also produce perceptual effects. Specifically, a systematic increase or decrease in the size of the object that is being foveated changes the perceptually equivalent size between fovea and periphery. Previous studies have shown that this recalibration of perceived size can be established within a few dozen trials, persists overnight, and generalizes across hemifields. In the current study, we use a novel adjustment paradigm to characterize both temporally and spatially the learning process that subtends this form of recalibration, and directly compare its properties to those of saccadic adaptation. We observed that sinusoidal oscillations in the amplitude of the trans-saccadic change produce sinusoidal oscillations in the reported peripheral size, with a lag of under 10 trials. This is qualitatively similar to what has been observed in the case of saccadic adaptation. We also tested whether learning is generalized to the mirror location on the opposite hemifield for both size recalibration and saccade adaptation. Here the results were markedly different, showing almost complete generalization for recalibration and no generalization for saccadic adaptation. We conclude that perceptual and visuomotor consequences of trans-saccadic changes rely on learning mechanisms that are distinct but develop on similar time scales.

Trans-saccadic adaptation of perceived size independent of saccadic adaptation

“…The observed modification of size perception was in line with several studies that demonstrated an interaction between the motor adaptation with a distortion of visual localization of the target executed by hand pointing or by perceptual reports (Awater, Burr, Lappe, Morrone, & Goldberg, 2005;Bahcall & Kowler, 1999;Bruno & Morrone, 2007;Collins, Doré-Mazars, & Lappe, 2007;Garaas & Pomplun, 2011;Gremmler, Bosco, Fattori, & Lappe, 2014;Zimmermann & Lappe, 2010). Several more recent studies have indicated that adaptation of visual features can be found without saccadic adaptation (Herwig & Schneider, 2014;Herwig, Weiß, & Schneider, 2015;Herwig, Weiß, & Schneider, 2018;Köller, Poth, & Herwig, 2020;Paeye, Collins, Cavanagh, & Herwig, 2018;Valsecchi & Gegenfurtner, 2016;Valsecchi, Cassanello, Herwig, Rolfs, & Gegenfurtner, 2020). Specifically, features for which this phenomenon occurs are spatial frequency (Herwig & Schneider, 2014;Herwig et al, 2018), shape (Herwig et al, 2015;Köller et al, 2020;Paeye et al, 2018) and size (Bosco et al, 2015;Valsecchi & Gegenfurtner, 2016;Valsecchi et al, 2020).…”

“…Many studies demonstrated that saccadic adaptation includes a mechanism that calibrates visual space perception by observing and correcting mismatches between the peripheral view of a target and the central view of the same target after a saccade toward it (Awater et al, 2005;Bahcall & Kowler, 1999;Bruno & Morrone, 2007;Collins et al, 2007;Garaas & Pomplun, 2011;Gremmler et al, 2014;Zimmermann & Lappe, 2010;Zimmermann & Lappe, 2016). As mentioned earlier, similar to changing position of the target in the traditional saccadic adaptation paradigm, other features such as spatial frequency (Herwig & Schneider, 2014), shape (Herwig et al, 2015;Köller et al, 2020;Paeye et al, 2018), and size (Bosco et al, 2015;Valsecchi & Gegenfurtner, 2016;Valsecchi et al, 2020) also appear adaptive across saccades. However, similar effects on shape and size perception have also been observed when objects were successively presented in peripheral and foveal view while observers maintained fixation.…”

“…They proposed that a generative associative process, independent of saccade execution, contributes to the perception of shape across peripheral and foveal viewpoints. Recently, Valsecchi et al (2020) showed that saccadic adaptation and size recalibration share the same temporal development. However, because size recalibration of the presented visual objects generalized to the opposite hemifield but saccadic adaptation did not, they concluded that distinct learning mechanisms were involved.…”

“…Several more recent studies have indicated that adaptation of visual features can be found without saccadic adaptation (Herwig & Schneider, 2014;Herwig, Weiß, & Schneider, 2015;Herwig, Weiß, & Schneider, 2018;Köller, Poth, & Herwig, 2020;Paeye, Collins, Cavanagh, & Herwig, 2018;Valsecchi & Gegenfurtner, 2016;Valsecchi, Cassanello, Herwig, Rolfs, & Gegenfurtner, 2020). Specifically, features for which this phenomenon occurs are spatial frequency (Herwig & Schneider, 2014;Herwig et al, 2018), shape (Herwig et al, 2015;Köller et al, 2020;Paeye et al, 2018) and size (Bosco et al, 2015;Valsecchi & Gegenfurtner, 2016;Valsecchi et al, 2020). Particular focus has to be given to these two latter studies that tested paradigms able to demonstrate a size recalibration independent of saccade adaptation.…”

Learning to see the Ebbinghaus illusion in the periphery reveals a top-down stabilization of size perception across the visual field

“…Such a prior should predict a specific perceived size according to eccentricity, and any deviation from this prediction would trigger the updating of the peripheral size percept. This updating should be fast 27 to maintain stability across the visual field and ensure efficient interactions with the environment. When perception stabilized, any perceived difference could then signify a veridical change in the size of the object or of its viewing distance.…”