Predicting object features across saccades: Evidence from object recognition and visual search.

Abstract

When we move our eyes, we process objects in the visual field with different spatial resolution due to the nonhomogeneity of our visual system. In particular, peripheral objects are only coarsely represented, whereas they are represented with high acuity when foveated. To keep track of visual features of objects across eye movements, these changes in spatial resolution have to be taken into account. Here, we develop and test a new framework proposing a visual feature prediction mechanism based on past experience to deal with changes in spatial resolution accompanying saccadic eye movements. In 3 experiments, we first exposed participants to an altered visual stimulation where, unnoticed by participants, 1 object systematically changed visual features during saccades. Experiments 1 and 2 then demonstrate that feature prediction during peripheral object recognition is biased toward previously associated postsaccadic foveal input and that this effect is particularly associated with making saccades. Moreover, Experiment 3 shows that during visual search, feature prediction is biased toward previously associated presaccadic peripheral input. Together, these findings demonstrate that the visual system uses past experience to predict how peripheral objects will look in the fovea, and what foveal search templates should look like in the periphery. As such, they support our framework based on ideomotor theory and shed new light on the mystery of why we are most of the time unaware of acuity limitations in the periphery and of our ability to locate relevant objects in the periphery.

Saccade Preparation Reshapes Sensory Tuning

“…These findings reveal how eye movements reshape feature processing at the site of a saccade target, and could represent underlying mechanisms of presaccadic enhancement [1–4] and perceptual stability [43, 45–47] reported in the literature, which illustrate functional benefits of the tight coupling between perception and movements.…”

“…Human observers can maintain a stable percept of a saccade target by integrating its presaccadic (in the periphery) and postsaccadic (at the fovea) representations of both SF [45] and orientation [46, 47]. The tuning modulations we found suggest that saccade preparation modifies the representation of the saccade target to be more fovea-like –i.e., higher resolution and finer orientation tuning– just before saccade onset.…”

Assessing Self-Awareness through Gaze Agency

“…Indeed, although both rely on an action at distance, social agency has a communicative function, whereas physical agency has only a performative function, such as for example button switching in gaze-operated devices. However, there is a growing literature on the different effects of saccadic eye movements suggesting that similar associative and predictive mechanisms may govern the acquisition and usage of social and non-social effects of eye movements [4,23,24,61]. It is therefore entirely possible that, similarly to other behaviors and traits (e.g., [62,63]), also gaze agency can take advantage of existing neural mechanisms to implement a new function.…”

“…This finding pointed to a failure of low-level sensori-motor mechanism in charge to compensate the sensory consequences of one’s own movements in schizophrenia [22]. More recently, other studies addressed the relation between saccades and their visual effects [23,24], thus further stressing the importance of proper sensori-motor contingencies in visual perception and action [25]. For example, in a recent study [26] observers were shown two different faces concurrently presented in the left and right sides of the visual field, and a tone paired with a given ocular action (i.e., making a spontaneous rightward or leftward saccade to one of the two faces).…”

Saccade latency indexes exogenous and endogenous object-based attention

“…When a potential target attracts our attention, we typically saccade to it (Herwig & Schneider, 2014). In general, we found parallel attention effects for keypress RT and saccade latency.…”