A decisional account of subjective inflation of visual perception at the periphery

Abstract

Human peripheral vision appears vivid compared to foveal vision; the subjectively perceived level of detail does not seem to drop abruptly with eccentricity. This compelling impression contrasts with the fact that spatial resolution is substantially lower at the periphery. A similar phenomenon occurs in visual attention, in which subjects usually overestimate their perceptual capacity in the unattended periphery. We have previously shown that at identical eccentricity, low spatial attention is associated with liberal detection biases, which we argue may reflect inflated subjective perceptual qualities. Our computational model suggests that this subjective inflation occurs because under the lack of attention, the trial-by-trial variability of the internal neural response is increased, resulting in more frequent surpassing of a detection criterion. In the current work, we hypothesized that the same mechanism may be at work in peripheral vision. We investigated this possibility in psychophysical experiments in which participants performed a simultaneous detection task at the center and at the periphery. Confirming our hypothesis, we found that participants adopted a conservative criterion at the center and liberal criterion at the periphery. Furthermore, an extension of our model predicts that detection bias will be similar at the center and at the periphery if the periphery stimuli are magnified. A second experiment successfully confirmed this prediction. These results suggest that, although other factors contribute to subjective inflation of visual perception in the periphery, such as top-down filling-in of information, the decision mechanism may be relevant too.

Eccentricity effects in vision and attention

“…Such an attentional bias would enhance perception in everyday life, as we are inclined to foveate behaviorally relevant objects even though we might not be consciously aware of our limited perceptual abilities peripherally. Indeed, subjects tend to overestimate their peripheral performance (Solovey et al, 2015). …”

Is fear perception special? Evidence at the level of decision-making and subjective confidence

“…Importantly, criteria could also reflect differences in perception itself, including perceptual shifts driven by visual illusions (Witt et al , 2015). Likewise, another study observed liberal criteria for detection in the peripheral vision, and the authors argued that this reflects the inflated subjective sense of perception in the periphery (Solovey et al , 2015). Perhaps the current results likewise reflect biases at the perceptual level.…”

An Investigation of Detection Biases in the Unattended Periphery During Simulated Driving

“…To address the question of whether liberal detection biases are evident when making judgments in the unattended periphery, we conducted a study where subjects engaged in a naturalistic task of simulated driving while they looked for (i.e., detected) specific colors of pedestrians' clothing in the visual periphery. Unlike in previous studies (Rahnev, Maniscalco, et al, 2011;Solovey et al, 2015), the stimuli were not degraded by noise or reduced contrast; instead, near-threshold task difficulty was created more naturalistically by having the pedestrians move at a fast speed. We reasoned that if the previous results (Rahnev, Maniscalco, et al, 2011;Solovey et al, 2015) were not due to idiosyncratic strategies adopted in artificial psychophysics experiments, here, subjects should exhibit similar liberal detection biases in the unattended periphery as well.…”

“…Previous work has addressed this question within the framework of Signal Detection Theory. Results show that observers tend to use liberal detection biases when evaluating peripheral or unattended stimuli, such as grating patterns embedded in noise (Rahnev, Maniscalco, et al, 2011;Solovey, Graney, & Lau, 2015); that is, participants were more likely to say that items were presented in peripheral or unattended locations, even when they were not. These results were interpreted to reflect a subjective sense of inflated phenomenology in the unattended periphery, because detection biases could in principle reflect both subjective perception and decisional or response strategies (Witt, Taylor, Sugovic, & Wixted, 2015).…”

“…These results were interpreted to reflect a subjective sense of inflated phenomenology in the unattended periphery, because detection biases could in principle reflect both subjective perception and decisional or response strategies (Witt, Taylor, Sugovic, & Wixted, 2015). It was argued that a decisional or cognitive account of these biases is less likely because results remain consistent even when subjects are given feedback and training (Rahnev, Maniscalco, et al, 2011;Solovey et al, 2015).…”