Attention does not always help: The role of expectancy, divided, and spatial attention on illusory conjunctions

Abstract

Humans have the subjective impression of a rich perceptual experience, but this perception is riddled with errors that might be produced by top-down expectancies or failures in feature integration. The role of attention in feature integration is still unclear. Some studies support the importance of attention in feature integration (Paul & Schyns, 2003), whereas others suggest that feature integration does not require attention (Humphreys, 2016). Understanding attention as a heterogeneous system, in this study we explored the role of divided (as opposed to focused – Experiment 1) attention, and endogenous-exogenous spatial orienting (Experiments 2 and 3) in feature integration. We also explored the role of feature expectancy, by presenting stimulus features that were completely unexpected to the participants. Results demonstrated that both endogenous and exogenous orienting improved feature integration while divided attention did not. Moreover, a strong and consistent feature expectancy effect was observed, demonstrating perceptual completion when an unexpected perceptual feature was presented in the scene. These results support the feature confirmation account (Humphreys, 2016), which proposes that attention is important for top-down matching of stable representations.

The role of brain oscillations in feature integration

“…This study aimed at exploring the role of different brain oscillations in feature integration. The experiment involved a dual-task combining a central number task nipulated attentional demands) and a peripheral task in which color and shape features needed to be integrated (Cobos & Chica, 2022;Esterman et al, 2004Esterman et al, , 2007Rodríguez-San Esteban et al, 2022). Responses were classified as correct (hits, around 70% of the trials) or incorrect (illusions, around 30% of the trials).…”

“…Participants were seated at an approximate distance of 60 cm from the computer screen (an LCD monitor, 24″, Benq BL2405HT, 1920 × 1080 pixels, with a refresh rate of 60 Hz). The experimental procedure was adapted from Esterman and colleagues (Esterman et al, 2004(Esterman et al, , 2007; see also Cobos & Chica, 2022;Rodríguez-San Esteban et al, 2022).…”

“…Behaviorally, errors in feature integration (known as illusory conjunctions) increase when the attentional system is overloaded, in conditions of divided attention (Treisman, 1996; Treisman & Gelade, 1980), when stimuli are briefly presented (Chen & Watanabe, 2021; Henderson & McClelland, 2020; Prinzmetal et al., 1995), when they are presented in the periphery of the visual field (Cohen & Ivry, 1989; Henderson & McClelland, 2020; Prinzmetal et al., 1995; Robertson, 2003; Treisman & Schmidt, 1982), when top‐down expectancies are manipulated (Aru et al., 2018; Aru & Bachmann, 2017; Cobos & Chica, 2022; de Gardelle et al., 2009; Kuhn & Rensink, 2016; Mack et al., 2016), and when spatial attention is diverted (Briand, 1998; Cobos & Chica, 2022; Cohen & Rafal, 1991; Grubb et al., 2013; Montaser‐Kouhsari & Rajimehr, 2005; Prinzmetal et al., 1986; Yeshurun & Rashal, 2010). Top‐down expectancies about perceptual information are well known to bias perception and decision making.…”

Task Demands Differentially Affect Processing of Intrinsic and Extrinsic Object Features in Working Memory

“…Moreover, at study, stimuli were presented at random locations, and the short presentation time made precise attentional shifts or tuning all but impossible. At test, however, the attentional spotlight may have been narrowed to the target shape (Cobos & Chica, 2022; also see Heitz & Engle, 2007), and the extrinsic frame may have thus been outside of the focus of attention. It is therefore possible that the observed effect of intrinsicality was due to the presence of the irrelevant feature within either the boundary of the attended object or the attentional spotlight.…”

The Distinctness of Illusory and Non-Illusory Conjunctions in the Perception of Chinese Words: Assessing the Roles of Stimulus Exposure Time

“…Another model, known as the Feature Confirmation Account (FCA), claims that attention is not necessary for feature integration, the combination of features is already encoded in the early stages of visual processing, but these encodings are noisy and relatively transient unless supported by top-down feedback from the cortical surface. This assumption proposes an initial bottom-up feature integration stage, which is based on the activation of neurons sensitive to the connection of visual features, followed by confirmation through top-down feedback from the parietal cortex (Cobos & Chica, 2022; Esteban et al, 2023; Humphreys, 2016).…”