Closing the Gates to Consciousness: Distractors Activate a Central Inhibition Process

Abstract

The paradigm of distractor-induced blindness has previously been used to track the transition from unconscious to conscious visual processing. In a variation of this paradigm used in this study, participants (n = 13) had to detect an orientation change of tilted bars (target) embedded in a dynamic random pattern; the onset of the target was signaled by the presentation of a color cue. Occasional orientation changes preceding the cue served as distractors and severely impaired the target's detection. ERPs showed that a frontal negativity was cumulatively activated by the distractors, and early sensory components were not affected. In a control condition, the target was defined by a coherent motion of the bars. Orientation changes preceding the motion target did not affect its detection, and the frontal suppression process was not observed. However, we obtained a significant reduction of the sensory components. The data support the notion that distractors that share the target's features trigger a cumulative inhibition process preventing the conscious representation of the inhibited features. Explorative source modeling suggests that this process originates in the pFC. A top-down modulation of sensory processing could not be observed.

Open and closed cortico-subcortical loops: A neuro-computational account of access to consciousness in the distractor-induced blindness paradigm

“…Niedeggen, Hesselmann, Sahraie, Milders, and Blakemore (2004) recorded ERPs during a distractor-induced blindness paradigm and concluded that the inhibition of target perception occurs at a post-sensory level. In a later study, moreover, they showed that the inhibition causes an ERP EEG negativity over frontal cortical areas (Niedeggen et al, 2012). These results fit well with our proposal that access to consciousness is controlled by those BG pathways that modulate activity in the prefrontal cortex.…”

“…In conclusion, Dehaene et al (2003) proposed a sensory model of access consciousness while we suggest a cognitive model of access consciousness. In line with our cognitive focus, Niedeggen et al (2012) observed a distractor-related EEG negativity over frontal cortical areas in their distractor-induced blindness paradigm, but no modulation of EEG activity over posterior, sensory cortices.…”

“…Sahraie et al, 2001). This blindness effect does not rely on an interaction of the two targets, in contrast to the attentional blink paradigm (Shapiro, 1994), but on cognitive effects of target-like episodes (i.e., distractors) preceding the onset of T1 (Hesselmann, Niedeggen, Sahraie, & Milders, 2006;Sahraie et al, 2001): these target-like episodes have been shown to result in a frontal negativity, cumulatively inhibiting target perception, as shown in a recent event-related brain potential (ERP) study (Niedeggen et al, 2012). This top-down inhibitory effect of distractors, i.e., their power to decrease the probability of getting conscious access to T2, is a unique characteristic of distractor-induced blindness.…”

“…In this paradigm, targets that follow previous targets by about 180-450 ms cannot be reliably detected by subjects (Raymond, Shapiro, & Arnell, 1992). Cognitive influences on access to consciousness, in contrast, have been investigated using the distractor-induced blindness paradigm (Niedeggen, Michael, & Hesselmann, 2012;Sahraie, Milders, & Niedeggen, 2001). In this paradigm, two separate RSVP streams are presented.…”

Model-Based Cognitive Neuroscience: A Conceptual Introduction

“…Most of this work involves an empirical comparison between groups, treatments, or experimental conditions. For instance, Rouw and Scholte [30] compared a group of control participants with a group of Playing a first-person shooter video game induces neuroplastic change [34] Closing the gates to consciousness: Distractors activate a central inhibition process [35] TMS of the FEF interferes with spatial conflict [36] Local field potential activity associated with temporal expectations in the macaque lateral intraparietal area [37] Spatio-temporal brain dynamics mediating post-error behavioral adjustments [38] Hippocampal involvement in processing of indistinct visual motion stimuli [39] grapheme-color synesthetes, people who experience a specific color whenever they see a particular letter or number (e.g., "T is bright red"). Diffusion tensor imaging confirmed the hypothesis that the added sensations in synesthesia are associated with more coherent white matter tracts in various brain areas in frontal, parietal, and temporal cortex.…”