Tales of the unexpected: Attentional awareness, goal relevance, and prior exposure to an unexpected change.

Abstract

We report an experiment where we examine whether an unexpected stimulus change that occurs whilst performing an engaging task is more likely to be noticed if it is relevant or irrelevant to the goal of that task. The goal was to count the number of times moving targets (white letters) hit the side of the frame on a computer screen but to ignore similarly moving distractors (black letters). We found that a highly goal-relevant change (i.e., a black distractor changing into a white target) was more likely to be noticed than a less-relevant change (a white target turning into a black distractor). However, people with high working memory were more likely to notice the goal-relevant change but less likely to notice the goal-irrelevant change. High working memory capacity appears to be associated with the more efficient strategy, which is to notice the change when it is goal-relevant but to inhibit it when it is not relevant to prevent the possibility of interference with the goal of the primary task. We then investigated whether previous exposure to an unexpected change influenced the likelihood that a different change (an unexpected red cross in a standard dynamic inattentional blindness task) would be noticed. We observed prior experience of a change reduced the incidence of Inattentional Blindness. These findings are discussed in terms of dual-route model of Inattentional blindness, in which the failure to notice the unexpected stimulus can result from a lack of processing or from inhibition.

Attentional gain and processing capacity limits predict the propensity to neglect unexpected visual stimuli

“…In a standard IB task participants are required to track a series of white Ls and Ts (but ignore similarly moving black Ls and Ts) as they move randomly on the screen when, after a few seconds, a moving red cross appears for several seconds (based on Most et al, 2001; see also Simons, 2003). However, the status of this unexpected stimulus is ambiguous since it is not clear whether the most appropriate strategy in this task would be to, for example, ignore it, process it or process it and then, at a later stage inhibit it (Richards, Hannon, Vohra, & Golan, 2014;Richards, Hannon, & Derakshan, 2010;Richards, Hannon, & Vitkovitch, 2010). In order to manipulate the status of the unexpected stimulus to make it relevant during the dynamic task we used a new task in which one of the target stimuli undergoes an unexpected change directly relevant to the goal (one target, i.e., a green T, turns suddenly into another type of target, i.e., a blue F).…”

“…This failure may be due to the power of intrinsic oscillatory activity that prevents visual information from low-level processor to be granted access to awareness (mainly in theta, alpha and beta band: see Dehaene & Changeux, 2011;Jensen, Bonnefond, & VanRullen, 2012, Klimesch, 1999. Another possibility is that the unexpected stimulus/change may be processed but then inhibited and prevented from accessing awareness due to it being irrelevant to the primary task (Richards, Hannon, Vohra, & Golan, 2014).…”

“…A blank screen was presented for 0.5 s before the presentation of the next trial. (c) In the IB task, participants track two blue Fs and two green Ts as they move in a linear but randomly around the screen and silently count how many times the Fs and Ts separately hit the frame on the screen but to ignore similarly moving distractors (i.e., orange Hs and purple Ls; see Richards, Hannon, Vohra, & Golan, 2014). Several seconds into the task, a green T unexpectedly turned into a blue F. This was an unexpected, yet task-relevant, change.…”

Interplay between supramodal attentional control and capacity limits in the low-level visual processors modulate the tendency to inattention

“…The IB task was programmed in MatLab™ and based on the work of Richards, Hannon, Vohra, and Golan (2014), where the unexpected event does not involve any addition of new stimuli, but rather an unexpected change to one of the stimuli already present in the visual dynamic scene (Fig. 1A).…”

“…Some researchers argue that failing to notice an unexpected stimulus occurs when early mechanism of exogenous attention and visual working memory (VWM) are predominantly involved in another task, resulting in too few resources remaining for the processing of an unexpected stimulus or change (Papera & Richards, 2016). Other accounts propose that in most IB tasks the unexpected event is not relevant to the primary task, making it susceptible to inhibition and therefore prevented from reaching awareness (Richards, Hannon, Vohra, & Golan, 2014). Furthermore, neural network modelling has argued that intrinsic oscillatory brain activity in high-order brain areas (particularly in the alpha and theta band: Mathewson, Gratton, Fabiani, Beck, & Ro, 2009;Jensen, Bonnefond, & VanRullen, 2012;Papera & Richards, 2016) may prevent low-level processors (i.e., parietal areas) to "ignite" a widespread activation across several regions that are thought to reflect the current conscious content (Dehaene & Changeux, 2005Dehaene, Sergen, & Changeux, 2003).…”