Investigating the Flexibility of Top-Down Feature Suppression Contingent on Search Goals


  • Anja Stojkovic Universiy of Vienna


Background Literature and Experiment Aims
According to the contingent-capture hypothesis of visual attention, task-relevant positive features capture attention in an involuntary manner [1] [2]. Recently, it has been shown that task-relevant features that negatively define a target also guide visual attention through top-down suppression (goal-driven). However, only when negative features are being used consistently.

In this experiment, we will investigate whether top-down suppression also applies if searching for a target requires flexibly switching between a top-down search for and top-down suppression of the very same feature. Therefore, we will use two instruction conditions (positive versus negative) presented intermixed. We will measure attentional guidance by target- defining features with target-preceding peripheral singleton cues (a unique feature that causes a stimulus to stand out from the background). It has been shown that such cues capture attention only if they share a target-defining feature [1]. This attentional capture by the cue is reflected in faster reaction times if the cue precedes the target at the same position (valid condition) versus a different position (invalid condition). In contrast, cues with a task irrelevant feature can be ignored. Furthermore, cues with a negative feature are suppressed and, thus, elicit slower reaction times in valid than invalid conditions, probably due to diminished visual processing at the suppressed position. The experiment will be performed using colour and orientation features and it will involve 40 subjects recruited from the LABS database of the University of Vienna.


Our hypothesis is that depending on task instructions, if top-down suppression can be flexibly and rapidly initiated, it is expected to observe an inverse validity effect in the negative instruction condition. In addition, it is expected to observe a standard validity effect for cues with the task-relevant feature in the positive instruction condition and not to observe a significant validity effect for cues with a task-irrelevant colour for any instruction condition. For instance, in positive instruction participants will search for a red horizontal bar and for a non-red horizontal bar in negative instruction. Thereby, the aim of this research is to better understand the flexibility of goal directed human attentional control.


[1] C. L. Folk and R. Remington, “Selectivity in distraction by irrelevant featural singletons: Evidence for two forms of attentional capture.,” Journal of Experimental Psychology: Human Perception and Performance, vol. 24, no. 3, pp. 847–858, 1998, 10.1037/00961523.24.3.847.

[2] C. L. Folk, R. W. Remington, and J. C. Johnston, “Involuntary covert orienting is contingent on attentional control settings.,” Journal of Experimental Psychology: Human Perception and Performance, vol. 18, no. 4, pp. 1030–1044, 1992, doi: 10.1037/0096–1523.18.4.1030