Differential activation of a central inhibition system by motion and colour distractors

ABSTRACT

The selection of relevant stimuli is partially achieved through inhibition of irrelevant distractors. Using the distractor induced blindness (DIB) paradigm, we investigated whether these inhibitory processes depend on the feature dimension that is used to define distractors. Following a pilot study that found motion and colour targets to be comparably salient, we analysed distractor effects of those two feature dimensions. In both feature dimensions, an inhibition effect depended on the number of distractors. Colour, however, was more sensitive to distractor episodes as compared to motion: The level of inhibition was more pronounced, and its activation required less distractors. The results of a control experiment provided further evidence that, in fact, the feature dimension -instead of design differences between tasks- is responsible for this observation. The dimension-sensitive bias in the activation of a central inhibition system may be attributed to a differential processing of visual signals, depending on their behavioural relevance.

KEYWORDS:

• Attention
• visual feature dimensions
• inhibition
• distractor induced blindness
• colour
• motion

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Please note that a cue is necessary to cause this relatively rapid degradation. When no cue is presented, the inhibition has been shown to degrade at a much slower rate (Hesselmann et al., 2006).

2. This was necessary because we concurrently recorded an EEG that was designed to test to what extent the temporal position of the distractor plays a role with regard to the electrophysiological response. Other than in previous EEG studies on DIB (Niedeggen et al., 2004, 2012, 2015; Winther & Niedeggen, 2017b), the position of the to-be-analysed distractor was kept constant in this design while the number of previously presented distractors was varied. Using this design, the electrophysiological response to distractors at frontal electrode sites did not differ significantly between feature dimensions.

Additional information

Funding

This work was supported by the German Research Foundation under Grant NI 513/8–2.