Age-related differences during visual search: the role of contextual expectations and cognitive control mechanisms

ABSTRACT

During the visual search, cognitive control mechanisms activate to inhibit distracting information and efficiently orient attention towards contextually relevant regions likely to contain the search target. Cognitive ageing is known to hinder cognitive control mechanisms, however little is known about their interplay with contextual expectations, and their role in visual search. In two eye-tracking experiments, we compared the performance of a younger and an older group of participants searching for a target object varying in semantic consistency with the search scene (e.g., a basket of bread vs. a clothes iron in a restaurant scene) after being primed with contextual information either congruent or incongruent with it (e.g., a restaurant vs. a bathroom). Primes were administered either as scenes (Experiment 1) or words (Experiment 2, which included scrambled words as neutral primes). Participants also completed two inhibition tasks (Stroop and Flanker) to assess their cognitive control. Older adults had greater difficulty than younger adults when searching for inconsistent objects, especially when primed with congruent information (Experiment 1), or a scrambled word (neutral condition, Experiment 2). When the target object violates the semantics of the search context, congruent expectations or perceptual distractors, have to be suppressed through cognitive control, as they are irrelevant to the search. In fact, higher cognitive control, especially in older participants, was associated with better target detection in these more challenging conditions, although it did not influence eye-movement responses. These results shed new light on the links between cognitive control, contextual expectations and visual attention in healthy ageing.

KEYWORDS:

• Visual search
• cognitive ageing
• contextual expectations
• cognitive control
• eye-tracking

Supplemental material

Supplementary data for this article can be accessed here

Notes

1. We exclude the neutral priming condition from this analysis as the two datasets can only be compared on the same levels of congruency, i.e., Congruent and Incongruent prime. Additionally, in order to obtain more solid insights about the influence of prime type (scene vs word) on visual search performance, we must directly compare the two.

2. See Figure 2 (page 112 of Friedman & Miyake, 2004), which shows a .68 relation between response inhibition and distractor inhibition.

3.. Note, the results observed with Stroop and Flanker as separate EFA factors are equivalent to those obtained by using the first component of the PCA (compare Table 5 and S1).

4. An increase on the first component of the PCA implies more difficult processing. Therefore, for interpretability, we reversed the sign of this predictor before entering it into the LME analysis, such that increase on Cognitive Control would imply easier, rather than more difficult, performance on the Stroop and Flanker tasks.

Additional information

Funding

This work was supported by the Leverhulme Trust with an Early Career Research Fellowship (ECF-2014-205) awarded to MIC.