Biased towards food: Electrophysiological evidence for biased attention to food stimuli

Sanjay Kumar,Suzanne Higgs,Femke Rutters,Glyn W Humphreys

doi:10.1016/j.bandc.2016.04.007

Sanjay Kumar, Suzanne Higgs + Show 2 more

Open Access

https://doi.org/10.1016/j.bandc.2016.04.007

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Abstract

We investigated the neural mechanisms involved in bias for food stimuli in our visual environment using event related lateralized (ERL) responses. The participants were presented with a cue (food or non-food item) to either identify or hold in working memory. Subsequently, they had to search for a target in a 2-item display where target and distractor stimuli were each flanked by a picture of a food or a non-food item. The behavioural data showed that performance was strongly affected by food cues, especially when food was held in WM compared to when the cues were merely identified. The temporal dynamics of electrophysiological measures of attention (the N1pc and N2pc) showed that the orienting of attention towards food stimuli was associated with two different mechanisms; an early stage of attentional suppression followed by a later stage of attentional orienting towards food stimuli. In contrast, non-food cues were associated only with the guidance of attention to or away from cued stimuli on valid and invalid trials. The results demonstrate that food items, perhaps due to their motivational significance modulate the early orienting of attention, including an initial suppressive response to food items.

Highlights

Food stimuli appear to have special attentional significance, and this can have practical consequences for eating behaviour
The current study examined the electrophysiological correlates of food-related attention selection
The behavioural data replicated earlier reported findings (Higgs et al, 2012); a food cue presented before a search display modulated the deployment of visual attention to a search target more than non-food cues, even though it was irrelevant for target selection

Summary

Introduction

Food stimuli appear to have special attentional significance, and this can have practical consequences for eating behaviour. Participants searched for a different target which appeared along with a distractor These search items were flanked by stimuli which could be the cue or a different item. On valid trials the cue reappeared flanking the target On invalid trials it re-appeared flanking the distractor. Relative to when neutral cues were present, performance benefited when cues were valid and it was disrupted when cues were invalid. This effect of cue validity was stronger when cues were held in WM relative to when they were merely identified, and the effects were larger when the cues were food items compared with when they were other stimuli (e.g., items of stationery). The data suggest that food cues may be influential in modulating visual attention

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