The Impact of Perceived Emotions on Early Word Learning

MA, LIZHI and Westermann, Gert and Twomey, Katherine and Parise, Eugenio (2021) The Impact of Perceived Emotions on Early Word Learning. PhD thesis, Lancaster University.

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Abstract

With the background that young word learners learn word-world associations in social interactions full of emotional expressions (Clark, 2016; Fernald et al., 1989) and others’ emotional expressions affect individuals’ attention allocation and memory during learning (Dolan & Vuilleumier, 2003; Kensinger, 2004; Yiend, 2010), the emotions perceived by individuals influence the learning process and outcome. Although, compared to affectively neutral expressions, infants allocated more attention to emotional vocal and facial expressions (e.g., Cooper & Aslin, 1990; Grossmann et al., 2011) and objects associated with negative emotions (e.g., Carver & Vaccaro, 2007), the impact of perceived emotions on early word learning remains unclear. To address the question, the current work encompasses three eye tracking experiments measuring proportion looking time of 24-, 30- and 36-month-old toddlers and adults when they learned three novel label-object associations respectively in affectively neutral, positive, and negative contexts in a referent selection learning task and when they recognised the new-learned label-object and emotion-object associations in retention testing tasks. The first experiment (Chapter 2) examined whether the perceived emotions influence adults’ and 30-month-old toddlers’ learning and retention of label-object and emotion-object associations and compared adults’ and toddlers’ looking behaviours during learning. Results suggested the recognition of newly learned association revealed the level of memory ability and the outcome of a competition for attention between top-down and bottom-up processing. Adults demonstrated a mature memory ability and top-down control and recognised all the13 label-object and emotion-object associations. But toddlers’ retention might be interfered with the presence of salient negative distractor. Based on the findings of the first experiment, the second experiment (Chapter 3) investigated the possibility that the salient negative distractor masked 30-month-olds’ retention and explored the implicit impact of negative objects on toddlers’ visual attention. After removing the negative distractor from half of a retention task, the 30-month-olds successfully recognised all the label-object associations regardless of the emotions that the objects associated with. Regarding the implicit impact of negative objects, toddlers tended to look to the negative object when it presented, suggesting it captured toddlers’ visual attention relative to its neutral and positive counterparts. Thus, a negativity bias was found. The third experiment (Chapter 4) measured the word learning outcome and retention of emotion-object associations in toddlers of 24-month-old and 36-month-old to further examined the effect perceived emotions on early learning. The older toddlers’ word learning was not affected by the perceived emotions while the younger toddlers’ word learning was promoted by the perceived negative affect during learning. Both age groups only recognised the negative emotion-object associations, revealing the ability to memorise the association between emotional cues and objects is still developing at the age of 36-month-olds. Overall, for the toddlers as young as 24-month-old, the perceived negative affect facilitates the learning of label-object associations. But for the toddlers older than 30-monthold, their word learning is not influenced by the perceived emotions. Meanwhile, toddlers’ visual attention is interfered with the distractor associated with negative affect, suggesting the14 negativity bias in terms of visual processing. Additionally, the finding of the impact of negativity bias on toddlers’ visual attention raises an issue relating the methodology that the reliability of proportion looking time as an index of retention is undermined when perceptually salient competitors are presented. All in all, the current thesis showed not only how the impact of perceived emotions on early word learning, but also the methodological consideration for the eye tracking word learning experiments.