Although their linguistic competence was significantly lower, children in the verb negative group showed significantly facilitated learning and marginally enhanced memory performances (suggested by the attentional switches- and bin-analyses) as compared to the verb neutral group.
This is consistent with previous findings indicating that emotional stimuli enhance cognitive processing in children and adults (see Chapter 2 and 3). The current results suggest that the word learning (i.e., attention and encoding) process is beneficially influenced by the intrinsic emotional input property, but they leave vague to what extent memory consolidation and retrieval processes were affected by the emotional input cue.
Since children’s overall attention to the presented stimuli did not differ among conditions and also no methods were used to control children’s neural (e.g. EEG) or physiological (e.g. heart rate) response to the perceived stimuli, it is not possible to relate children’s enhanced performances to an increased level of attention. To address this issue in detail, methods to control children’s attention by their neural or physiological response should be taken into consideration for further investigations. Richards and colleagues (Richards, 2003; Richards & Turner, 2001), for example, demonstrated that children’s heart rate deceleration and a specific event-related potential, labeled Negative central (Nc), were correlated with their level of focused attention. A further study, which used ERP measures and the visual preference paradigm simultaneously, indicated that infants’ Nc
component was associated with their novelty preferences. That is, a greater Nc amplitude occurred when infants were attentive to novel stimuli, whereas the amplitude did not increase when children focused on familiar stimuli (Reynolds, Courage, & Richards, 2010).
Despite this open issue, it is possible to assume an enhancing effect of the negative emotional input information on children’s verb encoding. Previous studies analyzing children’s novelty and familiarity preferences revealed that longer familiarization times and less complex stimuli increase the novelty effect (Caron & Caron, 1968, 1969; Hunter et al., 1983). Based on these results, Hunter and Ames (1988) postulated that an increased novelty effect results from better encoding. Thus, the enhanced novelty (during baseline) and familiarity preferences (during response) demonstrated by the verb negative group in the learning test suggest the conclusion that the intrinsic emotional information facilitated this group’s encoding of the presented pseudo-verbs.
With regard to the memory results, however, the marginal differences in the looking behavior between the neutral and negative verb group do not allow us to draw conclusions about an enhancing effect of the emotional input cue on verb consolidation and retrieval processes. The verb negative group demonstrated a reduced number of switches in the memory test as well as distinct looking toward the familiar action scene after the presentation of the test question, which both may be indicative of better verb consolidation and retrieval. However, even if this trend may point to an enhanced effect, it is not possible to distinguish whether the emotional information modulated either consolidation or retrieval of the verb’s concept or affected both, because children were presented with the negative input cue also during the memory test. To obtain a more detailed result on this question, one should explore whether children learning a verb in the negative condition will show better memory performances, even if the emotional input information is absent during memory retrieval.
Schmitz et al. (unpublished document) found a similarly decreased influence of an emotional input property on children’s word memory as compared to their word learning. Their results indicated enhanced learning of nouns presented with positive prosody compared to nouns presented with neutral prosody, but a reversed memory effect one day later (see Chapter 3). This similar
finding suggests that the emotional information is subject to alteration in the consolidation process of long-term memory (Bauer, 2004). However, one may ask why Schmitz et al. found a reversed effect, whereas the present study revealed a diminished effect. On the one hand, it is possible that the way the stimuli were presented during the memory test in both studies influenced children’s memory retrieval. As mentioned above, children in the current study were presented with the identical emotional facial information during the learning and memory test, whereas in the study by Schmitz et al. the emotional information was absent in the memory task. In this way, the emotional information in the present study might have affected children’s memory retrieval, leading to a marginally increased memory performance, while children’s verb consolidation in the present study as well as in Schmitz et al.’s study remained unaffected by the emotional input property. On the other hand, the negative emotional valence of the presented input cue might have caused that children showed a reduced, but not a reversed memory effect. According to evolutionary and functional accounts, stimuli in the environment can be associated with positive (e.g. reward, comfort) and negative (e.g. threat, punishment) experiences by an individual and, in this way, provide essential information for the individual’s well-being (e.g. Rolls, 2005; Tooby & Cosmides, 2008). Whereas positive emotions confirm continuing an activity, negative emotions provoke a rapid termination; otherwise, a negative experience would follow. Hence, it is proposed that stimuli associated with negative emotions receive privileged attention and processing as studies in adults and infants empirically supported (e.g. Öhman et al., 2001; Pratto & John, 1991; see also section 2.1.1). Thus, children in the present study might have been more affected in their processing and storing of the presented verbs by the emotional input property than children in the Schmitz et al.
study, which employed positive input information. The stronger effect might have been additionally reinforced by the way the emotional information was presented: Schmitz et al. used an extrinsic prosodic input cue, which had no potential to be considered by children as part of the word meaning. These assumptions require further investigations, which examine systematically how children’s verb learning and memory processes interact with intrinsic emotional input cues of different emotional valence in order to contrast these results with the current performance of the
verb negative group. For example, these experiments should involve (a) another control group, where children are not learning any verb, but are presented with a negative emotional input cue, and (b) a positive emotional condition.
Taken together, the present findings warrant replication and as the memory results revealed no reliable differences between the two verb learning groups, no conclusion regarding an enhancing effect of emotional information on lexical long-term consolidation and retrieval is drawn.