An electrophysiological comparison of recollection for emotional words using an exclusion recognition paradigm

The influence of negative emotional intensity on dual-processing recognition

Dual-processing theory assumes recognition memory involves two distinct processes: familiarity and recollection. Although the influence of emotional intensity on memory has been investigated, it remains unclear whether the influence of negative stimuli depends on familiarity or recollection. This study recorded event-related potentials as participants performed a modified remember/know procedure with highly negative, mildly negative, and neutral stimuli. The results showed that, relative to highly negative stimuli, mildly negative and neutral stimuli showed increased mean discrimination for responses of 'know' in the following pattern: highly negative < mildly negative < neutral. Neutral stimuli enhanced the frontal old/new effect. Relative to mildly negative and neutral stimuli, highly negative stimuli showed increased mean discrimination for responses of 'remember', and enhanced the parietal old/new effect. These results suggested negative emotional intensity influences recollection and familiarity differently, as recognition of highly negative stimuli depends on recollection, and recognition of neutral stimuli depends on familiarity.

False Recognition of Emotionally Categorized Pictures in Young and Older Adults

Normal aging is associated with the shift in motivational priorities from knowledge acquisition to emotion regulation. Current evidence indicates an age-related increase in preferences for positive over negative stimuli in true memory. In the present study, using the categorized pictures paradigm, we investigated whether older adults would exhibit a greater increase in false memory for positive versus negative lures, compared with young adults. We also examined the association of executive functioning with the preferences for positive over negative pictures in false recognition memory. A total of 27 young and 26 older adults studied emotional pictures from various categories during encoding and subsequently completed an old/new recognition test. In addition, all participants completed the executive functioning tests. The results revealed that both older and young adults showed higher rates of false recognition for positive pictures compared with negative pictures; no significant group by valence interaction was observed. Trail making scores were negatively correlated with positive processing preferences in false recognition rates in older but not young adults. These findings suggest that false recognition memory exhibits preferences toward positively valenced stimuli in both young and older adults. Cognitive control processes are necessary for older adults to distort memory in emotionally gratifying ways.

Electrophysiological evidence for the effects of emotional content on false recognition memory

Two competing hypotheses attempt to explain the effects of emotional content on the production of false memory. The conceptual relatedness account posits that negative emotion increases false memory by strengthening familiarity process, whereas the distinctiveness heuristic account postulates that negative emotion reduces false memory by influencing recollection process. Here, using the categorized pictures paradigm, we examined these hypotheses by investigating emotional influences on false recognition memory performance and the event-related potential (ERP) correlates of familiarity and recollection. Participants were presented with positive, neutral, or negative pictures from various categories during encoding and later completed a recognition test while electroencephalogram data were recorded. Behavioral results revealed lower corrected false recognition rates for negative and neutral pictures than for positive ones, with no significant difference between negative and neutral pictures. In addition, negative pictures were associated with a more conservative response bias in comparison with neutral and positive pictures. Importantly, ERP results revealed enhanced recollection-related parietal old/new effects for negative pictures relative to positive and neutral pictures, but comparable familiarity-related early frontal old/new effects across each type of emotional valence category during both true and false recognition. Our results suggest that emotionally negative content may affect production of false memory mainly by engaging a distinctiveness heuristic. Methodological implications of these findings are discussed.

The costs of target prioritization and the external requirements for using a recall-to-reject strategy in memory exclusion tasks: a meta-analysis

In event-related potential (ERP) studies, the left-parietal old/new effect is commonly considered as a neural correlate of recollection. In memory exclusion tasks, the effect is usually observed when the targeted information is identified, but it is not necessarily present when studied items are rejected as nontargets. Interestingly, both the presence and the absence of such old/new effects to nontargets have been regarded as indicator for strategic retrieval. We reviewed previous ERP studies using memory exclusion tasks to analyze the reaction time (RT) pattern in such studies, as well as the influence of task difficulty on the occurrence of nontarget retrieval. We identified 44 test conditions, reported in 24 studies, and subjected the behavioral data to a meta-analysis. The RTs to correctly rejected new items were shorter than the RTs to hits, in particular in studies that required differentiating conceptual or perceptual information at test. When the retrieval of target information was prioritized, RTs to nontargets were delayed relative to targets. Without such prioritization, no such RT differences were observed. For test conditions with nontarget retrieval, the retrieval accuracy was poorer compared with test conditions without such retrieval. The findings support previous studies that claimed that nontarget retrieval becomes more likely when target retrieval is difficult, but the strong overlap in task difficulty between conditions with and without nontarget retrieval indicates that other, partly yet to-be-identified factors contribute to the occurrence of nontarget retrieval as well.

Effects of Valence on Hemispheric Specialization for Emotion Word Processing

The use of emotion in language is a key element of human interactions and a rich area for cognitive research. The present study examined reactions to words of five types: positive emotion (e.g., happiness), negative emotion (e.g., hatred), positive emotion-laden (e.g., blessing), negative emotion-laden (e.g., prison), and neutral (e.g., chance). Words and nonwords were intermixed in a lexical decision task using hemifield presentation. Results revealed a general left hemisphere advantage. Overall, reaction times for positive words were faster than for negative or neutral words and this effect varied by hemifield of presentation. These results support a valence hypothesis of specialized processing in the left hemisphere of the brain for positive emotions and the right hemisphere for negative emotions.

Differential effects of emotional cues on components of prospective memory: an ERP study

So far, little is known about the neurocognitive mechanisms associated with emotion effects on prospective memory (PM) performance. Thus, this study aimed at disentangling possible mechanisms for the effects of emotional valence of PM cues on the distinct phases composing PM by investigating event-related potentials (ERPs). Participants were engaged in an ongoing N-back task while being required to perform a PM task. The emotional valence of both the ongoing pictures and the PM cues was manipulated (pleasant, neutral, unpleasant). ERPs were recorded during the PM phases, such as encoding, maintenance, and retrieval of the intention. A recognition task including PM cues and ongoing stimuli was also performed at the end of the sessions. ERP results suggest that emotional PM cues not only trigger an automatic, bottom-up, capture of attention, but also boost a greater allocation of top-down processes. These processes seem to be recruited to hold attention toward the emotional stimuli and to retrieve the intention from memory, likely because of the motivational significance of the emotional stimuli. Moreover, pleasant PM cues seemed to modulate especially the prospective component, as revealed by changes in the amplitude of the ERP correlates of strategic monitoring as a function of the relevance of the valence for the PM task. Unpleasant pictures seemed to modulate especially the retrospective component, as revealed by the largest old/new effect being elicited by unpleasant PM pictures in the recognition task.

Oh, it's you again: memory interference from irrelevant emotional and neutral faces

In two experiments, repeated runs of a continuous recognition task were employed to assess healthy participants' ability to handle interference from irrelevant emotional and neutral memories. Presumably, such interference can be due to salience from either emotional or mnemonic processing. In both experiments, participants made more false alarms to emotional faces that were familiar from preceding runs (i.e., emotion-induced temporal-context confusion). Participants performed well for neutral faces in the first experiment including only two runs. However, increasing the number of runs to four in the second experiment induced temporal context confusion also for neutral faces. The findings suggest that memory interference can be induced when the salience of irrelevant information is erroneously considered diagnostic for memory judgements.

Effects of recent word exposure on emotion-word Stroop interference: an ERP study

Attentional bias towards emotional linguistic material has been examined extensively with the emotion-word Stroop task. Although findings in clinical groups show an interference effect of emotional words that relate to the specific concern of the group, findings concerning healthy groups are less clear. In the present study, we investigated whether emotional Stroop interference in healthy individuals is affected by exposure of the words prior to the task. We used event-related potentials (ERPs) to examine the temporal aspects of Stroop interference. Participants took longer to indicate the colour of negative than of neutral words. Exposure of words prior to the Stroop task increased response latencies, but this effect was equal for neutral and negative words. At the neurophysiological level, we found more positive-going ERPs at later latencies (P290, N400 and LPP) in response to negative than in response to neutral Stroop words. The N400 was less negative for exposed than for new words, but this effect did not interact with the emotional valence of the words. For new (i.e., unexposed) words, the behavioural Stroop interference correlated with the P290, N400 and LPP emotion effects (negative minus neutral words). The successive ERP components suggest better prelexical, semantic, and sustained attentional processing of emotion words, even when the emotional content of the words is task-irrelevant.

ERP correlates of target-distracter differentiation in repeated runs of a continuous recognition task with emotional and neutral faces

The emotional salience of faces has previously been shown to induce memory distortions in recognition memory tasks. This event-related potential (ERP) study used repeated runs of a continuous recognition task with emotional and neutral faces to investigate emotion-induced memory distortions. In the second and third runs, participants made more false alarms to distracters (repeated from previous runs). Emotion did not modulate the amount of errors, but the extent to which recollection was employed to maximise performance as reflected in the putative ERP correlate of recollection; the parietal old-new effect. Targets from all stimulus classes (positive, negative, neutral) were associated with parietal ERP memory effects, but this was also the case for correctly rejected negative distracters. This suggests that recollection was strategically used to correctly reject negative distracters (recall-to-reject). This finding is consistent with the view that facilitated recollection of negative stimuli may be used to decrease the susceptibility to memory errors induced by emotional salience.