To-be-remembered Research Articles

Let me give you something to think about: Does needing to remember something new make it easier to forget something old?

In an item-method directed forgetting task, memory instructions presumably operate by promoting further rehearsal of to-be-remembered (TBR) items and limiting encoding of to-be-forgotten (TBF) items. We asked whether diverting attentional resources away from TBF items and towards a new item that needed to be committed to memory would improve forgetting. To this end, study words in our experiments were presented singly followed by a remember instruction (single-TBR), by a forget instruction (single-TBF), or else were replaced by a new word to be remembered (replace-TBR) in place of the original study word which could be forgotten (replace-TBF). A typical directed forgetting effect was observed across single and replace trials. However, there was no compelling evidence that forgetting was better for replace-TBF compared to single-TBF words, suggesting that, by itself, the explicit redirection of attentional and other processing resources away from forget items may not be sufficient to improve item-method directed forgetting.

To-be-forgotten information shows more relative forgetting over time than to-be-remembered information

People can intentionally forget studied material when cued to do so. Corresponding evidence has arisen from studies on item-method directed forgetting, in which participants are asked to forget single items directly upon presentation. We measured memory performance of to-be-remembered (TBR) and to-be-forgotten (TBF) items across retention intervals of up to 1 week and fitted power functions of time to the observed recall (Experiment 1) and recognition (Experiment 2) rates. In both experiments and each retention interval condition, memory performance for the TBR items was higher than for the TBF items, supporting the view that directed forgetting effects are lasting. Recall and recognition rates of both TBR and TBF items were well fit by the power function. However, the relative forgetting rates of the two item types differed, with a higher forgetting rate for the TBF than the TBR items. The findings are consistent with the view that TBR and TBF items differ (mainly) in recruitment of rehearsal processes and resulting memory strength.

The effect of chronic academic stress on intentional forgetting.

This study investigated whether chronic academic stress could affect the directed forgetting (DF) process. Both the stress group (undergoing preparation for a major academic examination) and the control group performed a DF task. A forgetting cue was presented after a to-be-forgotten (TBF) word, whereas no cue appeared after a to-be-remembered (TBR) item in the study phase. An old/new recognition test was used in the test phase. The results showed that (1) the stress group showed a higher level of self-reported stress, state anxiety, negative affect, and decreased cortisol awakening response (CAR) compared with the control group, suggesting a higher level of stress for the stress group. (2) Both groups showed superior recognition performance of TBR than TBF items, suggesting a DF effect. (3) The stress group showed inferior recognition performance of TBF items and an enhanced DF effect compared with the control group. These results demonstrated that the intentional memory control process might be enhanced under chronic academic stress.

A functional near-infrared spectroscopy investigation of item-method directed forgetting

Whether directed forgetting is passive or active remains debated. Using functional near-infrared spectroscopy (fNIRS), blood-oxygen level-dependent responses of intentional forgetting were investigated in the item-method directed forgetting (DF) paradigm. During the study phase, each word was followed by a random remembering or forgetting cue indicating whether the word is to be remembered (TBR) or to be forgotten (TBF). A recognition test was used in the test phase and four cue-response conditions were obtained: remembering/forgetting cues associated with the subsequently remembered (TBR-r/TBF-r) or forgotten (TBR-f/TBF-f) words. Data from 16 healthy adult participants showed a DF effect. The fNIRS data revealed that, during the 5–9 s time window, the oxygenate hemoglobin (oxy-Hb) levels were higher during intentional forgetting compared to intentional remembering in the left inferior frontal (TBF-f vs. TBR-f) and right superior frontal gyrus (TBF-r vs. TBR-r), indicating more frontal inhibition involved during intentional forgetting. During the 9–11 s time window, the oxy-Hb level in the frontal and parietal gyrus was higher for forgetting than remembering cues, indicating that the TBF words might be automatically encoded. In sum, the TBF words might receive inhibition control triggered by forgetting cues and then be automatically encoded with the increase of the post-cue interval.

Influence of Reward Motivation on Directed Forgetting in Younger and Older Adults.

An important feature of the memory system is the ability to forget, but aging is associated with declines in the ability to intentionally forget potentially due to declines in cognitive control. Despite cognitive deficits, older adults are sensitive to affective manipulations, such as reward motivation, and reward anticipation can improve older adults’ memory performance. The goal of the current studies was to examine the effect of reward motivation on directed remembering and forgetting. Participants were healthy CloudResearch/Turk Prime workers aged 18–35 and 60–85. In Experiment 1, we conducted a typical item-method directed forgetting task using neutral words presented one at a time followed by a to-be-remembered (TBR) or to-be-forgotten (TBF) cue. A recognition memory test followed that included all words from the encoding task, as well as new words. We replicated prior findings of better memory for TBR compared to TBF items, but not typical age-related differences in recognition of TBF items. In Experiments 2–4, we repeated this paradigm except that in the second block of trials, each word was presented with a high ($0.75) or low ($0.01) reward cue indicating the value that could be earned if the item was successfully Remembered or Forgotten (depending on cue). During recognition, correct responses to target items (both TBR and TBF) resulted in the associated reward, but incorrect “old” responses resulted in a loss of $0.50. In three experiments, high rewards led to better memory for younger and older adults compared to low rewards, regardless of the directed cue to remember or forget the word. In Experiments 3 and 4, older adults showed typical deficits in directed forgetting, but this was across reward conditions. For older adults, there was no evidence that including reward motivation improved cognitive control abilities as high value reward anticipation did not improve directed forgetting. Instead, in line with hypotheses, high compared to low value reward anticipation leads to engagement of processes that result in better memory regardless of the TBR or TBF cue, and reward anticipation bolsters memory in a relatively automatic, rather than strategic, fashion that overrides one’s ability to cognitively control encoding processes.

Does stimulus emotionality influence associative memory? Insights from directed forgetting

Prior research has demonstrated that stimulus emotionality can affect associative memory, but the patterns are varied: negative valence can either impair or improve it, while positive valence often facilitates it. In addition, it remains unclear whether the influence of stimulus emotionality on associative memory is sensitive to the manipulation of directed forgetting (DF). Thus, this experiment further explored the modulation of stimulus emotionality on associative memory in the case of DF. Besides the intact, rearranged, and new pairs usually adopted, we also included a fourth type of “old+new” pair. The results showed that the correct responses were not exactly the same among pair types; it tended to be better for both neutral and positive pairs vs negative pairs; significant DF effect was confirmed, but its susceptibility to stimulus emotionality only held true for “old+new” case. Further analyses of old proportions and response times provided further evidence for the above patterns. These findings demonstrate that the involvements of the recollection-driven process differ as the function of pair type; the modulation of stimulus emotionality on associative memory reinforces the dual representation account; reliable DF effect suggests both the pivotal roles of selective rehearsal to TBR (to-be-remembered) pairs and of inhibitory control to TBF (to-be-forgotten) pairs; furthermore, the susceptibility of the magnitude of DF effect to stimulus emotionality depends upon the involvement of recollection-driven process.

Elaborately rehearsed information can be forgotten: A new paradigm to investigate directed forgetting.

In previous item-method directed forgetting (DF) studies, forgetting may have occurred when the maintenance rehearsal of memory items was performed. In this study, a modified item-method DF paradigm was adopted to investigate whether forgetting instruction could produce a positive effect on forgetting the items that were elaborately rehearsed. During the study phase, a to-be-forgotten (TBF) word was followed by a forgetting cue. If no cue followed, the word was a to-be-remembered (TBR) item. Participants were required to intentionally memorize the word when it appeared. During the test phase, a yes/no recognition (Experiment 1) or a remember/know procedure (Experiment 2) was adopted. The behavioural results revealed that both the hit rate (Experiment 1) and remembering rate (Experiment 2) were higher for TBR relative to TBF words. For correctly identified old words, reaction times were consistently shorter for TBR compared to TBF words. These results revealed superior memory retention for TBR than for TBF words. The event-related potential (ERP) results revealed that, during both FN400 and late-positive complex (LPC) time windows, the remembered TBR words evoked more positive ERPs than the remembered TBF words and correctly rejected (CR) words (i.e., FN400 and LPC old/new effects). However, more negative ERPs were evoked for both remembered and forgotten TBF words than for CR words during the LPC time window (i.e., reversed LPC old/new effect). These results demonstrated that TBF words were associated with lower level of familiarity and recollection process than TBR words. The memory representation of TBF information might be inhibited.

Voices to remember: Comparing neural signatures of intentional and non-intentional voice learning and recognition

Recent electrophysiological evidence suggests a rapid acquisition of novel speaker representations during intentional voice learning. We investigated effects of learning intention on voice recognition, using a variant of the directed forgetting paradigm. In an old/new recognition task following voice learning, we compared performance and event-related brain potentials (ERPs) for studied voices, half of which had been prompted to be remembered (TBR) or forgotten (TBF). Furthermore, to assess incidental encoding of episodic information, participants indicated for each recognized test voice the ear of presentation during study. During study, TBR voices elicited more positive ERPs than TBF voices (from ∼250 ms), possibly reflecting deeper voice encoding. In parallel, subsequent recognition performance was higher for TBR than for TBF voices. Importantly, above-chance recognition for both learning conditions nevertheless suggested a degree of non-intentional voice learning. In a surprise episodic memory test for voice location, above-chance performance was observed for TBR voices only, suggesting that episodic memory for ear of presentation depended on intentional voice encoding. At test, a left posterior ERP OLD/NEW effect for both TBR and TBF voices (from ∼500 ms) reflected recognition of studied voices under both encoding conditions. By contrast, a right frontal ERP OLD/NEW effect for TBF voices only (from ∼800 ms) possibly reflected additional elaborative retrieval processes. Overall, we show that ERPs are sensitive 1) to strategic voice encoding during study (from ∼250 ms), and 2) to voice recognition at test (from ∼500 ms), with the specific pattern of ERP OLD/NEW effects partly depending on previous encoding intention.

On the Very-Long-Term Effect of Managing One's Own Memory: The Intention to Forget Improves Recognition After a Year's Delay.

While such factors as demand characteristics, encoding, and retrieval inhibition were shown to be significant in producing the directed forgetting effect, no attention was paid to whether the intention to manage one’s own memory, per se, matters. In the present article, we addressed this important gap in the literature. To control the quality of encoding we ensured that both the to-be-remembered (TBR) and to-be-forgotten (TBF) items were genuinely learned before the manipulation. We used extremely long delays between the memory instructions and testing to release inhibition associated with the content of instructions. 98 participants demonstrated flawless recall of 12 Russian - made up language word pairs. They then viewed each Russian word from a pair once, with randomized instructions “Forget”, “Remember”, “Repeat”, or a short cognitive task. Self-reports on the mnemonic strategies were collected. Free recall and recognition tests were administered three times - 45 minutes, a month and a year (N = 58) later. Despite a strong incentive to recall all word pairs, fewer TBF pairs were recalled in comparison with TBR pairs, both after 45 minutes and after one month’s delay. Recognition among all conditions was equally high. A year later free recall was close to zero. In contrast, the TBR and TBF pairs were recognized equally better than pairs presented in “Repeat” and “Task” conditions. Thus, our results show that the intention to manage one’s own memory enhances the accessibility of memories at a very long time delay, no matter what type of instruction is issued.

Too hard to forget? ERPs to remember, forget, and uninformative cues in the encoding phase of item-method directed forgetting.

In item-method directed forgetting, worse memory performance occurs for to-be-forgotten (TBF) than for to-be-remembered (TBR) items. However, recently TBF items have been found to be recognized more accurately than uninformative (UI) items not associated with any specific task. Here, we compare ERPs elicited by cues signaling the remember or the forget instruction with those elicited by uninformative cues. Participants were presented with a series of complex pictures, each followed by a symbolic TBR, TBF, or UI cue. On a yes-no recognition test, accuracy was higher for TBR than for both TBF and UI items. However, TBF items were recognized more accurately than UI items. ERPs elicited by the TBR cue were larger than ERPs elicited by both TBF and UI cues at the frontal P2, the late frontal negativity, and the late parietal positivity complex. This is consistent with more attention capture, selective rehearsal, and long-term memory encoding of TBR. In contrast, both TBF and UI cues induced a larger frontal N2 than TBR cues. Critically, TBF elicited a larger late right-frontal positivity than both UI and TBR cues and a larger late parietal positivity than UI cues. Moreover, the late right-frontal positivity was correlated with better recognition performance. It may therefore reflect processing orientation rather than inhibition per se. Results suggest that, when compared to UI cues, both TBR and TBF cues are processed actively. Distinct processing is seen at right frontal and centroparietal positive ERPs that may mediate better subsequent recognition of TBF than of UI items.

Age differences in the neural correlates underlying control of emotional memory: An event-related potential study

The ability to selectively remember important information and forget irrelevant details is fundamental to successful memory. Research has shown that both younger and older adults can intentionally remember and forget information varying in emotional valence; however, whether the neural correlates of these processes change with age is unknown. In this event-related potential (ERP) study, we sought to fill this knowledge gap using the item-directed forgetting (DF) task. Younger and older adults encoded positive, negative, or neutral words that were cued as either to-be-remembered (TBR) or to-be-forgotten (TBF), while brain activity was recorded with electroencephalography (EEG). Behaviorally, both age groups showed DF effects, although the magnitude of DF was reduced in older adults. Moreover, DF was not influenced by the emotional valence of words in either age group. In the brain, age differences emerged across both word- and cue-related ERPs. Whereas the late positive potential (LPP) was greater for negative than positive words in younger adults, older adults showed a reduced LPP for negative versus positive items. In response to memory cues, younger adults’ ERPs showed enhanced parietal and frontal positivity following TBR and TBF cues, respectively. In contrast, older adults displayed greater frontal activity while encoding TBR items than younger adults but age invariance in parietal ERPs following TBR cues. Together, these findings suggest that both younger and older adults are able to intentionally forget information that varies in emotional valence but that the neural mechanisms underlying these processes may change with age.

Do different salience cues compete for dominance in memory over a daytime nap?

Information that is the most salient and important for future use is preferentially preserved through active processing during sleep. Emotional salience is a biologically adaptive cue that influences episodic memory processing through interactions between amygdalar and hippocampal activity. However, other cues that influence the importance of information, such as the explicit direction to remember or forget, interact with the inherent salience of information to determine its fate in memory. It is unknown how sleep-based processes selectively consolidate this complex information. The current study examined the development of memory for emotional and neutral information that was either cued to-be-remembered (TBR) or to-be-forgotten (TBF) across a daytime period including either napping or wakefulness. Baseline memory revealed dominance of the TBR cue, regardless of emotional salience. As anticipated, napping was found to preserve memory overall significantly better than remaining awake. Furthermore, we observed a trending interaction indicating that napping specifically enhanced the discrimination between the most salient information (negative TBR items) over other information. We found that memory for negative items was positively associated with the percentage of SWS obtained during a nap. Furthermore, the magnitude of the difference in memory between negative TBR items and negative TBF items increased with greater sleep spindle activity. Taken together, our results suggest that although the cue to actively remember or intentionally forget initially wins out, active processes during sleep facilitate the competition between salience cues to promote the most salient information in memory.

An Online Intrusion Detection System to Cloud Computing Based on Neucube Algorithms

This article describes how as network traffic grows, attacks on traffic become more complicated and harder to detect. Recently, researchers have begun to explore machine learning techniques with cloud computing technologies to classify network threats. So, new and creative ways are needed to enhance intrusion detection system. This article addresses the source of the above issues through detecting an intrusion in cloud computing before it further disrupts normal network operations, because the complexity of malicious attack techniques have evolved from traditional malicious attack technologies (direct malicious attack), which include different malicious attack classes, such as DoS, Probe, R2L, and U2R malicious attacks, especially the zero-day attack in online mode. The proposed online intrusion detection cloud system (OIDCS) adopts the principles of the new spiking neural network architecture called NeuCube algorithm. It is proposed that this system is the first filtering system approach that utilizes the NeuCube algorithm. The OIDCS inherits the hybrid (supervised/unsupervised) learning feature of the NeuCube algorithm and uses this algorithm in an online system with lifelong learning to classify input while learning the system. The system is accurate, especially when working with a zero-day attack, reaching approximately 97% accuracy based on the to-be-remembered (TBR) encoding algorithm.

Memory and conceptual learning of relevant and non-relevant items in item-method directed forgetting

ABSTRACTThe present research investigates the fate of non-target information when people are trying to either intentionally memorise or forget target information. By using an object-based attentional manipulation within a directed forgetting paradigm (item-method), we show a directed forgetting effect (DFE, i.e., better memory for to-be-remembered (TBR) than for to-be-forgotten (TBF) items) for items that participants are explicitly instructed to attend but not for irrelevant items that happen to be part of the context. Alongside the classic DFE, we investigate how the category of the attended and unattended items are learned. The results obtained in three experiments, show that people can successfully learn only the category of the TBR attended items and that the DFE extends to new items that are related to the old TBR and TBF items (an effect that we call conceptual DFE). These results give us new insight about how TBR and TBF items are processed and conceptually learned.

Decomposing item-method directed forgetting of emotional pictures: Equivalent costs and no benefits.

Using an item-method directed forgetting task, we presented negative, neutral, and positive photographic pictures, one at a time, each followed by an instruction to remember or forget. We determined that the directed forgetting effect, defined as better subsequent recognition of to-be-remembered (TBR) items than to-be-forgotten (TBF) items, was equivalent across negative, neutral, and positive pictures. To disentangle the underlying costs (i.e., decrease in memory for TBF items) and benefits (i.e., increase in memory for TBR items), we compared recognition memory performance in the directed forgetting task to that of a novel within-subjects remember-all control condition (Experiment 1) and to a between-subjects remember-all control group (Experiment 2). We observed costs without benefits across all three emotions-negative, neutral, and positive-in both experiments. These results demonstrate that equivalent directed forgetting effects for emotional stimuli are not attributable to different underlying component processes. Instead, our results suggest that selection for encoding is accomplished in similar ways, regardless of emotional content.

Can We Retrieve the Information Which Was Intentionally Forgotten? Electrophysiological Correlates of Strategic Retrieval in Directed Forgetting.

Retrieval inhibition hypothesis of directed forgetting effects assumed TBF (to-be-forgotten) items were not retrieved intentionally, while selective rehearsal hypothesis assumed the memory representation of retrieved TBF (to-be-forgotten) items was weaker than TBR (to-be-remembered) items. Previous studies indicated that directed forgetting effects of item-cueing method resulted from selective rehearsal at encoding, but the mechanism of retrieval inhibition that affected directed forgetting of TBF (to-be-forgotten) items was not clear. Strategic retrieval is a control process allowing the selective retrieval of target information, which includes retrieval orientation and strategic recollection. Retrieval orientation via the comparison of tasks refers to the specific form of processing resulted by retrieval efforts. Strategic recollection is the type of strategies to recollect studied items for the retrieval success of targets. Using a “directed forgetting” paradigm combined with a memory exclusion task, our investigation of strategic retrieval in directed forgetting assisted to explore how retrieval inhibition played a role on directed forgetting effects. When TBF items were targeted, retrieval orientation showed more positive ERPs to new items, indicating that TBF items demanded more retrieval efforts. The results of strategic recollection indicated that: (a) when TBR items were retrieval targets, late parietal old/new effects were only evoked by TBR items but not TBF items, indicating the retrieval inhibition of TBF items; (b) when TBF items were retrieval targets, the late parietal old/new effect were evoked by both TBR items and TBF items, indicating that strategic retrieval could overcome retrieval inhibition of TBF items. These findings suggested the modulation of strategic retrieval on retrieval inhibition of directed forgetting, supporting that directed forgetting effects were not only caused by selective rehearsal, but also retrieval inhibition.

Local context effects during emotional item directed forgetting in younger and older adults

ABSTRACTThis paper explored the differential sensitivity young and older adults exhibit to the local context of items entering memory. We examined trial-to-trial performance during an item directed forgetting task for positive, negative, and neutral (or baseline) words each cued as either to-be-remembered (TBR) or to-be-forgotten (TBF). This allowed us to focus on how variations in emotional valence (independent of arousal) and instruction (TBR vs. TBF) of the previous item (trial n-1) impacted memory for the current item (trial n) during encoding. Different from research showing impairing effects of emotional arousal, both age groups showed a memorial boost for stimuli when preceded by items high in positive or negative valence relative to those preceded by neutral items. This advantage was particularly prominent for neutral trial n items that followed emotional items suggesting that, regardless of age, neutral memories may be strengthened by a local context that is high in valence. A trending age difference also emerged with older adults showing greater sensitivity when encoding instructions changed between trial n-1 and n. Results are discussed in light of age-related theories of cognitive and emotional processing, highlighting the need to consider the dynamic, moment-to-moment fluctuations of these systems.

Selective rehearsal is affected by the emotionality of the encoding context in item-method directed forgetting: An event-related potential study

Emotional items are often remembered more clearly than neutral items. However, whether stimuli embedded in an emotional context are more resistant to directed forgetting than those presented in a neutral context remains unclear. This question was tested by recording event-related potentials (ERPs) in an item-method directed forgetting paradigm involving neutral words that were embedded in neutral or negative contexts. During the study phase, participants were asked to associate a neutral word with a negative or neutral picture. A remember (R) or forget (F) cue was then designated to indicate whether the word was a to-be-remembered (TBR) or to-be-forgotten (TBF) word. In the test phase, participants were asked to identify all previously presented old words regardless of the R/F cues. The behavioral results indicated a significant interaction between the valence of the encoding contexts and the R/F cues. The hit rate was lower for the TBR words encoded in negative contexts relative to those encoded in neutral contexts. No such valence effect was observed in the hit rates of the TBF words. For the ERP data, the R cues elicited a P3b-like effect that has been linked to the selective rehearsal of the TBR items. This effect was more sustained in the negative encoding context than in the neutral context. The F cues elicited a frontal positivity that has been linked to the active inhibition of the TBF words; however, this positivity was not modulated by the valence of the encoding context. The sustained P3b-like effect for the R cues in the negative encoding context might reflect a compensative encoding for the TBR words caused by the attention-capturing negative contexts. Therefore, we argue that the emotional context affected the selective elaboration of the TBR words; however, we also argue that there was no supportive evidence of an emotional effect on the forgetting of TBF items.

What Is the Effect of Basic Emotions on Directed Forgetting? Investigating the Role of Basic Emotions in Memory.

Studies presenting memory-facilitating effect of emotions typically focused on affective dimensions of arousal and valence. Little is known, however, about the extent to which stimulus-driven basic emotions could have distinct effects on memory. In the present paper we sought to examine the modulatory effect of disgust, fear, and sadness on intentional remembering and forgetting using widely used item-method directed forgetting (DF) paradigm. Eighteen women underwent fMRI scanning during encoding phase in which they were asked either to remember (R) or to forget (F) pictures. In the test phase all previously used stimuli were re-presented together with the same number of new pictures and participants had to categorize them as old or new, irrespective of the F/R instruction. On the behavioral level we found a typical DF effect, i.e., higher recognition rates for to-be-remembered (TBR) items than to-be-forgotten (TBF) ones for both neutral and emotional categories. Emotional stimuli had higher recognition rate than neutral ones, while among emotional those eliciting disgust produced highest recognition, but at the same time induced more false alarms. Therefore, when false alarm corrected recognition was examined the DF effect was equally strong irrespective of emotion. Additionally, even though subjects rated disgusting pictures as more arousing and negative than other picture categories, logistic regression on the item level showed that the effect of disgust on recognition memory was stronger than the effect of arousal or valence. On the neural level, ROI analyses (with valence and arousal covariates) revealed that correctly recognized disgusting stimuli evoked the highest activity in the left amygdala compared to all other categories. This structure was also more activated for remembered vs. forgotten stimuli, but only in case of disgust or fear eliciting pictures. Our findings, despite several limitations, suggest that disgust have a special salience in memory relative to other negative emotions, which cannot be put down to differences in arousal or valence. The current results thereby support the suggestion that a purely dimensional model of emotional influences on cognition might not be adequate to account for observed effects.

Neural modulation of directed forgetting by valence and arousal: An event-related potential study

Intentional forgetting benefits memory by removing no longer needed information and promoting processing of more relevant materials. This study sought to understand how the behavioural and neurophysiological representation of intentional forgetting would be impacted by emotion. We took a novel approach by examining the unique contribution of both valence and arousal on emotional directed forgetting. Participants completed an item directed forgetting task for positive, negative, and neutral words at high and lower levels of arousal while brain activity was recorded using electroencephalography (EEG). Behaviourally, recognition of to-be-remembered (TBR) and to-be-forgotten (TBF) items varied as a function of valence and arousal with reduced directed forgetting for high arousing negative and neutral words. In the brain, patterns of frontal and posterior activation in response to TBF and TBR cues respectively replicated prior EEG evidence to support involvement of inhibitory and selective rehearsal mechanisms in item directed forgetting. Interestingly, emotion only impacted cue-related posterior activity, which varied depending on specific interactions between valence and arousal. Together, results suggest that the brain handles valence and arousal differently and highlights the importance of considering in a collective manner the multidimensional nature of emotion in experimentation.