Prior Negative Experience Biases Activity of Medial Amygdala during Interstrain Social Engagement in Male Rats.

Social recognition is an essential part of social function and often promotes specific social behaviors based on prior experience. Social and defensive behaviors in particular often emerge with prior experiences of familiarity or novelty/stress, respectively. This is also commonly seen in rodents toward same-strain and interstrain conspecifics. Medial amygdala (MeA) activity guides social choice based on age and sex recognition and is sensitive to social experiences. However, little is known about whether the MeA exhibits differential responses based on strain or how this is impacted by experience. Social stress impacts posterior MeA (MeAp) function and can shift measures of social engagement. However, it is unclear how stress impacts MeAp activity and contributes to altered social behavior. The primary goal of this study in adult male Sprague Dawley rats was to determine whether prior stress experience with a different-strain (Long-Evans) rat impacts MeAp responses to same-strain and different-strain conspecifics in parallel with a change in behavior using in vivo fiber photometry. We found that MeAp activity was uniformly activated during social contact with a novel same-strain rat during a three-chamber social preference test following control handling but became biased toward a novel different-strain rat following social stress. Socially stressed rats also showed initially heightened social interaction with novel same-strain rats but showed social avoidance and fragmented social behavior with novel different-strain rats relative to controls. These results indicate that heightened MeAp activity may guide social responses to novel, threatening, rather than non-threatening, social stimuli after stress.

The influence of time of day on memory recognition for faces.

Time of day can alter memory performance in general. Its influence on memory recognition performance for faces, which is important for daily encounters with new persons or testimonies, has not been investigated yet. Importantly, high levels of the stress hormone cortisol impair memory recognition, in particular for emotional material. However, some studies also reported high cortisol levels to enhance memory recognition. Since cortisol levels in the morning are usually higher than in the evening, time of day might also influence recognition performance. In this pre-registered study with a two-day design, 51 healthy men encoded pictures of male and female faces with distinct emotional expressions on day one around noon. Memory for the faces was retrieved two days later at two consecutive testing times either in the morning (high and moderately increased endogenous cortisol levels) or in the evening (low endogenous cortisol levels). Additionally, alertness as well as salivary cortisol levels at the different timepoints was assessed. Cortisol levels were significantly higher in the morning compared to the evening group as expected, while both groups did not differ in alertness. Familiarity ratings for female stimuli were significantly better when participants were tested during moderately increased endogenous cortisol levels in the morning than during low endogenous cortisol levels in the evening, a pattern which was previously also observed for stressed versus non-stressed participants. In addition, cortisol levels during that time in the morning were positively correlated with the recollection of face stimuli in general. Thus, recognition memory performance may depend on the time of day and as well as on stimulus type, such as the difference of male and female faces. Most importantly, the results suggest that cortisol may be meaningful and worth investigating when studying the effects of time of day on memory performance. This research offers both, insights into daily encounters as well as legally relevant domains as for instance testimonies.

Neural basis of false recognition in Alzheimer's disease and dementia with lewy bodies.

In Alzheimer's disease (AD), reports on the association between false recognition and brain structure have been inconsistent. In dementia with Lewy bodies (DLB), no such association has been reported. This study aimed to identify brain regions associated with false recognition in AD and DLB by analyzing regional gray matter volume (rGMV). We included 184 patients with AD and 60 patients with DLB. The number of false recognitions was assessed using the Alzheimer's Disease Assessment Scale' word recognition task. Brain regions associated with the number of false recognitions were examined by voxel-based morphometry analysis. The number of false recognitions significantly negatively correlated with rGMV in the bilateral hippocampus, left parahippocampal gyrus, bilateral amygdala, and bilateral entorhinal cortex in patients with AD (p < 0.05, family-wise error [FEW] corrected) and in the bilateral hippocampus, left parahippocampal gyrus, right inferior frontal gyrus, right middle frontal gyrus, right basal forebrain, right insula, left medial and lateral orbital gyri, and left fusiform in those with DLB (p < 0.05, FWE corrected). Bilateral hippocampus and left parahippocampal gyrus were associated with false recognition in both diseases. However, we found there were regions where the association between false recognition and rGMV differed from disease to disease.

The role of facial distinctiveness in the prioritisation of targets in disjunctive dual-target face search.

Two experiments explored the search for pairs of faces in a disjunctive dual-target face search (DDTFS) task for unfamiliar face targets. The distinctiveness of the target was manipulated such that both faces were typical or distinctive or contained one typical and one distinctive target. Targets were searched for in arrays of eight faces. In Experiment 1, participants completed a DDTFS block with targets learnt over the block of trials. In Experiment 2, the dual-target block was preceded by two training blocks of single-target trials. Participants also completed the upright and inverted long-form Cambridge Face Memory Test (CFMT+). The results showed that searching for two typical faces leads to one target being prioritised at the expense of the other. The ability to search for non-prioritised typical faces was associated with scores on the CFMT+. This association disappeared when faces were learnt before completing DDTFS. We interpret the findings in terms of the impact of typicality on face learning, individual differences in the ability to learn faces, and the involvement of capacity-limited working memory in the search for unfamiliar faces. The findings have implications for security-related situations where agents must search for multiple unfamiliar faces having been shown their images.

Security officers (e.g. police officers) are often required to be on the lookout for specific individuals or suspects. The present study shows that there is a profound challenge in finding unfamiliar targets when searching for more than one face at the same time. Importantly, the nature of this challenge depends on two factors: first, the relative typicality of the faces that are being sought at the same time, and second, the face processing ability of the searchers. The findings have implications for the design of the job roles and the recruitment of security officers tasked with searching for specific individuals.

Thinking outside the red box: Does the simultaneous Showup distinguish between filler siphoning and diagnostic feature detection accounts of lineup/Showup differences?

Lineups are considered a superior method of identification to showups, but why is contested. There are two main theories: diagnostic feature detection theory, which holds that surrounding the suspect with fillers causes the eyewitness to focus on the features that are most diagnostic, and differential filler siphoning theory that claims that the fillers draw incorrect choices away from the suspect. Colloff and Wixted (2020) created a novel identification task, called a simultaneous showup, designed to prevent filler siphoning, while still allowing comparison to occur between members of the array. However, even in the simultaneous showup, it is possible that covert filler siphoning occurs. In Experiment 1, we replicated the simultaneous showup condition and also asked participants if the other photos affected their decision making; we found evidence that participants self-reported both diagnostic feature detection and covert filler siphoning. In Experiment 2, we replicated Colloff and Wixted (2020, Experiment 3) main findings. Additionally, we found that participants self-reported both diagnostic feature detection and covert filler siphoning. This led us to conclude that the simultaneous showup procedure could not fully exclude covert filler siphoning from occurring.

Spatial dissociation between recognition and navigation in the primate hippocampus.

The primate hippocampus, crucial for both episodic memory and spatial navigation, remains an enigma regarding whether these functions share the same neural substrates. We investigated how identical hippocampal neurons in macaque monkeys dynamically shifted their representations between tasks. In a recognition memory task, a notable fraction of hippocampal neurons showed that rate modulation strongly correlated with recognition performance. During free navigation in an open arena, spatial view, rather than position, predominantly influenced the spatial selectivity of hippocampal neurons. Neurons selective for recognition memory displayed minimal spatial tuning, while spatially tuned neurons exhibited limited memory-related activity. These neural correlates of recognition memory and space were more pronounced in the anterior and posterior portions of the hippocampus, respectively. These opposing gradients extended further into the anterior and posterior neocortices. Overall, our findings suggest the presence of orthogonal long-axis gradients between recognition memory and spatial navigation in the hippocampal-neocortical networks of macaque monkeys.

Feasibility and effectiveness of transcutaneous auricular vagus nerve stimulation (taVNS) in awake mice.

AIMS: Transcutaneous auricular vagus nerve stimulation (taVNS) is widely used to treat a variety of disorders because it is noninvasive, safe, and well tolerated by awake patients. However, long-term and repetitive taVNS is difficult to achieve in awake mice. Therefore, developing a new taVNS method that fully mimics the method used in clinical settings and is well-tolerated by awake mice is greatly important for generalizing research findings related to the effects of taVNS. The study aimed to develop a new taVNS device for use in awake mice and to test its reliability and effectiveness. METHODS: We demonstrated the reliability of this taVNS device through retrograde neurotropic pseudorabies virus (PRV) tracing and evaluated its effectiveness through morphological analysis. After 3 weeks of taVNS application, the open field test (OFT) and elevated plus maze (EPM) were used to evaluate anxiety-like behaviors, and the Y-maze test and novel object recognition test (NORT) were used to evaluate recognition memory behaviors, respectively. RESULTS: We found that repetitive taVNS was well tolerated by awake mice, had no effect on anxiety-like behaviors, and significantly improved memory. CONCLUSION: Our findings suggest that this new taVNS device for repetitive stimulation of awake mice is safe, tolerable, and effective.

A revisit to interactions of stimulus quality and semantic context on N400 in visual word recognition.

Much behavioral research has revealed interactive effects between stimulus quality and semantic priming in visual word recognition, practically in favor of the interactive activation model. However, the limited number of event-related brain potential (ERP) studies have yielded inconsistent results considering this interaction's impact on N400 amplitude. The current ERP study aimed to examine whether the joint effects of stimulus quality and semantic priming were specific to the lexical decision task. We used both behavioral measures and ERP recordings to evaluate the joint effects of stimulus degradation (i.e. highly vs. slightly degraded) and semantic priming (i.e. semantically related vs. unrelated) in a lexical decision task involving visual recognition of Chinese characters. The results showed significant degradation-by-priming interactions on response times and N400 amplitude ( P  < 0.05), with larger semantic priming effects on slightly degraded targets. These converging behavioral and electrophysiological findings provide evidence in accordance with the interactive activation models of visual word recognition, in which the early-stage visual processing (i.e. degradation) cascades into the later-stage semantic processing (i.e. priming), thus yielding interactions observed in N400 amplitude.

Age-related changes in emotion recognition across childhood: A meta-analytic review.

Children's ability to accurately recognize the external emotional signals produced by those around them represents a milestone in their socioemotional development and is associated with a number of important psychosocial outcomes. A plethora of individual studies have examined when, and in which order, children acquire emotion knowledge over the course of their development. Yet, very few attempts have been made to summarize this body of work quantitatively. To address this, the present meta-analysis examined the age-related trajectories of emotion recognition across childhood and the extent to which typically developing children's recognition of external emotional cues (in the face, voice, and body) is influenced by a host of participant-, task-, and stimulus-related factors. We analyzed children's emotion recognition overall (independent of specific emotion categories) and for specific basic emotions. In total, k = 129 individual studies, investigating a total of N = 31,101 2-12-year-old children's emotion recognition abilities were included in our analyses. Children's recognition accuracy across all emotion categories was significantly above chance and improved with age in the same manner for all emotions. Emotion recognition accuracy was also moderated by region of study and task type. The order in which children became proficient at identifying specific emotions was consistent with previous qualitative reviews: Happiness was the easiest emotion to recognize, and disgust and fear were the most difficult to recognize across age. Task- and stimulus-related moderator variables also influenced specific emotion categories in different ways. We contextualize these results with regard to children's socioemotional development more broadly, and we discuss how our findings can be used to guide researchers and practitioners interested in children's social skills. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Cleaner fish with mirror self-recognition capacity precisely realize their body size based on their mental image.

Animals exhibiting mirror self-recognition (MSR) are considered self-aware; however, studies on their level of self-awareness remain inconclusive. Recent research has indicated the potential for cleaner fish (Labroides dimidiatus) to possess a sophisticated level of private self-awareness. However, as this study revealed only an aspect of private self-awareness, further investigation into other elements is essential to substantiate this hypothesis. Here, we show that cleaner fish, having attained MSR, construct a mental image of their bodies by investigating their ability to recall body size. A size-based hierarchy governs the outcomes of their confrontations. The mirror-naïve fish behaved aggressively when presented with photographs of two unfamiliar conspecifics that were 10% larger and 10% smaller than their body sizes. After passing the MSR test, they refrained from aggression toward the larger photographs but still behaved aggressively toward the smaller ones without re-examining their mirror images. These findings suggest that cleaner fish accurately recognize their body size based on mental images of their bodies formed through MSR. Additionally, mirror-experienced fish frequently revisited the mirror when presented with an intimidating larger photograph, implying the potential use of mirrors for assessing body size. Our study established cleaner fish as the first non-human animal to be demonstrated to possess private self-awareness.

Adaptation to Noise in Spectrotemporal Modulation Detection and Word Recognition.

Noise adaptation is the improvement in auditory function as the signal of interest is delayed in the noise. Here, we investigated if noise adaptation occurs in spectral, temporal, and spectrotemporal modulation detection as well as in speech recognition. Eighteen normal-hearing adults participated in the experiments. In the modulation detection tasks, the signal was a 200ms spectrally and/or temporally modulated ripple noise. The spectral modulation rate was two cycles per octave, the temporal modulation rate was 10 Hz, and the spectrotemporal modulations combined these two modulations, which resulted in a downward-moving ripple. A control experiment was performed to determine if the results generalized to upward-moving ripples. In the speech recognition task, the signal consisted of disyllabic words unprocessed or vocoded to maintain only envelope cues. Modulation detection thresholds at 0 dB signal-to-noise ratio and speech reception thresholds were measured in quiet and in white noise (at 60 dB SPL) for noise-signal onset delays of 50 ms (early condition) and 800 ms (late condition). Adaptation was calculated as the threshold difference between the early and late conditions. Adaptation in word recognition was statistically significant for vocoded words (2.1 dB) but not for natural words (0.6 dB). Adaptation was found to be statistically significant in spectral (2.1 dB) and temporal (2.2 dB) modulation detection but not in spectrotemporal modulation detection (downward ripple: 0.0 dB, upward ripple: -0.4 dB). Findings suggest that noise adaptation in speech recognition is unrelated to improvements in the encoding of spectrotemporal modulation cues.

The modulation of temporal predictability on attentional boost effect.

INTRODUCTION: The attentional boost effect, characterized by better memory for background scenes coinciding with a detection target than a nontarget, is believed to stem from a temporary increase in attentional capacity at the time of an acute behavior-related event occurring. Sisk and Jiang's study found that the attentional boost effect also occurs when the target's appearance was predictable. Unfortunately, the duration of the predictive interval in Sisk and Jiang's study was fixed. Since different predictive intervals had different weakening degrees to the acuteness of the target, this fixed duration hindered further investigation into the impact of different levels of predictability on the attentional boost effect. METHOD: Using the encoding-recognition paradigm and the remembering/knowing paradigm, and setting target stimuli with different predictive interval in target detection tasks, the current study aimed to explore the influence of varying the duration of the predictive interval on the attentional boost effect. RESULTS: The attentional boost effect was observed only in the short and medium predictive duration conditions, but not in the long predictive duration condition. Moreover, as the duration of the predictive interval increased, participants' memory performance on target-paired words gradually declined, while their memory performance on distractor-paired and baseline-paired words gradually improved. CONCLUSIONS: Predictability may alter the task demands, allowing participants to more effectively allocate attentional resources to the two tasks at hand.

Improving the diagnostic value of lineup rejections.

Erroneous eyewitness identification evidence is likely the leading cause of wrongful convictions. To minimize this error, scientists recommend collecting confidence. Research shows that eyewitness confidence and accuracy are strongly related when an eyewitness identifies someone from an initial and properly administered lineup. However, confidence is far less informative of accuracy when an eyewitness identifies no one and rejects the lineup instead. In this study, I aimed to improve the confidence-accuracy relationship for lineup rejections in two ways. First, I aimed to find the lineup that yields the strongest confidence-accuracy relationship for lineup rejections by comparing the standard, simultaneous procedure used by police worldwide to the novel "reveal" procedure designed by scientists to boost accuracy. Second, I aimed to find the best method for collecting confidence. To achieve this secondary aim, I made use of machine-learning techniques to compare confidence expressed in words to numeric confidence ratings. First, I find a significantly stronger confidence-accuracy relationship for lineup rejections in the reveal than in the standard procedure regardless of the method used to collect confidence. Second, I find that confidence expressed in words captures unique diagnostic information about the likely accuracy of a lineup rejection separate from the diagnostic information captured by numeric confidence ratings. These results inform models of recognition memory and may improve the criminal-legal system by increasing the diagnostic value of a lineup rejection.

In Spiderman we trust: The influence of familiar media characters on the decision-making of primary school children.

Children are increasingly active consumers in the media world and are thus confronted with a wide range of information. Making good decisions in such an environment is a major challenge. Weighting valid information in decision-making is an important skill that children must learn and apply. Yet, how do children weight information and which weights do they use? We developed a measuring instrument for children's weighting of advices by cue validity - the so-called Space Treasure Hunt. It is an easy to understand, child-friendly decision game. By anchoring it in the reality of children's media lives, we are able to assess the influence of familiarity and affect on children's decision making. During a treasure hunt in game situated in outer space, children are confronted with various characters who provide contradictory advice regarding where to find treasures. One of the advice-givers was an expert (valid cue), whereas the other advice-giver varied in terms of its media familiarity and affect. In our study (N = 372), we found that media familiar characters had a strong influence on children's decision-making. Media idols showed an assimilation effect, meaning that children followed the expert's advice the least often when it contradicted their media idol. Conversely, media familiar but less liked characters showed a contrast effect, meaning that children followed the expert's advice most often when it contradicted the media familiar, less liked character. Moreover, we found differences between children in terms of a three-way split: One third of the children, respectively, systematically followed the expert's advice, the media idol, or made their decisions unsystematically. We discuss how our results indicate the use of different weights in children's decision making.

Sensitive periods in language development: Do children outperform adults on auditory word-form segmentation?

Children are more successful language learners than adults, yet the nature and cause of this phenomenon are still not well understood. Auditory statistical learning from speech has been a prominent focus of research in the field of language development because it is regarded as a fundamental learning mechanism underlying word segmentation in early language acquisition. However, a handful of studies that investigated developmental trajectories for auditory statistical learning found no clear child advantages. The degree to which the learning task measures explicit rather than implicit mechanisms might obscure a potential advantage for younger learners, as suggested by recent findings. In the present study, we compared children aged 7-12 years and young adults on an adapted version of the task that disentangles explicit and implicit contributions to learning. They were exposed to a continuous stream of speech sounds comprising four repeating trisyllabic pseudowords. Learning of the hidden words was tested (a) online through a target-detection task and (b) offline via a forced-choice word recognition test that included a memory judgement procedure. Both measures revealed comparable learning abilities. However, children's performance on the recognition task showed evidence for both explicit and implicit word knowledge while adults appeared primarily sensitive to explicit memory. Since implicit memory is more stable in time than explicit memory, we suggest that future work should focus more on developmental differences in the nature of the memory that is formed, rather than the strength of learning, when trying to understand child advantages in language acquisition.

Astrocytic glutamate transport is essential for the memory-enhancing effects of 17ß-estradiol in ovariectomized mice.

Infusion of 17ß-estradiol (E2) into the dorsal hippocampus (DH) of ovariectomized (OVX) mice enhances memory consolidation, an effect that depends on rapid phosphorylation of extracellular signal-regulated kinase (ERK) and Akt. Astrocytic glutamate transporter 1 (GLT-1) modulates neurotransmission via glutamate uptake from the synaptic cleft. However, little is known about the contribution of DH astrocytes, and astrocytic glutamate transport, to the memory-enhancing effects of E2. This study was designed to test whether DH astrocytes contribute to estrogenic modulation of memory consolidation by determining the extent to which DH GLT-1 is necessary for E2 to enhance memory in object recognition and object placement tasks and trigger rapid phosphorylation events in DH astrocytes. OVX female mice were bilaterally cannulated into the DH or the DH and dorsal third ventricle (ICV). Post-training DH infusion of the GLT-1 inhibitor dihydrokainic acid (DHK) dose-dependently impaired memory consolidation in both tasks. Moreover, the memory-enhancing effects of ICV-infused E2 in each task were blocked by DH DHK infusion. E2 increased p42 ERK and Akt phosphorylation in DH astrocytes, and these effects were blocked by DHK. Results suggest the necessity of DH GLT-1 activity for object and spatial memory consolidation, and for E2 to enhance consolidation of these memories and to rapidly activate cell signaling in DH astrocytes. Findings indicate that astrocytic function in the DH of OVX females is necessary for memory formation and is regulated by E2, and suggest an essential role for DH astrocytic GLT-1 activity in the memory-enhancing effects of E2.

Correcting fake news headlines after repeated exposure: memory and belief accuracy in younger and older adults.

The efficacy of fake news corrections in improving memory and belief accuracy may depend on how often adults see false information before it is corrected. Two experiments tested the competing predictions that repeating fake news before corrections will either impair or improve memory and belief accuracy. These experiments also examined whether fake news exposure effects would differ for younger and older adults due to age-related differences in the recollection of contextual details. Younger and older adults read real and fake news headlines that appeared once or thrice. Next, they identified fake news corrections among real news headlines. Later, recognition and cued recall tests assessed memory for real news, fake news, if corrections occurred, and beliefs in retrieved details. Repeating fake news increased detection and remembering of corrections, correct real news retrieval, and erroneous fake news retrieval. No age differences emerged for detection of corrections, but younger adults remembered corrections better than older adults. At test, correct fake news retrieval for earlier-detected corrections was associated with better real news retrieval. This benefit did not differ between age groups in recognition but was greater for younger than older adults in cued recall. When detected corrections were not remembered at test, repeated fake news increased memory errors. Overall, both age groups believed correctly retrieved real news more than erroneously retrieved fake news to a similar degree. These findings suggest that fake news repetition effects on subsequent memory accuracy depended on age differences in recollection-based retrieval of fake news and that it was corrected.

Recognition of Emotional Prosody in Mandarin-Speaking Children: Effects of Age, Noise, and Working Memory.

Age, babble noise, and working memory have been found to affect the recognition of emotional prosody based on non-tonal languages, yet little is known about how exactly they influence tone-language-speaking children's recognition of emotional prosody. In virtue of the tectonic theory of Stroop effects and the Ease of Language Understanding (ELU) model, this study aimed to explore the effects of age, babble noise, and working memory on Mandarin-speaking children's understanding of emotional prosody. Sixty Mandarin-speaking children aged three to eight years and 20 Mandarin-speaking adults participated in this study. They were asked to recognize the happy or sad prosody of short sentences with different semantics (negative, neutral, or positive) produced by a male speaker. The results revealed that the prosody-semantics congruity played a bigger role in children than in adults for accurate recognition of emotional prosody in quiet, but a less important role in children compared with adults in noise. Furthermore, concerning the recognition accuracy of emotional prosody, the effect of working memory on children was trivial despite the listening conditions. But for adults, it was very prominent in babble noise. The findings partially supported the tectonic theory of Stroop effects which highlights the perceptual enhancement generated by cross-channel congruity, and the ELU model which underlines the importance of working memory in speech processing in noise. These results suggested that the development of emotional prosody recognition is a complex process influenced by the interplay among age, background noise, and working memory.

Reading books: The positive impact of print exposure on written word recognition.

Regular print exposure is thought to benefit reading and language processes: those who read more have a larger vocabulary and better spelling and comprehension skills. Yet, there is little or no direct evidence that exposure to print facilitates reading. Here, we used an ecologically valid design to test the impact of print exposure on the early stages of reading in skilled adult readers. Participants read a novel at their own pace. Reading was followed by a lexical decision task, in which the positive trials were words that were exposed in the novel, and matched controls not exposed in the novel. If exposure during reading had a positive impact on subsequent word recognition, exposed words would be processed more efficiently than not-exposed words (exposure effect). This effect was obtained in three experiments. In addition, the effect was not modulated by the amount of exposure (1 vs. 3 occurrences in the text; Experiment 1), or the timing between reading and the exposure test (immediately after reading vs. on the following day; Experiment 3). However, the effect was present only in low-frequency words (Experiment 3). Interpretations of the exposure effect in terms of activation threshold and lexical quality are discussed.

Humans' extreme face recognition abilities challenge the well-established familiarity effect.

Classification performance is better for learned than unlearned stimuli. This was also reported for faces, where identity matching of unfamiliar faces is worse than for familiar faces. This familiarity advantage led to the conclusion that variability across appearances of the same identity is partly idiosyncratic and cannot be generalized from familiar to unfamiliar identities. Recent advances in machine vision challenge this claim by showing that the performance for untrained (unfamiliar) identities reached the level of trained identities as the number of identities that the algorithm is trained with increases. We therefore asked whether humans who reportedly can identify a vast number of identities, such as super recognizers, may close the gap between familiar and unfamiliar face classification. Consistent with this prediction, super recognizers classified unfamiliar faces just as well as typical participants who are familiar with the same faces, on a task that generates a sizable familiarity effect in controls. Additionally, prosopagnosics' performance for familiar faces was as bad as that of typical participants who were unfamiliar with the same faces, indicating that they struggle to learn even identity-specific information. Overall, these findings demonstrate that by studying the extreme ends of a system's ability we can gain novel insights into its actual capabilities.