Hippocampal brain-network coordination during volitional exploratory behavior enhances learning

Brain and eye movement dynamics track the transition from learning to memory-guided action

Learning never stops. As we navigate life, we continuously acquire and update knowledge to optimize memory-guided action, with a gradual shift from the former to the latter as we master our environment. How are these learning dynamics expressed in the brain and in behavioral patterns? Here, we devised a spatiotemporal image learning task ("Memory Arena") in which participants learn a set of 50 items to criterion across repeated exposure blocks. Critically, brief task-free periods between successive image presentations allowed us to assess multivariate electroencephalogram (EEG) patterns representing the previous and/or upcoming image identity, as well as anticipatory eye movements toward the upcoming image location. As expected, participants eventually met the performance criterion, albeit with different learning rates. During task-free periods, we were able to readily decode representations of both previous and upcoming image identities. Importantly though, decoding strength followed opposing slopes for previous vs. upcoming images across time, with a gradual decline of evidence for the previous image and a gradual increase of evidence for the upcoming image. Moreover, the ratio of upcoming vs. previous image evidence directly followed behavioral learning rates. Finally, eye movement data revealed that participants increasingly used the task-free period to anticipate upcoming image locations, with target-precision slopes paralleling both behavioral performance measures as well as EEG decodability of the upcoming image across time. Together, these results unveil the neural and behavioral dynamics underlying the gradual transition from learning to memory-guided action.

A cross-cultural comparison of intrinsic and extrinsic motivational drives for learning

Intrinsic motivational drives, like the autonomous feeling of control, and extrinsic motivational drives, like monetary reward, can benefit learning. Extensive research has focused on neurobiological and psychological factors that affect these drives, but our understanding of the sociocultural factors is limited. Here, we compared the effects of autonomy and rewards on episodic recognition memory between students from Dutch and Chinese universities. In an exploratory learning task, participants viewed partially obscured objects that they needed to subsequently remember. We independently manipulated autonomy, as volitional control over an exploration trajectory, as well as the chance to receive monetary rewards. The learning task was followed by memory tests for objects and locations. For both cultural groups, we found that participants learned better in autonomous than non-autonomous conditions. However, the beneficial effect of reward on memory performance was stronger for Chinese than for Dutch participants. By incorporating the sociocultural brain perspective, we discuss how differences in norms and values between Eastern and Western cultures can be integrated with the neurocognitive framework about dorsal lateral and ventral medial prefrontal cortex and dopaminergic reward modulations on learning and memory. These findings have important implications for understanding the neurocognitive mechanisms in which both autonomy and extrinsic rewards are commonly used to motivate students in the realm of education and urge more attention to investigate cultural differences in learning.

Drawing promotes memory retention in a patient with sleep-related anterograde amnesia

Drawing is a powerful tool to enhance memory in healthy participants and patients with probable dementia. Here, we investigated whether the drawing effect could extend to patient CT, a young woman with severe anterograde amnesia. Following surgery for a midline tumor involving her septum pellucidium and extending down into her fornices bilaterally, CT experienced a severe case of sleep-related amnesia. She can remember information encountered throughout the day, but when waking up in the morning or following a nap she forgets information learned prior to sleep. Here, we tested CT and 21 age-matched controls in a 3-day within-subjects design, during which participants encoded words by either drawing or writing them down. Memory for encoded words was tested in two conditions that each followed a 12-h delay, once after a night of sleep, and once after 12 h of wake. Despite her severe memory impairment, CT showed a drawing effect that was comparable to controls in both sleep and wake conditions. Whereas CT's memory for written words was consistently impaired relative to controls, her memory for drawn words was at the lower control range following a waking delay and above chance following a sleep delay. We suggest that amnesic patients may benefit from the drawing effect due to the recruitment of brain regions outside of the hippocampal system for encoding and consolidation. Furthermore, in control participants, sleep benefited memory for written words, but not for drawn words, suggesting that sleep preferentially consolidates memories that are more dependent on the hippocampal system.

The neuroscience of active learning and direct instruction

Throughout the educational system, students experiencing active learning pedagogy perform better and fail less than those taught through direct instruction. Can this be ascribed to differences in learning from a neuroscientific perspective? This review examines mechanistic, neuroscientific evidence that might explain differences in cognitive engagement contributing to learning outcomes between these instructional approaches. In classrooms, direct instruction comprehensively describes academic content, while active learning provides structured opportunities for learners to explore, apply, and manipulate content. Synaptic plasticity and its modulation by arousal or novelty are central to all learning and both approaches. As a form of social learning, direct instruction relies upon working memory. The reinforcement learning circuit, associated agency, curiosity, and peer-to-peer social interactions combine to enhance motivation, improve retention, and build higher-order-thinking skills in active learning environments. When working memory becomes overwhelmed, additionally engaging the reinforcement learning circuit improves retention, providing an explanation for the benefits of active learning. This analysis provides a mechanistic examination of how emerging neuroscience principles might inform pedagogical choices at all educational levels.

Peripheral vision contributes to implicit attentional learning: Findings from the "mouse-eye" paradigm

The central visual field is essential for activities like reading and face recognition. However, the impact of peripheral vision loss on daily activities is profound. While the importance of central vision is well established, the contribution of peripheral vision to spatial attention is less clear. In this study, we introduced a "mouse-eye" method as an alternative to traditional gaze-contingent eye tracking. We found that even in tasks requiring central vision, peripheral vision contributes to implicit attentional learning. Participants searched for a T among Ls, with the T appearing more often in one visual quadrant. Earlier studies showed that participants' awareness of the T location probability was not essential for their ability to learn. When we limited the visible area around the mouse cursor, only participants aware of the target's location probability showed learning; those unaware did not. Adding placeholders in the periphery did not restore implicit attentional learning. A control experiment showed that when participants were allowed to see all items while searching and moving the mouse to reveal the target's color, both aware and unaware participants acquired location probability learning. Our results underscore the importance of peripheral vision in implicitly guided attention. Without peripheral vision, only explicit, but not implicit, attentional learning prevails.

Seeking versus receiving help: How children integrate suggestions in memory decisions

The current research examined how seeking versus receiving help affected children's memory and confidence decisions. Baseline performance, when no help was available, was compared to performance when help could be sought (Experiment 1: N = 83, 41 females) or was provided (Experiment 2: N = 84, 44 females) in a sample of predominately White 5-, 7-, and 9-year-olds from Northern California. Data collection occurred from 2018 to 2019. In Experiment 1, 5-year-olds agreed most often with sought-help, whereas 9-year-olds were the only age group reporting lower confidence for sought-help relative to baseline trials. In Experiment 2, agreement and confidence after provided help were similar across age groups. Different developmental patterns when help was sought versus provided underscore the importance of active help-seeking for memory decision-making.

Memory benefits when actively, rather than passively, viewing images

Serial visual presentations of images exist both in the laboratory and increasingly on virtual platforms such as social media feeds. However, the way we interact with information differs between these. In many laboratory experiments participants view stimuli passively, whereas on social media people tend to interact with information actively. This difference could influence the way information is remembered, which carries practical and theoretical implications. In the current study, 821 participants viewed streams containing seven landscape images that were presented at either a self-paced (active) or an automatic (passive) rate. Critically, the presentation speed in each automatic trial was matched to the speed of a self-paced trial for each participant. Both memory accuracy and memory confidence were greater on self-paced compared to automatic trials. These results indicate that active, self-paced progression through images increases the likelihood of them being remembered, relative to when participants have no control over presentation speed and duration.

The effect of choice on memory: The role of theta oscillations

People value the opportunity to exercise control over the environment or make their own choices. Recent studies have revealed that simply having the opportunity to make choices can facilitate memory performance, suggesting an interaction between reward (due to choice making) and memory systems. However, little is known about the electrophysiological basis of choice-related memory. In the current study, we used scalp electroencephalography combined with a choice encoding task to examine the role of theta oscillations (which have been widely connected to reward and memory processing) in choice-related memory formation. The encoding task had two conditions. In the choice condition, participants were asked to choose between two occluded memoranda by themselves, whereas in the fixed condition, the decision was made by the computer. Behavioral results showed the choice effect, with better performance in the choice condition than the fixed condition on the recognition test given after a 24-h delay. Increases in theta power during an early latency of encoding period predicted successful memory formation in the choice condition, but not in the fixed condition. Furthermore, decreases in theta power during a late latency predicted successful memory formation in both the fixed and the choice conditions. Finally, we observed increased theta power in the choice condition compared to the fixed condition during an early latency of encoding period and decreased theta power in the choice condition compared to the fixed condition during a late latency. Our results suggest that theta oscillations play a significant role in choice-related memory formation.

The interactive effect of external rewards and self-determined choice on memory

Both external motivational incentives (e.g., monetary reward) and internal motivational incentives (e.g., self-determined choice) have been found to promote memory, but much less is known about how these two types of incentives interact with each other to affect memory. The current study (N = 108) examined how performance-dependent monetary rewards affected the role of self-determined choice in memory performance, also known as the choice effect. Using a modified and better controlled version of the choice paradigm and manipulating levels of reward, we demonstrated an interactive effect between monetary reward and self-determined choice on 1-day delayed memory performance. Specifically, the choice effect on memory decreased when we introduced the performance-dependent external rewards. These results are discussed in terms of understanding how external and internal motivators interact to impact learning and memory.

Chronic Kidney Disease Induces Cognitive Impairment in the Early Stage

OBJECTIVE

Previous research indicates a link between cognitive impairment and chronic kidney disease (CKD), but the underlying factors are not fully understood. This study aimed to investigate the progression of CKD-induced cognitive impairment and the involvement of cognition-related proteins by developing early- and late-stage CKD models in Sprague-Dawley rats.

METHODS

The Morris water maze test and the step-down passive avoidance task were performed to evaluate the cognitive abilities of the rats at 24 weeks after surgery. Histopathologic examinations were conducted to examine renal and hippocampal damage. Real-time PCR, Western blotting analysis, and immunohistochemical staining were carried out to determine the hippocampal expression of brain-derived neurotrophic factor (BDNF), choline acetyltransferase (ChAT), and synaptophysin (SYP).

RESULTS

Compared with the control rats, the rats with early-stage CKD exhibited mild renal damage, while those with late-stage CKD showed significantly increased serum creatinine levels as well as apparent renal and brain damage. The rats with early-stage CKD also demonstrated significantly impaired learning abilities and memory compared with the control rats, with further deterioration observed in the rats with late-stage CKD. Additionally, we observed a significant downregulation of cognition-related proteins in the hippocampus of rats with early-stage CKD, which was further exacerbated with declining renal function as well as worsening brain and renal damage in rats with late-stage CKD.

CONCLUSION

These results suggest the importance of early screening to identify CKD-induced cognitive dysfunction promptly. In addition, the downregulation of cognition-related proteins may play a role in the progression of cognitive dysfunction.

Paving the Way for Memory Enhancement: Development and Examination of a Neurofeedback System Targeting the Medial Temporal Lobe

Neurofeedback (NF) shows promise in enhancing memory, but its application to the medial temporal lobe (MTL) still needs to be studied. Therefore, we aimed to develop an NF system for the memory function of the MTL and examine neural activity changes and memory task score changes through NF training. We created a memory NF system using intracranial electrodes to acquire and visualise the neural activity of the MTL during memory encoding. Twenty trials of a tug-of-war game per session were employed for NF and designed to control neural activity bidirectionally (Up/Down condition). NF training was conducted with three patients with drug-resistant epilepsy, and we observed an increasing difference in NF signal between conditions (Up-Down) as NF training progressed. Similarities and negative correlation tendencies between the transition of neural activity and the transition of memory function were also observed. Our findings demonstrate NF's potential to modulate MTL activity and memory encoding. Future research needs further improvements to the NF system to validate its effects on memory functions. Nonetheless, this study represents a crucial step in understanding NF's application to memory and provides valuable insights into developing more efficient memory enhancement strategies.

Integrated science, technology, engineering, and mathematics project-based learning for physics learning from neuroscience perspectives

For many students, learning physics is difficult because of its abstractness. To help students to learn physics, we have developed the Integrated Science, Technology, Engineering, and Mathematics Projects Based Learning (STEM-PjBL) method based on principles from neuroscience. We believe that incorporating principles from educational neuroscience would help students learn better. This paper describes our experiments of implementing the integrated STEM-PjBL Module in physics, i.e., classical mechanics, to secondary school students in Malaysia and South Korea. The study consists of two groups of students: the experiment group, 77 in total, comprising those who have undergone the integrated STEM-PjBL, and the control group, again 77 in total, who experienced the traditional approach. The Colorado Learning Attitudes Science Survey (CLASS) was conducted for the two groups on students' beliefs about physics and learning physics before and after the implementation. The paired sample t-test from the pre-survey and post-survey shows that the integrated STEM-PjBL group has a more positive shift in belief about physics and learning physics than the traditional group. The results of the independent samples t-test for students' beliefs about physics and learning physics, compared with the post-survey between the experimental group and the traditional group for both Malaysian and Korean perspectives, show that the experimental group has a higher mean compared to the traditional group. This paper explains why the integrated STEM-PjBL has improved students' beliefs about physics and learning physics, from the neuroscience education perspective. Finally, the paper concludes with guidelines for teachers who wish to implement the integrated STEM-PjBL in the classroom.

Self-motivated and directed learning across the lifespan

Self-motivated and directed learning is integral to knowledge base expansion for learners of all ages. Both motivational and cognitive processes drive self-motivated and directed lifelong learning, yet how these different processes operate together from childhood through adulthood is largely unknown. In this review, we discuss the role of personal motivators, such as beliefs in self-efficacy and personality traits in self-motivated and directed learning across the lifespan. We then consider the role of cognitive processes that contribute to knowledge base expansion in learners of all ages, specifically executive functions. We focus on working memory, inhibitory control, and task switching as potential determinants of lifelong learning. Finally, we integrate the two literatures, to discuss ways in which personal motivators may influence deployment of executive functions under self-motivated and directed conditions as a learner advances along a developmental trajectory. We also suggest ways to move the study of self-motivated and directed learning beyond observation and self-report measures thus affording experimental control. We aim to provide a more comprehensive understanding and novel insight to the mechanisms and processes of self-motivated and directed learning across the lifespan.

VR for Cognition and Memory

This chapter will provide a review of research into human cognition through the lens of VR-based paradigms for studying memory. Emphasis is placed on why VR increases the ecological validity of memory research and the implications of such enhancements.

Controllability boosts neural and cognitive signatures of changes-of-mind in uncertain environments

In uncertain environments, seeking information about alternative choice options is essential for adaptive learning and decision-making. However, information seeking is usually confounded with changes-of-mind about the reliability of the preferred option. Here, we exploited the fact that information seeking requires control over which option to sample to isolate its behavioral and neurophysiological signatures. We found that changes-of-mind occurring with control require more evidence against the current option, are associated with reduced confidence, but are nevertheless more likely to be confirmed on the next decision. Multimodal neurophysiological recordings showed that these changes-of-mind are preceded by stronger activation of the dorsal attention network in magnetoencephalography, and followed by increased pupil-linked arousal during the presentation of decision outcomes. Together, these findings indicate that information seeking increases the saliency of evidence perceived as the direct consequence of one's own actions.

Cerebellar glutamatergic system impacts spontaneous motor recovery by regulating Gria1 expression

Peripheral nerve injury (PNI) often results in spontaneous motor recovery; however, how disrupted cerebellar circuitry affects PNI-associated motor recovery is unknown. Here, we demonstrated disrupted cerebellar circuitry and poor motor recovery in ataxia mice after PNI. This effect was mimicked by deep cerebellar nuclei (DCN) lesion, but not by damaging non-motor area hippocampus. By restoring cerebellar circuitry through DCN stimulation, and reversal of neurotransmitter imbalance using baclofen, ataxia mice achieve full motor recovery after PNI. Mechanistically, elevated glutamate-glutamine level was detected in DCN of ataxia mice by magnetic resonance spectroscopy. Transcriptomic study revealed that Gria1, an ionotropic glutamate receptor, was upregulated in DCN of control mice but failed to be upregulated in ataxia mice after sciatic nerve crush. AAV-mediated overexpression of Gria1 in DCN rescued motor deficits of ataxia mice after PNI. Finally, we found a correlative decrease in human GRIA1 mRNA expression in the cerebellum of patients with ataxia-telangiectasia and spinocerebellar ataxia type 6 patient iPSC-derived Purkinje cells, pointing to the clinical relevance of glutamatergic system. By conducting a large-scale analysis of 9,655,320 patients with ataxia, they failed to recover from carpal tunnel decompression surgery and tibial neuropathy, while aged-match non-ataxia patients fully recovered. Our results provide insight into cerebellar disorders and motor deficits after PNI.

AAV9-MCT8 Delivery at Juvenile Stage Ameliorates Neurological and Behavioral Deficits in a Mouse Model of MCT8-Deficiency

Background: Allan-Herndon-Dudley syndrome (AHDS) is a severe psychomotor disability disorder that also manifests characteristic abnormal thyroid hormone (TH) levels. AHDS is caused by inactivating mutations in monocarboxylate transporter 8 (MCT8), a specific TH plasma membrane transporter widely expressed in the central nervous system (CNS). MCT8 mutations cause impaired transport of TH across brain barriers, leading to insufficient neural TH supply. There is currently no successful therapy for the neurological symptoms. Earlier work has shown that intravenous (IV), but not intracerebroventricular adeno-associated virus serotype 9 (AAV9) -based gene therapy given to newborn Mct8 knockout (Mct8^-/y) male mice increased triiodothyronine (T₃) brain content and partially rescued TH-dependent gene expression, suggesting a promising approach to treat this neurological disorder. Methods: The potential of IV delivery of AAV9 carrying human MCT8 was tested in the well-established Mct8^-/y/Organic anion-transporting polypeptide 1c1 (Oatp1c1)^{-/ -} double knockout (dKO) mouse model of AHDS, which, unlike Mct8^-/y mice, displays both neurological and TH phenotype. Further, as the condition is usually diagnosed during childhood, treatment was given intravenously to P30 mice and psychomotor tests were carried out blindly at P120-P140 after which tissues were collected and analyzed. Results: Systemic IV delivery of AAV9-MCT8 at a juvenile stage led to improved locomotor and cognitive functions at P120-P140, which was accompanied by a near normalization of T₃ content and an increased response of positively regulated TH-dependent gene expression in different brain regions examined (thalamus, hippocampus, and parietal cortex). The effects on serum TH concentrations and peripheral tissues were less pronounced, showing only improvement in the serum T₃/reverse T₃ (rT₃) ratio and in liver deiodinase 1 expression. Conclusion: IV administration of AAV9, carrying the human MCT8, to juvenile dKO mice manifesting AHDS has long-term beneficial effects, predominantly on the CNS. This preclinical study indicates that this gene therapy has the potential to ameliorate the devastating neurological symptoms in patients with AHDS.

Temporal order memory impairments in individuals with moderate-severe traumatic brain injury

INTRODUCTION

Temporal order memory is a core cognitive function that underlies much of our behavior. The ability to bind together information within and across events, and to reconstruct that sequence of information, critically relies upon the hippocampal relational memory system. Recent work has suggested traumatic brain injury (TBI) may particularly impact hippocampally mediated relational memory. However, it is currently unclear whether such deficits extend to temporal order memory, and whether deficits only arise at large memory loads. The present study assessed temporal order memory in individuals with chronic, moderate-severe TBI across multiple set sizes.

METHOD

Individuals with TBI and Neurotypical Comparison participants studied sequences of three to nine objects, one a time. At test, all items were re-presented in pseudorandom order, and participants indicated the temporal position (i.e., first, second, etc.) in which each object had appeared. Critically, we assessed both the frequency and the magnitude of errors (i.e., how far from its studied position was an item remembered).

RESULTS

Individuals with TBI were not impaired for the smallest set size, but showed significant impairments at 5+ items. Group differences in the error frequency did not increase further with larger set sizes, but group differences in error magnitude did increase with larger memory loads. Individuals with TBI showed spared performance for the first object of each list (primacy) but were impaired on the last object (recency), though error frequency was better for last compared to middle items.

CONCLUSIONS

Our findings demonstrate that TBI results in impaired temporal order memory for lists as small as five items, and that impairments are exacerbated with increasing memory loads. Assessments that test only small set sizes may be insufficient to detect these deficits. Further, these data highlight the importance of additional, sensitive measures in the assessment of cognitive impairments in TBI.

Decision uncertainty during hypothesis testing enhances memory accuracy for incidental information

Humans actively seek information to reduce uncertainty, providing insight on how our decisions causally affect the world. While we know that episodic memories can help support future goal-oriented behaviors, little is known about how hypothesis testing during exploration influences episodic memory. To investigate this question, we designed a hypothesis testing paradigm, in which participants figured out rules to unlock treasure chests. Using this paradigm, we characterized how hypothesis testing during exploration influenced memory for the contents of the treasure chests. We found that there was an inverted U-shaped relationship between decision uncertainty and memory, such that memory was best when decision uncertainty was moderate. An exploratory analysis also showed that surprising outcomes lead to lower memory confidence independent of accuracy. These findings support a model in which moderate decision uncertainty during hypothesis testing enhances incidental information encoding.

Control over sampling boosts numerical evidence processing in human decisions from experience

When acquiring information about choice alternatives, decision makers may have varying levels of control over which and how much information they sample before making a choice. How does control over information acquisition affect the quality of sample-based decisions? Here, combining variants of a numerical sampling task with neural recordings, we show that control over when to stop sampling can enhance (i) behavioral choice accuracy, (ii) the build-up of parietal decision signals, and (iii) the encoding of numerical sample information in multivariate electroencephalogram patterns. None of these effects were observed when participants could only control which alternatives to sample, but not when to stop sampling. Furthermore, levels of control had no effect on early sensory signals or on the extent to which sample information leaked from memory. The results indicate that freedom to stop sampling can amplify decisional evidence processing from the outset of information acquisition and lead to more accurate choices.

Working memory and active sampling of the environment: Medial temporal contributions

Working memory (WM) refers to the ability to maintain and actively process information-either derived from perception or long-term memory (LTM)-for intelligent thought and action. This chapter focuses on the contributions of the temporal lobe, particularly medial temporal lobe (MTL) to WM. First, neuropsychological evidence for the involvement of MTL in WM maintenance is reviewed, arguing for a crucial role in the case of retaining complex relational bindings between memorized features. Next, MTL contributions at the level of neural mechanisms are covered-with a focus on WM encoding and maintenance, including interactions with ventral temporal cortex. Among WM use processes, we focus on active sampling of environmental information, a key input source to capacity-limited WM. MTL contributions to the bidirectional relationship between active sampling and memory are highlighted-WM control of active sampling and sampling as a way of selecting input to WM. Memory-based sampling studies relying on scene and object inspection, visual-based exploration behavior (e.g., vicarious behavior), and memory-guided visual search are reviewed. The conclusion is that MTL serves an important function in the selection of information from perception and transfer from LTM to capacity-limited WM.

Multimodal Three-Dimensional Visualization Enhances Novice Learner Interpretation of Basic Cross-Sectional Anatomy

While integrated delivery of anatomy and radiology can support undergraduate anatomical education, the interpretation of complex three-dimensional spatial relationships in cross-sectional and radiological images is likely to be demanding for novices. Due to the value of technology-enhanced and multimodal strategies, it was hypothesized that simultaneous digital and physical learning could enhance student understanding of cross-sectional anatomy. A novel learning approach introduced at a United Kingdom university medical school combined visualization table-based thoracic cross-sections and digital models with a three-dimensional printed heart. A mixed-method experimental and survey approach investigated student perceptions of challenging anatomical areas and compared the multimodal intervention to a two-dimensional cross-section control. Analysis of seven-point Likert-type responses of new medical students (n = 319) found that clinical imaging (mean 5.64 SD ± 1.20) was significantly more challenging (P < 0.001) than surface anatomy (4.19 ± 1.31) and gross anatomy (4.92 ± 1.22). Pre-post testing of students who used the intervention during their first anatomy class at medical school (n = 229), identified significant increases (P < 0.001) in thoracic cross-sectional anatomy interpretation performance (mean 31.4% ± 15.3) when compared to the subsequent abdominal control activity (24.1% ± 17.6). Student test scores were independent of mental-rotation ability. As depicted on a seven-point Likert-type scale, the intervention may have contributed to students considering cross-sectional interpretation of thoracic images (4.2 ± 1.23) as significantly less challenging (P < 0.001) than comparable abdominal images (5.59 ± 1.14). These findings could have implications for how multimodal cross-sectional anatomy learning approaches are implemented within medical curricula.

A Platform for Cognitive Monitoring of Neurosurgical Patients During Hospitalization

Intracranial recordings in epilepsy patients are increasingly utilized to gain insight into the electrophysiological mechanisms of human cognition. There are currently several practical limitations to conducting research with these patients, including patient and researcher availability and the cognitive abilities of patients, which limit the amount of task-related data that can be collected. Prior studies have synchronized clinical audio, video, and neural recordings to understand naturalistic behaviors, but these recordings are centered on the patient to understand their seizure semiology and thus do not capture and synchronize audiovisual stimuli experienced by patients. Here, we describe a platform for cognitive monitoring of neurosurgical patients during their hospitalization that benefits both patients and researchers. We provide the full specifications for this system and describe some example use cases in perception, memory, and sleep research. We provide results obtained from a patient passively watching TV as proof-of-principle for the naturalistic study of cognition. Our system opens up new avenues to collect more data per patient using real-world behaviors, affording new possibilities to conduct longitudinal studies of the electrophysiological basis of human cognition under naturalistic conditions.

The effect of choice on intentional and incidental memory

Recent studies have revealed that memory performance is better when participants have the opportunity to make a choice regarding the experimental task (choice condition) than when they do not have such a choice (fixed condition). These studies, however, used intentional memory tasks, leaving open the question whether the choice effect also applies to incidental memory. In the current study, we first repeated the choice effect on the 24-h delayed intentional memory performance (experiment 1). Next, using an incidental paradigm in which participants were asked to judge the category of the items instead of intentionally memorizing them, we observed the choice effect on judgment during encoding and memory performance in a 24-h delayed surprise test (experiment 2). Participants judged more accurately and quickly and had better recognition memory for items in the choice condition than for items in the fixed condition. These results are discussed in terms of the role of choice in both intentional and incidental memory.

The Prefrontal-Hippocampal Comparator: Volition and Episodic Memory

This review describes recent research that is relevant to the prefrontal-hippocampal comparator model with the following conclusions: 1. Hippocampal area CA1 serves, at least in part, as an associative match-mismatch comparator. 2. Voluntary movement strengthens episodic memories for goal-directed behavior. 3. Hippocampal theta power serves as a prediction error signal during hippocampal dependent tasks. 4. The self-referential component of episodic memory in humans is mediated by the corollary discharge (the efference copy of the action plan developed by prefrontal cortex and transmitted to hippocampus where it is stored as a working memory; CA1 uses this efference copy to compare the expected consequences of action to the actual consequences of action). 5. Impairments in the production or transmission of this corollary discharge may contribute to some of the symptoms of schizophrenia. Unresolved issues and suggestions for future research are discussed.

Volitional learning promotes theta phase coding in the human hippocampus

While behavioral evidence shows that volitionally controlled learning benefits human memory, little is known about the neural mechanisms underlying this effect. Insights from spatial navigation research in rodents point to the relevance of hippocampal theta oscillations. However, the mechanisms through which theta might support the beneficial effects of active learning in humans are currently unknown. Here, we demonstrate hippocampal theta oscillations increase during volitional learning, promoting a segregation of task-relevant representational signals according to their semantic content. Our results constitute a direct link to the animal literature on hippocampal theta oscillations and its relation to volition and memory processes.

Electrophysiological studies in rodents show that active navigation enhances hippocampal theta oscillations (4–12 Hz), providing a temporal framework for stimulus-related neural codes. Here we show that active learning promotes a similar phase coding regime in humans, although in a lower frequency range (3–8 Hz). We analyzed intracranial electroencephalography (iEEG) from epilepsy patients who studied images under either volitional or passive learning conditions. Active learning increased memory performance and hippocampal theta oscillations and promoted a more accurate reactivation of stimulus-specific information during memory retrieval. Representational signals were clustered to opposite phases of the theta cycle during encoding and retrieval. Critically, during active but not passive learning, the temporal structure of intracycle reactivations in theta reflected the semantic similarity of stimuli, segregating conceptually similar items into more distant theta phases. Taken together, these results demonstrate a multilayered mechanism by which active learning improves memory via a phylogenetically old phase coding scheme.

Chained study and the discovery of relational structure

Prior knowledge of relational structure allows people to quickly make sense of and respond to new experiences. When awareness of such structure is not necessary to support learning, however, it is unclear when and why individuals "spontaneously discover" an underlying relational schema. The present study examines the determinants of such discovery in discrimination-based transitive inference (TI), whereby people learn about a hierarchy of interrelated premises and are tested on their ability to draw inferences that bridge studied relations. Experiencing "chained" sequences of overlapping premises during training was predicted to facilitate the discovery of relational structure. Among individuals without prior knowledge of the hierarchy, chaining improved relational learning and was most likely to result in explicit awareness of the underlying relations between items. Observation of chained training sequences was also more effective than the self-generation of training sequences. These findings add to growing evidence that the temporal dynamics of training, including successive presentation of overlapping associations, are key to understanding spontaneous relational discovery during learning.

Individual differences in theta-band oscillations in a spatial memory network revealed by electroencephalography predict rapid place learning

Spatial memory has been closely related to the medial temporal lobe and theta oscillations are thought to play a key role. However, it remains difficult to investigate medial temporal lobe activation related to spatial memory with non-invasive electrophysiological methods in humans. Here, we combined the virtual delayed-matching-to-place task, reverse-translated from the watermaze delayed-matching-to-place task in rats, with high-density electroencephalography recordings. Healthy young volunteers performed this computerised task in a virtual circular arena, which contained a hidden target whose location moved to a new place every four trials, allowing the assessment of rapid memory formation. Using behavioural measures as predictor variables for source reconstructed frequency-specific electroencephalography power, we found that inter-individual differences in ‘search preference’ during ‘probe trials’, a measure of one-trial place learning known from rodent studies to be particularly hippocampus-dependent, correlated predominantly with distinct theta-band oscillations (approximately 7 Hz), particularly in the right temporal lobe, the right striatum and inferior occipital cortex or cerebellum. This pattern was found during both encoding and retrieval/expression, but not in control analyses and could not be explained by motor confounds. Alpha-activity in sensorimotor and parietal cortex contralateral to the hand used for navigation also correlated (inversely) with search preference. This latter finding likely reflects movement-related factors associated with task performance, as well as a frequency difference in (ongoing) alpha-rhythm for high-performers versus low-performers that may contribute to these results indirectly. Relating inter-individual differences in ongoing brain activity to behaviour in a continuous rapid place-learning task that is suitable for a variety of populations, we could demonstrate that memory-related theta-band activity in temporal lobe can be measured with electroencephalography recordings. This approach holds great potential for further studies investigating the interactions within this network during encoding and retrieval, as well as neuromodulatory impacts and age-related changes.

Reduced Information Transmission of Medial Prefrontal Cortex to Basolateral Amygdala Inhibits Exploratory Behavior in Depressed Rats

Depression is a mental and neurological disease that reduces the desire for exploration. Dysregulation of the information transmission between medial prefrontal cortex (mPFC) and basolateral amygdala (BLA) is associated with depression. However, which direction of information transmission (mPFC-BLA or BLA-mPFC) related to the decline of exploratory interests in depression is unclear. Therefore, it is important to determine what specific changes occur in mPFC and BLA information transmission in depressed rats during exploratory behavior. In the present study, local field potentials (LFPs) were recorded via multi-electrodes implanted in the mPFC and BLA for the control and depression groups of rats when they were exploring in an open field. The theta band was determined to be the characteristic band of exploratory behavior. The direct transfer function (DTF) was used to calculate the mPFC and BLA bidirectional information flow (IF) to measure information transmission. Compared with the control group, the theta IF of mPFC-BLA in the depression group was significantly reduced, and there was no significant difference in theta IF of BLA-mPFC between the two groups. Our results indicated that the reduction of mPFC-BLA information transmission can inhibit the exploratory behavior of depressed rats.

The rhythm of learning: Theta oscillations as an index of active learning in infancy

Active learning is a critical component of human development, however, the mechanisms supporting it are not fully understood. Given that early learning experiences may affect both infants' immediate learning success, as well as their motivation to learn, it is particularly important to investigate the mechanisms of active learning in this period, when the foundations of learning habits and curiosity are built. Traditional behavioural approaches of studying infant learning face challenges that emerging tools from neuroscience may help relieve. We introduce one such tool, EEG theta oscillations, and propose this neural marker has great potential for offering novel insights into active learning. Theta activity, recorded prior to or during learning, has been shown to be predictive of learning success. We argue that this involvement in memory formation, combined with theta activity's tight association with reward processing, makes theta oscillations a uniquely suited tool for the investigation of motivational mechanisms underlying active learning. We outline research questions as well as methodological approaches pertinent to infant learning and suggest how and why theta oscillations may offer complementary insights. As such, we aim to bridge the gap between cognitive and neural approaches, and advance our knowledge of active learning in development more broadly.

Temporal context guides visual exploration during scene recognition

Memories for episodes are temporally structured. Cognitive models derived from list-learning experiments attribute this structure to the retrieval of temporal context information that indicates when a memory occurred. These models predict key features of memory recall, such as the strong tendency to retrieve studied items in the order in which they were first encountered. Can such models explain ecological memory behaviors, such as eye movements during encoding and retrieval of complex visual stimuli? We tested predictions from retrieved-context models using three data sets involving recognition memory and free viewing of complex scenes. Subjects reinstated sequences of eye movements from one scene-viewing episode to the next. Moreover, sequence reinstatement decayed over time and was associated with successful memory. We observed memory-driven reinstatement even after accounting for intrinsic scene properties that produced consistent eye movements. These findings confirm predictions of retrieved-context models, suggesting retrieval of temporal context influences complex behaviors generated during naturalistic memory experiences. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

"Walk this way": specific contributions of active walking to the encoding of metric properties during spatial learning

The effect of body-based information on spatial memory has been traditionally described as a facilitating factor for large-scale spatial learning in the field of active learning research (Chrastil & Warren, Psychonomic Bulletin and Review, 19(1):1-23; 2012). The specific contribution of body-based information to spatial representation properties is however not yet well defined and the mechanisms through which body-based information contributes to spatial learning are not clear enough. To disambiguate the effect of active spatial learning on the quality of spatial representations from the beneficial effect of physiological arousal, we compared four experimental conditions (walking on a unidirectional treadmill during learning, retrieval, both phases or no walking). Results showed no effect of the walking condition for a route perspective task, but a significant effect on a survey perspective task (landmark positioning on a map): participants who walked during encoding (encoding group and encoding + retrieval group) obtained better results than those who did not walk or walked only during retrieval. Geometrical analysis of spatial positions on maps revealed that the activity of walking during encoding improves the correlation between participants' coordinates and actual coordinates through better distance estimations and angular accuracy, even though the optic flow was not matched with individual walking speed. Control group variance in all measures was higher than that of the walking groups (regardless of the moment of walking). Taken together, these results provide arguments for the multimodal nature of spatial representations, where body-related information derived from walking is involved in metric properties accuracy and perspective switching.

Information about action outcomes differentially affects learning from self-determined versus imposed choices

The valence of new information influences learning rates in humans: good news tends to receive more weight than bad news. We investigated this learning bias in four experiments, by systematically manipulating the source of required action (free versus forced choices), outcome contingencies (low versus high reward) and motor requirements (go versus no-go choices). Analysis of model-estimated learning rates showed that the confirmation bias in learning rates was specific to free choices, but was independent of outcome contingencies. The bias was also unaffected by the motor requirements, thus suggesting that it operates in the representational space of decisions, rather than motoric actions. Finally, model simulations revealed that learning rates estimated from the choice-confirmation model had the effect of maximizing performance across low- and high-reward environments. We therefore suggest that choice-confirmation bias may be adaptive for efficient learning of action-outcome contingencies, above and beyond fostering person-level dispositions such as self-esteem.

Visual Exploration at Higher Fixation Frequency Increases Subsequent Memory Recall

Only a small proportion of what we see can later be recalled. Up to date it is unknown how far differences in visual exploration during encoding affect the strength of episodic memories. Here, we identified individual gaze characteristics by analyzing eye tracking data in a picture encoding task performed by 967 healthy subjects during fMRI. We found a positive correlation between fixation frequency during visual exploration and subsequent free recall performance. Brain imaging results showed a positive correlation of fixation frequency with activations in regions related to vision and memory, including the medial temporal lobe. To investigate if higher fixation frequency is causally linked to better memory, we experimentally manipulated visual exploration patterns in an independent population of 64 subjects. Doubling the number of fixations within a given exploration time increased subsequent free recall performance by 19%. Our findings provide evidence for a causal relationship between fixation frequency and episodic memory for visual information.

Relational Memory at Short and Long Delays in Individuals With Moderate-Severe Traumatic Brain Injury

Memory deficits are a common and frequently-cited consequence of moderate-severe traumatic brain injury (TBI). However, we know less about how TBI influences relational memory, which allows the binding of the arbitrary elements of experience and the flexible use and recombination of relational representations in novel situations. Relational memory is of special interest for individuals with TBI, given the vulnerability of the hippocampus to injury mechanisms, as well as a growing body of literature establishing the role of relational memory in flexible and goal-directed behavior. In this study, participants with and without a history of moderate-severe TBI completed a continuous relational memory task for face-scene pairings. Participants with TBI exhibited a disruption in relational memory not only when tested after a delay, but also when tested with no experimenter-imposed delay after stimulus presentation. Further, canonical assessments of working and episodic memory did not correspond with performance on the face-scene task, suggesting that this task may tap into relational memory differently and with greater sensitivity than standardized memory assessments. These results highlight the need for rigorous assessment of relational memory in TBI, which is likely to detect deficits that have specific consequences for community reintegration and long-term functional outcomes.

Focused Multisensory Anatomy Observation and Drawing for Enhancing Social Learning and Three-Dimensional Spatial Understanding

The concept that multisensory observation and drawing can be effective for enhancing anatomy learning is supported by pedagogic research and theory, and theories of drawing. A haptico-visual observation and drawing (HVOD) process has been previously introduced to support understanding of the three-dimensional (3D) spatial form of anatomical structures. The HVOD process involves exploration of 3D anatomy with the combined use of touch and sight, and the simultaneous act of making graphite marks on paper which correspond to the anatomy under observation. Findings from a previous study suggest that HVOD can increase perceptual understanding of anatomy through memorization and recall of the 3D form of observed structures. Here, additional pedagogic and cognitive underpinnings are presented to further demonstrate how and why HVOD can be effective for anatomy learning. Delivery of a HVOD workshop is described as a detailed guide for instructors, and themes arising from a phenomenological study of educator experiences of the HVOD process are presented. Findings indicate that HVOD can provide an engaging approach for the spatial exploration of anatomy within a supportive social learning environment, but also requires modification for effective curricular integration. Consequently, based on the most effective research-informed, theoretical, and logistical elements of art-based approaches in anatomy learning, including the framework provided by the observe-reflect-draw-edit-repeat (ORDER) method, an optimized "ORDER Touch" observation and drawing process has been developed. This is with the aim of providing a widely accessible resource for supporting social learning and 3D spatial understanding of anatomy, in addition to improving specific anatomical knowledge.

Visual exploration differences during relational memory encoding in early psychosis

Relational memory, or the ability to form contextual associations among items encountered closely in time, is impaired in schizophrenia. The ability to bind items into a relational memory is dependent on the hippocampus, a region that is abnormal in schizophrenia. However, the hippocampus is also involved in exploratory behavior, leaving open the question whether relational memory deficits in schizophrenia are due to failure of relational binding or diminished visual exploration of individual items during encoding. We studied visual exploration patterns during the encoding of face-scene pairs in 66 healthy control subjects and 69 early psychosis patients, to test the hypothesis that differences in visual exploration during the encoding phase can explain task accuracy differences between the two groups. Psychosis patients had lower explicit test accuracy and were less likely to transition from mouth to eyes during encoding. The visual exploration pattern differences between groups did not mediate the relationship between group and explicit test accuracy. We conclude that early psychosis patients have an abnormal pattern of binding items together during encoding that warrants further research.

Active transitive inference: When learner control facilitates integrative encoding

A growing body of research indicates that active control of learning improves episodic memory for material experienced during study. It is less clear how active learning impacts the integration of those experiences into flexible, generalizable knowledge. This study uses a novel active transitive inference task to investigate how people learn a relational hierarchy through active selection of premise pairs. Active control improved memory for studied premises as well as transitive inferences involving items that were never experienced together during study. Active learners also exhibited a systematic search preference, generating sequences of overlapping premises that may facilitate relational integration. Critically, however, advantages from active control were not universal: Only participants with higher working memory capacity benefited from the opportunity to select premise pairs during learning. These findings suggest that active control enhances integrative encoding of studied material, but only among individuals with sufficient cognitive resources.

A common mechanism underlying choice's influence on preference and memory

Individual control over learning leads to better memory outcomes, yet it is still unclear which aspects of control matter. One's sense of agency could be a key component, but it can be challenging to dissociate it from its consequences on the environment. Here we used a paradigm in which participants in one condition had the opportunity to choose between cues (choice condition) and in another were instructed which cue to select (fixed condition). Because the cues had no effect on the memoranda, we could isolate the effect of choice on memory. Participants also rated the cues for preference before and after encoding, allowing us to test how the number of times a cue was chosen affected its preference. By pooling multiple behavioral studies, we were able to use an individual differences approach to examine the relationship between choice effects on preference and memory. Replicating previous work, we found that immediate and delayed (24-h) recognition memory was higher for items encountered in the choice condition. We also found that cues that were selected more often increased their preference in the choice condition, but actually decreased their preference in the fixed condition, suggesting that choice engaged value-related processes. Critically, we found a positive across-subjects relationship between choice memory enhancements and choice-induced preference change for delayed but not for immediate memory. These data suggest that a shared value-based mechanism enhances preference for choice cues and memory consolidation of the choice outcomes. Thus, the value of choice may play an important role in learning enhancements.

Searching for Semantic Knowledge: A Vector Space Semantic Analysis of the Feature Generation Task

A recent neuropsychological study found that amnesic patients with hippocampal damage (HP) and severe declarative memory impairment produce markedly fewer responses than healthy comparison (CO) participants in a semantic feature generation task (Klooster and Duff, 2015), consistent with the idea that hippocampal damage is associated with semantic cognitive deficits. Participants were presented with a target word and asked to produce as many features of that word as possible (e.g., for target word "book," "read words on a page"). Here, we use the response sequences collected by Klooster and Duff (2015) to develop a vector space model of semantic search. We use this model to characterize the dynamics of semantic feature generation and consider the role of the hippocampus in this search process. Both HP and CO groups tended to initiate the search process with features close in semantic space to the target word, with a gradual decline in similarity to the target word over the first several responses. Adjacent features in the response sequence showed stronger similarity to each other than to non-adjacent features, suggesting that the search process follows a local trajectory in semantic space. Overall, HP patients generated features that were closer in semantic space to the representation of the target word, as compared to the features generated by the CO group, which ranged more widely in semantic space. These results are consistent with a model in which a compound retrieval cue (containing a representation of the target word and a representation of the previous response) is used to probe semantic memory. The model suggests that the HP group's search process is restricted from ranging as far in semantic space from the target word, relative to the CO group. These results place strong constraints on the structure of models of semantic memory search, and on the role of hippocampus in probing semantic memory.

Spatial relational memory in individuals with traumatic brain injury

Introduction: Relational memory is the ability to bind arbitrary relations between elements of experience into durable representations and the flexible expression of these representations. It is well known that individuals with traumatic brain injury (TBI) have declarative memory impairments, but less is known about how TBI affects relational memory binding, the deficit at the heart of declarative, or relational, memory impairment. The aim of the current study is to examine such deficits.Method: We used a spatial reconstruction task (SRT) with 29 individuals with TBI and 23 normal comparison (NC) participants to investigate four different types of spatial relations: (A) identity-location relations, i.e., the relationship between a specific item and its known location; (B) item-item relations, or the relationship between one item and another; (C) item-display relations, or the relationship between an item and its position in the display; and (D) compound-item relations, i.e., relations that involve combinations of A, B, and C.Results: Our data revealed that individuals with TBI showed impairments in learning identity-location relations and increased compound errors compared to NCs. We also found evidence that when item identity is disregarded, individuals with TBI do not perform differently from NCs. An exploratory analysis revealed that while relational memory performance was significantly correlated with scores on the California Verbal Learning Test (CVLT), more participants with TBI exhibited impairment on the SRT than of the CVLT.Conclusions: Our findings show that relational memory is impaired following TBI, and provide preliminary evidence for an easy-to-administer task with increased sensitivity to memory impairment.

Action boosts episodic memory encoding in humans via engagement of a noradrenergic system

We are constantly interacting with our environment whilst we encode memories. However, how actions influence memory formation remains poorly understood. Goal-directed movement engages the locus coeruleus (LC), the main source of noradrenaline in the brain. Noradrenaline is also known to enhance episodic encoding, suggesting that action could improve memory via LC engagement. Here we demonstrate, across seven experiments, that action (Go-response) enhances episodic encoding for stimuli unrelated to the action itself, compared to action inhibition (NoGo). Functional magnetic resonance imaging, and pupil diameter as a proxy measure for LC-noradrenaline transmission, indicate increased encoding-related LC activity during action. A final experiment, replicated in two independent samples, confirmed a novel prediction derived from these data that emotionally aversive stimuli, which recruit the noradrenergic system, modulate the mnemonic advantage conferred by Go-responses relative to neutral stimuli. We therefore provide converging evidence that action boosts episodic memory encoding via a noradrenergic mechanism.

Coordinated representational reinstatement in the human hippocampus and lateral temporal cortex during episodic memory retrieval

Theoretical models of episodic memory have proposed that retrieval depends on interactions between the hippocampus and neocortex, where hippocampal reinstatement of item-context associations drives neocortical reinstatement of item information. Here, we simultaneously recorded intracranial EEG from hippocampus and lateral temporal cortex (LTC) of epilepsy patients who performed a virtual reality spatial navigation task. We extracted stimulus-specific representations of both item and item-context associations from the time-frequency patterns of activity in hippocampus and LTC. Our results revealed a double dissociation of representational reinstatement across time and space: an early reinstatement of item-context associations in hippocampus preceded a later reinstatement of item information in LTC. Importantly, reinstatement levels in hippocampus and LTC were correlated across trials, and the quality of LTC reinstatement was predicted by the magnitude of phase synchronization between hippocampus and LTC. These findings confirm that episodic memory retrieval in humans relies on coordinated representational interactions within a hippocampal-neocortical network.

Episodic memory retrieval is hypothesized to rely on hippocampal reinstatement of item-context associations which drives reinstatement of item information in cortex. Here, the authors confirm this sequence of events, using iEEG recordings from the human hippocampus and lateral temporal cortex.