Hippocampal theta codes for distances in semantic and temporal spaces

Solomon, Ethan A.; Lega, Bradley; Sperling, Michael R.; Kahana, Michael J.

doi:10.1073/pnas.1906729116

Cited by 119 publications

(70 citation statements)

References 69 publications

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“…In line with these observations, previous theories have argued that reasoning about abstract conceptual information follows the same computational principles as spatial reasoning [6][7][8]. This has recently gained new support from neuroscientific evidence suggesting that common neural substrates are the basis for knowledge representation across domains [9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 73%

Similarities and differences in spatial and non-spatial cognitive maps

Schulz

Garvert

et al. 2020

PLoS Comput Biol

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Learning and generalization in spatial domains is often thought to rely on a "cognitive map", representing relationships between spatial locations. Recent research suggests that this same neural machinery is also recruited for reasoning about more abstract, conceptual forms of knowledge. Yet, to what extent do spatial and conceptual reasoning share common computational principles, and what are the implications for behavior? Using a within-subject design we studied how participants used spatial or conceptual distances to generalize and search for correlated rewards in successive multi-armed bandit tasks. Participant behavior indicated sensitivity to both spatial and conceptual distance, and was best captured using a Bayesian model of generalization that formalized distance-dependent generalization and uncertainty-guided exploration as a Gaussian Process regression with a radial basis function kernel. The same Gaussian Process model best captured human search decisions and judgments in both domains, and could simulate realistic learning curves, where we found equivalent levels of generalization in spatial and conceptual tasks. At the same time, we also find characteristic differences between domains. Relative to the spatial domain, participants showed reduced levels of uncertainty-directed exploration and increased levels of random exploration in the conceptual domain. Participants also displayed a one-directional transfer effect, where experience in the spatial task boosted performance in the conceptual task, but not vice versa. While confidence judgments indicated that participants were sensitive to the uncertainty of their knowledge in both tasks, they did not or could not leverage their estimates of uncertainty to guide exploration in the conceptual task. These results support the notion that value-guided learning and generalization recruit cognitive-map dependent computational mechanisms in spatial and conceptual domains. Yet both behavioral and model-based analyses suggest domain specific differences in how these representations map onto actions.

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Section: Introductionmentioning

confidence: 73%

Similarities and differences in spatial and non-spatial cognitive maps

Schulz

Garvert

et al. 2020

PLoS Comput Biol

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“…This architecture could allow operations implemented by the internal hippocampal circuitry, such as pattern separation and completion ( Rolls, 2016 ; Neunuebel and Knierim, 2014 ; Staresina et al, 2016 ; Nakazawa et al, 2002 ), to be realised across multiple cortical processing zones in a distributed and coordinated manner. In this way, the coarse representations in the MTL could be mirrored by neural motifs present across the broader cortical system, helping to explain the regions’ contribution to multiple aspects of memory ( Clark, 2018 ), and to cognitive maps describing the structure of many different tasks ( Eichenbaum and Cohen, 2014 ; Solomon et al, 2019 ; Tavares et al, 2015 ). Contemporary neuroscience has established that whole-brain functional organisation can be understood as discrete communities such as the sensory, attention, and transmodal networks ( Yeo et al, 2011 ) and that the relationships between these communities can be represented by gradients of cortex-wide connectivity ( Margulies et al, 2016 ).…”

Section: Introductionmentioning

confidence: 99%

Convergence of cortical types and functional motifs in the human mesiotemporal lobe

Paquola

Benkarim

DeKraker

et al. 2020

eLife

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The mesiotemporal lobe (MTL) is implicated in many cognitive processes, is compromised in numerous brain disorders, and exhibits a gradual cytoarchitectural transition from six-layered parahippocampal isocortex to three-layered hippocampal allocortex. Leveraging an ultra-high-resolution histological reconstruction of a human brain, our study showed that the dominant axis of MTL cytoarchitectural differentiation follows the iso-to-allocortical transition and depth-specific variations in neuronal density. Projecting the histology-derived MTL model to in-vivo functional MRI, we furthermore determined how its cytoarchitecture underpins its intrinsic effective connectivity and association to large-scale networks. Here, the cytoarchitectural gradient was found to underpin intrinsic effective connectivity of the MTL, but patterns differed along the anterior-posterior axis. Moreover, while the iso-to-allocortical gradient parametrically represented the multiple-demand relative to task-negative networks, anterior-posterior gradients represented transmodal versus unimodal networks. Our findings establish that the combination of micro- and macrostructural features allow the MTL to represent dominant motifs of whole-brain functional organization.

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“…Moreover, low frequency components of iEEG data, such as theta, can measure widespread network changes that can also be observed at the level of scalp EEG ( Buzsáki, 2006 ; Burke et al, 2013 ; Solomon et al, 2017 ; Bickel et al, 2018 ). Our approach was to use task-related HFA increases to identify electrodes that were in proximity to task-related neural populations and then assess interactions between these regions by measuring theta synchrony between them ( Solomon et al, 2017 , 2019 )…”

Section: Introductionmentioning

confidence: 99%

Theta Synchrony Is Increased near Neural Populations That Are Active When Initiating Instructed Movement

Ramayya

Yang

Buch

et al. 2020

eNeuro

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Theta oscillations (3–8 Hz) in the human brain have been linked to perception, cognitive control, and spatial memory, but their relation to the motor system is less clear. We tested the hypothesis that theta oscillations coordinate distributed behaviorally relevant neural representations during movement using intracranial electroencephalography (iEEG) recordings from nine patients ( n = 490 electrodes) as they performed a simple instructed movement task. Using high frequency activity (HFA; 70–200 Hz) as a marker of local spiking activity, we identified electrodes that were positioned near neural populations that showed increased activity during instruction and movement. We found that theta synchrony was widespread throughout the brain but was increased near regions that showed movement-related increases in neural activity. These results support the view that theta oscillations represent a general property of brain activity that may also play a specific role in coordinating widespread neural activity when initiating voluntary movement.

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Hippocampal theta codes for distances in semantic and temporal spaces

Cited by 119 publications

References 69 publications

Similarities and differences in spatial and non-spatial cognitive maps

Similarities and differences in spatial and non-spatial cognitive maps

Convergence of cortical types and functional motifs in the human mesiotemporal lobe

Theta Synchrony Is Increased near Neural Populations That Are Active When Initiating Instructed Movement

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