scholarly journals Goal-oriented predictive representations in the human hippocampus

2021 ◽  
Author(s):  
Jordan Crivelli-Decker ◽  
Alex Clarke ◽  
Seongmin Park ◽  
Derek Huffman ◽  
Erie Boorman ◽  
...  
Keyword(s):  
Recent Work ◽  
Spatial Information ◽  
Activity Patterns ◽  
Cognitive Maps ◽  
Navigation Task ◽  
Systems Neuroscience ◽  
Human Hippocampus ◽  
Hippocampal Activity ◽  
Context Specific ◽  
Physical Spaces

Recent work in cognitive and systems neuroscience has suggested that the hippocampus might support planning, imagination, and navigation by forming "cognitive maps" that capture the structure of physical spaces, tasks, and situations. Critically, navigation involves planning within a context and disambiguating similar contexts to reach a goal. We examined hippocampal activity patterns in humans during a goal-directed navigation task to examine how contextual and goal information are incorporated in the construction and execution of navigational plans. Results demonstrate that, during planning, the hippocampus carries a context-specific representation of a future goal. Importantly, this effect could not be explained by stimulus or spatial information alone. During navigation, we observed reinstatement of activity patterns in the hippocampus ahead of participants' required actions, which was strongest for behaviorally relevant points in the sequence. These results suggest that, rather than simply representing overlapping associations, hippocampal activity patterns are powerfully shaped by context and goals.

scholarly journals Representation of Task Structure in Human Hippocampus

2019 ◽  
Author(s):  
Eda Mizrak ◽  
Nichole R. Bouffard ◽  
Laura A. Libby ◽  
Erie Boorman ◽  
Charan Ranganath
Keyword(s):  
Decision Making ◽  
Activity Patterns ◽  
Cognitive Maps ◽  
Relevant Information ◽  
Task Structure ◽  
Functional Magnetic Resonance ◽  
Customer Preference ◽  
Human Hippocampus ◽  
Hippocampal Activity ◽  
Support Decision Making

ABSTRACTMemories of previous experiences can be used to guide future decisions in similar situations. Recent evidence suggests that the hippocampus might support decision-making by forming representations that capture common elements across different events (e.g., “cognitive maps” or “schemas”). Here, we used functional magnetic resonance imaging (fMRI) to test how the human hippocampus represents decision relevant information extracted from previous experiences. Participants performed a task in which they learned to predict a customer preference for foods in four different store contexts. The task was structured such that we could examine the degree to which hippocampal representations reflected generalized information about the store contexts, food items, and also the kind of information that was relevant to decisions on a given trial. Results showed that hippocampal activity patterns carried information about the kind of information that was currently relevant to a decision. Across different store contexts, hippocampal representations differentiated between context-determined (deterministic) decisions and context-invariant (probabilistic) decisions. Results also showed that information about store contexts was represented by the hippocampus, but contrary to what might be expected, similar contexts were hyper-differentiated from one another. These results suggest that the hippocampus may support decision-making by systematically mapping relationships between task relevant information, decisions, and outcomes.

scholarly journals The human hippocampus plays a time-limited role in retrieving autobiographical memories

2020 ◽  
Author(s):  
Adrian W. Gilmore ◽  
Alina Quach ◽  
Sarah E. Kalinowski ◽  
Estefanía I. Gonzalez-Araya ◽  
Stephen J. Gotts ◽  
...  
Keyword(s):  
Standard Model ◽  
Activity Patterns ◽  
Temporal Gradient ◽  
Human Hippocampus ◽  
Limited Role ◽  
Hippocampal Activity ◽  
Autobiographical Recall ◽  
The Standard Model ◽  
Potential Benefits ◽  
Graded Activity

ABSTRACTThe necessity of the human hippocampus for remote autobiographical recall remains fiercely debated. The standard model of consolidation predicts a time-limited role for the hippocampus, but the competing multiple trace/trace transformation theories posit indefinite involvement. Lesion evidence remains inconclusive, and the inferences one can draw from fMRI have been limited by reliance on covert (silent) recall, which obscures dynamic, moment-to-moment content of retrieved memories. Here, we capitalized on advances in fMRI denoising to employ overtly spoken recall. Forty participants retrieved recent and remote memories, describing each for approximately two minutes. Details associated with each memory were identified and modeled in the fMRI timeseries data using a variant of the Autobiographical Interview procedure, and activity associated with the recall of recent and remote memories was then compared. Posterior hippocampal regions exhibited temporally-graded activity patterns (recent events > remote events), as did several regions of frontal and parietal cortex. Consistent with predictions of the standard model, recall-related hippocampal activity differed from a non-autobiographical control task only for recent, and not remote, events. Task-based connectivity between posterior hippocampal regions and others associated with mental scene construction also exhibited a temporal gradient, with greater connectivity accompanying the recall of recent events. These findings support predictions of the standard model of consolidation and demonstrate the potential benefits of overt recall in neuroimaging experiments.

scholarly journals Time-resolved neural reinstatement and pattern separation during memory decisions in human hippocampus

2018 ◽  
Vol 115 (31) ◽  
pp. E7418-E7427 ◽  
Author(s):  
Lynn J. Lohnas ◽  
Katherine Duncan ◽  
Werner K. Doyle ◽  
Thomas Thesen ◽  
Orrin Devinsky ◽  
...  
Keyword(s):  
Critical Role ◽  
Pattern Separation ◽  
Time Resolved ◽  
Memory Processing ◽  
Fine Grained ◽  
Human Hippocampus ◽  
Hippocampal Activity ◽  
High Frequency Activity ◽  
Occipitotemporal Cortex

Mnemonic decision-making has long been hypothesized to rely on hippocampal dynamics that bias memory processing toward the formation of new memories or the retrieval of old ones. Successful memory encoding may be best optimized by pattern separation, whereby two highly similar experiences can be represented by underlying neural populations in an orthogonal manner. By contrast, successful memory retrieval is thought to be supported by a recovery of the same neural pattern laid down during encoding. Here we examined how hippocampal pattern completion and separation emerge over time during memory decisions. We measured electrocorticography activity in the human hippocampus and posterior occipitotemporal cortex (OTC) while participants performed continuous recognition of items that were new, repeated (old), or highly similar to a prior item (similar). During retrieval decisions of old items, both regions exhibited significant reinstatement of multivariate high-frequency activity (HFA) associated with encoding. Further, the extent of reinstatement of encoding patterns during retrieval was correlated with the strength (HFA power) of hippocampal encoding. Evidence for encoding pattern reinstatement was also seen in OTC on trials requiring fine-grained discrimination of similar items. By contrast, hippocampal activity showed evidence for pattern separation during these trials. Together, these results underscore the critical role of the hippocampus in supporting both reinstatement of overlapping information and separation of similar events.

Differences in Spatial Knowledge of Individuals With Blindness When Using Audiotactile Maps, Using Tactile Maps, and Walking

2018 ◽  
Vol 84 (3) ◽  
pp. 330-343 ◽  
Author(s):  
Konstantinos Papadopoulos ◽  
Marialena Barouti ◽  
Eleni Koustriava
Keyword(s):  
Spatial Information ◽  
Visual Impairments ◽  
Cognitive Maps ◽  
Cognitive Map ◽  
Spatial Knowledge ◽  
Spatial Coding ◽  
Direct Experience ◽  
Tactile Maps ◽  
Experimental Trials ◽  
Blind Individuals

To examine how individuals with visual impairments understand space and the way they develop cognitive maps, we studied the differences in cognitive maps resulting from different methods and tools for spatial coding in large geographical spaces. We examined the ability of 21 blind individuals to create cognitive maps of routes in unfamiliar areas using (a) audiotactile maps, (b) tactile maps, and (c) direct experience of movement along the routes. We also compared participants’ cognitive maps created with the use of audiotactile maps, tactile maps, and independent movement along the routes with regard to their precision (i.e., the correctness or incorrectness of spatial information location) and inclusiveness (i.e., the amount of spatial information included correctly in the cognitive map). The results of the experimental trials demonstrated that becoming familiar with an area is easier for blind individuals when they use a tactile aide, such as an audiotactile map, as compared with walking along the route.

Object, Space, and Object-Space Representations in the Primate Hippocampus

2005 ◽  
Vol 94 (1) ◽  
pp. 833-844 ◽  
Author(s):  
Edmund T. Rolls ◽  
Jianzhong Xiang ◽  
Leonardo Franco
Keyword(s):  
Episodic Memory ◽  
Spatial Information ◽  
Hippocampal Formation ◽  
Memory Task ◽  
Memory System ◽  
Important Advance ◽  
Object Space ◽  
Place Memory ◽  
Human Hippocampus ◽  
Spatial View

A fundamental question about the function of the primate including human hippocampus is whether object as well as allocentric spatial information is represented. Recordings were made from single hippocampal formation neurons while macaques performed an object-place memory task that required the monkeys to learn associations between objects and where they were shown in a room. Some neurons (10%) responded differently to different objects independently of location; other neurons (13%) responded to the spatial view independently of which object was present at the location; and some neurons (12%) responded to a combination of a particular object and the place where it was shown in the room. These results show that there are separate as well as combined representations of objects and their locations in space in the primate hippocampus. This is a property required in an episodic memory system, for which associations between objects and the places where they are seen are prototypical. The results thus provide an important advance by showing that a requirement for a human episodic memory system, separate and combined neuronal representations of objects and where they are seen “out there” in the environment, is present in the primate hippocampus.

scholarly journals Representations of local spatial information in the human medial temporal lobe during memory-guided navigation

2020 ◽  
Author(s):  
Shao-Fang Wang ◽  
Valerie A. Carr ◽  
Serra E. Favila ◽  
Jeremy N. Bailenson ◽  
Thackery I. Brown ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Spatial Information ◽  
Activity Patterns ◽  
Critical Role ◽  
Neural Representations ◽  
Parahippocampal Cortex ◽  
Pattern Similarity ◽  
Cortical Regions ◽  
Goal Directed Behavior

AbstractThe hippocampus (HC) and surrounding medial temporal lobe (MTL) cortical regions play a critical role in spatial navigation and episodic memory. However, it remains unclear how the interaction between the HC’s conjunctive coding and mnemonic differentiation contributes to neural representations of spatial environments. Multivariate functional magnetic resonance imaging (fMRI) analyses enable examination of how human HC and MTL cortical regions encode multidimensional spatial information to support memory-guided navigation. We combined high-resolution fMRI with a virtual navigation paradigm in which participants relied on memory of the environment to navigate to goal locations in two different virtual rooms. Within each room, participants were cued to navigate to four learned locations, each associated with one of two reward values. Pattern similarity analysis revealed that when participants successfully arrived at goal locations, activity patterns in HC and parahippocampal cortex (PHC) represented room-goal location conjunctions and activity patterns in HC subfields represented room-reward-location conjunctions. These results add to an emerging literature revealing hippocampal conjunctive representations during goal-directed behavior.

Ordering

2014 ◽  
Vol 8 (1) ◽  
pp. 67-78 ◽  
Author(s):  
Sahib Jan ◽  
Angela Schwering ◽  
Jia Wang ◽  
Malumbo Chipofya
Keyword(s):  
Spatial Information ◽  
Empirical Work ◽  
Cognitive Maps ◽  
Computational Approach ◽  
Cognitive Effects ◽  
Constraint Networks ◽  
Spatial Objects ◽  
Sketch Maps ◽  
Map Alignment ◽  
Street Segments

Sketch maps are externalizations of cognitive maps which are typically distorted, schematized, incomplete, and generalized. Processing spatial information from sketch maps automatically requires reliable formalizations which are not subject to schematization, distortion or other cognitive effects in sketch maps. Based on previous empirical work, the authors identified different sketch aspects such as ordering, topology and orientation to align and integrate spatial information from sketch maps with metric maps qualitatively. This research addresses the question how these qualitative sketch aspects can be formalized for a computational approach for sketch map alignment. In this study, the authors focus on the ordering aspect: ordering of landmarks and street segments along routes and around junctions. The authors first investigate different qualitative representations and propose suitable representations to formalize these aspects. The proposed representations capture qualitative relations between spatial objects in the form of qualitative constraint networks. The authors then evaluate the proposed representations by testing the accuracy of qualitative constraints between sketched objects and their corresponding objects in a metric map. The results of the evaluation show that the proposed representations are suitable for the alignment of spatial objects from sketch maps with metric maps.

Sign in / Sign up

Export Citation Format

Share Document