scholarly journals Volitional learning promotes theta phase coding in the human hippocampus

2021 ◽  
Vol 118 (10) ◽  
pp. e2021238118
Author(s):  
Daniel Pacheco Estefan ◽  
Riccardo Zucca ◽  
Xerxes Arsiwalla ◽  
Alessandro Principe ◽  
Hui Zhang ◽  
...  

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.

2019 ◽  
Vol 5 (7) ◽  
pp. eaav8192 ◽  
Author(s):  
Lukas Kunz ◽  
Liang Wang ◽  
Daniel Lachner-Piza ◽  
Hui Zhang ◽  
Armin Brandt ◽  
...  

Humans are adept in simultaneously following multiple goals, but the neural mechanisms for maintaining specific goals and distinguishing them from other goals are incompletely understood. For short time scales, working memory studies suggest that multiple mental contents are maintained by theta-coupled reactivation, but evidence for similar mechanisms during complex behaviors such as goal-directed navigation is scarce. We examined intracranial electroencephalography recordings of epilepsy patients performing an object-location memory task in a virtual environment. We report that large-scale electrophysiological representations of objects that cue for specific goal locations are dynamically reactivated during goal-directed navigation. Reactivation of different cue representations occurred at stimulus-specific hippocampal theta phases. Locking to more distinct theta phases predicted better memory performance, identifying hippocampal theta phase coding as a mechanism for separating competing goals. Our findings suggest shared neural mechanisms between working memory and goal-directed navigation and provide new insights into the functions of the hippocampal theta rhythm.


2015 ◽  
Vol 32 (2) ◽  
pp. 1-16 ◽  
Author(s):  
Jennifer Riley ◽  
Kerry Ward

ABSTRACT We report the results of a study to examine the effectiveness of active versus passive learning methods in the accounting information systems area. Two groups of students completed an assignment under two active learning conditions (individual and cooperative), while a third group covered the same topic in a passive lecture. Our findings indicate support for active learning, measured through student performance on exam questions and student feedback on a questionnaire. However, compared to passive learners, we find significantly improved exam performance only for students who work individually in an active environment. Students in the cooperative active environment posted exam scores that were not statistically different from passive participants' scores. Students in both individual and cooperative active environments reported positive feedback on satisfaction, perceived learning, and effectiveness of the method. We conclude that active learning enhances student outcomes, particularly for those who work individually. Data Availability: Data are available upon request.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Andrew J. Kesner ◽  
Rick Shin ◽  
Coleman B. Calva ◽  
Reuben F. Don ◽  
Sue Junn ◽  
...  

AbstractThe supramammillary region (SuM) is a posterior hypothalamic structure, known to regulate hippocampal theta oscillations and arousal. However, recent studies reported that the stimulation of SuM neurons with neuroactive chemicals, including substances of abuse, is reinforcing. We conducted experiments to elucidate how SuM neurons mediate such effects. Using optogenetics, we found that the excitation of SuM glutamatergic (GLU) neurons was reinforcing in mice; this effect was relayed by their projections to septal GLU neurons. SuM neurons were active during exploration and approach behavior and diminished activity during sucrose consumption. Consistently, inhibition of SuM neurons disrupted approach responses, but not sucrose consumption. Such functions are similar to those of mesolimbic dopamine neurons. Indeed, the stimulation of SuM-to-septum GLU neurons and septum-to-ventral tegmental area (VTA) GLU neurons activated mesolimbic dopamine neurons. We propose that the supramammillo-septo-VTA pathway regulates arousal that reinforces and energizes behavioral interaction with the environment.


Author(s):  
Bankim S. Chander ◽  
Matthias Witkowski ◽  
Christoph Braun ◽  
Stephen E. Robinson ◽  
Jan Born ◽  
...  

2016 ◽  
Vol 40 (4) ◽  
pp. 446-453 ◽  
Author(s):  
Alexander Tsang ◽  
David M. Harris

Patients expect physicians to be lifelong learners who are able to interpret and evaluate diagnostic tests, and most medical schools list the development of lifelong learning in their program objectives. However, lecture is the most often utilized form of teaching in the first two years and is considered passive learning. The current generation of medical students has many characteristics that should support active learning pedagogies. The purpose of this study was to analyze student and faculty perceptions of active learning in an integrated medical curriculum at the second-year mark, where students have been exposed to multiple educational pedagogies. The first hypothesis of the study was that faculty would favor active learning methods. The second hypothesis was that Millennial medical students would favor active learning due to their characteristics. Primary faculty for years 1 and 2 and second-year medical students were recruited for an e-mail survey consisting of 12 questions about active learning and lecture. Students perceived that lecture and passive pedagogies were more effective for learning, whereas faculty felt active and collaborative learning was more effective. Students believed that more content should be covered by lecture than faculty. There were also significant differences in perceptions of what makes a good teacher. Students and faculty both felt that lack of time in the curriculum and preparation time were barriers for faculty. The data suggest that students are not familiar with the process of learning and that more time may be needed to help students develop lifelong learning skills.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Hemmings Wu ◽  
Hartwin Ghekiere ◽  
Dorien Beeckmans ◽  
Tim Tambuyzer ◽  
Kris van Kuyck ◽  
...  

Abstract Conventional deep brain stimulation (DBS) applies constant electrical stimulation to specific brain regions to treat neurological disorders. Closed-loop DBS with real-time feedback is gaining attention in recent years, after proved more effective than conventional DBS in terms of pathological symptom control clinically. Here we demonstrate the conceptualization and validation of a closed-loop DBS system using open-source hardware. We used hippocampal theta oscillations as system input and electrical stimulation in the mesencephalic reticular formation (mRt) as controller output. It is well documented that hippocampal theta oscillations are highly related to locomotion, while electrical stimulation in the mRt induces freezing. We used an Arduino open-source microcontroller between input and output sources. This allowed us to use hippocampal local field potentials (LFPs) to steer electrical stimulation in the mRt. Our results showed that closed-loop DBS significantly suppressed locomotion compared to no stimulation and required on average only 56% of the stimulation used in open-loop DBS to reach similar effects. The main advantages of open-source hardware include wide selection and availability, high customizability and affordability. Our open-source closed-loop DBS system is effective and warrants further research using open-source hardware for closed-loop neuromodulation.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Angus Chadwick ◽  
Mark CW van Rossum ◽  
Matthew F Nolan

Encoding of behavioral episodes as spike sequences during hippocampal theta oscillations provides a neural substrate for computations on events extended across time and space. However, the mechanisms underlying the numerous and diverse experimentally observed properties of theta sequences remain poorly understood. Here we account for theta sequences using a novel model constrained by the septo-hippocampal circuitry. We show that when spontaneously active interneurons integrate spatial signals and theta frequency pacemaker inputs, they generate phase precessing action potentials that can coordinate theta sequences in place cell populations. We reveal novel constraints on sequence generation, predict cellular properties and neural dynamics that characterize sequence compression, identify circuit organization principles for high capacity sequential representation, and show that theta sequences can be used as substrates for association of conditioned stimuli with recent and upcoming events. Our results suggest mechanisms for flexible sequence compression that are suited to associative learning across an animal’s lifespan.


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