scholarly journals Charting closed-loop collective cultural decisions: from book best sellers and music downloads to Twitter hashtags and Reddit comments

2021 ◽  
Vol 94 (8) ◽  
Author(s):  
Lukas Schneider ◽  
Johannes Scholten ◽  
Bulcsú Sándor ◽  
Claudius Gros
Keyword(s):  
Closed Loop ◽  
Internal Representation ◽  
Traditional Music ◽  
External Factors ◽  
Network Activity ◽  
Information Maximization ◽  
Generic Theory ◽  
Music Streaming ◽  
Organizing Principles ◽  
Decision Times

AbstractCharts are used to measure relative success for a large variety of cultural items. Traditional music charts have been shown to follow self-organizing principles with regard to the distribution of item lifetimes, the on-chart residence times. Here we examine if this observation holds also for (a) music streaming charts (b) book best-seller lists and (c) for social network activity charts, such as Twitter hashtags and the number of comments Reddit postings receive. We find that charts based on the active production of items, like commenting, are more likely to be influenced by external factors, in particular by the 24 h day–night cycle. External factors are less important for consumption-based charts (sales, downloads), which can be explained by a generic theory of decision-making. In this view, humans aim to optimize the information content of the internal representation of the outside world, which is logarithmically compressed. Further support for information maximization is argued to arise from the comparison of hourly, daily and weekly charts, which allow to gauge the importance of decision times with respect to the chart compilation period.

scholarly journals KCC2 overexpression prevents the paradoxical seizure-promoting action of somatic inhibition

2018 ◽  
Author(s):  
Vincent Magloire ◽  
Jonathan Cornford ◽  
Andreas Lieb ◽  
Dimitri M. Kullmann ◽  
Ivan Pavlov
Keyword(s):  
Potassium Chloride ◽  
Cortical Neurons ◽  
Closed Loop ◽  
Network Activity ◽  
Intracellular Chloride ◽  
Cortical Interneurons ◽  
The Face ◽  
Somatic Inhibition

AbstractAlthough cortical interneurons are apparently well-placed to suppress seizures, several recent reports have highlighted a paradoxical role of parvalbumin-positive perisomatic-targeting (PV+) interneurons in ictogenesis. Here, we use an acute in vivo model of focal cortical seizures in awake behaving mice, together with closed-loop optogenetic manipulation of PV+ interneurons, to investigate their function during seizures. We show that photo-depolarization of PV+ interneurons rapidly switches from an anti-ictal to a pro-ictal effect within a few seconds of seizure initiation. The pro-ictal effect of delayed photostimulation of PV+ interneurons was not shared with dendrite-targeting somatostatin-positive (SOM+) interneurons. We also show that this switch can be prevented by overexpression of the neuronal potassium-chloride co-transporter KCC2 in principal cortical neurons. These results suggest that strategies aimed at improving the ability of principal neurons to maintain intracellular chloride levels in the face of excessive network activity can prevent interneurons from contributing to seizure perpetuation.

Such stuff as dreams are made on? Elaborative encoding, the ancient art of memory, and the hippocampus

2013 ◽  
Vol 36 (6) ◽  
pp. 589-607 ◽  
Author(s):  
Sue Llewellyn
Keyword(s):  
Episodic Memory ◽  
Eye Movement ◽  
Memory Performance ◽  
Internal Representation ◽  
Nrem Sleep ◽  
Rapid Eye Movement ◽  
Composite Image ◽  
Conscious Level ◽  
Episodic Memories ◽  
Organizing Principles

AbstractThis article argues that rapid eye movement (REM) dreaming is elaborative encoding for episodic memories. Elaborative encoding in REM can, at least partially, be understood through ancient art of memory (AAOM) principles: visualization, bizarre association, organization, narration, embodiment, and location. These principles render recent memories more distinctive through novel and meaningful association with emotionally salient, remote memories. The AAOM optimizes memory performance, suggesting that its principles may predict aspects of how episodic memory is configured in the brain. Integration and segregation are fundamental organizing principles in the cerebral cortex. Episodic memory networks interconnect profusely within the cortex, creating omnidirectional “landmark” junctions. Memories may be integrated at junctions but segregated along connecting network paths that meet at junctions. Episodic junctions may be instantiated during non–rapid eye movement (NREM) sleep after hippocampal associational function during REM dreams. Hippocampal association involves relating, binding, and integrating episodic memories into a mnemonic compositional whole. This often bizarre, composite image has not been present to the senses; it is not “real” because it hyperassociates several memories. During REM sleep, on the phenomenological level, this composite image is experienced as a dream scene. A dream scene may be instantiated as omnidirectional neocortical junction and retained by the hippocampus as an index. On episodic memory retrieval, an external stimulus (or an internal representation) is matched by the hippocampus against its indices. One or more indices then reference the relevant neocortical junctions from which episodic memories can be retrieved. Episodic junctions reach a processing (rather than conscious) level during normal wake to enable retrieval. If this hypothesis is correct, the stuff of dreams is the stuff of memory.

scholarly journals Modulation of electrocorticographic seizure features predicts response to closed-loop brain stimulation

2018 ◽  
Author(s):  
Vasileios Kokkinos ◽  
Nathaniel D. Sisterson ◽  
Thomas A. Wozny ◽  
R. Mark Richardson
Keyword(s):  
Clinical Outcomes ◽  
Brain Stimulation ◽  
Frequency Modulation ◽  
Indirect Effects ◽  
Closed Loop ◽  
Seizure Control ◽  
Network Activity ◽  
Direct Effects ◽  
Neuronal Populations ◽  
Patients With Epilepsy

AbstractWhy does closed-loop invasive brain stimulation improve seizure control in some patients with epilepsy, but not others? The RNS System, the only FDA-approved bi-directional brain-computer interface, has been shown to improve seizure control in patients with refractory epilepsy, although the mechanisms behind this success are undefined. We analyzed recordings from the RNS System and discovered two main categories of electrophysiological signatures of stimulation-induced modulation of the seizure network. Direct effects included ictal inhibition and early frequency modulation but did not correlate with improved clinical outcomes. Only indirect effects, those occurring remote from triggered stimulation, predicted improved clinical outcomes. These indirect effects, which included spontaneous ictal inhibition, frequency modulation, fragmentation, and ictal duration modulation, may reflect progressive local epileptogenic network compartmentalization that hinders the spread of pathological synchrony from recruiting neuronal populations. Our findings suggest that responsiveness to RNS may be explained by chronic stimulation-induced modulation of seizure network activity, rather than direct effects on each detected seizure.

scholarly journals Internal representation of hippocampal neuronal population spans a time-distance continuum

2019 ◽  
Vol 116 (15) ◽  
pp. 7477-7482 ◽  
Author(s):  
Caroline Haimerl ◽  
David Angulo-Garcia ◽  
Vincent Villette ◽  
Susanne Reichinnek ◽  
Alessandro Torcini ◽  
...  
Keyword(s):  
Critical Role ◽  
Experimental Studies ◽  
Cell Activity ◽  
Internal Representation ◽  
Population Level ◽  
Neuronal Population ◽  
Network Activity ◽  
Drive Power ◽  
Distance Information ◽  
Space And Time

The hippocampus plays a critical role in episodic memory: the sequential representation of visited places and experienced events. This function is mirrored by hippocampal activity that self organizes into sequences of neuronal activation that integrate spatiotemporal information. What are the underlying mechanisms of such integration is still unknown. Single cell activity was recently shown to combine time and distance information; however, it remains unknown whether a degree of tuning between space and time can be defined at the network level. Here, combining daily calcium imaging of CA1 sequence dynamics in running head-fixed mice and network modeling, we show that CA1 network activity tends to represent a specific combination of space and time at any given moment, and that the degree of tuning can shift within a continuum from 1 day to the next. Our computational model shows that this shift in tuning can happen under the control of the external drive power. We propose that extrinsic global inputs shape the nature of spatiotemporal integration in the hippocampus at the population level depending on the task at hand, a hypothesis which may guide future experimental studies.

Intestinal Bacteriology of Closed Loop, Strangulated Obstruction in Dogs.

1961 ◽  
Vol 41 (3) ◽  
pp. 245-250 ◽  
Author(s):  
George H. Bornside ◽  
Isidore Cohn
Keyword(s):  
Closed Loop

Disfluent, But Fast

2019 ◽  
Vol 66 (5) ◽  
pp. 346-354
Author(s):  
Štěpán Bahník
Keyword(s):  
Cognitive Processing ◽  
Response Times ◽  
Processing Fluency ◽  
Retrieval Fluency ◽  
Decision Times

Abstract. Processing fluency, a metacognitive feeling of ease of cognitive processing, serves as a cue in various types of judgments. Processing fluency is sometimes evaluated by response times, with shorter response times indicating higher fluency. The present study examined existence of the opposite association; that is, it tested whether disfluency may lead to faster decision times when it serves as a strong cue in judgment. Retrieval fluency was manipulated in an experiment using previous presentation and phonological fluency by varying pronounceability of pseudowords. Participants liked easy-to-pronounce and previously presented words more. Importantly, their decisions were faster for hard-to-pronounce and easy-to-pronounce pseudowords than for pseudowords moderate in pronounceability. The results thus showed an inverted-U shaped relationship between fluency and decision times. The findings suggest that disfluency can lead to faster decision times and thus demonstrate the importance of separating different processes comprising judgment when response times are used as a measure of processing fluency.

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