Learning and memory

  • Article
    | Open Access

    Haque et al. demonstrate that the episodic memory of a single visual scene is sufficient for humans to recognize if a visual scene has subsequently changed. A prediction error signal first arises in the visual association cortex when individuals recognize these changes.

    • Rafi U. Haque
    • , Sara K. Inati
    •  & Kareem A. Zaghloul
  • Article
    | Open Access

    The challenge of sensory substitution as a therapeutic approach is to design systems that are well accepted by subjects. Here, in deaf songbirds, the authors substitute hearing with vision, suggesting substitution devices could provide sensory feedback for the key actions that are deprived.

    • Anja T. Zai
    • , Sophie Cavé-Lopez
    •  & Richard H. R. Hahnloser
  • Article
    | Open Access

    When asked to imagine an event such as a party, individuals will vary in their mental imagery based on their specific experience of parties. Here, the authors show that such signatures of personal experience can be read from brain activity elicited as events are imagined.

    • Andrew James Anderson
    • , Kelsey McDermott
    •  & Feng V. Lin
  • Article
    | Open Access

    Acute administration of EPA impairs learning and memory and hippocampal LTP in mice that was mediated through enhancing GABAergic transmission via the 5-HT6R. DHA can prevent EPA-induced impairments at a ratio of EPA to DHA similar to that in marine fish oil via the 5-HT2CR.

    • Ji-Hong Liu
    • , Qian Wang
    •  & Tian-Ming Gao
  • Article
    | Open Access

    Decisions under uncertainty involve a balance between exploiting familiar valuable options and exploring unfamiliar ones. Here, the authors study hippocampal responses using fMRI during a reinforcement learning task, and show the differential involvement of the anterior-posterior regions in the explore-exploit aspects of the task.

    • Alexandre Y. Dombrovski
    • , Beatriz Luna
    •  & Michael N. Hallquist
  • Article
    | Open Access

    Young songbirds learn to imitate their parents’ songs. Here, the authors find that, in baby birds, neurons in a brain region at the interface of auditory and motor circuits signal the onsets of song syllables during both tutoring and babbling, suggesting a specific neural mechanism for vocal imitation.

    • Emily L. Mackevicius
    • , Michael T. L. Happ
    •  & Michale S. Fee
  • Article
    | Open Access

    The average spiking frequency in the fronto-striatal network encodes multiple types of learning-relevant information. Here, the authors show that populations of neurons in non-human primates also carry significant information in their phase-of-firing when learning-relevant outcomes are processed.

    • Benjamin Voloh
    • , Mariann Oemisch
    •  & Thilo Womelsdorf
  • Article
    | Open Access

    Inhibitory interneuron subtypes differentially control place cell representations in CA1. Here, the authors show that parvalbumin and somatostatin interneuron synapses onto CA1 pyramidal neurons exhibit distinct plasticity mechanisms and incorporating this insight into circuit-level modeling leads to stable place cell representations.

    • Matt Udakis
    • , Victor Pedrosa
    •  & Jack R. Mellor
  • Article
    | Open Access

    Theta range oscillations in the basolateral amygdala (BLA) and the medial prefrontal cortex (mPFC) are associated with conditioned fear. Here, the authors use exogenous oscillatory stimulation of the BLA and mPFC in mice to determine the dynamic roles of theta-range oscillatory states across conditioned fear and extinction learning.

    • Minagi Ozawa
    • , Patrick Davis
    •  & Leon Reijmers
  • Article
    | Open Access

    Using a combination of two-photon imaging and single-cell electrophysiology, the authors discover that associative learning induces the emergence of a unique subset of neurons in the auditory cortex, exhibiting high-rate bursting responses to the learned complex sounds but not to any of the constituents.

    • Meng Wang
    • , Xiang Liao
    •  & Xiaowei Chen
  • Article
    | Open Access

    Stein, Barbosa et al. show that anti-NMDAR encephalitis and schizophrenia are characterized by reduced serial dependence in spatial working memory. Cortical network simulations show that this can be parsimoniously explained by a reduction in NMDAR-dependent short-term synaptic potentiation in these diseases.

    • Heike Stein
    • , Joao Barbosa
    •  & Albert Compte
  • Article
    | Open Access

    Neurons with grid firing fields are thought to play important roles in spatial cognition. Here, the authors show that in contrast to assumptions underlying current models and analyses, grid fields are modulated by local head direction; this suggests different mechanisms and new roles for grid firing.

    • Klara Gerlei
    • , Jessica Passlack
    •  & Matthew F. Nolan
  • Article
    | Open Access

    Individuals with PTSD are unable to recollect contextual cues related to the trauma. Here the authors show that this contextual amnesia, associated with the inhibition of hippocampal activity, is causally involved in PTSD-like hypermnesia in mice, and that re-exposure to all trauma-related cues eliminates PTSD-like memory while promoting normal fear memory.

    • Alice Shaam Al Abed
    • , Eva-Gunnel Ducourneau
    •  & Aline Desmedt
  • Article
    | Open Access

    One challenge that faces artificial intelligence is the inability of deep neural networks to continuously learn new information without catastrophically forgetting what has been learnt before. To solve this problem, here the authors propose a replay-based algorithm for deep learning without the need to store data.

    • Gido M. van de Ven
    • , Hava T. Siegelmann
    •  & Andreas S. Tolias
  • Article
    | Open Access

    Although everyday life unfolds continuously, we tend to remember past experiences as discrete events. Here, the authors show that dynamic, pupil-linked arousal states track the encoding of such episodes, as revealed by changes in memory for the temporal order and duration of recent event sequences.

    • David Clewett
    • , Camille Gasser
    •  & Lila Davachi
  • Article
    | Open Access

    How can rodents make sense of the olfactory environment without supervision? Here, the authors formulate olfactory learning as an integrated Bayesian inference problem, then derive a set of synaptic plasticity rules and neural dynamics that enables near-optimal learning of odor identification.

    • Naoki Hiratani
    •  & Peter E. Latham
  • Article
    | Open Access

    Wittmann and colleagues show that not only single outcome events but also the global reward state (GRS) impact learning in macaques; low GRS drives explorative choices. Analyses of macaque BOLD signal reveals that GRS impacts activity in the anterior insula as well as the dorsal raphe nucleus.

    • Marco K. Wittmann
    • , Elsa Fouragnan
    •  & Matthew F. S. Rushworth
  • Article
    | Open Access

    The vCA1-BA projection is enriched in shock responsive neurons, which are necessary for fear memory encoding and become correlated with a network of neurons during retrieval. Here the authors show that the magnitude of vCA1 correlated activity is proportional to memory strength and requires the shock response during encoding.

    • Jessica C. Jimenez
    • , Jack E. Berry
    •  & Rene Hen
  • Article
    | Open Access

    When our expectations are violated, it is adaptive to update our internal models to improve predictions in the future. Here, the authors show that during mnemonic violations, hippocampal networks are biased towards an encoding state and away from a retrieval state to potentially update these predictions.

    • Oded Bein
    • , Katherine Duncan
    •  & Lila Davachi
  • Article
    | Open Access

    It is not entirely understood how network plasticity produces the coding of predicted value during stimulus-outcome learning. Here, the authors reveal a reinforcing loop in distributed limbic circuits, transforming sensory stimuli into reward prediction coding broadcasted by dopamine neurons to the brain.

    • Lars-Lennart Oettl
    • , Max Scheller
    •  & Wolfgang Kelsch
  • Article
    | Open Access

    Our brain derives a sense of direction from visual inputs. Here, the authors combine 7T-fMRI with predictive modeling of virtual navigation to show that the strength, width and topology of directional coding in the human brain reflect ongoing memory-guided behavior.

    • Matthias Nau
    • , Tobias Navarro Schröder
    •  & Christian F. Doeller
  • Article
    | Open Access

    Keinath et al. show that information about the recent past is represented in the hippocampus through changes in firing rates in the absence of task demands. This representation is eliminated when DG–CA3 circuitry is inhibited.

    • Alexandra T. Keinath
    • , Andrés Nieto-Posadas
    •  & Mark P. Brandon
  • Article
    | Open Access

    Working memory is a critical component of executive function that allows people to complete complex tasks in the moment. Here, the authors show that this ability is underpinned by two newly defined brain networks.

    • Andrew C. Murphy
    • , Maxwell A. Bertolero
    •  & Danielle S. Bassett
  • Article
    | Open Access

    Here, the authors show that rats’ performance on olfactory decision tasks is best explained by a Bayesian model that combines reinforcement-based learning with accumulation of uncertain sensory evidence. The results suggest that learning is a critical factor contributing to speed-accuracy tradeoffs.

    • André G. Mendonça
    • , Jan Drugowitsch
    •  & Zachary F. Mainen
  • Article
    | Open Access

    Path integration abilities, important for spatial navigation, vary widely across individuals and deteriorate in old age. This work shows that path integration errors in general, as well as age-related path integration deficits, are mainly caused by accumulating noise in people’s velocity estimation.

    • Matthias Stangl
    • , Ingmar Kanitscheider
    •  & Thomas Wolbers
  • Article
    | Open Access

    Alcohol is the leading cause of preventable birth defects in the US, collectively referred to as Fetal Alcohol Spectrum Disorder. Here, the authors show that fetal alcohol exposure induces lasting neurophysiological changes in dorsal striatum that contribute to less efficient decision making.

    • Verginia C. Cuzon Carlson
    • , Christina M. Gremel
    •  & David M. Lovinger
  • Article
    | Open Access

    Thalamic head direction (HD) cells are necessary to establish spatial maps in the hippocampus. Here, the authors show that HD cells tuned to a particular direction are coupled to individual hippocampal ripple events during sleep, suggesting an influence of the replay of specific trajectories during sleep memory consolidation.

    • Guillaume Viejo
    •  & Adrien Peyrache
  • Article
    | Open Access

    We show that the human hippocampus exhibits two distinct theta oscillations during spatial navigation with the faster oscillation in posterior regions showing movement modulation. This result suggests a distinct feature of the human hippocampus compared to rodents, which generally show a single 8 Hz rhythm.

    • Abhinav Goyal
    • , Jonathan Miller
    •  & Joshua Jacobs
  • Article
    | Open Access

    Trajectory-coding neurons in the hippocampus convey important information for performing memory tasks. Here, Kinsky et al. track long-term neural activity in the hippocampus to find that trajectory-coding emerges rapidly and remains stable across long time-scales.

    • Nathaniel R. Kinsky
    • , William Mau
    •  & Michael E. Hasselmo
  • Article
    | Open Access

    Working memory training reshapes the brain functional network reorganization. Here, the authors demonstrate an increase of the whole-brain network segregation during the n-back task, accompanied by alterations in dynamic communication between the default mode system and task-positive systems.

    • Karolina Finc
    • , Kamil Bonna
    •  & Danielle S. Bassett
  • Article
    | Open Access

    Memory recollection involves reactivation of neural activity that occurred during the recalled experience. Here, the authors show that neural reactivation can be decomposed into visual-semantic features, is widely synchronized throughout the brain, and predicts memory vividness and accuracy.

    • Michael B. Bone
    • , Fahad Ahmad
    •  & Bradley R. Buchsbaum
  • Article
    | Open Access

    Head direction neurons constitute the brain’s compass, and are classically known to indicate head orientation in the horizontal plane. Here, the authors show that head direction neurons form a three-dimensional compass that can also indicate head tilt, and anchors to gravity.

    • Dora E. Angelaki
    • , Julia Ng
    •  & Jean Laurens
  • Article
    | Open Access

    Neuronal patterns during working memory show low-frequency oscillatory activity. Here, the authors demonstrate a rhythmic retention of working memory information in theta and alpha frequency ranges. Moreover, phase-locked amplification of the retained information improves working memory performance.

    • Sanne ten Oever
    • , Peter De Weerd
    •  & Alexander T. Sack
  • Article
    | Open Access

    Rewarded stimuli are better encoded in memory. Here, the authors show that the average accumulation of reward over consecutive trials provides an additive, non-linear (inverted U-shape) modulation of memory encoding, paralleled by a similar recruitment of dopaminergic memory circuitry.

    • Kristoffer Carl Aberg
    • , Emily Elizabeth Kramer
    •  & Sophie Schwartz
  • Article
    | Open Access

    The neuronal pathway that signals the positive or negative value of memories is not well understood. Here, the authors report that an excitatory projection from the ventral tegmental area to the dorsal hippocampus carries the valence information, contributing, especially in females, to the recurrence of fear and to drug seeking behavior.

    • Yuan Han
    • , Yi Zhang
    •  & Jelena Radulovic
  • Article
    | Open Access

    The formation of functional synaptic clusters (FSCs) and their impact on somatic membrane potential (sVm) in vivo are poorly understood. Here, the authors develop a computational approach to show that FSCs have to form via local rather than global plasticity and be moderately large to impact sVm.

    • Balázs B. Ujfalussy
    •  & Judit K. Makara