Learning and memory

  • 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
  • Article
    | Open Access

    Previous studies implicate the hippocampal–amygdala pathway in contextual fear conditioning, in which animals learn to associate a neutral context with an aversive stimulus and display fear responses to dangerous situations. Here the authors show that selective strengthening of hippocampal–amygdala pathway contributes to encoding adaptive fear memory for threat-predictive context.

    • Woong Bin Kim
    •  & Jun-Hyeong Cho
  • Article
    | Open Access

    Odours are powerful stimuli used by most organisms to guide behaviour. Here, the authors identify populations of neurons within the anterior olfactory nucleus (AON) which are necessary and sufficient for the behavioural expression of odour memory.

    • Afif J. Aqrabawi
    •  & Jun Chul Kim
  • Article
    | Open Access

    The regulation of cellular neuronal properties distinct from synaptic plasticity has been proposed as a mechanism of functional network organization. Here, the authors show that the magnitude of five ion currents in basal ganglia projection song system forebrain neurons covary across life, rapidly and dynamically relating to learned features of individual zebra finches’ songs.

    • Arij Daou
    •  & Daniel Margoliash
  • Article
    | Open Access

    The mechanisms underlying the maturation of learning and memory abilities are poorly understood. Here, authors show that episodic learning produces persistent neuronal activation, BDNF-dependent increase in excitatory synapse markers (synaptophysin and PSD-95), and significant maturation of AMPA receptor synaptic responses in the hippocampus of infant rats and mice compared to juveniles and adults.

    • Benjamin Bessières
    • , Alessio Travaglia
    •  & Cristina M. Alberini
  • Article
    | Open Access

    Learned conditioned fear associations can be weakened (extinction learning), but extinction is less effective if performed too soon after the original fear conditioning. Here, the authors show that persistent activation of CRF-expressing neurons in the central amygdala is involved in the early fear extinction deficit.

    • Yong S. Jo
    • , Vijay Mohan K. Namboodiri
    •  & Larry S. Zweifel
  • Article
    | Open Access

    Ageing affects several brain areas causing a decrease in cognitive abilities and memory. We find that increasing the endogenous potential of the hippocampus to generate new neurons throughout life rejuvenates learning and memory, indicating that neural reserves can be exploited during ageing to compensate for age- or disease-related cognitive impairments.

    • Gabriel Berdugo-Vega
    • , Gonzalo Arias-Gil
    •  & Federico Calegari
  • Article
    | Open Access

    Dopamine neurons are proposed to signal the reward prediction error in model-free reinforcement learning algorithms. Here, the authors show that when given during an associative learning task, optogenetic activation of dopamine neurons causes associative, rather than value, learning.

    • Melissa J. Sharpe
    • , Hannah M. Batchelor
    •  & Geoffrey Schoenbaum
  • Article
    | Open Access

    Pavlovian and instrumentally driven actions often conflict when determining the best outcome. Here, the authors present an arbitration theory supported by human behavioral data where Pavlovian predictors drive action selection in an uncontrollable environment, while more flexible instrumental prediction dominates under conditions of high controllability.

    • Hayley M. Dorfman
    •  & Samuel J. Gershman
  • Article
    | Open Access

    The neural mechanisms underlying feature based attention to targets in a cluttered scene are not well understood. Here, the authors show that inactivation of the ventral prearcuate region leads to deficits in picking out a target among many stimuli as well as eliminates the feature based modulation of responses of V4 neurons.

    • Narcisse P. Bichot
    • , Rui Xu
    •  & Robert Desimone
  • Article
    | Open Access

    Spatial maps in the medial temporal lobe (MTL) have been proposed to map abstract conceptual knowledge. Rather than grounding abstract knowledge in a spatial map, the authors propose a general-purpose clustering algorithm that explains how both spatial (including place and grid cells) and higher-dimensional conceptual representations arise during learning.

    • Robert M. Mok
    •  & Bradley C. Love
  • Article
    | Open Access

    People can easily extract task-relevant gist features from visual scenes and hold those features in working memory. Here, the authors show that this gist information is gradually abstracted from posterior to anterior regions of the brain and stably represented at the anterior region.

    • Byung-Il Oh
    • , Yee-Joon Kim
    •  & Min-Suk Kang
  • Article
    | Open Access

    Memories linking environmental cues to alcohol reward are involved in the development and maintenance of heavy drinking. Here, the authors show that a single dose of ketamine, given after retrieval of alcohol-reward memories, disrupts the reconsolidation of these memories and reduces drinking in humans.

    • Ravi K. Das
    • , Grace Gale
    •  & Sunjeev K. Kamboj
  • Article
    | Open Access

    Interference from overlapping memories can cause forgetting. Here, the authors show using fMRI decoding approaches that spontaneous reactivation of older memories during new encoding leads to integration, and less interference, between overlapping items.

    • Avi J. H. Chanales
    • , Nicole M. Dudukovic
    •  & Brice A. Kuhl
  • Article
    | Open Access

    Slow gamma oscillations are associated with memory and have been reported to be disrupted in patients with Alzheimer’s disease. Here the authors show that optogenetic stimulation of medial septum parvalbumin neurons at 40 Hz rescues memory retrieval in the J20 mouse model of Alzheimer’s disease.

    • Guillaume Etter
    • , Suzanne van der Veldt
    •  & Sylvain Williams
  • Perspective
    | Open Access

    The auditory frequency-following response (FFR) indexes the quality of neural sound encoding in the brain. In this Perspective, the authors discuss the potential of the FFR to provide a better understanding of sound encoding in the auditory system and its relationship to behavior.

    • Emily B. J. Coffey
    • , Trent Nicol
    •  & Nina Kraus
  • Article
    | Open Access

    Exaggerated synaptic inhibition is hypothesised to be a main cause of cognitive deficits in Down syndrome models. The authors identify triplication of the kainate receptor encoding gene Grik1 as the cause of memory deficits due to a reorganization of synaptic inhibition along the CA1 dendritic tree.

    • Sergio Valbuena
    • , Álvaro García
    •  & Juan Lerma
  • Article
    | Open Access

    Deposition of tau protein aggregates occurs during aging and Alzheimer disease. Here, the authors show that tau burden in the anterior-temporal memory network is associated with disrupted fMRI connectivity and functional isolation of the hippocampus from other memory network components.

    • Theresa M. Harrison
    • , Anne Maass
    •  & William J. Jagust
  • Article
    | Open Access

    Neuronal tuning is typically measured in response to a priori defined behavioural variables of interest. Here, the authors use an unsupervised learning approach to recover neuronal tuning with respect to the recorded network activity and show that this can reveal the relevant behavioural variables.

    • Alon Rubin
    • , Liron Sheintuch
    •  & Yaniv Ziv
  • Article
    | Open Access

    The degree of subjective confidence in deciding based on ambiguous sensory cues facilitates learning. Here, the authors report distinct functions of the basolateral amygdala and anterior cingulate cortex on implicit confidence judgements as well as flexible learning under uncertain conditions in rats.

    • A. Stolyarova
    • , M. Rakhshan
    •  & A. Izquierdo
  • Article
    | Open Access

    The precise role of the thalamic reticular nucleus in fear is not understood. Here, the authors report that the rostroventral part of the reticular nucleus is involved in the extinction of tone conditioned fear memory through its inhibitory projections to the dorsal midline thalamus.

    • Joon-Hyuk Lee
    • , Charles-Francois V. Latchoumane
    •  & Hee-Sup Shin
  • Article
    | Open Access

    In rodents, cells in the medial entorhinal cortex and subiculum are known to encode the allocentric direction to nearby walls and boundaries. Here, using fMRI the authors show that this is also true in humans, with allocentric boundary direction being encoded in posterior entorhinal cortex and subiculum.

    • J. P. Shine
    • , J. P. Valdés-Herrera
    •  & T. Wolbers
  • Article
    | Open Access

    In familiar environments, humans automatically anticipate the sensory consequences of their motor actions. Here, the authors show how action-based predictions arise from interactions between the hippocampus and visual cortex, and how these interactions strengthen and weaken over time.

    • Nicholas C. Hindy
    • , Emily W. Avery
    •  & Nicholas B. Turk-Browne
  • Article
    | Open Access

    Here, using ex-vivo human adult cortical tissue and a mouse model, the authors investigate the functional consequences of Zika virus (ZIKV) infection in the adult brain, and show that ZIKV causes synapse damage and altered brain function that impacts cognition via activation of innate and inflammatory factors.

    • Claudia P. Figueiredo
    • , Fernanda G. Q. Barros-Aragão
    •  & Sergio T. Ferreira
  • Article
    | Open Access

    Impairments in memory flexibility are associated with neuropsychiatric disorders such as PTSD and autism. Here, the authors report that the transcriptional repressor Wilm's Tumor 1 regulates synaptic plasticity leading to weakening of memory strength and enabling memory flexibility.

    • Chiara Mariottini
    • , Leonardo Munari
    •  & Ravi Iyengar
  • Article
    | Open Access

    Microsaccades are small-amplitude, fixational eye movements that are largely thought to be involuntary. Here, the authors demonstrate that monkeys (and humans) can be easily trained to respond to a remembered target location with a volitional microsaccade, and that a population of superior colliculus neurons is selectively associated with them.

    • Konstantin F. Willeke
    • , Xiaoguang Tian
    •  & Ziad M. Hafed
  • Article
    | Open Access

    Associative memory is the main type of learning by which complex organisms respond to certain environmental stimuli. Here, De la Fuente et al. describe a motility pattern consistent with associative conditioned behaviour in unicellular amoebae.

    • Ildefonso M. De la Fuente
    • , Carlos Bringas
    •  & María Dolores Boyano
  • Article
    | Open Access

    Recent experimental work has revealed non-linear dendritic integration in interneurons. Here, the authors show, through detailed biophysical modeling, that fast spiking interneurons are better described with a 2-stage artificial neural network model calling into question the use of point neuron models.

    • Alexandra Tzilivaki
    • , George Kastellakis
    •  & Panayiota Poirazi
  • Article
    | Open Access

    Practice can improve the perception of stimuli used to achieve a task (perceptual learning). Here, the authors show in monkeys that perceptual learning can be produced even for irrelevant stimuli if the stimuli are paired with stimulation of a dopaminergic centre, the ventral tegmental area (VTA).

    • John T. Arsenault
    •  & Wim Vanduffel
  • Article
    | Open Access

    Goal-directed movement is known to promote release of noradrenaline in the brain, and noradrenaline is known to enhance memory encoding. Here, the authors provide evidence that active movement, compared to action inhibition, boosts episodic memory encoding in humans via a noradrenergic mechanism.

    • Mar Yebra
    • , Ana Galarza-Vallejo
    •  & Bryan A. Strange
  • Article
    | Open Access

    Memory is hypothesised to depend on different brain regions that interact in a network. Here, the authors use case studies of stroke patients with amnesia from the literature to identify brain regions that are part of this network.

    • Michael A. Ferguson
    • , Chun Lim
    •  & Michael D. Fox
  • Article
    | Open Access

    Neural representations in working memory are susceptible to internal noise, which scales with memory load. Here, the authors show that attractor dynamics mitigate the influence of internal noise by pulling memories towards a few stable representations.

    • Matthew F. Panichello
    • , Brian DePasquale
    •  & Timothy J. Buschman
  • Article
    | Open Access

    Bats are long-lived animals that can produce a complex vocabulary of social communication calls. Here, the authors show that even in adulthood, bats retain the ability to adaptively introduce long-term modifications to their vocalizations, showing persistent vocal plasticity.

    • Daria Genzel
    • , Janki Desai
    •  & Michael M. Yartsev
  • Article
    | Open Access

    Disruption of cerebellar activity impairs working memory during evidence accumulation in mice. Here, the authors show that optogenetic perturbation of Purkinje cell activity disrupts the accurate accumulation of somatosensory information in working memory during perceptual decision-making.

    • Ben Deverett
    • , Mikhail Kislin
    •  & Samuel S.-H. Wang
  • Article
    | Open Access

    Olfactory information from Kenyon cells in the mushroom body and reward information from pPAM dopaminergic neurons is required for appetitive olfactory learning and memory. Here, the authors report evidence for a feedback circuit mechanism between Kenyon cells and pPAM neurons for reward memory that involves short neuropeptide F.

    • Radostina Lyutova
    • , Mareike Selcho
    •  & Dennis Pauls