Read by QxMD icon Read

Learning & Memory

Syanah C Wynn, Marc P H Hendriks, Sander M Daselaar, Roy P C Kessels, Dennis J L G Schutter
Functional neuroimaging studies suggest a role for the left angular gyrus (AG) in processes related to memory recognition. However, results of neuropsychological and transcranial magnetic stimulation (TMS) studies have been inconclusive regarding the specific contribution of the AG in recollection, familiarity, and the subjective experience of memory. To obtain further insight into this issue, 20 healthy right-handed volunteers performed a memory task in a single-blind within-subject controlled TMS study. Neuronavigated inhibitory repetitive TMS (rTMS) was applied over the left AG and the vertex in a randomized and counterbalanced order...
August 2018: Learning & Memory
Alyssa H Sinclair, Morgan D Barense
Through the process of "reconsolidation," reminders can temporarily destabilize memories and render them vulnerable to change. Recent rodent research has proposed that prediction error, or the element of surprise, is a key component of this process; yet, this hypothesis has never before been extended to complex episodic memories in humans. In our novel paradigm, we used naturalistic stimuli to demonstrate that prediction error enables adaptive updating of episodic memories. In Study 1, participants ( N = 48) viewed 18 videos, each depicting an action-outcome event...
August 2018: Learning & Memory
Elizabeth M Doncheck, Madalyn Hafenbreidel, Sarah A Ruder, Michael K Fitzgerald, Lilith Torres, Devin Mueller
In cocaine use disorder, relapse can be elicited by drug-associated cues despite long periods of abstinence. The persistence of drug-associated cues in eliciting drug seeking suggests enduring changes in structural and functional plasticity, which may be mediated by basic fibroblast growth factor (bFGF, FGF2). Stimulant drug use increases bFGF expression in reward- and learning-related brain regions, such as the infralimbic medial-prefrontal cortex (IL-mPFC), and we previously found that this increase was reversed by extinction...
August 2018: Learning & Memory
Darya Frank, Daniela Montaldi, Bianca Wittmann, Deborah Talmi
Mental schemas provide a framework into which new information can easily be integrated. In a series of experiments, we examined how incongruence that stems from a prediction error modulates memory for multicomponent events that instantiated preexisting schemas as noted in a previous study. Each event consisted of four stimulus pairs with overlapping components, presented in four blocks (A-B, B-C, C-D, D-A). A-B pairs elicited contextual expectations (A: Farm, B: Tractor) that were either met by a congruent C component (C: Farmer) or violated by an incongruent one (C: Lawyer)...
August 2018: Learning & Memory
Nuttida Rungratsameetaweemana, Larry R Squire
The hippocampus has long been recognized as important for the formation of long-term memory. Recent work has suggested that the hippocampus might also be important for certain kinds of spatial operations, as in constructing scenes, shifting perspective, or perceiving the geometry of scenes and their boundaries. We explored this proposal using a task similar to one used previously that related hippocampal activity to scenes and their boundaries. In our study, participants viewed scenes from above that displayed walls and towers...
August 2018: Learning & Memory
Justine E Cohen, Robert S Ross, Chantal E Stern
Previous research has demonstrated that areas in the medial temporal lobe and prefrontal cortex (PFC) show increased activation during retrieval of overlapping sequences. In this study, we designed a task in which degree of overlap varied between conditions in order to parse out the contributions of hippocampal and prefrontal subregions as overlap between associations increased. In the task, participants learned sequential associations consisting of a picture frame, a face within the picture frame, and an outdoor scene...
August 2018: Learning & Memory
Zhisen J Urgolites, Daniel A Levy, Ramona O Hopkins, Larry R Squire
We tested the proposal that medial temporal lobe (MTL) structures support not just memory but also high-level object perception. In one task, participants decided whether a line drawing could represent an object in three-dimensional space and, in another task, they saw the components of an object and decided what object could be formed if the components were assembled. Patients with hippocampal lesions were intact, indicating that the hippocampus is not needed for perceiving the structural coherence of objects or appreciating the relations among object parts...
July 2018: Learning & Memory
Timothy P Brawn, Howard C Nusbaum, Daniel Margoliash
Newly encoded, labile memories are prone to disruption during post-learning wakefulness. Here we examine the contributions of retroactive and proactive interference to daytime forgetting on an auditory classification task in a songbird. While both types of interference impair performance, they do not develop concurrently. The retroactive interference of task-B on task-A developed during the learning of task-B, whereas the proactive interference of task-A on task-B emerged during subsequent waking retention...
July 2018: Learning & Memory
Wendie N Marks, Madeline E Parker, Nadine K Zabder, Quentin Greba, Terrance P Snutch, John G Howland
The roles of low-voltage-activated (T-type) calcium channels in brain diseases have been studied extensively. Less is known regarding the involvement of T-type channels in cognition and behavior. Sensory integration (SI) is a cognitive process whereby the brain uses unimodal or multimodal sensory features to create a comprehensive representation of the environment. The multisensory object oddity (MSO) task assesses SI using combinations of sensory features of objects, either in the same or different sensory modalities...
July 2018: Learning & Memory
Mark W Schurgin, Jonathan I Flombaum
A person sees an object once, and then seconds, minutes, hours, days, or weeks later, she sees it again. How is the person's visual memory for that object changed, improved, or degraded by the second encounter, compared to a situation in which she will have only seen the object once? The answer is unknown, a glaring lacuna in the current understanding of visual episodic memory. The overwhelming majority of research considers recognition following a single exposure to a set of objects, whereas objects reoccur regularly in lived experience...
July 2018: Learning & Memory
Gabrielle A Pollack, Jessica L Bezek, Serena H Lee, Miranda J Scarlata, Leah T Weingast, Hadley C Bergstrom
Fear memory is a highly stable and durable form of memory, even over vast (remote) time frames. Nevertheless, some elements of fear memory can be forgotten, resulting in generalization. The purpose of this study is to determine how cued fear memory generalizes over time and measure underlying patterns of cortico-amygdala synaptic plasticity. We established generalization gradients at recent (1-d) and remote (30-d) retention intervals following auditory cued fear conditioning in adult male C57BL/6 mice. Results revealed a flattening of the generalization gradient (increased generalization) that was dissociated from contextual fear generalization, indicating a specific influence of time on cued fear memory performance...
July 2018: Learning & Memory
Leslie Rollins, Elizabeth B Cloude
The present study examined mnemonic discrimination in 5- and 6-yr-old children, 8- and 9-yr-old children, 11- and 12-yr-old children, and young adults. Participants incidentally encoded pictorial stimuli and subsequently judged whether targets (i.e., repeated stimuli), lures (i.e., mnemonically related stimuli), and foils (i.e., novel stimuli) were old, similar, or new. Compared to older age groups, younger children were more likely to (1) incorrectly identify lures as "old" (rather than "similar") and (2) fail to recognize lures altogether, especially when lures were more mnemonically distinct from targets...
June 2018: Learning & Memory
Dirk Schümann, Tobias Sommer
Emotional arousal enhances memory encoding and consolidation leading to better immediate and delayed memory. Although the central noradrenergic system and the amygdala play critical roles in both effects of emotional arousal, we have recently shown that these effects are at least partly independent of each other, suggesting distinct underlying neural mechanisms. Here we aim to dissociate the neural substrates of both effects in 70 female participants using an emotional memory paradigm to investigate how neural activity, as measured by fMRI, and a polymorphism in the α2B -noradrenoceptor vary for these effects...
June 2018: Learning & Memory
Somayeh Ahmadiantehrani, Elisa O Gores, Sarah E London
Nonassociative learning is considered simple because it depends on presentation of a single stimulus, but it likely reflects complex molecular signaling. To advance understanding of the molecular mechanisms of one form of nonassociative learning, habituation, for ethologically relevant signals we examined song recognition learning in adult zebra finches. These colonial songbirds learn the unique song of individuals, which helps establish and maintain mate and other social bonds, and informs appropriate behavioral interactions with specific birds...
June 2018: Learning & Memory
Erin M Sanders, Akua O Nyarko-Odoom, Kevin Zhao, Michael Nguyen, Hong Hong Liao, Matthew Keith, Jane Pyon, Alyssa Kozma, Mohima Sanyal, Daniel G McHail, Theodore C Dumas
N -methyl-d-aspartate receptors (NMDARs) at excitatory synapses are central to activity-dependent synaptic plasticity and learning and memory. NMDARs act as ionotropic and metabotropic receptors by elevating postsynaptic calcium concentrations and by direct intracellular protein signaling. In the forebrain, these properties are controlled largely by the auxiliary GluN2 subunits, GluN2A and GluN2B. While calcium conductance through NMDAR channels and intracellular protein signaling make separate contributions to synaptic plasticity, it is not known if these properties individually influence learning and memory...
June 2018: Learning & Memory
James W Antony, Ken A Paller
Repeatedly studying information is a good way to strengthen memory storage. Nevertheless, testing recall often produces superior long-term retention. Demonstrations of this testing effect, typically with verbal stimuli, have shown that repeated retrieval through testing reduces forgetting. Sleep also benefits memory storage, perhaps through repeated retrieval as well. That is, memories may generally be subject to forgetting that can be counteracted when memories become reactivated, and there are several types of reactivation: (i) via intentional restudying, (ii) via testing, (iii) without provocation during wake, or (iv) during sleep...
June 2018: Learning & Memory
Christian König, Afshin Khalili, Mathangi Ganesan, Amrita P Nishu, Alejandra P Garza, Thomas Niewalda, Bertram Gerber, Yoshinori Aso, Ayse Yarali
Painful events establish opponent memories: cues that precede pain are remembered negatively, whereas cues that follow pain, thus coinciding with relief are recalled positively. How do individual reinforcement-signaling neurons contribute to this "timing-dependent valence-reversal?" We addressed this question using an optogenetic approach in the fruit fly. Two types of fly dopaminergic neuron, each comprising just one paired cell, indeed established learned avoidance of odors that preceded their photostimulation during training, and learned approach to odors that followed the photostimulation...
June 2018: Learning & Memory
Jiyeon Cho, Krzysztof A Sypniewski, Shoko Arai, Kazuo Yamada, Sonoko Ogawa, Constantine Pavlides
It is well established that protein kinase A (PKA) is involved in hippocampal dependent memory consolidation. Sleep is also known to play an important role in this process. However, whether sleep-dependent memory consolidation involves PKA activation has not been clearly determined. Using behavioral observation, animals were categorized into sleep and awake groups. We show that intrahippocampal injections of the PKA inhibitor Rp-cAMPs in post-contextual fear conditioning sleep produced a suppression of long-term fear memory, while injections of Rp-cAMPs during an awake state, at a similar time point, had no effect...
May 2018: Learning & Memory
Lorianna Colon, Natalie Odynocki, Anthony Santarelli, Andrew M Poulos
Development and sex differentiation impart an organizational influence on the neuroanatomy and behavior of mammalian species. Prior studies suggest that brain regions associated with fear motivated defensive behavior undergo a protracted and sex-dependent development. Outside of adult animals, evidence for developmental sex differences in conditioned fear is sparse. Here, we examined in male and female Long-Evans rats how developmental age and sex affect the long-term retention and generalization of Pavlovian fear responses...
May 2018: Learning & Memory
Sydney Aten, Katelin F Hansen, Kaitlin Snider, Kelin Wheaton, Anisha Kalidindi, Ashley Garcia, Diego Alzate-Correa, Kari R Hoyt, Karl Obrietan
The microRNA miR-132 serves as a key regulator of a wide range of plasticity-associated processes in the central nervous system. Interestingly, miR-132 expression has also been shown to be under the control of the circadian timing system. This finding, coupled with work showing that miR-132 is expressed in the hippocampus, where it influences neuronal morphology and memory, led us to test the idea that daily rhythms in miR-132 within the forebrain modulate cognition as a function of circadian time. Here, we show that hippocampal miR-132 expression is gated by the time-of-day, with peak levels occurring during the circadian night...
May 2018: Learning & Memory
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"