Despite much research, the role of the medial temporal lobes (MTL) in category learning is unclear. Two unstructured categorization experiments explored conditions that might recruit MTL category learning and memory systems--namely, whether the stimulus display includes one or two stimuli, and whether category membership depends on configural…

Learning and memory involves a large neural network of many brain regions, including the notable hippocampus along with the retrosplenial cortex (RSC) and lateral septum (LS). Previous studies have established that the dorsal hippocampus (dHPC) plays a critical role during the acquisition and retrieval/expression of episodic memories. However, the…

An essential feature of episodic memory is the ability to recall the multiple elements relating to one event from the multitude of elements relating to other, potentially similar events. Hippocampal pattern separation is thought to play a fundamental role in this process, by orthogonalizing the representations of overlapping events during…

Nonprotein coding dendritic BC1 RNA regulates translation of mRNAs in neurons. We examined two lines of BC1 knockout mice and report that loss of BC1 RNA exaggerates group I mGluR-stimulated LTD of the Schaffer collateral synapse, with one of the lines showing a much more enhanced DHPG-induced LTD than the other. When the animals were given the…

There are mixed results regarding the differentiation of neurofunctional correlates of spatial abilities. Previous studies employed complex environments or alternate memory tasks which could potentially add to inconsistencies across studies of navigation. To help elucidate the existing mixed findings, we conducted a study in a simplistic…

We investigated the in vivo role of protein degradation during intermediate (ITM) and long-term memory (LTM) in "Aplysia" using an operant learning paradigm. The proteasome inhibitor MG-132 inhibited the induction and molecular consolidation of LTM with no effect on ITM. Remarkably, maintenance of steady-state protein levels through…

The declarative/procedural (DP) model posits that the learning, storage, and use of language critically depend on two learning and memory systems in the brain: declarative memory and procedural memory. Thus, on the basis of independent research on the memory systems, the model can generate specific and often novel predictions for language. Till…

Using pharmacologic and genetic approaches targeting actin or the actin-driving molecular motor, nonmuscle myosin II (NMII), we previously discovered an immediate, retrieval-independent, and long-lasting disruption of methamphetamine- (METH-) and amphetamine-associated memories. A single intrabasolateral amygdala complex infusion or systemic…

The hippocampus has recently been implicated in the brief representation of visual information, but its specific role is not well understood. We investigated this role using a paradigm that distinguishes quantity and quality of visual memory as described in a previous study. We found that amnesic patients with bilateral hippocampal damage (N = 5)…

The hippocampal formation has been extensively described as a key component for object recognition in conjunction with place and context. The present study aimed at describing neural mechanisms in the hippocampal formation that support olfactory-tactile (OT) object discrimination in a task where space and context were not taken into account. The…

Numerous investigations have definitively shown amygdalar involvement in delay and contextual fear conditioning. However, much less is known about amygdala contributions to trace fear conditioning, and what little evidence exists is conflicting as noted in previous studies. This discrepancy may result from selective targeting of individual nuclei…

Long-term fear memory formation in the hippocampus and neocortex depends upon brain-derived neurotrophic factor (BDNF) signaling after acquisition. Incremental, appetitive odor discrimination learning is thought to depend substantially on the differentiation of adult-born neurons within the olfactory bulb (OB)--a process that is closely associated…

The study of development vacillates between a focus on change (i.e., studying how and why infants are so different from adults) and excitement about early competence and continuity (i.e., studying how capable infants are, and marveling at how similar they turn out to be to adults). The study of memory development has been no exception. This…

Balancing habitual and deliberate forms of choice entails a comparison of their respective merits--the former being faster but inflexible, and the latter slower but more versatile. Here, we show that arbitration between these two forms of control can be derived from first principles within an Active Inference scheme. We illustrate our arguments…

It has been suggested that memories become more stable and less susceptible to the disruption of reconsolidation over weeks after learning. Here, we test this by targeting the anterior cingulate cortex (ACC) and test its involvement in the formation, consolidation, and reconsolidation of recent and remote contextual fear memory. We found that…