scholarly journals Optogenetic scrambling of hippocampal theta oscillations alters working memory retrieval but not hippocampal spatiotemporal codes

2021 ◽  
Author(s):  
Guillaume Etter ◽  
Suzanne van der Veldt ◽  
Jisoo Choi ◽  
Sylvain Williams
Keyword(s):  
Working Memory ◽  
Memory Retrieval ◽  
Recognition Task ◽  
Medial Septum ◽  
Inhibitory Neurons ◽  
Memory Encoding ◽  
Exact Role ◽  
Match To Sample ◽  
Hippocampal Theta

The precise temporal coordination of activity in the brain is thought to be fundamental for memory encoding and retrieval. The medial septum (MS) provides the largest source of innervation to the hippocampus (HPC), and its inhibitory neurons play a major role in controlling HPC theta (~8 Hz) oscillations. While pharmacological inhibition of the MS is associated with memory impairment, the exact role of MS inhibitory neurons in HPC function and memory is not fully understood. While HPC place cells were previously reported to not depend on MS inputs, the exact role of MS inputs on HPC temporal codes is still a matter of debate. Moreover, pharmacological manipulations do not have the temporal resolution to distinguish the role of MS activity on working memory encoding, retention and retrieval. Here we stimulated the MS with optogenetics to either pace or ablate theta, while recording large hippocampal assemblies over time using calcium imaging along with local field potentials to monitor theta control. Using scrambled light stimulation, we could robustly ablate theta signals, which was associated with direct modulation of a subpopulation of neurons in the HPC. We found that such stimulation led to decreased working memory retrieval, but not encoding in both a delayed non-match to sample task and a novel place object recognition task. Strikingly, scrambled stimulations were not associated with disrupted spatiotemporal codes. Importantly, we show that our opsin did not transfect cholinergic cells and stimulation did not disrupt HPC ripple activity or running speed, suggesting a specific role for MS GABAergic cells in memory maintenance and retrieval that is independent from these other potential confounding mechanisms. Our study suggests that theta signals play a specific and essential role in supporting working memory retrieval and maintenance while not being necessary for hippocampal spatiotemporal codes.

EXPRESS: Bored, distracted and forgetful – The impact of mind wandering and boredom on memory encoding

2021 ◽  
pp. 174702182110263
Author(s):  
Philippe Blondé ◽  
Marco Sperduti ◽  
Dominique Makowski ◽  
Pascale Piolino
Keyword(s):  
Working Memory ◽  
Memory Load ◽  
Memory Performance ◽  
Load Condition ◽  
Recognition Task ◽  
Mind Wandering ◽  
Memory Encoding ◽  
Working Memory Load ◽  
Thought Probes ◽  
The Impact

Mind wandering, defined as focusing attention toward task unrelated thoughts, is a common mental state known to impair memory encoding. This phenomenon is closely linked to boredom. Very few studies, however, have tested the potential impact of boredom on memory encoding. Thus, the present study aimed at manipulating mind wandering and boredom during an incidental memory encoding task, to test their differential impact on memory encoding. Thirty-two participants performed a variant of the n-back task in which they had to indicate if the current on-screen object was the same as the previous one (1-back; low working memory load) or the one presented three trials before (3-back; high working memory load). Moreover, thought probes assessing either mind wandering or boredom were randomly presented. Afterward, a surprise recognition task was delivered. Results showed that mind wandering and boredom were highly correlated, and both decreased in the high working memory load condition, while memory performance increased. Although both boredom and mind wandering predicted memory performance taken separately, we found that mind wandering was the only reliable predictor of memory performance when controlling for boredom and working memory load. Model comparisons also revealed that a model with boredom only was outperformed by a model with mind wandering only and a model with both mind wandering and boredom, suggesting that the predictive contribution of boredom in the complete model is minimal. The present results confirm the high correlation between mind wandering and boredom and suggest that the hindering effect of boredom on memory is subordinate to the effect of mind wandering.

scholarly journals The neuropsychology of emerging psychosis and the role of working memory in episodic memory encoding

2018 ◽  
Vol Volume 11 ◽  
pp. 157-168 ◽  
Author(s):  
Marlon O Pflueger ◽  
Pasquale Calabrese ◽  
Erich Studerus ◽  
Ronan Zimmermann ◽  
Ute Gschwandtner ◽  
...  
Keyword(s):  
Working Memory ◽  
Episodic Memory ◽  
Memory Encoding

Imaging Cognition II: An Empirical Review of 275 PET and fMRI Studies

2000 ◽  
Vol 12 (1) ◽  
pp. 1-47 ◽  
Author(s):  
Roberto Cabeza ◽  
Lars Nyberg
Keyword(s):  
Working Memory ◽  
Episodic Memory ◽  
Semantic Memory ◽  
Memory Retrieval ◽  
Procedural Memory ◽  
Spatial Problem ◽  
Memory Encoding ◽  
Functional Neuroanatomy ◽  
Activation Patterns ◽  
Space Motion

Positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) have been extensively used to explore the functional neuroanatomy of cognitive functions. Here we review 275 PET and fMRI studies of attention (sustained, selective, Stroop, orientation, divided), perception (object, face, space/motion, smell), imagery (object, space/ motion), language (written/spoken word recognition, spoken/ no spoken response), working memory (verbal/numeric, object, spatial, problem solving), semantic memory retrieval (categorization, generation), episodic memory encoding (verbal, object, spatial), episodic memory retrieval (verbal, nonverbal, success, effort, mode, context), priming (perceptual, conceptual), and procedural memory (conditioning, motor, and nonmotor skill learning). To identify consistent activation patterns associated with these cognitive operations, data from 412 contrasts were summarized at the level of cortical Brodmann's areas, insula, thalamus, medial-temporal lobe (including hippocampus), basal ganglia, and cerebellum. For perception and imagery, activation patterns included primary and secondary regions in the dorsal and ventral pathways. For attention and working memory, activations were usually found in prefrontal and parietal regions. For language and semantic memory retrieval, typical regions included left prefrontal and temporal regions. For episodic memory encoding, consistently activated regions included left prefrontal and medial-temporal regions. For episodic memory retrieval, activation patterns included prefrontal, medial-temporal, and posterior midline regions. For priming, deactivations in prefrontal (conceptual) or extrastriate (perceptual) regions were consistently seen. For procedural memory, activations were found in motor as well as in non-motor brain areas. Analysis of regional activations across cognitive domains suggested that several brain regions, including the cerebellum, are engaged by a variety of cognitive challenges. These observations are discussed in relation to functional specialization as well as functional integration.

scholarly journals When study-abroad experience fails to deliver: The internal resources threshold effect

2009 ◽  
Vol 30 (1) ◽  
pp. 79-99 ◽  
Author(s):  
GRETCHEN SUNDERMAN ◽  
JUDITH F. KROLL
Keyword(s):  
Working Memory ◽  
Study Abroad ◽  
English Learners ◽  
Recognition Task ◽  
Naming Task ◽  
Threshold Effect ◽  
Cognitive Resources ◽  
Internal Resources ◽  
Memory Resources

ABSTRACTSome second language (L2) learners return from study-abroad experiences (SAEs) with seemingly no change in their L2 ability. In this study we investigate whether a certain level of internal cognitive resources is necessary in order for individuals to take full advantage of the SAE. Specifically, we examine the role of working memory resources in lexical comprehension and production for learners who had or had not studied abroad. Participants included native English learners of Spanish. Participants completed a translation recognition task and a picture-naming task. The results suggest that individuals who lack a certain threshold of working memory resources are unable to benefit from the study-abroad context in terms of being able to produce accurately in the L2.

scholarly journals The role of hippocampal theta oscillations in working memory impairment in multiple sclerosis

2020 ◽  
Author(s):  
Lars Costers ◽  
Jeroen Van Schependom ◽  
Jorne Laton ◽  
Johan Baijot ◽  
Martin Sjøgård ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Working Memory ◽  
Memory Impairment ◽  
Theta Oscillations ◽  
Hippocampal Theta

scholarly journals Eye Movements Actively Reinstate Spatiotemporal Mnemonic Content

Vision ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 21 ◽  
Author(s):  
Jordana S. Wynn ◽  
Kelly Shen ◽  
Jennifer D. Ryan
Keyword(s):  
Eye Movements ◽  
Memory Retrieval ◽  
Memory Systems ◽  
Task Demands ◽  
Oculomotor Control ◽  
Cognitive Resources ◽  
Memory Encoding ◽  
Neural Integration ◽  
Spatial Locations

Eye movements support memory encoding by binding distinct elements of the visual world into coherent representations. However, the role of eye movements in memory retrieval is less clear. We propose that eye movements play a functional role in retrieval by reinstating the encoding context. By overtly shifting attention in a manner that broadly recapitulates the spatial locations and temporal order of encoded content, eye movements facilitate access to, and reactivation of, associated details. Such mnemonic gaze reinstatement may be obligatorily recruited when task demands exceed cognitive resources, as is often observed in older adults. We review research linking gaze reinstatement to retrieval, describe the neural integration between the oculomotor and memory systems, and discuss implications for models of oculomotor control, memory, and aging.

scholarly journals The Dorsal Attention Network Reflects Both Encoding Load and Top–down Control during Working Memory

2018 ◽  
Vol 30 (2) ◽  
pp. 144-159 ◽  
Author(s):  
Steve Majerus ◽  
Frédéric Péters ◽  
Marion Bouffier ◽  
Nelson Cowan ◽  
Christophe Phillips
Keyword(s):  
Working Memory ◽  
Recognition Task ◽  
Top Down ◽  
Sensory Stimuli ◽  
Attention Network ◽  
Large Sets ◽  
Dorsal Attention Network ◽  
Memory Control ◽  
And Control

The dorsal attention network is consistently involved in verbal and visual working memory (WM) tasks and has been associated with task-related, top–down control of attention. At the same time, WM capacity has been shown to depend on the amount of information that can be encoded in the focus of attention independently of top–down strategic control. We examined the role of the dorsal attention network in encoding load and top–down memory control during WM by manipulating encoding load and memory control requirements during a short-term probe recognition task for sequences of auditory (digits, letters) or visual (lines, unfamiliar faces) stimuli. Encoding load was manipulated by presenting sequences with small or large sets of memoranda while maintaining the amount of sensory stimuli constant. Top–down control was manipulated by instructing participants to passively maintain all stimuli or to selectively maintain stimuli from a predefined category. By using ROI and searchlight multivariate analysis strategies, we observed that the dorsal attention network encoded information for both load and control conditions in verbal and visuospatial modalities. Decoding of load conditions was in addition observed in modality-specific sensory cortices. These results highlight the complexity of the role of the dorsal attention network in WM by showing that this network supports both quantitative and qualitative aspects of attention during WM encoding, and this is in a partially modality-specific manner.

scholarly journals The state of memory-matched distractor in working memory influence the visual attention

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0242721
Author(s):  
Quanshan Long ◽  
Ting Luo ◽  
Sheng Zhang ◽  
Yuanling Jiang ◽  
Na Hu ◽  
...  
Keyword(s):  
Working Memory ◽  
Visual Attention ◽  
Cognitive Control ◽  
Sensory Processing ◽  
Dual Task ◽  
The State ◽  
Attentional Guidance ◽  
Match To Sample ◽  
Multivariate Pattern

Information in working memory (WM) can guide visual attention towards matched features. While recent work has suggested that cognitive control can act upon WM guidance of visual attention, little is known about how the state of memorized items retaining in WM contribute to its influence over attention. Here, we disentangle the role of inhibition and maintenance on WM-guided attention with a novel delayed match-to-sample dual-task. The results showed that active inhibition facilitated searching by diminishing sensory processing and deterring attentional guidance, indexed by an attenuated P1 amplitude and unaffected N2pc amplitude, respectively. By contrast, active maintenance impaired searching by attentional guidance while sensory processing remained unimpaired, indexed by an enhanced N2pc amplitude and unchanged P1 amplitude, respectively. Furthermore, multivariate pattern analyses could sucessfully decode maintenance and inhibition, suggesting that two states differed in modulating visual attention. We propose that remembered contents may play an anchoring role for attentional guidance, and the state of those contents retaining in WM may directly influence the shifting of attention. The maintenance could guide attention by accessing input information, while the inhibition could deter the shifting of attention by suppressing sensory processing. These findings provide a possible reinterpretation of the influence of WM on attention.

scholarly journals Optogenetic suppression of the medial septum impairs working memory maintenance

2021 ◽  
Vol 28 (10) ◽  
pp. 361-370
Author(s):  
Zachary M. Gemzik ◽  
Margaret M. Donahue ◽  
Amy L. Griffin
Keyword(s):  
Working Memory ◽  
Conditional Discrimination ◽  
Discrimination Task ◽  
Spatial Information ◽  
Spatial Working Memory ◽  
Relevant Information ◽  
Medial Septum ◽  
Temporal Delay ◽  
Choice Accuracy

Spatial working memory (SWM) is the ability to encode, maintain, and retrieve spatial information over a temporal gap, and relies on a network of structures including the medial septum (MS), which provides critical input to the hippocampus. Although the role of the MS in SWM is well-established, up until recently, we have been unable to use temporally precise circuit manipulation techniques to examine the specific role of the MS in SWM, particularly to distinguish between encoding, maintenance, and retrieval. Here, we test the hypothesis that the MS supports the maintenance of spatial information over a temporal gap using precisely timed optogenetic suppression delivered during specific portions of three different tasks, two of which rely on SWM and one that does not. In experiment 1, we found that MS optogenetic suppression impaired choice accuracy of a SWM dependent conditional discrimination task. Moreover, this deficit was only observed when MS suppression was delivered during the cue-sampling, but not the cue-retrieval, portion of the trial. There was also no deficit when MS neurons were optogenetically suppressed as rats performed a SWM-independent variant of the task. In experiment 2, we tested whether MS suppression affected choice accuracy on a delayed nonmatch to position (DNMP) task when suppression was limited to the sample, delay, and choice phases of the task. We found that MS suppression delivery during the delay phase of the DNMP task, but not during the sample or choice phases, impaired choice accuracy. Our results collectively suggest that the MS plays an important role in SWM by maintaining task-relevant information over a temporal delay.

The Role of the Hippocampus and LIFGs in Working Memory Retrieval

2007 ◽  
Author(s):  
Ilke Oztekin ◽  
Brian McElree ◽  
Bernhard P. Staresina ◽  
Lila Davachi
Keyword(s):  
Working Memory ◽  
Memory Retrieval
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