Optogenetic suppression of the medial septum impairs working memory maintenance

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.

Download Full-text

A Tactile-visual Conditional Discrimination Task for Testing Spatial Working Memory in Rats

BIO-PROTOCOL ◽

10.21769/bioprotoc.2282 ◽

2017 ◽

Vol 7 (10) ◽

Author(s):

Alicia Edsall ◽

Zachary Gemzik ◽

Amy Griffin

Keyword(s):

Working Memory ◽

Conditional Discrimination ◽

Discrimination Task ◽

Spatial Working Memory

Download Full-text

Working Memory and Number Sense as Predictors of Mathematical (Dis-)Ability

Zeitschrift für Psychologie ◽

10.1027/2151-2604/a000208 ◽

2015 ◽

Vol 223 (2) ◽

pp. 102-109 ◽

Cited By ~ 13

Author(s):

Evelyn H. Kroesbergen ◽

Marloes van Dijk

Keyword(s):

Working Memory ◽

Learning Disabilities ◽

Spatial Working Memory ◽

Number Sense ◽

Mathematical Learning ◽

Visual Spatial ◽

Mathematical Learning Disabilities ◽

Visual Spatial Working Memory ◽

And Mathematics

Recent research has pointed to two possible causes of mathematical (dis-)ability: working memory and number sense, although only few studies have compared the relations between working memory and mathematics and between number sense and mathematics. In this study, both constructs were studied in relation to mathematics in general, and to mathematical learning disabilities (MLD) in particular. The sample consisted of 154 children aged between 6 and 10 years, including 26 children with MLD. Children performing low on either number sense or visual-spatial working memory scored lower on math tests than children without such a weakness. Children with a double weakness scored the lowest. These results confirm the important role of both visual-spatial working memory and number sense in mathematical development.

Download Full-text

Role of the striatonigral neurons in basal ganglia in the performance of conditional discrimination task

Neuroscience Research ◽

10.1016/j.neures.2010.07.2391 ◽

2010 ◽

Vol 68 ◽

pp. e185

Author(s):

Ryoji Fukabori ◽

Kana Okada ◽

Nobuyuki Kai ◽

Kenta Kobayashi ◽

Yuji Tsutsui ◽

...

Keyword(s):

Basal Ganglia ◽

Conditional Discrimination ◽

Discrimination Task

Download Full-text

The effect of visual salience on memory-based choices

Journal of Neurophysiology ◽

10.1152/jn.00068.2013 ◽

2014 ◽

Vol 111 (3) ◽

pp. 481-487 ◽

Cited By ~ 7

Author(s):

Arezoo Pooresmaeili ◽

Dominik R. Bach ◽

Raymond J. Dolan

Keyword(s):

Working Memory ◽

Sensory Information ◽

Relevant Information ◽

Visual Selective Attention ◽

Visual Salience ◽

Perceptual Decision Making ◽

Capacity Limitations ◽

Course Of Action ◽

Task Irrelevant

Deciding whether a stimulus is the “same” or “different” from a previous presented one involves integrating among the incoming sensory information, working memory, and perceptual decision making. Visual selective attention plays a crucial role in selecting the relevant information that informs a subsequent course of action. Previous studies have mainly investigated the role of visual attention during the encoding phase of working memory tasks. In this study, we investigate whether manipulation of bottom-up attention by changing stimulus visual salience impacts on later stages of memory-based decisions. In two experiments, we asked subjects to identify whether a stimulus had either the same or a different feature to that of a memorized sample. We manipulated visual salience of the test stimuli by varying a task-irrelevant feature contrast. Subjects chose a visually salient item more often when they looked for matching features and less often so when they looked for a nonmatch. This pattern of results indicates that salient items are more likely to be identified as a match. We interpret the findings in terms of capacity limitations at a comparison stage where a visually salient item is more likely to exhaust resources leading it to be prematurely parsed as a match.

Download Full-text

Negative Effects of Embodiment in a Visuo-Spatial Working Memory Task in Children, Young Adults, and Older Adults

Frontiers in Psychology ◽

10.3389/fpsyg.2021.688174 ◽

2021 ◽

Vol 12 ◽

Author(s):

Gianluca Amico ◽

Sabine Schaefer

Keyword(s):

Older Adults ◽

Working Memory ◽

Young Adults ◽

Spatial Information ◽

Spatial Working Memory ◽

Cognitive Task ◽

Memory Performance ◽

Age Groups ◽

Memory Task ◽

Negative Effects

Studies examining the effect of embodied cognition have shown that linking one’s body movements to a cognitive task can enhance performance. The current study investigated whether concurrent walking while encoding or recalling spatial information improves working memory performance, and whether 10-year-old children, young adults, or older adults (Mage = 72 years) are affected differently by embodiment. The goal of the Spatial Memory Task was to encode and recall sequences of increasing length by reproducing positions of target fields in the correct order. The nine targets were positioned in a random configuration on a large square carpet (2.5 m × 2.5 m). During encoding and recall, participants either did not move, or they walked into the target fields. In a within-subjects design, all possible combinations of encoding and recall conditions were tested in counterbalanced order. Contrary to our predictions, moving particularly impaired encoding, but also recall. These negative effects were present in all age groups, but older adults’ memory was hampered even more strongly by walking during encoding and recall. Our results indicate that embodiment may not help people to memorize spatial information, but can create a dual-task situation instead.

Download Full-text

Fine Spike Timing in Hippocampal–Prefrontal Ensembles Predicts Poor Encoding and Underlies Behavioral Performance in Healthy and Malformed Brains

Cerebral Cortex ◽

10.1093/cercor/bhaa216 ◽

2020 ◽

Vol 31 (1) ◽

pp. 147-158

Author(s):

Amanda E Hernan ◽

J Matthew Mahoney ◽

Willie Curry ◽

Seamus Mawe ◽

Rod C Scott

Keyword(s):

Working Memory ◽

Spatial Information ◽

Spatial Working Memory ◽

Spike Timing ◽

Functional Network ◽

Long Term Memory ◽

Encode Task ◽

To Receive ◽

Task Parameters

Abstract Spatial working memory (SWM) is a central cognitive process during which the hippocampus and prefrontal cortex (PFC) encode and maintain spatial information for subsequent decision-making. This occurs in the context of ongoing computations relating to spatial position, recall of long-term memory, attention, among many others. To establish how intermittently presented information is integrated with ongoing computations we recorded single units, simultaneously in hippocampus and PFC, in control rats and those with a brain malformation during performance of an SWM task. Neurons that encode intermittent task parameters are also well modulated in time and incorporated into a functional network across regions. Neurons from animals with cortical malformation are poorly modulated in time, less likely to encode task parameters, and less likely to be integrated into a functional network. Our results implicate a model in which ongoing oscillatory coordination among neurons in the hippocampal–PFC network describes a functional network that is poised to receive sensory inputs that are then integrated and multiplexed as working memory. The background temporal modulation is systematically altered in disease, but the relationship between these dynamics and behaviorally relevant firing is maintained, thereby providing potential targets for stimulation-based therapies.

Download Full-text

Persistent Spatial Information in the FEF during Object-based Short-term Memory Does Not Contribute to Task Performance

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00599 ◽

2014 ◽

Vol 26 (6) ◽

pp. 1292-1299 ◽

Cited By ~ 2

Author(s):

Kelsey L. Clark ◽

Behrad Noudoost ◽

Tirin Moore

Keyword(s):

Task Performance ◽

Spatial Information ◽

Short Term Memory ◽

Spatial Working Memory ◽

Memory Performance ◽

Persistent Activity ◽

Short Term ◽

Object Based ◽

Saccade Task

We previously reported the existence of a persistent spatial signal in the FEF during object-based STM. This persistent activity reflected the location at which the sample appeared, irrespective of the location of upcoming targets. We hypothesized that such a spatial signal could be used to maintain or enhance object-selective memory activity elsewhere in cortex, analogous to the role of a spatial signal during attention. Here, we inactivated a portion of the FEF with GABAa agonist muscimol to test whether the observed activity contributes to object memory performance. We found that, although RTs were slowed for saccades into the inactivated portion of retinotopic space, performance for samples appearing in that region was unimpaired. This contrasts with the devastating effects of the same FEF inactivation on purely spatial working memory, as assessed with the memory-guided saccade task. Thus, in a task in which a significant fraction of FEF neurons displayed persistent, sample location-based activity, disrupting this activity had no impact on task performance.

Download Full-text