scholarly journals Targeted photostimulation uncovers circuit motifs supporting short-term memory

2019 ◽  
Author(s):  
Kayvon Daie ◽  
Karel Svoboda ◽  
Shaul Druckmann
Keyword(s):  
Neural Activity ◽  
Neural Circuit ◽  
Short Term Memory ◽  
Functional Organization ◽  
Neuronal Population ◽  
Delayed Response ◽  
Short Term ◽  
Population Activity ◽  
Term Memory ◽  
Stimulus Offset

AbstractShort-term memory is associated with persistent neural activity without sustained input, arising from the interactions between neurons with short time constants1,2. A variety of neural circuit motifs could account for measured neural activity3–7. A mechanistic understanding of the neural circuits supporting short-term memory requires probing network connectivity between functionally characterized neurons8. We performed targeted photostimulation of small (< 10) groups of neurons, while imaging the response of hundreds of other neurons9,10, in anterior-lateral motor cortex (ALM) of mice performing a delayed response task11. Mice were instructed with brief auditory stimuli to make directional movements (lick left or lick right), but only after a three second delay epoch. ALM contains neurons with delay epoch activity that is selective for left or right choices. Targeted photostimulation of groups of neurons during the delay epoch allowed us to observe the functional organization of population activity and recurrent interactions underlying short-term memory. These experiments revealed strong coupling between neurons sharing similar selectivity. Brief photostimulation of functionally related neurons produced changes in activity in sparse subpopulations of nearby neurons that persisted for several seconds following stimulus offset, far outlasting the duration of the perturbation. Photostimulation produced behavioral biases that were predictable based on the selectivity of the perturbed neuronal population. These results suggest that ALM contains multiple intercalated modules, consisting of recurrently coupled neurons, that can independently maintain persistent activity.

scholarly journals Discrete attractor dynamics underlying selective persistent activity in frontal cortex

2017 ◽  
Author(s):  
Hidehiko K. Inagaki ◽  
Lorenzo Fontolan ◽  
Sandro Romani ◽  
Karel Svoboda
Keyword(s):  
Short Term Memory ◽  
Network Modeling ◽  
Motor Planning ◽  
Delayed Response ◽  
Persistent Activity ◽  
Short Term ◽  
Population Activity ◽  
Term Memory ◽  
Attractor Dynamics ◽  
Response Task

AbstractShort-term memories link events separated in time, such as past sensation and future actions. Short-term memories are correlated with selective persistent activity, which can be maintained over seconds. In a delayed response task that requires short-term memory, neurons in mouse anterior lateral motor cortex (ALM) show persistent activity that instructs future actions. To elucidate the mechanisms underlying this persistent activity we combined intracellular and extracellular electrophysiology with optogenetic perturbations and network modeling. During the delay epoch, both membrane potential and population activity of ALM neurons funneled towards discrete endpoints related to specific movement directions. These endpoints were robust to transient shifts in ALM activity caused by optogenetic perturbations. Perturbations occasionally switched the population dynamics to the other endpoint, followed by incorrect actions. Our results are consistent with discrete attractor dynamics underlying short-term memory related to motor planning.

scholarly journals Visual short-term memory for 3D shapes reveals similar properties to simple 2D features

2019 ◽  
Author(s):  
Joel Robitaille ◽  
Stephen Emrich
Keyword(s):  
Short Term Memory ◽  
Memory Load ◽  
Memory Performance ◽  
Delayed Response ◽  
Short Term ◽  
Complex Objects ◽  
Term Memory ◽  
Visual Short Term Memory ◽  
2D And 3D ◽  
3D Shapes

In the past two decades, significant advances have been made to understand the psychophysical properties of visual short-term memory (VSTM). Most studies, however, make inferences based on memory for simple surface features of 2D shapes. Here, we examined the role of object complexity and dimensionality on the psychophysical properties of VSTM by comparing orientation memory for 2D lines and complex 3D objects in a delayed-response continuous report task, where memory load (Experiment 1) or axis of rotation (Experiment 2) was manipulated. In both experiments, our results demonstrate an overall cost of complexity that affected participants raw errors as well as their guess rate and response precision derived from mixture modelling. We also demonstrate that participants’ memory performance is correlated between stimulus types and that memory performance for both 2D and 3D shapes is better fit to the variable precision model of VSTM than to tested competing models. Interestingly, the ability to report complex objects is not consistent across axes of rotation. These results indicate that, despite the fact that VSTM shares similar properties for 2D and 3D shapes, VSTM is far from being a unitary process and is affected by stimulus properties such as complexity and dimensionality.

Neuromodulation of Reactive Sensorimotor Mappings as a Short-Term Memory Mechanism in Delayed Response Tasks

2002 ◽  
Vol 10 (3-4) ◽  
pp. 185-199 ◽  
Author(s):  
Tom Ziemke ◽  
Mikael Thieme
Keyword(s):  
Short Term Memory ◽  
Neural Nets ◽  
Memory Representation ◽  
Delayed Response ◽  
Short Term ◽  
Term Memory ◽  
Memory Mechanism ◽  
Control Networks ◽  
Behavioral Dynamics ◽  
Sensorimotor Mechanisms

This article addresses the relation between memory, representation, and adaptive behavior. More specifically, it demonstrates and discusses the use of synaptic plasticity, realized through neuromodulation of sensorimotor mappings, as a short-term memory mechanism in delayed response tasks. A number of experiments with extended sequential cascaded networks, that is, higher-order recurrent neural nets, controlling simple robotic agents in six different delayed response tasks are presented. The focus of the analysis is on how short-term memory is realized in such control networks through the dynamic modulation of sensorimotor mappings (rather than through feedback of neuronal activation, as in conventional recurrent nets), and how these internal dynamics interact with environmental/behavioral dynamics. In particular, it is demonstrated in the analysis of the last experimental scenario how this type of network can make very selective use of feedback/memory, while as far as possible limiting itself to the use of reactive sensorimotor mechanisms and occasional switches between them.

scholarly journals Estimation of Bladder Pressure and Volume from the Neural Activity of Lumbosacral Dorsal Horn Using a Long-Short-Term-Memory-based Deep Neural Network

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Milad Jabbari ◽  
Abbas Erfanian
Keyword(s):  
Neural Network ◽  
Neural Activity ◽  
Short Term Memory ◽  
Field Potential ◽  
Bladder Function ◽  
Bladder Pressure ◽  
Short Term ◽  
Term Memory ◽  
Deep Recurrent Neural Network ◽  
Long Short Term Memory

AbstractIn this paper, we propose a deep recurrent neural network (DRNN) for the estimation of bladder pressure and volume from neural activity recorded directly from spinal cord gray matter neurons. The model was based on the Long Short-Term Memory (LSTM) architecture, which has emerged as a general and effective model for capturing long-term temporal dependencies with good generalization performance. In this way, training the network with the data recorded from one rat could lead to estimating the bladder status of different rats. We combined modeling of spiking and local field potential (LFP) activity into a unified framework to estimate the pressure and volume of the bladder. Moreover, we investigated the effect of two-electrode recording on decoding performance. The results show that the two-electrode recordings significantly improve the decoding performance compared to single-electrode recordings. The proposed framework could estimate bladder pressure and volume with an average normalized root-mean-squared (NRMS) error of 14.9 ± 4.8% and 19.7 ± 4.7% and a correlation coefficient (CC) of 83.2 ± 3.2% and 74.2 ± 6.2%, respectively. This work represents a promising approach to the real-time estimation of bladder pressure/volume in the closed-loop control of bladder function using functional electrical stimulation.

False recognitions in short-term memory – Age-differences in neural activity

2021 ◽  
Vol 151 ◽  
pp. 105728
Author(s):  
B. Sikora-Wachowicz ◽  
A. Keresztes ◽  
M. Werkle-Bergner ◽  
K. Lewandowska ◽  
T. Marek ◽  
...  
Keyword(s):  
Age Differences ◽  
Neural Activity ◽  
Short Term Memory ◽  
Short Term ◽  
Term Memory ◽  
False Recognitions

False memory for face in short-term memory and neural activity in human amygdala

2014 ◽  
Vol 1591 ◽  
pp. 74-85 ◽  
Author(s):  
Tetsuya Iidaka ◽  
Tokiko Harada ◽  
Norihiro Sadato
Keyword(s):  
False Memory ◽  
Neural Activity ◽  
Short Term Memory ◽  
Short Term ◽  
Term Memory

scholarly journals Spatial Patterns of Persistent Neural Activity Vary with the Behavioral Context of Short-Term Memory

Neuron ◽  
2015 ◽  
Vol 85 (4) ◽  
pp. 847-860 ◽  
Author(s):  
Kayvon Daie ◽  
Mark S. Goldman ◽  
Emre R.F. Aksay
Keyword(s):  
Spatial Patterns ◽  
Neural Activity ◽  
Short Term Memory ◽  
Behavioral Context ◽  
Short Term ◽  
Term Memory

scholarly journals Attention Modulates Maintenance of Representations in Visual Short-term Memory

2012 ◽  
Vol 24 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Bo-Cheng Kuo ◽  
Mark G. Stokes ◽  
Anna Christina Nobre
Keyword(s):  
Neural Activity ◽  
Short Term Memory ◽  
Memory Load ◽  
Spatial Location ◽  
Relevant Information ◽  
Maintenance Period ◽  
Top Down ◽  
Short Term ◽  
Term Memory ◽  
Visual Short Term Memory

Recent studies have shown that selective attention is of considerable importance for encoding task-relevant items into visual short-term memory (VSTM) according to our behavioral goals. However, it is not known whether top–down attentional biases can continue to operate during the maintenance period of VSTM. We used ERPs to investigate this question across two experiments. Specifically, we tested whether orienting attention to a given spatial location within a VSTM representation resulted in modulation of the contralateral delay activity (CDA), a lateralized ERP marker of VSTM maintenance generated when participants selectively encode memory items from one hemifield. In both experiments, retrospective cues during the maintenance period could predict a specific item (spatial retrocue) or multiple items (neutral retrocue) that would be probed at the end of the memory delay. Our results revealed that VSTM performance is significantly improved by orienting attention to the location of a task-relevant item. The behavioral benefit was accompanied by modulation of neural activity involved in VSTM maintenance. Spatial retrocues reduced the magnitude of the CDA, consistent with a reduction in memory load. Our results provide direct evidence that top–down control modulates neural activity associated with maintenance in VSTM, biasing competition in favor of the task-relevant information.

Application of the Method of Second Order Sign Behavior To the Study of Non-Spatial Delayed Response in Rhesus Monkeys

Behaviour ◽  
1969 ◽  
Vol 35 (1-2) ◽  
pp. 128-136 ◽  
Author(s):  
Bruno Cardu
Keyword(s):  
Rhesus Monkeys ◽  
Short Term Memory ◽  
Memory Span ◽  
Second Order ◽  
Delayed Response ◽  
Short Term ◽  
Term Memory ◽  
First Order ◽  
The Moment ◽  
Sign Behavior

AbstractThe behavior of seven rhesus monkeys on a test of non-spatial delayed response based on the method of second order sign behavior is reported. Four stimuli were used: two first order stimuli presented individually (two sounds or two lights) and two second order stimuli presented simultaneously (two objects). Subjects first learned to associate one of the objects to each of the two first order stimuli. An interval between the termination of the first signal and the moment of choice was then introduced; hence the subjects' short-term memory could be estimated. All subjects succeeded in this task; the limits of the memory span ranged from 20 to 45 seconds.

Sign in / Sign up

Export Citation Format

Share Document