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 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.

scholarly journals mixtur: An R package for designing, analysing, and modelling continuous report visual short-term memory studies

2020 ◽  
Author(s):  
Jim Grange ◽  
Stuart Bryan Moore ◽  
Ed David John Berry
Keyword(s):  
Mixture Models ◽  
Short Term Memory ◽  
R Package ◽  
Memory Representation ◽  
Angular Deviation ◽  
Short Term ◽  
Target Feature ◽  
Component Mixture ◽  
Term Memory ◽  
Visual Short Term Memory

Visual short-term memory (vSTM) is often measured via continuous-report tasks whereby participants are presented with stimuli that vary along a continuous dimension (e.g., colour) with the goal of memorising the stimuli features. At test, participants are probed to recall the feature value of one of the memoranda in a continuous manner (e.g., by clicking on a colour wheel). The angular deviation between the participant response and the true feature value provides an estimate of recall---and hence, vSTM---precision. Two prominent models of performance on such tasks are the two- and three-component mixture models (Bays et al., 2009; Zhang & Luck, 2008). Both models decompose participant responses into probabilistic mixtures of: (1) responses to the true target value based on a noisy memory representation; (2) random guessing when memory fails. In addition, the three-component model proposes (3) responses to a non-target feature value (i.e., binding errors). Here we report the development of mixtur, an open-source package written for the statistical programming language R that facilitates the fitting of the 2- and 3-component mixture models to continuous report data. We also report the results of several simulations conducted to develop recommendations for researchers on trial numbers, set-sizes and memoranda similarity, as well as conducting parameter recovery and model recovery simulations. It is our hope that mixtur will lower the barrier of entry for utilising mixture modelling

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.

scholarly journals Slow and Persistent Postinhibitory Rebound Acts as an Intrinsic Short-Term Memory Mechanism

2010 ◽  
Vol 30 (13) ◽  
pp. 4687-4692 ◽  
Author(s):  
J. M. Goaillard ◽  
A. L. Taylor ◽  
S. R. Pulver ◽  
E. Marder
Keyword(s):  
Short Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Memory Mechanism ◽  
Postinhibitory Rebound

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.

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