Motor-Transformation Learning

Perception ◽  
1974 ◽  
Vol 3 (4) ◽  
pp. 487-496 ◽  
Author(s):  
J C Hay
Keyword(s):  
Memory Retrieval ◽  
Visual Space ◽  
Position Constancy ◽  
Transformation Learning ◽  
Recent Computer ◽  
Displacement Experiments ◽  
Prism Displacement ◽  
Computer Controlled ◽  
Motor Actions ◽  
Parameter Values

Motor-transformation learning theory asserts that people learn through experience what stimulus transformations are under the control of their behavior. More specifically, it asserts that the parameter values of certain predetermined transformation groups are learned. This theory was inferred, in the first place, from research on adaptation to optical rearrangement—in particular, from position-constancy adaptation in inverting-spectacles experiments, prism-displacement experiments, and in more recent computer-controlled feedback experiments. The detailed characteristics of position-constancy adaptation are found to be consistent with the theory. Diverse consequences radiate from the theory for other human abilities, both in perception and in memory retrieval. These diverse implications are tested in studies of (a) learning to manipulate ‘objects’ in an artificial computer-controlled visual space; (b) learning to compute, in the absence of overt action, the consequences of such action; (c) learning how to access the features of prior stimuli by the execution of motor actions.

scholarly journals Active sensing without efference copy: referent control of perception

2016 ◽  
Vol 116 (3) ◽  
pp. 960-976 ◽  
Author(s):  
Anatol G. Feldman
Keyword(s):  
Visual Space ◽  
Position Sense ◽  
Efference Copy ◽  
Body Motion ◽  
Phantom Limb ◽  
Active Sensing ◽  
Motor Commands ◽  
Sensory Experiences ◽  
Space Constancy ◽  
Motor Actions

Although action and perception are different behaviors, they are likely to be interrelated, as implied by the notions of perception-action coupling and active sensing. Traditionally, it has been assumed that the nervous system directly preprograms motor commands required for actions and uses a copy of them called efference copy (EC) to also influence our senses. This review offers a critical analysis of the EC concept by identifying its limitations. An alternative to the EC concept is based on the experimentally confirmed notion that sensory signals from receptors are perceived relative to referent signals specified by the brain. These referents also underlie the control of motor actions by predetermining where, in the spatial domain, muscles can work without preprogramming how they should work in terms of motor commands or EC. This approach helps solve several problems of action and explain several sensory experiences, including position sense and the sense that the world remains stationary despite changes in its retinal image during eye or body motion (visual space constancy). The phantom limb phenomenon and other kinesthetic illusions are also explained within this framework.

Putting action into testing: Enacted retrieval benefits long-term retention more than covert retrieval

2020 ◽  
Vol 73 (12) ◽  
pp. 2093-2105
Author(s):  
Veit Kubik ◽  
Fredrik U Jönsson ◽  
Mario de Jonge ◽  
Artin Arshamian
Keyword(s):  
Memory Retrieval ◽  
Testing Effect ◽  
Recall Test ◽  
Retrieval Practice ◽  
Memory Performance ◽  
Cued Recall ◽  
Term Retention ◽  
Long Term Retention ◽  
Motor Actions

Retrieval practice improves long-term retention. However, it is currently debated if this testing effect can be further enhanced by overtly producing recalled responses. We addressed this issue using a standard cued-recall testing-effect paradigm with verb–noun action phrases (e.g., water the plant) to prompt motor actions as a specifically powerful response format of recall. We then tested whether motorically performing the recalled verb targets (e.g., ?–the plant) during an initial recall test ( enacted retrieval) led to better long-term retention than silently retrieving them ( covert retrieval) or restudying the complete verb–noun phrases ( restudy). The results demonstrated a direct testing effect, in that long-term retention was enhanced for covert retrieval practice compared to restudy practice. Critically, enactment during retrieval further improved long-term retention beyond the effect of covert memory retrieval, both in a congruent noun-cued recall test after 1 week (Experiment 1) and in an incongruent verb-cued recall test of nouns after 2 weeks (Experiment 2). This finding suggests that successful memory retrieval and ensuing enactment contribute to future memory performance in parts via different mechanisms.

AN ANALYSIS ON INSTANTANEOUS STABILITY OF AN ASSOCIATIVE CHAOTIC NEURAL NETWORK

1999 ◽  
Vol 09 (11) ◽  
pp. 2157-2163 ◽  
Author(s):  
MASAHARU ADACHI ◽  
KAZUYUKI AIHARA
Keyword(s):  
Neural Network ◽  
Discrete Time ◽  
Memory Retrieval ◽  
Chaotic Dynamics ◽  
Chaos Control ◽  
Dynamical Property ◽  
Neuron Models ◽  
Chaotic Neural Network ◽  
Time Step ◽  
Parameter Values

We analyze instantaneous stability of a chaotic neural network which shows nonperiodic associative dynamics. The network is composed of discrete-time neuron models of which individuals show chaotic dynamics with certain parameter values. The synaptic weights of the network are determined by an auto-associative matrix so that four binary patterns are stored as a basal memory of the network. It has been reported that the network retrieves stored patterns nonperiodically. However, the dynamical property of the network in each discrete-time step has not been clarified. In this paper, instantaneous stability of the network during the nonperiodic memory retrieval is analyzed by calculating eigenvalues of the Jacobian matrix. From the analysis, it is found that in every instance when the network retrieves stored patterns, all the eigenvalues are always less than unity. This implies that such states of the memory retrieval cannot be a target of the OGY-like chaos control methods.

Recent Computer Installations at the Hale Observations

1971 ◽  
Vol 11 ◽  
pp. 8-11 ◽  
Author(s):  
Edwin W. Dennison
Keyword(s):  
Digital Systems ◽  
Digital Data ◽  
Small Computer ◽  
Data Systems ◽  
Controlled System ◽  
New Device ◽  
Recent Computer ◽  
Computer Controlled ◽  
Equipment Configuration ◽  
And Control

Approximately two and a half years ago we started to design a comprehensive computer controlled system to handle data and control telescopes at the Hale Observatories. Our previous experience with hard-wired digital data systems had adequately demonstrated that digital systems can increase the astronomical observer’s efficiency by at least a factor of two, that is, we had found that our observers, when using these digital data systems were able to observe twice as many stars per night as they had previously. We became painfully aware of the fact that the hard-wired systems were extremely difficult to modify for new observing requirements. It therefore appeared logical to develop a data system using a small computer which had the facility of permitting the addition of a large number of new devices without modifying the hardware which had been previously constructed. This concept has the advantage that new observing instruments can be added by constructing new hardwire peripheral devices and developing new software. During the development time of a new device it is always possible to insure that the instrument can be returned to its previous configuration by loading the computer with its previous program. This permits an observer to use the same equipment configuration for a period of years even though the capability of the basic system has been greatly enlarged.

scholarly journals Trilobite vision: a comparison of schizochroal and holochroal eyes with the compound eyes of modern arthropods

1992 ◽  
Vol 6 ◽  
pp. 103-103
Author(s):  
David. Fordyce ◽  
Thomas W. Cronin
Keyword(s):  
Visual Field ◽  
National Science Foundation ◽  
Compound Eye ◽  
Visual Fields ◽  
Visual Space ◽  
Compound Eyes ◽  
Central Processing ◽  
Corneal Lens ◽  
Bright Sunlight ◽  
Parameter Values

The compound eyes of trilobites provide the best examples of fossilized sensory organs for which the function in life can be worked out today, because the optical array of their corneal lenses preserves the geometry with which the eye originally sampled the visual world. An analysis of trilobite vision is strengthened by the use of new mathematical approaches to compound eye design. In particular, the product of the facet diameter (D) and the interommatidial angle (Δϕ) gives the value of the eye parameter, DΔϕ, which is a reliable indicator of the photic conditions in which the eye was used. In modern arthropods, DΔϕ values range from 0.3 for animals active in bright sunlight to 20 or more for nocturnal or deep-sea animals.Three types of compound eyes existed in trilobites: schizochroal, holochroal, and abathochroal. We examined the schizochroal and holochroal types. Schizochroal eyes were studied in the phacopid species Phacops rana crassituberculata and Phacops rana milleri. We measured the diameter of every corneal lens, and estimated its optical axis by taking the normal to the plane of the lens's diameter. In both species, each eye covered almost exactly 180° of visual space in azimuth with no binocular overlap, from directly anterior to directly posterior. Vertically, the visual field extended from the horizon to about 40° in elevation. Facet diameters and interommatidial angles were large, giving eye parameter values ranging from 10 to > 150. These are much greater than in any living arthropod, implying that modern compound eye theory does not apply to schizochroal eyes. We believe that each ommatidium of the schizochroal eye served as a miniature lens eye. If so, phacopid vision must have been unique, with multiply overlapping visual fields. Such a design would have required considerable central processing, but could have provided exceptional opportunities for spatial, spectral, and polarizational analysis.We examined holochroal compound eyes in Asaphus cornutus and Isotelus “gigas”. Here, visual field coverage was greater than in the schizochroal eye type, with a small amount of frontal binocular overlap. Holochroal eyes contain far more ommatidia than do schizochroal types, reducing both facet diameter (D) and interommatidial angle (Δϕ). Thus, DΔϕ values in these species fall into the same range as in modern compound eyes. This implies that function of the holochroal eye was similar to that of modern crustaceans and insects.This material is based on research supported by the National Science Foundation under Grants No. BNS-8518769 and BNS-8917183.

SPECTRA: A program for processing electron images of crystals

1992 ◽  
Vol 50 (1) ◽  
pp. 132-133
Author(s):  
M.F. Schmid ◽  
R. Dargahi ◽  
M. W. Tam
Keyword(s):  
Lattice Distortion ◽  
Data Transfer ◽  
Reciprocal Lattice ◽  
Data Entry ◽  
Image Data ◽  
Distortion Correction ◽  
Specimen Preparation ◽  
Electron Image ◽  
Computer Controlled ◽  
Program Modules

Electron crystallography is an emerging field for structure determination as evidenced by a number of membrane proteins that have been solved to near-atomic resolution. Advances in specimen preparation and in data acquisition with a 400kV microscope by computer controlled spot scanning mean that our ability to record electron image data will outstrip our capacity to analyze it. The computed fourier transform of these images must be processed in order to provide a direct measurement of amplitudes and phases needed for 3-D reconstruction.In anticipation of this processing bottleneck, we have written a program that incorporates a menu-and mouse-driven procedure for auto-indexing and refining the reciprocal lattice parameters in the computed transform from an image of a crystal. It is linked to subsequent steps of image processing by a system of data bases and spawned child processes; data transfer between different program modules no longer requires manual data entry. The progress of the reciprocal lattice refinement is monitored visually and quantitatively. If desired, the processing is carried through the lattice distortion correction (unbending) steps automatically.

Applications of CCEM to Environmental Health Problems

1985 ◽  
Vol 43 ◽  
pp. 102-103
Author(s):  
R. J. Lee ◽  
J. S. Walker
Keyword(s):  
Electron Microscopy ◽  
Image Analysis ◽  
Environmental Health ◽  
Computer Control ◽  
External Agent ◽  
External Agents ◽  
Computer Controlled ◽  
Primitive State ◽  
Textural Changes ◽  
General Aspects

Electron microscopy (EM), with the advent of computer control and image analysis techniques, is rapidly evolving from an interpretative science into a quantitative technique. Electron microscopy is potentially of value in two general aspects of environmental health: exposure and diagnosis.In diagnosis, electron microscopy is essentially an extension of optical microscopy. The goal is to characterize cellular changes induced by external agents. The external agent could be any foreign material, chemicals, or even stress. The use of electron microscopy as a diagnostic tool is well- developed, but computer-controlled electron microscopy (CCEM) has had only limited impact, mainly because it is fairly new and many institutions lack the resources to acquire the capability. In addition, major contributions to diagnosis will come from CCEM only when image analysis (IA) and processing algorithms are developed which allow the morphological and textural changes recognized by experienced medical practioners to be quantified. The application of IA techniques to compare cellular structure is still in a primitive state.

High-speed brightfield 3-D imaging and 3-D image analysis of thick and overlapped cell clusters in cytological preparations

1994 ◽  
Vol 52 ◽  
pp. 218-219
Author(s):  
Robert W. Mackin
Keyword(s):  
Image Analysis ◽  
High Speed ◽  
Three Dimensional ◽  
Image Data ◽  
Ccd Camera ◽  
Objective Lens ◽  
Array Processor ◽  
Vaginal Smears ◽  
Low Contrast ◽  
Computer Controlled

This paper presents two advances towards the automated three-dimensional (3-D) analysis of thick and heavily-overlapped regions in cytological preparations such as cervical/vaginal smears. First, a high speed 3-D brightfield microscope has been developed, allowing the acquisition of image data at speeds approaching 30 optical slices per second. Second, algorithms have been developed to detect and segment nuclei in spite of the extremely high image variability and low contrast typical of such regions. The analysis of such regions is inherently a 3-D problem that cannot be solved reliably with conventional 2-D imaging and image analysis methods.High-Speed 3-D imaging of the specimen is accomplished by moving the specimen axially relative to the objective lens of a standard microscope (Zeiss) at a speed of 30 steps per second, where the stepsize is adjustable from 0.2 - 5μm. The specimen is mounted on a computer-controlled, piezoelectric microstage (Burleigh PZS-100, 68/μm displacement). At each step, an optical slice is acquired using a CCD camera (SONY XC-11/71 IP, Dalsa CA-D1-0256, and CA-D2-0512 have been used) connected to a 4-node array processor system based on the Intel i860 chip.

The new CM-Series TEMs: integration of a five-axis motorized, fully computer-controlled goniometer

1993 ◽  
Vol 51 ◽  
pp. 258-259
Author(s):  
Marc J.C. de Jong ◽  
P. Emile S.J. Asselbergs ◽  
Max T. Otten
Keyword(s):  
Mechanical Design ◽  
Computer Control ◽  
Objective Lens ◽  
Access Port ◽  
Vibration Stability ◽  
Transmission Electron ◽  
Computer Controlled ◽  
High Degree ◽  
Five Axis ◽  
Five Axes

A new step forward in Transmission Electron Microscopy has been made with the introduction of the CompuStage on the CM-series TEMs: CM120, CM200, CM200 FEG and CM300. This new goniometer has motorization on five axes (X, Y, Z, α, β), all under full computer control by a dedicated microprocessor that is in communication with the main CM processor. Positions on all five axes are read out directly - not via a system counting motor revolutions - thereby providing a high degree of accuracy. The CompuStage enters the octagonal block around the specimen through a single port, allowing the specimen stage to float freely in the vacuum between the objective-lens pole pieces, thereby improving vibration stability and freeing up one access port. Improvements in the mechanical design ensure higher stability with regard to vibration and drift. During stage movement the holder O-ring no longer slides, providing higher drift stability and positioning accuracy as well as better vacuum.

Computer-Controlled Hrem Alignment Using Automated Diffractogram Analysis

1990 ◽  
Vol 48 (1) ◽  
pp. 532-533
Author(s):  
G.Y. Fan ◽  
O.L. Krivanek
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
The Other ◽  
Full Information ◽  
Resolution Electron ◽  
Skilled Operator ◽  
Automatic Alignment ◽  
High Resolution Electron Microscope ◽  
Computer Controlled ◽  
Recorded Image

Full alignment of a high resolution electron microscope (HREM) requires five parameters to be optimized: the illumination angle (beam tilt) x and y, defocus, and astigmatism magnitude and orientation. Because neither voltage nor current centering lead to the correct illumination angle, all the adjustments must be done on the basis of observing contrast changes in a recorded image. The full alignment can be carried out by a computer which is connected to a suitable image pick-up device and is able to control the microscope, sometimes with greater precision and speed than even a skilled operator can achieve. Two approaches to computer-controlled (automatic) alignment have been investigated. The first is based on measuring the dependence of the overall contrast in the image of a thin amorphous specimen on the relevant parameters, the other on measuring the image shift. Here we report on our progress in developing a new method, which makes use of the full information contained in a computed diffractogram.

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