scholarly journals Executive Functions in Motor Imagery: Support for the Motor-Cognitive Model over the Functional Equivalence Model

2018 ◽  
Author(s):  
Scott Glover ◽  
Elys Bibby ◽  
Elsa Tuomi
Keyword(s):  
Executive Functions ◽  
Motor Imagery ◽  
Cognitive Model ◽  
Functional Equivalence ◽  
Interference Task ◽  
Generation Task ◽  
Popular View ◽  
Calculation Task ◽  
Equivalence Model ◽  
Time Required

The Motor-Cognitive Model holds that motor imagery relies on executive resources to a much greater extent than do overt actions. According to this view, engaging executive resources with an interference task during motor imagery or overt actions will lead to a greater lengthening of the time required to imagine a movement than to execute it physically. This model is in contrast to a currently popular view, the Functional Equivalence Model, which holds that motor imagery and overt action use identical mental processes, and thus should be equally affected by task manipulations. The two competing frameworks were tested in three experiments that varied the amount and type of executive resources needed to perform an interference task concurrent with either an overt or imagined version of a grasping and placing action. In Experiment 1, performing a concurrent calculation task led to a greater lengthening of the time required to execute motor imagery than overt action relative to a control condition involving no interference task. Further, an increase in the number of responses used to index performance affected the timing of motor imagery but not overt actions. In Experiment 2, a low load repetition task interfered with the timing of motor imagery, but less so than a high load calculation task; both tasks had much smaller effects on overt actions. In Experiment 3, a word generation task also interfered with motor imagery much more than with overt actions. The results of these experiments provide broad support for the Motor-Cognitive Model over the Functional Equivalence Model in showing that interfering with executive functions had a much greater impact on the timing of motor imagery than on overt actions. The possible roles of different executive processes in motor imagery are discussed.

On the relation between motor imagery and visual imagery

1994 ◽  
Vol 17 (2) ◽  
pp. 212-213 ◽  
Author(s):  
Roberta L. Klatzky
Keyword(s):  
Motor Imagery ◽  
Visual Imagery ◽  
Motor Preparation ◽  
Functional Equivalence ◽  
Neurological Findings ◽  
Target Article ◽  
Spatial Environment

Jeannerod's target article describes support, through empirical and neurological findings, for the intriguing idea of motor imagery, a form of representation hypothesized to have levels of functional equivalence with motor preparation, while being consciously accessible. Jeannerod suggests that the subjectively accessible content of motor imagery allows it to be distinguished from motor preparation, which is unconscious. Motor imagery is distinguished from visual imagery in terms of content. Motor images are kinesthetic in nature; they are parametrized by variables such as force and time and they are potentially governed by kinematic rules. Jeannerod acknowledges, however, that motor and visual imagery may not easily be separated, because actions take place in a spatial environment. I agree; in fact, I suggest here that visualization may generally be concomitant with, and may even subjectively dominate, motor imagery.

scholarly journals BLACK-BOX FAULT MODELS

2006 ◽  
Vol 35 (3) ◽  
Author(s):  
Eduardas Bareiša ◽  
Vacius Jusas ◽  
Kęstutis Motiejūnas ◽  
Rimantas Šeinauskas
Keyword(s):  
Test Generation ◽  
Critical Factor ◽  
Fault Model ◽  
Black Box ◽  
Synthesis Process ◽  
Circuit Synthesis ◽  
Fault Models ◽  
Generation Task ◽  
Time To Market ◽  
Time Required

Four black-box fault models are introduced in the paper. The test generation task for the black-box model is more complicated, because possible realizations of the design must be taken into account. However, the time required to generate tests is not very critical factor, because the test generation can be done in parallel with the circuit synthesis process without a prolongation of Time-to-Market. All the proposed fault models were analyzed and investigated experimentally. On the basis of these results, an appropriate fault model responding to the complexity of the problem being solved can be selected.

scholarly journals Increased Time Difference between Imagined and Physical Walking in Older Adults at a High Risk of Falling

2020 ◽  
Vol 10 (6) ◽  
pp. 332
Author(s):  
Hideki Nakano ◽  
Shin Murata ◽  
Kayoko Shiraiwa ◽  
Koji Nonaka
Keyword(s):  
Older Adults ◽  
High Risk ◽  
Motor Imagery ◽  
Risk Group ◽  
High Risk Group ◽  
Low Risk ◽  
Time Difference ◽  
Imagery Ability ◽  
Risk Of Falling ◽  
Time Required

Walking motor imagery ability is thought to be associated with a fear of falling; however, no studies have compared fall risk and motor imagery ability. This study aimed to ascertain the time difference between imagined and physical walking in older adults at low and high risks of falling. Motor imagery ability was assessed using mental chronometry, which measures the imagined time required for movement. Participants included 31 older adults classified as having a high (n = 15) or low (n = 16) risk of falling based on single leg stance time. The time required for imagined and physical walking was measured using 5 m long walkways with three different widths (15, 25, and 50 cm), and the temporal errors (absolute and constant error) were compared. Physical walking time was significantly longer in the high-risk group than in the low-risk group for the 15 and 25 cm wide walkways. The absolute error between the imagined and physical walking times was significantly larger in the high-risk group than in the low-risk group for the 15 and 25 cm wide walkways. There was also a significant difference in the constant error between the high- and low-risk groups between the imagined and physical walking times for all three walkways. Older adults who may be at a higher risk of falling showed longer walking times during action execution but overestimated their performance (i.e., they believe they would be faster) during motor imagery. Therefore, the time difference between imagined and physical walking could, in part, be useful as a tool for assessing fall risk based on motor imagery.

The Functional Equivalence of Imagery and Movement

1982 ◽  
Vol 34 (3) ◽  
pp. 349-365 ◽  
Author(s):  
Peter Johnson
Keyword(s):  
Visual Inspection ◽  
Motor Task ◽  
Movement Control ◽  
Motor Memory ◽  
Functional Equivalence ◽  
Short Term ◽  
Interference Task ◽  
Criterion Movement ◽  
Inspection Task

A method of investigating mental imagery is presented which shows that movements and imagery of movements are functionally equivalent. Experiment I uses a short-term-motor-memory linear positioning task in which a novel movement interpolated between initial presentation and recall of a criterion movement length can bias recall. It was predicted that if a similar bias occurred when the interpolated novel movement was imagined rather than performed, then imagery of movements had effects on memory which were functionally similar to producing movements. The results showed that imagery for movements did produce a similar bias. In Experiment II a second order interference task was introduced while instructions to imagine movements were carried out. It was predicted that if imagery for movements were based on the visual/perceptual system then a simultaneous visual inspection task should inhibit imagery. If imagery were based on the motor system though, a simultaneous motor task should prohibit imagery. The results showed that a visual task inhibited imagery. The role of visual imagery in movement control is discussed in terms of spatial representations.

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