Perception and Action

Perception and Action

  • Klaus Blischke added an answer:
    How are upper limb movements coded by motor cortex?

    In the last years I have studied how CNS and Spinal Cord interact for generating a reaching movement.

    I'm writing on the current opinions about how CNS controls reaching movements. Because there are a lot of different positions about this topic i want to be sure that no one is omitted in my thesis.

    So, in your opinion, which are the parameters encoded by the motor cortex in a motor command? Or, in other words, how CNS controls reaching movements?

    Klaus Blischke · Universität des Saarlandes

    Hi all!

    I very much go along with Andreas Kalckert's recommendations, too.

    But when it comes down to specifically address the question of cortico-spinal interplay in upper-limb control, the concept of threshold position control (cf. tonic stretch reflex) as advocated by Anatol Fel'dman, Mindy Levin (both Université de Montréal, i believe), and also by Mark Latash (PennState University) might be worthwhile to be taken into closer consideration.

    See for instance the paper by Raptis, H., Burtet, L., Forget, R., and Feldman , A.G. (2010). Control of wrist position and muscle relaxation by shifting spatial frames of reference for motoneuronal recruitment: possible involvement of corticospinal pathways. J Physiol 588.9 (2010), pp. 1551-1570.


    Klaus Blishcke

  • Brandon Thomas added an answer:
    How can a coach/teacher design affordances into learning programmes?
    I am looking for any experience or paper in which a coach/teacher designs affordances into learning programmes, especially in motor learning and acquisition of movement skills, in nonlinear pedagogy and constraints-led approach.
    Brandon Thomas · University of Cincinnati

    I am not aware of any applications of the theory of affordances to teaching or learning. But, the publication below may be a good starting point for how affordances fit into a coaching context.



  • Behzad Behzadnia added an answer:
    How to exploit self-organisation coordination tendencies that exist in human movement systems?
    I am looking for any experience or publication about how a coach can create a learning environment, in learning design, for exploiting self-organisation coordination tendencies that exist in human movement systems?
    Behzad Behzadnia · Urmia University

    Hi Dr. Passos,

    Thank you so much for your great paper.

    with your opinion, how a coach can manipulate the self-organization tendencies in novice players, or  in skilled players? ; in exercising and transforming this tendencies to competitive (invasion) in skilled players? 

    Do you have any info about Self-Organization in Badminton or Volleyball?

    Thank you very much in advance,


  • Richard Atkins added an answer:
    What is perceived? What are the contents of perception?
    Do we perceive light, sound, and so on? Or, do we perceive the world, as such; the shape, size, location, of things in the world? Or, do we perceive the world in relation to ourselves, and ourselves in relation to the world?
    Richard Atkins · Boston College, USA

    From a philosophical point of view, the answers to this question fall on a continuum, the extremes of which are found in the developments of British Empiricism and the Scottish Enlightenment. The broadest conception is due to Francis Hutcheson, who holds that the “every Determination of our Minds to receive Ideas independently of our Will, and to have Perceptions of Pleasure and Pain, [I call] a SENSE.” C.S. Peirce inherits this view and argues that whatever is stated in involuntary perceptual judgments must be regarded as a content of perception (that is, the percept), even though it need not be veridical. Consequently, Peirce (and Hutcheson, I think) must deny that perception is a success term. On the other end of the continuum is James Mill, who goes so far as to claim that “[i]t is Light alone which enters the eye” and “[s]ome of the things suggested by the sensations of sight, as extension and figure, are suggested so instantaneously that they appear to be objects of sight, things actually seen. But this important law of our nature, by which so many things appear to be seen, which are only suggested by the feelings of sight, it requires the knowledge of other elements of the mental phenomena to explain.” The Millian view predominated until the mid-1990’s, most notably with W.V.O Quine claiming that all of our knowledge depends on “surface irritations.” However, recently Susanna Siegel and Jesse Prinz have called the Millian view into question (though not explicitly calling it the Millian view). Siegel has argued that we perceive natural kinds and Prinz has extended his dual content view of perception to sensation, though an explanation of their view lies outside of this brief answer to the question. Personally, I have a preference for the Hutcheson-Peirce view since it can make better sense of mathematical knowledge on the basis of perception (e.g. proofs of the Pythagorean theorem on the basis of perceiving relations among triangles and squares) and since the Mill-Quine view seems to require an implausible amount of offloading to the “inferential” (scare quotes because it is open question whether “inference” should be limited to refer to self-controlled processes alone) processes of the mind.

  • What is the easiest way in Matlab to achieve true parallel programming?

    I have a situation where I'm controlling my robot, which has a Kinect, via Matlab. I also have matlab code that gets depth information directly from Kinect. The robots actuators behave in synchronous fashion, i.e., the Matlab code won't return unless the action is completed. Thus, during action execution, I'm not getting depth information.

    I would like to keep getting depth info from the kinect (perception) in thread/process 1 and would like to send signals to actuators, if necessary, in another thread/process. The tricky part is that the perception and action may or may not communicate with each other, i.e., they may or may not be independent. This being said, parfor etc in Matlab is not a good option for me since this is not parallel computation, rather two parallel processes that are completely different. 

    I'm using Freenect wrapper for perception and iCreate_toolbox wrapper for actuation, in Matlab.

    Omar Andres Carmona Cortes · Dalhousie University

    Anshul, the Parallel Computing Toolbox is a very powerful tool for programming parallel applications. You can use automatic parallelization (parfor), SPMD or GPU programming. However, in your particular case where you want to program completely different processes I would say that maybe Matlab is not the right choice for you. This paper gives an overview of you can do using the Parallel Computing Toolbox:, excepting the GPU case.  I hope the article be useful. 

  • Otto Lappi added an answer:
    Can anyone give me examples of real-world tasks where 'habitual motor responses' or 'response inhibition' play a role?
    I am looking for examples of real-world tasks (e.g. jobs, situations, etc.) where habitual motor responses are a factor, for good or for bad.

    For example, a situation where a simple motor task or response is performed many times in rapid succession, until it becomes 'automatic', and then when there is eventually a need to withhold from performing this task/response it is difficult to do so.

    Any help would be much appreciated.
    Otto Lappi · University of Helsinki

    If you learn to drive using a stick shift, you are very likely to hit the brake pedal when manoeuvering with an automatic, e.g. at  a car park. (You need to make sure your "clutch foot" keeps away from the pedals - this may take some effort at first).

  • Justin Fine added an answer:
    What is the interpretation of negative nonlinear Duffing stiffness (-x^3) in limit-cycle models of biologic rhythmic actions?
    In modeling biologic rhythmic actions as limit-cycles, it has been reported that a negative Duffing term (i.e. -x^3) represents decreasing of variability near reversal points (or softening spring). The question is what type of "variability" we mean here? Spatial? Temporal? Any other type?
    How could it be proved or visualized based on Duffing equations or any other method that variability decreases near reversal points?
    Justin Fine · Arizona State University
    Space-time, actually. You could, for example, see the influence of a x^3 term by creating a Hooke plot. That plot is position~aceleration. A completely straight lined plot means the oscillator (limit-cycle) reduces to a harmonic oscillator; one only with a linear stiffness term. On the other hand, a x^3 term means the angular frequency , or velocity if that's easier to imagine, in the cycle is not constant.

    Now, the problem faced by your question is it's slightly under defined. Are you basing your question on an analytic model such as x"+b*x'+c*x+d*x^3=0 ? (Note this has no nonlinear damping. So it won't give you a limit cycle, per se, but a damped out cycle.). If you are, the variability means nothing because it's a noise free system. However, try simulating this an adding a Gaussian noise term ( I think), and then making the hooke plot. If there is less variability around the endpoint, this is I believe , as you might guess, due to a softening spring. This implies a slowing down as an endpoint is reached. This also predicts an increased deceleration in a Hooke plgot, which is where the 3rd order term comes from. See the Hooke plot I attached (it's my data): It is several cycles of a handheld pendulum being swung, with the average superimposed. Arrows are added to where the variability would be expected to start decreasing.

    If you're familiar with Fitts' law, look up Mottet and Bootsma (1999) "Dynamics of goal-directed rhythmical aiming", I believe. They fit this type of model to movement data and give a good description.

    P.s., I wrote this quickly, but if you have more questions (model fitting, etc...) let me know.

    Good Luck:
    Justin F.
  • Miranda Yeoh added an answer:
    Does physical activity like sports help during research? In which do you participate and how do they promote researching?
    Does participation in sport help during a research project? Recreation, it has been said, may well promote serious creativity. Through what psychological mechanism, in your opinion does this work? In what vigorous activities do you participate and how does it improve your research? What frame of mind does this activity inspire in you? How does that attitude affect your serious work?
    Miranda Yeoh · Selangor Matriculation College, Malaysia (Kolej Matrikulasi Selangor)
    @Ljubomir, for the 'scientists who are physically handicapped and are not able to practice exercise' they will feel healthier if they do physiotherapy exercises :)
    When healthy people like us live till 80 years or more, we all also have to do physio exercises...
  • Arnold Trehub added an answer:
    Does anyone know of experiments assessing bidirectional influences of action on perception?
    Action and perception interactions are being studied extensively however I have not been able to find experiments which test in a single paradigm both action perception and perception to action influences.
    Arnold Trehub · University of Massachusetts Amherst
    We commonly think of action in terms of overt motor acts. Maybe we should also consider action in terms of covert acts of spatially-directed attention. An example of this kind of action is the movement of the heuristic self-locus in our phenomenal world. An example is given in Fig. 5, here:
  • Shruti Sharma added an answer:
    What has sport psychology done for mainstream psychology?
    I contend that it has influenced the emergence of positive psychology, led to the application of mental practice in a variety of settings (including rehabilitation) and enhanced our understanding of motor cognition, and finally, inspired the interdisciplinary fields of physical activity and social cognitive neuroscience. What are your thoughts?
    Shruti Sharma · Indian Spinal Injuries Centre
    I affirm the opinions, sportsmen are under a lot of stress anyways and fitness has a dimension in the psychological aspect too and it is more important or i should say an equally important part as the physical health. Of course sports psychology has added quality to our understanding of varied interdisciplinary fields. The incoming of sports psychology over the years has widened the understanding and application of mainstream psychology and increased its utility to rehabilitation in a major way.

Topic Followers (760) See all