Many current neurophysiological, psychophysical, and psychological approaches to vision rest on the idea that when we see, the brain produces an internal representation of the world. The activation of this internal representation is assumed to give rise to the experience of seeing. The problem with this kind of approach is that it leaves unexplained how the existence of such a detailed internal representation might produce visual consciousness. An alternative proposal is made here. We propose that seeing is a way of acting. It is a particular way of exploring the environment. Activity in internal representations does not generate the experience of seeing. The outside world serves as its own, external, representation. The experience of seeing occurs when the organism masters what we call the governing laws of sensorimotor contingency. The advantage of this approach is that it provides a natural and principled way of accounting for visual consciousness, and for the differences in the perceived quality of sensory experience in the different sensory modalities. Several lines of empirical evidence are brought forward in support of the theory, in particular: evidence from experiments in sensorimotor adaptation, visual \"filling in,\" visual stability despite eye movements, change blindness, sensory substitution, and color perception.

A sensorimotor account of vision and visual consciousness-Authors' Response-Acting out our sensory experience

Many current neurophysiological, psychophysical, and psychological approaches to vision rest on the idea that when we see, the brain produces an internal representation of the world. The activation of this internal representation is assumed to give rise to the experience of seeing. The problem with this kind of approach is that it leaves unexplained how the existence of such a detailed internal representation might produce visual consciousness. An alternative proposal is made here. We propose that seeing is a way of acting. It is a particular way of exploring the environment. Activity in internal representations does not generate the experience of seeing. The outside world serves as its own, external, representation. The experience of seeing occurs when the organism masters what we call the governing laws of sensorimotor contingency. The advantage of this approach is that it provides a natural and principled way of accounting for visual consciousness, and for the differences in the perceived quality of sensory experience in the different sensory modalities. Several lines of empirical evidence are brought forward in support of the theory, in particular: evidence from experiments in sensorimotor adaptation, visual “filling in,” visual stability despite eye movements, change blindness, sensory substitution, and color perception.

/pdf/a-sensorimotor-account-of-vision-and-visual-consciousness-1o8kf5szfs.pdf

A sensorimotor account of vision and visual consciousness

Let's read! We will often find out this sentence everywhere. When still being a kid, mom used to order us to always read, so did the teacher. Some books are fully read in a week and we need the obligation to support reading. What about now? Do you still love reading? Is reading only for you who have obligation? Absolutely not! We here offer you a new book enPDFd the perception of the visual world to read.

The Perception of the Visual World. By James J. Gibson. U.S.A.: Houghton Mifflin Company, 1950 (George Allen & Unwin, Ltd., London). Price 35s.

Until recently, gait was generally viewed as a largely automated motor task, requiring minimal higher-level cognitive input. Increasing evidence, however, links alterations in executive function and attention to gait disturbances. This review discusses the role of executive function and of attention in healthy walking and gait disorders while summarizing the relevant, recent literature. We describe the variety of gait disorders that may be associated with different aspects of executive function, and discuss the changes occurring in executive function as a result of aging and disease as well the potential impact of these changes on gait. The attentional demands of gait are often tested using dual tasking methodologies. Relevant studies in healthy adults and patients are presented, as are the possible mechanisms responsible for the deterioration of gait during dual tasking. Lastly, we suggest how assessments of executive function and attention could be applied in the clinical setting as part of the process of identifying and understanding gait disorders and fall risk.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/mds.21720

The role of executive function and attention in gait

During object manipulation tasks, the brain selects and implements action-phase controllers that use sensory predictions and afferent signals to tailor motor output to the physical properties of the objects involved. Analysis of signals in tactile afferent neurons and central processes in humans reveals how contact events are encoded and used to monitor and update task performance.

Coding and use of tactile signals from the fingertips in object manipulation tasks

Motor control is concerned with the processes that allow the central nervous system to interact with the world. How we learn to control movement is central to our understanding of all human behavior.


Keywords:

movement;
speed–accuracy;
sensory feedback;
training;
kinematics

Motor Control and Learning

Three classes of task appear to involve time-to-contact (TTC) information: coincidence anticipation (CA) tasks, relative judgment (RJ) tasks, and interceptive actions (IAs). An important type of CA task used to study the perception of TTC is the prediction-motion (PM) task. The question of whether it is possible to study the perceptual processes involved in the timing of IAs using PM and RJ tasks is considered. A revised version of the tau hypothesis is proposed as an account of the perceptual information processing involved in the control of fast IAs. This draws on the distinction between “motor” and “cognitive” visual systems. It is argued that task variables affect whether “cognitive” information processing is involved in performance and can determine whether TTC information is used at all. Evidence is reviewed that suggests that PM and RJ tasks involve cognitive processing. It is argued that target viewing time, TTC at response initiation, amount of practice, and whether there is a period between target disappearance and response are task variables that determine whether cognitive processing will influence responding.

/pdf/perceptual-and-cognitive-processes-in-time-to-contact-45w4dahnci.pdf

Perceptual and cognitive processes in time-to-contact estimation: analysis of prediction-motion and relative judgment tasks.

The authors examined the coupling of grip force and load force during point-to-point and cyclic arm movements while holding an object in a variety of grips, including 1- and 2-handed grips and "inverted" grips. In all grips, grip force is modulated in phase with fluctuations in load force that are induced by the arm movement. The tight temporal coupling between grip force and load force seen when moving an object held in a precision grip (J. R. Flanagan, J. Tresilian, & A. M. Wing, 1993) is observed in other grips. The control of precision grip force during whole-body jumping movements was also investigated. Grip force was modulated in phase with changes in load force induced by jumping even though the arm's joint angles were fixed. The tight temporal coupling between grip force and load force during object transport reflects a general control strategy that is not specific to any particular grip or mode of transport. Models of the coordination of grasp and transport in prehensile behaviors are discussed.

Grip-load force coupling: a general control strategy for transporting objects

https://www.cell.com/trends/cognitive-sciences/pdf/S1364-6613(99)01352-2.pdf

Visually timed action: time-out for `tau'?

http://wexler.free.fr/library/files/flanagan%20(1993)%20coupling%20of%20grip%20force%20and%20load%20force%20during%20arm%20movements%20with%20grasped%20objects.pdf

James R. Tresilian

Papers

Motor Control and Learning

Perceptual and cognitive processes in time-to-contact estimation: analysis of prediction-motion and relative judgment tasks.

Grip-load force coupling: a general control strategy for transporting objects

Visually timed action: time-out for `tau'?

Coupling of grip force and load force during arm movements with grasped objects