Scientific Understanding of Consciousness
Consciousness as an Emergent Property of Thalamocortical Activity

Movement Control

Movement control is nearly always the functional result of wake-time brain activity.  In the course of normal conversation, for example, the brain activity of listening to a friend and composing your own thoughts is then followed by the muscular movements of vocalization of speech, facial gestures, and gesticulations of arm and body movements.  Even brain activities of passively watching a movie or reading a book can result in memories being formed, which are later transformed into vocalization and facial movements of subsequent conversation, finger movements of typing thoughts on a keyboard, etc.  And of course the brain activity of active sports results in movement.

Natural selection has evolved brain functions that provide guidance signals to control movement. The ever-increasing complexity of the environment has compelled ever-increasing complexity of brain functions to meet the competition. Brain functions of reptiles, mammals, primates and humans have become increasingly complex to provide selective advantages in a competitive environment.

Animal locomotion depends on proprioceptive feedback, which is generated by mechanosensory neurons.

The sensations of movement contribute, through the peripheral nervous system, to the sense of self that forms a basis of consciousness. Thoughts of imagined movement are mediated by memory of prior events of movement. Humans have their contemplation about choice of a mate, financial investments, etc. before decisions and action.

The pirouette of a ballet dancer, the powered backhand of a tennis player, the fingering technique of the pianist, and the coordinated eye movements of a reader all require a remarkable degree of motor skill. (Kandel; Principles of Neural Science, 653)

The motor command sequences that underlie the production of human speech are arguably the most complex that ordinary people attain. (Philip Lieberman; Human Language, 44)

Brain's motor function affects so much more than just physical motion.  It is crucial to all of the brain functions -- perception, attention, emotion -- and so affects the highest cognitive processes of memory, thinking, and learning. (Ratey; User's Guide to Brain, 175)

From the subtleties of body language to the precision of the spoken word to the unambiguity of a simple hug, virtually all communication relies on movement. (Greenfield; Human Brain, 33)

The anterior cingulate cortex (ACC) occupies approximately the anterior one third of the cingulate cortex and is implicated in emotion. The ACC is distinguished from the mid-cingulate cortex (MCC), which occupies approximately the middle third of the cingulate cortex and contains part of the caudal cingulate motor area that may be involved in response selection. (Vogt; Cingulate Neurobiology, 192)

 

Research Study — Motor Neurons Control Retrogradely via Gap Junctions

Research Study — Neural Basis of Contagious Itch

Research Study — Basal Ganglia Circuit for Evaluating Action Outcomes

Research Study — Motor Cortex Neurons Directly Influence Motor Output

Research Study — A motor cortex circuit for motor planning and movement

Research Study — Motor Learning Spatiotemporal Neural Activity Patterns

Research Study — Motor Tasks via Brainstem Nucleus

Research Study — Movement Control via Propriospinal Internal Copy Circuit

Research Study — Movement Control Smoothed via Presynaptic Inhibition

Research Study — Speech Organization in Cortex Production of fluent speech requires the precise, coordinated movement of multiple articulators (for example, the lips, jaw, tongue and larynx) over rapid time scales.  We found speech-articulator representations that are arranged somatotopically on ventral pre- and post-central gyri, which were coordinated temporally as sequences during syllable production.

Research Study — Motor Neurons Relay Neural Commands to Drive Skeletal Muscle Movements

 

Anterior Cingulate Cortex a Focus of Movement Control

Antonio Damasio has noted that damage to the anterior cingulate cortex, which receives input from many higher perceptual areas and is connected to the higher levels of the motor system, leaves a patient in a seemingly alert but strangely unresponsive state. (Pinker; How the Mind Works, 144)

 

Research study — Interneuron Types in Distinct Behavior

 

Rhythmic Neuronal Activity during Movement

Neural Population Dynamics -- Quasi-oscillatory neural responses are present when a monkey 'reaches'. Rotations of the population state are a prominent feature of the cortical response during reaching. These population-level rotations are a relatively simple dynamical feature yet explain seemingly complex features of individual-neuron responses,

 

Unconscious Stereotyped Motor Control

Rhythm is a universal components of music.  People dance, nod, shake, swing, stride, clap, and snap to music, and that is a strong hint that music taps into the system of motor control. (Pinker; How the Mind Works, 537)

Control of behavior is sometimes conscious and sometimes unconscious (e.g. walking vs. mountain climbing). (Shiffrin; Attention, Automatism, Consciousness, 640)

Anyone who skis mountain trails,    plays a piano,    or drives an automobile home on 'automatic pilot,'    knows that  stereotyped sensory-motor skills -- dubbed zombie behaviors -- require rapid and sophisticated sensory processing. (Tsuchiya & Koch; Consciousness and Attention, 74)

From the subtleties of body language to the precision of the spoken word to the unambiguity of a simple hug, virtually all communication relies on movement. (Greenfield; Human Brain, 33)

The motivational circuitry of the brain connects the prefrontal cortex decision process to the premotor and motor cortex, which then use FAPs stored in the brain stem and spinal cord to produce movement.

Motivational circuitry of the brain, (diagram)  -  Dopaminergic projection from the ventral tegmental area (VTA) to the nucleus accumbens is a key feature of the circuitry. (LeDoux; Synaptic Self, 248)

Unconscious neural processes occurring in the sensory and motor periphery can influence the dynamic core. Ongoing unconscious assistance to our conscious life occurs whenever we speak aloud or only to ourselves, write or type, play a musical instrument, perform athletic routines, drive an auto or simply set a table. It occurs when we perform a mental calculation or merely follow a train of thought without doing or saying anything. (Edelman; Universe of Consciousness, 182)

Cerebellum and basal ganglia do not send significant output to the spinal cord, but they do act directly on projection neurons in the brainstem. (Kandel; Principles of Neural Science, 665)

Optimal Control of Movement

The brain generates the best behavior it can, subject to the constraints imposed by the body and environment.  This makes optimal control theory an appealing computational framework for studying the neural control of movement. (Doya, et al.; Bayesian Brain, 294)

Optimal control and optimal estimation are closely related mathematical problems, the best-known example being the linear quadratic regulator and the Kalman filter. (Doya, et al.; Bayesian Brain, 290)

Uncertainty that stems from noise of the lack of complete knowledge places estimation of attributes of the world and control of our actuators firmly within a statistical framework.  The knowledge about movement outcomes must be described by a probability distribution. (Doya, et al.; Bayesian Brain, 302)

 

          Motor Movement Diagram

 

           Voluntary Movement Diagram -

 

 

Hierarchy of Modular Motor Programs

Movement is facilitated in the brain and nervous system by a hierarchy of modular functionality  referred to variously by a number of names, including CPGs, FAPs, dispositions, gestures, synergy, schemas, motor programs, stereotypical patterns of movement, etc.

 

           Link to — Summary discussion of CPGs, FAPs, dispositions

           Link to — Fixed Action Patterns (FAPs)

           Link to — Movement Planning in Dorsal Premotor Cortex

 

Dispositions produce a variety of results.  They can generate actions of many kinds in many levels of complexity -- the release of hormones into the bloodstream; the contraction of muscles in the viscera or of muscles in a limb or in the vocal apparatus. (Damasio; Self Comes to Mind, 143)

Motor commands are organized hierarchically. (Kandel; Principles of Neural Science, 672)

Progression of the processing from the general to the particular, down the frontal motor hierarchy, is reflected in the patterns of frontal cell discharge in anticipation of motor acts. (Fuster; Memory in Cerebral Cortex, 78)

Motor programs are sets of muscle commands put together before the beginning of a movement sequence. (Edelman; Remembered Present, 133)

Motor programs permit the movement sequence to be carried out without peripheral feedback and are linked by the motor system into complexes. (Edelman; Remembered Present, 133)

Succession, planning, and choice; the Basal Ganglia. (Edelman; Remembered Present, 133)

Parallel organization of the functionally segregated circuits going to and from cortex to basal ganglia to thalamus and back to cortex. (Edelman; Remembered Present, 134)

Main anatomical connections of the basal ganglia and their relation to the cerebral cortex. - (diagram) (Edelman; Remembered Present, 135)

Parkinson's disease, nigral dopaminergic neurons are destroyed; central role of the basal ganglia in motion and in the construction of motor plans. (Edelman; Remembered Present, 136)

Perception-Action Cycle built upon Hierarchy of Programs

Joaquin Fuster’s Perception-Action Cycle uses reentry and recursion on all hierarchical layers between the frontal motor cortical areas and the posterior sensory cortical areas.

 

Central Pattern Generators (CPGs)

Central pattern generators and autonomous reflexes can give rise to a highly adaptive and complex forms of behavior.   (Edelman; Mindful Brain, 90)

Central pattern generators function unconsciously with procedural memory.

Central Pattern Generating networks (CPGs). -- (diagram)  (Squire; Fundamental Neuroscience, 757)

 

Research study — Central Pattern Generators

 

Fixed Action Patterns (FAPs)

The Fixed Action Patterns (FAPs) term used by Rudolfo Llinás refers is to stereotyped behavior patterns. Some FAPs are innate, such as the movements of crying, sucking, etc. that a baby has at birth. Other FAPs are learned, such as the movements of walking, or the voice and throat movements of talking.

An enormous amount of our activity is control automatically on the basis of environmental cues, existing habits and schemata, supplemented when necessary by automatic conflict resolution processes. (Baddeley; Working Memory, 344)

Cognition and consciousness probably evolved from the emotional states that trigger FAPs. (Llinás; I of the Vortex, 168)

Spinal reflex includes sensory neurons, motor neurons and interneurons in the spinal cord. (LeDoux; Synaptic Self, 46)

 

Combine FAPs, emotions and consciousness into one directed output: Thalamocortical system, especially the non-specific intralaminar system, projects extremely aggressively to the basal ganglia. (Llinás; I of the Vortex, 169)

Motor system is capable of selecting among a large repertoire of stereotyped motor routines. (Van Essen; Dynamic Routing Strategies, 274)

 

FAPs are most probably implemented at the level of the basal ganglia and put into context by the reentry of the basal ganglia output into the ever-cycling thalamocortical system. (Llinás; I of the Vortex, 144)

FAPs are ingrained in motor cortical areas together with subcortical areas of the basal ganglia and cerebellum. Either innate or learned, the neural network of synaptic efficacies is conformed to provide appropriate neural circuitry for FAPs.

Epileptic activity

Epileptic activity may be among the most primitive of all functional states -- a bit like sneezing. (Llinás; I of the Vortex, 63)

 

Facial expressions of emotion

One example of FAPs is the facial expressions of emotion. Think of the muscular movements of a smile, the movements of laughter, the facial expression of horror, etc. These facial expressions form unconsciously as a result of an emotional state.

Hierarchy of FAPs, riding a bicycle

Learning to ride a bicycle is a process of developing a hierarchy of FAPs composed of an immense combination of LTPed synapses in the motor cortical areas along with the basal ganglia and cerebellum. For these procedural memories, the hippocampus is not required in the learning process. HM could gain new procedural memories, although he had no memory of the learning process.

Brain stem stereotypic motor responses

Basic behaviors are organized by the brain stem and consist of relatively simple stereotypic motor responses. (Kandel; Principles of Neural Science, 873)

Feeding involves coordination of chewing, licking, and swallowing, motor responses that are controlled by local ensembles of neurons in the brain stem. (Kandel; Principles of Neural Science, 873)

Many complex human responses are made up of relatively simple, stereotyped motor responses governed by the brain stem. (Kandel; Principles of Neural Science, 873)

Infants can cry, smile, suckle, and move their eyes, face, arms, and legs. (Kandel; Principles of Neural Science, 873)

Brain stem can organize virtually the entire repertory of newborn's behavior. (Kandel; Principles of Neural Science, 873)

Reticular formation of the brain stem coordinates the firing pattern of distant neurons in the spinal cord engaged in reflexive or stereotypical somatic motor behavior. (Purves; Neuroscience, 399)

Basic movements concatenated to generate complex movements

All of life is motion. Motion is perpetual. (Hobson; Dreaming as Delirium, 141)

Planning motor actions can be implemented in terms of a sequence of movement trajectories based on a stored repertoire of elementary movements. (FAPs) These basic movements can then be transformed and concatenated together to generate more complex movements. (Ullman; Sequence Seeking Counterstreams, 264)

 

Musicians develop FAPs from an early age

Brain imaging studies of musicians have shown musicians have more neuronal connections in the area of the brain that regulates the hand movements involved in musical performance. (Greenspan; First Idea, 7)

Concert musicians typically start lessons at an early age, learning the finger movement of a violin, for example. During a concert, the musician has no thought of the individual finger movements produced by FAPs, but instead is concentrating on the eliciting the desired emotional sound from the instrument.

Music and Movement -- Rhythm, (Sacks; Musicophilia, 254)

 

FAPs for routine, Attentional for novelty

Behavior is controlled at two levels. One is relatively automatic, based on habits and schemas whereby predicable events give rise to appropriate behavior (e.g., driving along a familiar route). The other component, termed the Supervisory Attentional System (SAS), is a mechanism for overriding such habits, used when the existing habit patterns are no longer adequate (e.g., rerouting around a traffic jam). (Baddeley; Working Memory, 11)

Fastest movement, 10 Hz (Llinás; I of the Vortex, 55)

Inferior Olive (IO) oscillation

Inferior Olive (IO) neurons play a fundamental role in movement coordination. Oscillation of the inferior olive results in a slight tremor at close to 10 Hz, even when we are not moving. (Llinás; I of the Vortex, 44, 48)

The inferior olive is shown clearly in the neuroanatomy of the brainstem. (Hirsch, Neuroanatomy, 80, 84)

Regardless of training or personal effort, we cannot make movements faster than 10 Hz. (Llinás; I of the Vortex, 55)

Children's facial expressions are automatic and controlled by subcortical centers within the extrapyramidal motor system. (Johnston, Why We Feel, 101)

Self-activating system is capable of emulating reality, even in the absence of input from reality, as occurs in dream states and daydreaming. (Llinás; I of the Vortex, 57)

Play behavior by young animals is an exploration of internal functional space. (Llinás; I of the Vortex, 58)

Some FAPs are innate; sucking, crying of an infant.

Complex combination of motions: sneeze, hiccup

Exclusive human laugh, crying

Many FAPs must be learned; walking, ride a bicycle.

Spinal reflex (Koch 213)

Pheromomes (Koch 215) Armpits men, women; V organ, pheromomes, amygdale.

 

Cerebellum, surrounding the upper brain stem; timing and smoothing of successions of movements. (Edelman, Bright Air, 105)

Motor learning and skilled movements (Eccles, Evolution of the Brain, 140)

Dreaming; integration of vision with other sensory modalities, hyperactivity of the parietal operculum, where vision, space, and movement meld. (Drugstore 59)

 

Controlling Movement

Sensing, memory and perceptual categorization, limbic and forebrain valuation, movement control, prefrontal cortex motor control, basal ganglia, cerebellum, PNS.

Primary motor cortex and the premotor cortex work in close concert with two major subcortical structures, the striatum and the cerebellum. (Eichenbaum; Neuroscience of Memory, 238)

Pattern of anatomical connectivity suggests that striatum is not directly involved  in controlling the details of motor output. (Eichenbaum; Neuroscience of Memory, 239)

Connections to premotor and prefrontal cortex suggests that the cortical-striatal loop contributes to higher motor functions including the planning and execution of complex motor sequences. (Eichenbaum; Neuroscience of Memory, 239)

FAPS are subject to modification; they can be learned, remembered, and perfected. (Llinás; I of the Vortex, 153)

The corticospinal pyramidal tract, with one million axons the largest descending fiber tract from the human brain, originates in layer 5 of primary motor, supplementary motor, and premotor cortical areas and projects onto interneurons and motorneurons in the spinal cord. (Koch and Crick; Neuronal Basis, 102)

 

FAPs of Vocalization

For humans, our FAPs for vocalization of speech are some of our most important FAPs. The FAPs to produce and control throat and breath muscular movements are probably ingrained in synapses in Broca’s area and in the subcortical pathway of the basal ganglia. Synapses in these muscular control pathways are established through sustained activity and practice of speech in early childhood.

Gerald Edelman discusses movement behavior

Although Edelman does not use the term ‘FAPs’, he uses his own terms in a context that connotes nearly identical meaning. Notice these terms in the following excerpts from his discussion: ‘gestures’, ‘succession of gestures’, ‘synergies’, ‘spontaneous gestures’, ‘motor programs’, ‘successions of motor programs’, ‘motor plans’.

Cerebellum, motor cortex, spinal cord, contribute to global mappings that allow smooth succession of movements. (Edelman; Remembered Present, 121)

Categorization of motion, particularly in novel tasks and situations; categorization of gestures. (Edelman; Remembered Present, 121)

Cerebellum has a very large sensory input. Mossy fiber inputs come from spinal cord tracts serving somatosensory roles as well as from vestibular nuclei and the pons. (Edelman; Remembered Present, 122)

Climbing fiber inputs arising in the inferior olive. (Edelman; Remembered Present, 122)

Simplified diagram of basic features of working of cerebellum with brain stem area and cerebral cortex. Pons, mossy fiber projection, granular cell layer of cerebellar cortex; Inferior Olive, climbing fibers to Purkinje cells. (Edelman; Remembered Present, 122)

Motor cortex signals initiating a movement is relayed via climbing fibers to Purkinje cell. Connection with the inferior olive are involved in sequencing these signals. (Edelman; Remembered Present, 124)

Cerebellum - rapid response to successive sensory inputs; "sculpt" a series of cortical or spinal outputs for gestures. (Edelman; Remembered Present, 126)

Cerebellum acts to carry out synchronization and reflex gain control in motor programs, but it is not likely to initiate motor sequences. (Edelman; Remembered Present, 126)

Cerebellum is a modulating device, working with the cortex to categorize together the smooth succession of motions in gestures and the succession of gestures in synergies. (Edelman; Remembered Present, 126)

Selection of spontaneous gestures during motor learning. (Edelman; Remembered Present, 126)

Rapid, parallel sensory activity engaging many parts of the cerebellum in different successions that yields the basis of the smoothing of motor activity that is essential to the categorical perceptions leading to Consciousness. (Edelman; Remembered Present, 126)

Motor activity is rapid and reflexive and is carried out in global mappings without conscious intervention. (Edelman; Remembered Present, 126)

Cerebellum is essential in early motor learning that relates the categorization of gestures to perceptual categorizations. (Edelman; Remembered Present, 126)

Cerebellum contributes to feature correlation and is an indispensable early component in forming the basis of memory and ultimately of primary Consciousness. (Edelman; Remembered Present, 126)

Cerebellum has no direct role in Consciousness. (Edelman; Remembered Present, 126)

Cerebellum, signaling of errors in movement control, 300 msec intervals or less, timing and synchronization of smooth movements. (Edelman; Remembered Present, 137)

Organs of Succession - (table) (Edelman; Remembered Present, 138)

Hippocampus is important in connecting perceptual responses to the flux of external events, its responses extend over time periods longer than the cerebellum. (Edelman; Remembered Present, 138)

Hippocampus is necessary for long-term memory, but does not subserve it. Changes in cortical synapses subserve long-term memory. (Edelman; Remembered Present, 138)

Successions directly controlled by the hippocampus concern events in reentrant systems related to short-term memory, act in time periods up to minutes. (Edelman; Remembered Present, 139)

Basal ganglia may be involved in choices and initiations of output during planning of successions of motor programs, main activity is in short time periods, between 300 msec and several seconds. (Edelman; Remembered Present, 139)

Basal ganglia are among the major areas to increase in size during evolution of the mammalian brain in the therapsid-mammalian transition and during primate evolution. (Edelman; Remembered Present, 139)

 

 

 Link to — Consciousness Subject Outline

 Further discussion — Covington Theory of Consciousness