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| Question | Answer |
| In Jenkins et al. (1994), when was the posterior patieral cortex active? | Particularly during new sequence learning, but not exclusive. Sensory guidance of movements |
| In Jenkins et al. (1994), when was the dorslated prefrontal cortex active? | Only during learning of new sequences. Reflecting need to generate new responses. |
| In Jenkins et al. (1994), when was the premotor cortex active? | New sequence learning, sensory guidance |
| In Jenkins et al. (1994) which areas were active in practised sequence production? | Supplementary motor area and right temporal lobe |
| Jenkins et al. (1994) and Shadmehr and Holcomb (1997) both show, what? | Demonstrate involvement of the dorsolated prefrontal cortex at an early stage of learning. |
| How do Jenkins et al. (1994) and Shadmehr and Holcomb (1997) differ in terms of PPE, PMd and Cerebellum? | S&H reported increased in these after memory consolidation, J contrasted with novel sequences |
| How do Jenkins et al. (1994) and Shadmehr and Holcomb (1997) differ in terms of explainantion activations in PPC, PMd and cerebellar? | J sensory guidence, S&H, neural representation of consolidated internal model |
| Jenkins et al. (1994) found representation of learned sequence associated with supplementary motor area and hippocampus, but what is the problem? | They did not study memory consolidation |
| Who contrasted tasks with and without the requirement for set shifting, in both a motor and cognitive domain? | Keele et al. |
| What did Keele et al. do in their study? | Patients were taught two sequences of 3 key presses, after which were required to produce a 6 element sequence, either repeated or different. |
| What did Keele et al. do for the cognitive task? | Patients were trained on reaction time tasks involving either colours or shape discrimination. After training on each dimension, pair of trails were introducted, either same of different. |
| What were the results of Keele et al.? | Shifting sequence in both conditions saw parkinson's patients being slower when having to switch in both motor and cognitive. |
| How did the shifting effect in Keele et al. seem to be dopmaine based? | As magnitude of shifting deicit was related to the degree to which 1-dopa-based medication ameliorated patients' motor symptoms. Temporarily with-holding it made them worse |
| What does the shifting hypothesis offer? | A unified framework for understanding the basal gangila function in both action and cognition. Also role in reinforcement learning, dopmaine release bias system to certain responses |
| What gives evidence that motor learning is down to lower levels of hierachy? | We speak of muscle memory, or our muscles learning to respond. Plus we have great difficulty in verbalising these skills. |
| What is an instance of some aspect of motor learning being independent of muscular system used to perform action? | Writing your own name with different affectors, small differences but roughly the same. |
| Who devised an apparatus, similar to population vector studies, but imposed novel force filed to device which perturbed movements in clockwise direction in learning? | Shadmer and Holcomb (1997) |
| What were the results of Shadmehr and Holcomb (1997)? | Practise Prefrontal cortex strongley engaged (relative to forcefield), when returned later after break, PET signal increased in left posterior parietal cortex, left dorsal premotor cortex and right anterior cellebrum |
| What was the conclusion of Shadmehr and Holcomb (1997)? | Shift was specific to recall of established motor skill and suggests that with passage of time there is a change in neural representation of internal model, where premotor cortex no longer needed |
| Who, using a PET, studied the performance of sequences of finger movements in three conditions; practised sequence production, learning new sequences, rest? | Jenkins et al. (1994) |
| What was the task in Jenkins et al. (1994)? | Eyes closed participants were asked to produce a sequence of 8 key presses using 4 keys. A tone sounded every 3 seconds signalling next key, p's learnt via trial and error with tones for correct and wrong answers |
| What have some cells in the premotor cortex been shown to represent? | Action goals more abstractly |
| What has been found with monkeys and neurons in premotor area F5? | Discharge whenever monkey grasp and object, regardless of the effector |
| What did Rizzolatti et al. (1988) propose about the neurons which represent action goals? | They form a basic vocabulary of motor acts over individual movements which form them. In turn expect competition at this level |
| What is the difference between the posterior parietal and associated premotor regions identified by Batista et al. (1999)? | Representations within parietal cortex tend to be in an eye-centered frame of reference whereas those in premotor cortex are more hand-centred |
| What is the difference between the posterior parietal and associated premotor regions identified by Desmurget et al.(2009) using electrical stimulation in patients undergoing brain surgery? | Stimulating the inferior parietal regions triggered a strong intention desire to move contralateral hand/arm/foot. When increased believed moved. Premotor the mouth or contralateral limb moved, denied it |
| What is the difference between posterior parietal and associated premotor regions identified by Grafton and Hamilton (2008)? | Posterior paretial cortex is more linked to motor goals, premotor cortex for kinematic details. |
| What did Grafton and Hamilton (2008) do in their study? | fMRI repetition suppression effect (repeated presentation of an item produces lower signal intensity), participants watched two videos, either same/different action goal/kinematics |
| What were the results of Grafton and Hamilton (2008)? | Repetition suppression for goals was found in right inferior parietal cortex, and weaker in right inferior frontal gyrus. No sig effect of kinematics, only voxel count left interior frontal gyrus. |
| What seems to play a critical role in movement initiation, settling the competition? | Basal ganglia |
| Where does the striatum of the basal gangila get most of it's input? | Cerebral cortex, including sensory, motor and association cortexices |
| What sort of output signal does the basal gangila let out? | Inhibitory |
| What are the three phases of basal gangila of modulating action? | At rest provides a strong inhibitory baseline allowing for representations and no movement. Then when a plan gains strength, signal decreased for selected neurons. Then striatal activation along indirect route |
| What are the three phases of basal gangila of modulating action? | At rest provides a strong inhibitory baseline allowing for representations and no movement. Then when a plan gains strength, signal decreased for selected neurons. Then striatal activation along indirect route |
| What does the different time scales of the direct and indirect pathway of basal gangila position it as? What does it mean? | Gatekeep, less inhibition from direct pathway is followed by more inhibition from indirect pathway. Playing a crtical role in movement initiation, holding potential responses in check. |
| What sort of system does the basal gangila seem to be? | Winner takes all |
| How can the basal ganglia explain the excessive movements and co-ordination problems in Hungtington's disease? | There is promient atrophy in basal ganglia, and is associated with reduced inhibitory output from basal gangila (in the indirect pathway) and thus a greater excitation of thalamic neurons |
| How can the basal gangila explain the symptoms of parkingsons disease, such as problems initiating movement? | It reduces inhibtion via the direct route, seen in loss of dopaminergic neurons in the substintia nigra par compata. Thus creating greater inhibition |
| What are affordances in Cisek and Kalaska's hypothesis? | Opportunities for actions available in the enviroment |
| What is the thought process behind Cisek and Kalaska's affordance competition hypothesis? | Ancestors evolved in changing environment, had to be ready at all times, with little time to plan movements, better survival strategy is to develop multiple plans in parallel |
| What does the affordance competition hypothesis propose? | Processes of action selection, what to do, and action specification, how to do it, occur simultaneously within an interactive neural network. |
| In the affordance competition hypothesis, what are the action specification processes? | Multiple affordances in environment are changed in parallel into potential actions. Process begins in visual cortex, moves to the parietal lobe to premotor regions. Potential actions compete at various stages of process |
| What are the action selection processes in affordance competition hypothesis? | Competition is biased by input basal gangila and prefrontal cortical regions about our internal drive states, long-term goals, expected rewards, and anticipated costs. All info to assess utility of different actions |
| When is an action executed in the affordance competition hypothesis? | When a option wins, and is selected |
| How did Cisek and Kalaska (2005) give evidence for their affordance competition hypothesis? | 2 reaching directions encoded in parallel, single cell recordings of monkey's premotor cortex, task with waiting period. Where monkey prepared for both actions, then cued to one and activation for uncued lost |
| What evidence did Ledberg et al. (2007) find for parallel operations? | First there was fast sweep of activity in dorsal stream up to frontal eye fields, then target dection in prestriate areas, then slower widely disrubuted processes of action selection modualted by target detection |
| Which circuits play a key role in affordance competition hypothesis? | Various parieto-promotor circuits |
| What is the evidence for the role of parieto-promotor circuits in affordance hypothesis? | When spatial target presented to monkey, neurons begin to discharge in two regions in postieor parietal cortex. Then when movement occurs or just looks stronger activation in 1 |
| The findings which emphasizes planing for both reaching and eye movements are simultaneously prepared are consistent with.. | Affordance competition hypothesis |
| Ronald et al. (1980;1993) registered the regional blood flow via SPECT, what was found regarding complex movements? | Further involved supplemenary motor area, prefrontal cortex and subcortical areas |
| Ronald et al. (1980;1993) registered the regional blood flow via SPECT, what was found regarding motor imagery? | Motor imagery of finger movements only the supplementary motor area was involved |
| What is the main different in functions between premotor cortex and supplementary motor area? | Supplementary is mainly interally guided actions and it's dominate sensory input is somatosensory. Premotor mediates externally guided actions, strong reciprocal connections with parietal lobe, visually guided |
| Which part of the parietal cortex forms a circuit with the dorsal premotor cortex, and what does this circuit do? | Superior parietal regions, involved in visuospatial control of reaching movements |
| Which part of parietal cortex forms a circuit with the ventral premotor cortex, and what is it involved in? | Inferior parietal regions which are primarily involved with the visuomotor transformation necessary for grasping movement |
| What condition do people tend to suffer from when they have lesions on the secondary motor areas? What is this condition? | Apraxia, have problems performing purposeful and coordinated movements. |
| Patients with apraxia can do simple gestures, but where do the problems arise? | Linking the gestures into meaningful actions |
| Where do lesions tend to be which cause Apraxia, in which limb does the problem seem evident in? | Left-sided lesion, either limb |
| What is ideomotor apraxia? | Patient appears to have a rough sense of desired action by has problems executing it properly |
| What is ideotional apraxia, and damage to which area typically results in this? | Patient knowledge about action is disrupted. Patieral cortex damage |
| What did Sherrington find when he severed the spinal cord, disconnecting spine from cortex and subcortex, in cats? | Stretch reflexes remained in tact, but became exaggerated. Also could still do alternate movements of hind limbs (walking) |
| How did Brown take the findings of Sherrington's cat study further? | Cut the dorsal root fibers, removing sensory feedback, and found cat was still able to walk. Also in fish with swimming |
| What has spinal circuitry become known as? And why? | Central pattern generators, as they offer a powerful mechanism for the hierarchical control of movement and can generate relatively stereotyped movements |
| Who found evidence that action specifies movements by endpoint only, as an attractor state, and how? | Bizzi et al. (1984), deafferented (sensory feedback removed) monkeys trained in pointing task without visual feedback. In trails forces applied to elbow and movement, unknown to monkey, limbs adjusted after force |
| What is Mackay (1987) model of understanding action? | Conceptual level is a representation of action goal. Next level actor needs to select a response system and a response. Next motor implementation level 1 movement plan is translated into patter of muscular activity |
| What sort of process is motor control? | Distributed process, higher levels need not be concerned with lower-level details. |
| What is Miller et al. (1980) cognitive process which could help explain motor control? | Test-operate-test-exit |
| Who said hierarchical control of action sequences could be used to explain the pattern of response times in executing a sequence of key strokes? | Rosenbaum et al. (1983) |
| What were the results of Rosenbaum et al. (1983)? | Interresponse times and errors were highest at transition points between chunks and coresponded to the number of nodes in Rosenbaum's hierachical pattern, linear would be flat |
| Who recorded movement from single cells in primary motor cortex of rhesus monkeys whilst they moved lever from a centre location to one of eight locations? Results? | Georgopoulos et al. (1995), more activation for angles over 90 degrees, and movement direction could be predicted accurately when this was calculated from neuronal population's preferred tuning and firing rate |
| What did the results of Georgopoulos et al. (1995) show in terms of the primary motor cortex? | It is involved in coding of movement direction |
| What has further work by Georgopoulos et al. found? | Population vector can shift in the direction of a signaled target well before motor execution. Also primary motor cortex is involved in planning, and activity in it does not mean movement |
| Even though directional tuning and population vectors are key concepts, what is it important to note? | Many cells do not show strong directional tuning and show activity that is more closely correlated to muscular activation patterns |
| What is the representation of a population vector based on? | Combining the activity of many neurons |
| Who created the affordance competition hypothesis? | Cisek and Kalsaka |
| What type of models did Cisek and Kalsaka criticized for not being accurate? | Cognitive |
| What did Cisek and Kalsaka propose brains have evolved for? | Sensorimotor control and retained much of that architecture, even the neocortex is still part of old circuit |
| What did Cisek and Kalsaka propose natural interactive behaviour require? | Sensorimotor control and selection system to operate continuously and in parallel |
| What did Cisek and Kalsaka say there has been distinctions between, and what did they say about them? | Perceptual, cognitive, and motor processes. Said descriptively useful, but might not reflect natural categories of the brain's functional organisation |
| What did Cisek and Kalsaka say decisions appear to be made through? | Distributed consensus which emerges in competitive populations |
| What did Cisek and Kalsaka say neurophysiological data may be more readily interpreted from? | A perceptive of interactive behaviour than from the perspective of serial information processing |
| What does Cisek and Kalaska offer? What is their hypothesis rooted in, and how? | A general framework for how we set goals and plan actions. Rooted in evolutionary theory, consider's the brain's functional architercture has evolved to mediate real-time ineractions |
| Which part of the brain are used in preparing the act? | Premotor cortex, visual cortex, amygalda, and hypothalamus |
| Which parts of the brain are used when executing the act? | Basal gangila, motor cortex, posetor hippocampus, brain stem nuceli, cellebrum, spinal cord |
| What is at the top of the hierachical organization of the motor system? | Premotor cortex and supplementary motor area |
| What are the middle components of the hierarchical organization of the motor system? | Basal gangila, motor cortex, cerebellum, brain stem. |
| What are the five nuclei which make up the basal ganglia? | Caudale nucleus, putamen, the global pallidus, the subthalamic nucleus, substantia nigra |
| What is at the bottom of the hierarchy of control? | Spinal cord |
| Which parts of the brain are critical for action selection and planning? | Lateral premotor cortex and supplementary motor area |
| What are the two nuclei which are referred to together as the straitum? | Caudate nucleus and putamen |
| What are the medial systems involved in? | In control of posture via intergrating visual and vesibular information with somatosensory input |
| What are the lateral systems involved in? | Control for distal muscles of the limbs and more important for goal-directed movements |
| Where is input and output to the basal gangila restricted to? | Input-Striatum, output-internal segment of globus pallidus terminate in thalamus. |
| What translates action plans into movement, with help of the cerebellum and basal gangila? | Primary motor cortex and brainstem structures |
| Which other hierachy has counterparts with the motor hierachy, with links between the two and similar structures? | Sensory |
| What projects to motor and frontal regions of the cerebral cortex? | Globus pallidus terminate in thalamus |
| What are sensory-motor circuits? | Sensory and motor processes which are coupled together |
| What do the nuceli of the basal ganglia not involved in input or output do? | Modulate activity within basal gangila, with a critical role in motor control, particularly in selection and initiation of action |
| What are the three cortical motor areas? | Primary motor cortex, premotor cortex, supplementary motor area |
| What does movement result from? | Stimulation of the skeletal muscle fibers of an effector |
| What are the cortical motor areas involved? | Voluntary motor functions (planning, control and execution of movement) |
| Aside from cortical motor areas, what other areas are involved in guiding and controlling movement? | Posterior patietal cortex, primary somatosensory cortex, and parts of the prefrontal cortex |
| How do muscles act in pairs? | Flexors bend or flex a joint, extensors extend it. |
| Where is the major point of departure of sensorimotor signals from the cortex to spinal cord and muscles? | Primary Motor Cortex |
| What are antagonistic muscles? | Muscles which act in oppisites |
| From where does the primary motor cortex receive input? | From almost all areas implicated in motor control. |
| What are synergistic muscles? | Muscles which work together |
| What did the primary motor cortex used to be referred to? Why not anymore? | Cortical keyboard/upper motor neuron, as stimulation of it produces movement, but it ignores the fact conspiratorial axons diverge to motor neurons innervating more than one muscle |
| Did Penfield claim that each body part was controlled by a single separate part of the motor map? | No |
| What is the neurotransmitter makes muscles produce force by contracting? | Acetylcholine |
| Where does acetylcholine get released? | By motor neurons t the neuromuscular junction |
| Who recorded single cells in monkey's primary motor cortex during movement in different fingers? What was found? | Schieber and Hibbard (1993). Found single primary motor neurons were active with movements of different fingers, with overlap of active neuronal populations between fingers |
| What is a motor unit? | The smallest functional unit of motor activity |
| What does a motor unit consist of? | A single alpha motor neuron (located in spinal cord) and muscle fibre is innervated by only one motor neuron |
| What is the innervation ration? | Number of muscle fibers innervated by one motor neuron |
| How has research shown that motor homuculus is not an adequate model of limb control? | Control of any finger movement appears to ultize a population of neurons distributed though out the primary motor cortex hand area, over a somatotopically segregated population |
| Do muscles need innervation to have spring-like properties? | No |
| What determines the force of muscle contraction? | Frequency of the action potentials in a motor neuron and number of muscle fibers recruited |
| What is the primary motor cortex a part of? | A distributed network of cortical motor areas, each with it's own role in voluntary motor control. |
| What are the two types of receptor organs of muscles? | Muscle spindles, and golgi tendon organs |
| What do muscle spindles respond to and how are they arranged? | Respond to stretch of muscle fibres (muscle length) amd are arranged in parallel with main muscle fibers |
| How should the network of cortical motor areas be viewed? | A dynamic computational map, with an internal organisation and spinal connections convert central signals about motor intentions, and sensory feedback, into motor commands. |
| What provides a substrate for adaptive alternations during the acquisition of motor skills and recovery of function after lesions? | Motor cortex |
| What do lesions in primary motor cortex usually result in? | Hemiplegia |
| What is hemiplegia? | Loss of voluntary movements on the contralateral side of the body. |
| What are common causes of hemiplegia? | A hemorrhage in the middle cerebral artery, common symptom of a stroke as it leaves patient unable to move affected limb |
| What is absent immediately after a stroke, and do they return? | Reflexes, but do return within a couple of weeks, possibly becoming hyperactive or spastic (resistant to stretch), reflecting the change in muscle tone, resulting from a shift in control. |
| What does voluntary movement need to inhibit to do, and thus what happens when cortical influence is removed? | Reflexive movement, and primitive reflex mechanisms take over. |
| What are therapies for hemiplegia? Is success common? | Constraint-induced movement (patients restricted from using unaffected limb) repetitive TMS and video therapy. Recovery is uncommon |
| What do the secondary motor areas do? | Project to primary motor cortex. |
| What are the secondary motor areas? | Premotor cortex and supplementary motor area |
| What does stimulation of premotor cortex often evoke? | Complex movements involving multiple joints and resembling natural coordinated hand shaping or reaching movements |
| What is processing of the motor system like in regard to the sensory system? | Reverse |
| What is the sequence of motor planning? | Begins in polymodal prefrontal areas, which project to premotor cortex, which inturn projects to primary motor cortex for motor execution |
| How are golgi tendon organs arranged, and what function do they serve and why? | Arranged in series with the muscle fibres, a protective and complementary function to muscle spindles as they are sensitive to changes in tension |
| Who found stimulating the supplementary motor areas creates complex and often bilateral movements? | Penfield and Rasmussen (1950) |
| How can the sensitivity of the muscle spindles be modulated? | Via contraction of intrafusal muscle fibres, located within muscle spindle, which are innervated by gamma motorneurons |
| What do lesions in supplementary motor are result in? What does this indicate? | Problems of sequencing and timing of movement, indicates supplementary motor area is a major structure of preparation of complex sequential movements |
| What do alpha motoneurons innervate? | Extrafusal fibers |
| What is alpha gamma co-activation? What does it allow for? | When alpha motoneurons and gamma motorneurons are activated together (usually occurs), allows for a delay free adjustment of muscle spindle sensitivty |
| Ronald et al. (1980;1993) registered the regional blood flow via SPECT, what was found regarding simple finger movements | Simple finger movements, regional blood flow increases were restricted to primary motor cortex, prefrontal areas and subcortical structures |
| What does the spinal cord contain? | Neuronal circuits capable of producing a rich variety of automatic and relatively stereotyped, yet adaptable, motor patterns |
| What can activate the neural circuits in the spinal cord? | By sensory stimuli or from the brain stem and cerebral cortex |
| What is anatomy of the spinal cords? | Spinal cord consists of an outer zone of white matter containing longitudinally running axons and of a central H shaped region of gray matter. |
| Regarding the spinal cord, what are the two arms of the H called, and which is in and which is out? | Dorsal horns, in, and ventral horn, out. |
| Where does the ventral horns of the spinal cord go? | Cell bodies of the motor neurons are located which innervate muscles. |
| What is Sherrington's Final Common Path? | The ventral horns path |
| What is Sherrington's Final Common Path? | The ventral horns path |
| Where do afferent fibers enter the spinal cord, and efferent fibers leave? | Afferent-Dorsal horns, efferent-ventral |
| What is the stretch reflex? | A muscle contraction brought on by a sudden external force on that muscle |
| What do reflexes allow? | To maintain postural stability without help from the cortex and also serve a protective function |
| What are the two things Sherrington discovered a stretch reflex requires? | Sensory input from muscle spindle to the spinal cord, and a motor path to muscle |
| What are the three steps to stretch reflex? | A brisk passive stretch give rise to an increased firing rate of afferent spindle fibres, some branches of these make direct excitation connection with the motor neurons which innervate same muscle, causing muscle to contract |
| In the stretch reflex, what do other afferent branches do? | Project to motor neurons which innervate synergist muscles, and yet other branches inhibit the antagonist muscle via interneurons |
| What are the subcortical motor structures? | Descending motor pathways originate in the primary motor cortex and descend to the motor neurons in the spinal cord. |
| What is the largest descending fiber tract? | Pyramidal tract/corticospinal tract |
| Where do most cortico-spinal fibers cross the midline? | In the pyramidal decussation |
| How does the motor cortex act on spinal motor neurons? | Directly via corticospinal tracts, and indirectly through extrapyramidal (brain stem) pathways |
| What does the direct path of the motor cortex allow? | It enables the primary motor cortex to control hands and fingers in a uniquely dexterous and skillful way |
| What are the characteristics of the cerebrum? | Massive, densely packed structure, containing more neurons than the rest of the central nervous system combined |
| Where do inputs to the cerebellum primarily project to? | Cerebellar cortex |
| Where does the output from the cerebellum originate in? | Deep cerebellar nuceli, projecting to the brainstem nuceli and the cerebral cortex via the thalamus |
| What is an unusual feature of the cerebellum? | Input from and output to the cortex both cross over to the contralateral side, causing the cerebellum to have an ipsilateral organization (right side is movement of right side of body, same with left) |
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