Textbook Notes (369,082)
Canada (162,376)
Psychology (9,699)
PSYB65H3 (479)
Ted Petit (185)
Chapter 5

PSYB65 - chapter 5.docx

5 Pages

Course Code
Ted Petit

This preview shows pages 1 and half of page 2. Sign up to view the full 5 pages of the document.
Chapter 5: The Sensorimotor System Sensorimotor System Why Sensorimotor? - The somatosensory information that your skin, joints, and muscles provide ensures that your brain makes accurate movements - Many of the adjustments that we make to our movements are guided by somatosensory feedback Somatosensory Receptors - Much of the somatosensory information that we receive about the world comes from sensory receptors in the skin. The 3 main types of receptors include:  Nociception: sensations of pain and temperature (Ventral Spinothalamic Tract)  Hapsis: sensations of fine touch and pressure (Dorsal Spinothalamic Tract)  Proprioception: awareness of the body and its position in space (Dorsal Spinothalamic Tract) - Most of the sensory receptors in the skin are mechanoreceptors, which react to distortion such as bending or stretching Somatosensory Pathways in the Brain - There are 2 main sensory pathways in the brain, which are named for their position in the spinal cord and the connections made:  The Dorsal Spinothalamic Tract  The Ventral Spinothalamic Tract Association Cortex - Hierarchical Organization of the Sensorimotor System: Association cortex, secondary motor cortex, primary motor cortex, brain stem motor nuclei, spinal motor circuits - Posterior Parietal Association Cortex: determines both the original position of the body and objects around the body in space (an association cortex because it receives input from a variety of sensory systems, including proprioception, hapsis, and vision) - Dorsolateral Prefrontal Cortex: involved with the decision to execute voluntary movements Secondary Motor Cortex - Areas of the secondary motor cortex include the:  Supplementary motor area Chapter 5: The Sensorimotor System  Premotor cortex  Cingulate motor areas Primary Motor Cortex - Primary motor cortex controls the movements of the muscles, and it plans out the coordinated activity of the muscles - Damage to the primary motor cortex does not lead to limb paralysis; rather, it reduces the speed, accuracy, and force with which an individual makes a movement - The Primary Somatosensory and motor Cortices from top to bottom: legs, hip, trunk, neck, head, shoulders, arms, hands, eyes, nose, face, lips, teeth, tongue, abdomen Basal Ganglia and Cerebellum - Basal Ganglia: subdivision of the telecephalon, and they are composed of: the caudate nucleus, the putamen, and the globus pallidus  Critically important for initiating movements and maintaining muscle tone  Huntington’s chorea results from damage to the striatum – both the caudate nucleus and the putamen - The Cerebellum: important role in the modulation of motor movements and the acquisition of motor skills. The cerebellum can be described in terms of 3 zones:  The lateral zone  The intermediate zone  The Vermis (lies between the hemispheres) Spinal Motor Pathways - There are 2 main systems of motor projections that descend from the brain to the spinal cord to initiate and control movement  Ventromedial System o The brainstem projections form 3 tracts, the vestibulospinal tract (balance), the reticulospinal tract (posture), and the tectospinal tract (head and eye movements) o The cortical projection form the ventral corticospinal tract (trunk/legs for walking)  Lateral System o Brainstem projections form the rubrospinal tract (limbs and hands movement) Chapter 5: The Sensorimotor System o Cortical projections form the lateral corticospinal tract (finger and toes movement) Sensorimotor Disorders Cortical Sensorimotor Disorders - Apraxia: “lack of action”, however apraxic individual are still capable of action, but their actions are often unorganized and inappropriate. It is a deficit in performing skilled voluntary movements. Possible problem with associating objects with movements (“motor agnosia”). Today, apraxia is generally regarded as a disorder of motor planning. Can be unilateral or bilateral, impairing 1 or both sides of the body. There is 4 major classes of apraxia:  Ideomotor apraxia: an individual cannot execute or imitate simple gestures in response to a command.  Ideational apraxia: some proposed that ideomotor apraxia is an inability to correctly form single movements, whereas ideational apraxia is the inability to correctly sequence a series of movements  Constructional apraxia: inability to construct a complex object, wherein one cannot arrange the elements of the object correctly (deficit in processing spatial aspects of the task, but
More Less
Unlock Document

Only pages 1 and half of page 2 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.