PSYCH 160D Test #3
Somatotopic organization
organization that follows a map of the body (i.e., neighboring body parts have neighboring representations in cortex)
Upper motor neurons
originate in the M1 motor region of the cerebral cortex and carry motor information down to a specific spinal cord level. The cell bodies of the upper motor neurons are in M1, and their axons make up the corticospinal tract. When upper motor neurons are damaged (either cell bodies in M1 or axons along spinal cord), 'function goes up', because at rest the cortex sends inhibitory signals to the lower motor neurons. When a movement is made, the upper motor neurons stop this inhibitory signal to allow the lower motor neurons to fire and produce a movement. With damage to the upper motor neurons, the baseline inhibitory inputs from the cortex is lost, and the lower motor neurons are hyper-active, causing spastic muscles.
Chronic pain
pain that extends beyond the expected period of healing. Affects 1/3 of all Americans, has major impacts on quality of life, and creates a large economic burden on society. Patients are severely undertreated, yet chronic pain affects more people than heart disease, cancer, and diabetes COMBINED. There are affective (mood) and emotional effects on pain perception, but chronic pain is NOT 'all in the patient's head.'
Cutaneous senses
perception of touch and pain from stimulation of the skin
Hemiparesis
weakness on one side of the body
Outer ear
includes the pinna (AKA auricle) and auditory canal and ends at the tympanic membrane. The pinna consists of cartilage covered by skin and is shaped to capture sound waves and funnel them through the ear canal to the tympanic membrane. The pinna is important in localizing sound from front vs. back and helps with vertical sound localization (i.e., is sound higher or lower). The ear canal directs the sound pressure wave onto the tympanic membrane and also amplifies sounds that are between 3 and 12 kHz.
Cochlear implant
is a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf or severely hard of hearing. Most commonly, a cochlear implant is used when the hair cells of the patient are damaged/developed with a genetic abnormally affecting action potentials. In order for a cochlear implant to work, the auditory nerve fibers (along the basilar membrane) must still be intact, as the electrodes of the implant serve to activate these auditory nerve fibers. (If the auditory nerve is damaged, a cochlear implant will not work.)
Ventral root
is the motor nerve exiting the spinal cord to innervate muscle fibers.
Somatotopy
is the point-for-point correspondence of an area of the body to a specific point on the central nervous system; somatotopic organization is present in both S1 and M1.
Tonotopic organization
map of tones: Each section of the basilar membrane responds to a preferential frequency and the sections are organized from high to low. Tonotopic organization is also seen in the cortex as tonotopic gradients (organized cortical representations of tones).
Hairy skin
most of our skin has hair. The primary somatosensory receptor in hairy skin is the follicle receptor, which is a mechanoreceptor triggered by distortion of the hair shaft
Tympanic membrane
(AKA eardrum) is a thin membrane that separates the external ear from the middle ear whose function is to transmit sound from the air to the ossicles inside the middle ear
Chronic inflammatory pain
- Inflammatory nociceptive pain is associated with tissue damage and the resulting inflammatory process. - It is adaptive in that it elicits physiologic responses that promote healing.
Chronic neuropathic pain
- Neuropathic pain is produced by damage to the neurons in the peripheral and central nervous systems and involves sensitization of these systems. - In peripheral sensitization, there is an increase in the stimulation of peripheral nociceptors that amplifies pain signals to the central nervous system. - In central sensitization, neurons that originate in the dorsal horn of the spinal cord become hyperstimulated, increasing pain signals to the brain and thereby increasing pain sensation.
Acute nociceptive pain
- Part of a rapid warning relay instructing the motor neurons of the central nervous system to minimize detected physical harm. It is mediated by nociceptors, on A-δ and C fibers. - These nociceptors are free nerve endings that terminate just below the skin, in tendons, joints, and in body organs. They serve to detect cutaneous pain, somatic pain and visceral pain. - Nociceptors (pain sensors) are specialized for heat, chemicals, severe pressure, and cold. Hot and cold sensations are carried via thermoreceptors - Threshold of eliciting receptor response must be balanced to warn of damage but not be affected by normal activity
Sound pressure wave
- Sound is a mechanical wave that results from the back and forth vibration of the particles of the medium through which the sound wave is moving. If a sound wave is moving from left to right through air, then particles of air will be displaced both rightward and leftward as the energy of the sound wave passes through it. The motion of the particles is parallel (and anti-parallel) to the direction of the energy transport. A sine wave can be used to encode information about the compression and rarefaction (expansion) of a sound pressure wave. - Increases of the physical property of frequency from low to high are associated with increases in the perceptual experience of pitch. - Increases of the physical property of amplitude from small to large (blue arrow) are associated with increases in the perceptual experience of loudness - The wavelength stays constant over distance, but the amplitude of the sound pressure wave decreases. Basically, the energy contained in the sound pressure wave is lost as the sound pressure wave propagates through the atmosphere. As a result, the amount of compression and rarefaction (amplitude of the wave) decreases over distance, but the timing of the compression and rarefaction (frequency) does not.
Otosclerosis
- a form of conductive hearing loss - A condition in which there is abnormal growth of bone of the middle ear which can result in hearing loss. Seen in 0.5%-10% of population, usually starts in middle age. Exact cause is unclear - genetic factors play a role, viruses like measles may be involved as well. Treated with hearing aids and/or surgery to remove the stapes.
Corticospinal (C.S.) tract
- the fibers that connect motor cortex through the spinal cord to motor neurons throughout the body - Lateral corticospinal tract - Anterior corticospinal tract
Inner hair cells
- the sensory receptors of the auditory system located on the basilar membrane in the cochlea that convert sound waves to nerve signals by having their hairlike stereocilia being physically moved by sound waves in the cochlear fluid. Hair cells are columnar cells, each with a bundle of 100-200 specialized stereocilia at the top, for which they are named. These cilia are the mechanosensors for hearing. Lightly resting atop the longest cilia is the tectorial membrane, which moves back and forth with each cycle of sound, tilting the cilia and allowing electric current into the hair cell. Hair cells, like the photoreceptors of the eye, show a graded response, instead of the spikes typical of other neurons. Loud noise can damage and destroy hair cells, which do not regrow. Continued exposure to loud noise causes progressive damage, eventually resulting in hearing loss and sometimes ringing in the ears (tinnitus).
Phantom limb syndrome
A disorder characterized by having sensations (usually pain) in a limb that is no longer attached to the body; mirror therapy or virtual reality may provide some relief. Although phantom pain can be debilitating, the sensation of a phantom limb can actually improve a person's ability to use a prosthetic.
Anterior corticospinal tract
20% of the C.S. axons don't cross; these generally go to the trunk
Lateral corticospinal tract
80% of the C.S. axons cross to other side; these generally go to the limbs
Pure word deafness (auditory verbal agnosia)
: the selective inability to comprehend the spoken word, in the absence of aphasia or defective basic hearing. Perception of environmental sounds and other complex, non-speech sounds is generally normal. Pure word deafness is usually caused by bilateral damage to temporal lobes (often including white matter connecting temporal and frontal lobes). Patients can still read and write.
Tactile agnosia
A disorder characterized by the inability to identify by touch an object (or specific characteristics of an object, e.g., weight); possibly caused by damage to S1. Much like visual agnosia, but symptoms now apply to touch. Specific tactile agnosias may also arise from damage to higher-order regions of the somatosensory system, including inability to identify an object's weight or size (but still identify the object with tactile info).
Fascicle
A bundle of neuronal axons surrounded by connective tissue; a component of a nerve
Spinal reflex pathway
A neural pathway that controls a reflex action (e.g., withdrawal reflex). As most sensory neurons synapse in the spinal cord before going to cortex, spinal motor neurons can be rapidly activated without waiting for signals to go to/come from the brain first. Sensory input is sent to the brain while the reflex is being carried out.
Primary motor cortex (M1)
A strip of cortex just anterior to the central sulcus in the frontal lobes, where the primary control of motor movements occurs. M1 contains a body-based motor map similar to the somatotopic representation in S1. M1 controls the execution of movement. Lesions: spastic paralysis; Stimulation: executes a movement
Primary somatosensory cortex (S1)
A strip of cortex just posterior to the central sulcus, where the primary control of sensation occurs. S1 contains a somatotopic (bodymap) representation. S2 is the second somatosensory area located just inferior and posterior to S1.
Basement membrane
Immediately below the epidermis is the basement membrane, a specialized structure that lies between the epidermis and dermis. It includes various protein structures linking the basal layer of keratinocytes (skin cells) to the basement membrane and the basement membrane to the underlying dermis. Once skin-cancer cells cross this boundary, they can begin to spread through the body through the vascular system of the dermis.
Lateral superior olive
Interaural level difference - the difference of the intensity level of sounds between the ears
Medial superior olive
Interaural time difference - the time difference of arrival of sounds between the ears
Premotor cortex (PMA)
Located just anterior to M1 and inferior to SMA, it controls postural/trunk and large limb muscles, the planning of actions based on sensory cues, and refinement of movements based on sensory input with cerebellum. Lesions: disruption of learned responses to visual cues
Supplementary motor area (SMA)
Located just anterior to M1 and superior to PMA, it is involved in planning learned sequences of movements, activity just prior to movement, and has strong connections with subcortical structures. Unilateral lesions: disruption of learned sequences of movement; Bilateral lesions: blocks all movement; Stimulation: creates strong urge to move
Inferior colliculus (IC)
Located just below the visual processing centers known as the superior colliculus. It also contains neurons that are tonotopically organized, and it likely integrates information regarding sound localization. The IC projects to the thalamus (MGN) and cortex.
Posterior parietal cortex (PPC)
Located posterior to sensorimotor cortex, it integrates sensory and motor portions of the brain, processes position of body and objects in space, and controls eye movements. Lesions: Problems with visual-spatial coordination, problems with attention, neglect syndromes
Conductive hearing loss
Mechanical hearing loss, resulting from blockage in the ear canal, a ruptured eardrum, or restriction of the movement of the tiny bones in the middle ear, which prevents sound vibrations being transferred to the cochlea. Seen in otosclerosis
Incus
The incus or anvil is the anvil-shaped small bone or ossicle in the middle ear. It connects the malleus to the stapes.
Basilar membrane
The basilar membrane within the cochlea of the inner ear is a stiff structural element that separates two liquid-filled tubes (the scala - you don't need to know these) that run along the coil of the cochlea, forming a base for the hair cells to transduce the sound waves in the cochlear fluid to electrochemical signals in the brain
Cochlea
The coiled and channeled main structure of the inner ear, which contains three fluid-filled canals that run along its entire convoluted length; the fluid-filled canals are separated by membranes, one of which is the basilar membrane, on which thousands of hair cells (auditory receptors) are arranged and are stimulated by the vibration of the stapes.
Subcutaneous tissue
The deepest layer of the skin, made up of vessels, fat, and connective tissue
Cotard syndrome
The delusional belief that one is dead, does not exist, is putrefying or has lost his/her blood or internal organs ('walking corpse syndrome'); paradoxical delusions of immortality may also occur ('I am dead already, so now I can't be killed'). Associated with depression, schizophrenia, Capgras syndrome, bipolar disorder, migraine, herpes medication (acyclovir). May arise from a disconnection between highorder sensation/face perception(?) and emotional processing of limbic cortex. Treatments may include electro-convulsive shock therapy (ECT).
Lateral sulcus
The lateral sulcus (also called Sylvian fissure or lateral fissure; fissure = large sulcus) is the sulcus that divides the frontal and temporal lobes of the brain. Primary auditory cortex (A1) is located within the lateral sulcus.
Malleus
The malleus or hammer is a hammer-shaped small bone or ossicle of the middle ear which connects with the incus and is attached to the inner surface of the eardrum
Superior temporal gyrus
The most superior gyrus in the temporal lobe, situated just below the lateral sulcus, on which is much of auditory cortex
Superior temporal sulcus
The most superior sulcus in the temporal lobe, situated just below the superior temporal gyrus
Organ of Corti
The organ of Corti is the organ in the inner ear of mammals that contains the hair cells (the auditory sensory cells). Transduction occurs through vibrations of structures in the inner ear causing displacement of cochlear fluid and movement of hair cells at the organ of Corti to produce electrochemical signals that activate the auditory nerve fibers synapsing on the inner hair cells.
Ossicles
The ossicles (also called auditory ossicles) are the three smallest bones in the human body. They are contained within the middle ear space and serve to transmit and amplify sounds from the air to the fluid-filled cochlea. The absence of the auditory ossicles would constitute a moderate-to-severe hearing loss. - Malleus - Incus - Stapes
Epidermis
The outermost, protective layer of the skin, composed mostly of dead cells
Oval window
The oval window is a membrane-covered opening which leads from the middle ear to the vestibule of the inner ear
Thalamus
The sensory 'relay station' in the brain (located subcortically) to which all sensory neuronal pathways project prior to entering cortex, except for those involved in olfaction.
Dorsal root ganglion
The sensory nerves of the peripheral nervous system have their cell bodies in the dorsal root ganglion (ganglion means a group of cell bodies) .These cells have projections (really like dendrites) that carry information from the peripheral sensory receptors -peripheral nerve- and also projections (axons) that carry information into the spinal cord - dorsal root.
Stapes
The stapes or stirrup is the stirrup-shaped small bone or ossicle in the middle ear which is attached to the incus and oval window; the bottom of the stapes on the oval window is called the footplate
Word-meaning deafness
a comprehension deficit specific to the auditory modality. Written comprehension is unimpaired. It is distinct from pure word deafness in that the ability to repeat is intact. (See similar selective retention of repetition in language aphasias next.)
Tonotopy
a cortical map of sound frequency (single tones)
Periodotopy
a cortical map of sound time duration (periodicity)
Apraxia
a disorder of motor planning involving the loss of the ability to carry out learned purposeful movements, despite having the desire and the physical ability to perform the movements. There are several sub-types. [Verbal apraxia - apraxia of speech in childhood - will be discussed in more detail in the Language Disorders lecture.]
Anosognosia
a disorder where the patient is unaware of and denies their disability, often associated with paralysis and right dorsal parietal damage (also seen in Anton's syndrome, eating disorders). Patients typically use confabulations to 'explain' why they have the symptoms.
Audibility curve
a graph that depicts the relationship between the loudness of a pure tone, expressed in decibels, sound-pressure level (dB SPL), and the frequency of the tone.
Basal ganglia
a group of cell bodies below cortex interconnected with the cortex, thalamus and brainstem that is involved in motor control and also cognition, emotions, and learning; circuitry includes 'direct'/excitatory and 'indirect'/inhibitory pathways.
Cochlear nucleus
a group of cell bodies in the lower section (medulla) of the brainstem that receives the inputs from all the auditory nerve fibers coming from the cochlea
Huntington's chorea
a hyperkinetic disease characterized by - Cause: an autosomal dominant genetic mutation that causes proteins to build up in and ultimately kill cortical neurons (especially in the inhibitory 'indirect' pathway of basal ganglia). This cell death is progressive and causes a decline in mental abilities (personality changes, memory issues, dementia) and uncoordinated, jerky body movements (chorea), and eventually leads to death (usually from malnutrition due to constant movement or other complications like pneumonia) - genetic testing can identify disease risk (if you have the genetic mutation, you will get the disease); medications for symptoms (that reduce neural signaling); nutrition management; physical therapy)
Parkinson's disease
a hypokinetic disease characterized by slowing or loss of movement (akinesia), muscle rigidity, and a 'pill-rolling' tremor at rest - Cause: due to a loss of dopamine neurons in the basal ganglia that causes a decrease in activity in basal ganglia's excitatory 'direct' pathway - Treatments: include medication (L-Dopa), Fetal neural tissue graft, deep brain stimulation (DBS)
Spinal cord
a long, thin, tubular bundle of nervous tissue and support cells (like glia) that extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column. The brain and spinal cord together make up the central nervous system (CNS). In contrast to cortex, gray matter is in the inside of the spinal cord (beige butterfly shape in image) and is surrounded by white matter. The spinal cord has three major functions: as a conduit for motor information, which travels down the spinal cord, as a conduit for sensory information in the reverse direction, and finally as a center for coordinating certain reflexes.
Dopamine
a neurotransmitter that plays a key role in the basal ganglia motor circuit and the inhibitory and excitatory pathways. (It is also a key neurotransmitter in the arousal and reward systems.)
Pain matrix
a number of different areas of the brain involved in pain perception. Signals from nociceptors travel up the spinothalamic pathway and activate many of these areas. New research demonstrates that S1 and S2 are also directly involved in pain perception.
Auditory agnosia
a rare form of agnosia that manifests itself primarily in the inability to recognize or differentiate between sounds. It is not a defect of the ear or "hearing", but rather a neurological inability of the brain to process sound meaning. It is caused by bilateral damage to the anterior superior temporal gyrus, which is part of the auditory pathway responsible for sound recognition, the auditory "what" pathway. Persons with auditory agnosia can physically hear the sounds and describe them using unrelated terms, but are unable to recognize them. They do not tend to report 'feeling deaf.'
Cortical deafness
a rare form of sensorineural hearing loss caused by bilateral cortical lesions in the primary auditory cortex located in the temporal lobes of the brain (although it is likely actually damage to primary and/or neighboring regions of auditory cortex). Cortical deafness is an auditory disorder where the patient is unable to hear sounds but has no apparent damage to the anatomy of the ear, which can be thought of as the combination of auditory verbal agnosia and auditory agnosia. Patients with cortical deafness cannot hear any sounds, that is, they are not aware of sounds including nonspeech, voices, and speech sounds. Although patients appear and feel completely deaf, they can still exhibit some reflex responses such as turning their head towards a loud sound.
Hemiballismus
a relatively rare hyperkinetic disorder characterized by involuntary flinging motions of the extremities that increase with increased activity. Symptoms stop during sleep. - Causes: due to damage of the inhibitory pathway of the motor loop, especially from damage to the subthalamic nucleus - Deep brain stimulation, surgery to remove more basal ganglia, drugs (that reduce neural signaling)
Mechanoreceptor
a sensory receptor that responds to mechanical pressure or distortion (stretching, vibration) via mechanotransduction: movement of the cell membrane physically pulls open/pushes closed ion channels in the memberane, leading to changes in cell signaling. Normally there are four main types in glabrous mammalian skin: Pacinian corpuscles, Meissner's corpuscles, Merkel's discs (also known as Merkel's receptors), and Ruffini cylinders (also known as Ruffini endings). These differ along several factors, including morphology, skin location, rate of adaption, frequency selectivity, spatial receptive field, and perceptual task.
Anterior spinothalamic tract
a set of somatosensory white matter tracts in the anterior spinal cord that carries information about crude touch and pressure from the spinal cord to the thalamus; dorsal root ganglion axons synapse and cross immediately to opposite side. Organized somatotopically.
Lateral spinothalamic tract
a set of somatosensory white matter tracts in the lateral spinal cord that carries information about pain and temperature from the spinal cord to the thalamus; dorsal root ganglion axons synapse and cross immediately to opposite side. Organized somatotopically.
Posterior columns
a set of somatosensory white matter tracts in the posterior spinal cord that carry information about fine touch, vibration, pressure, and joint position from the spinal cord to the thalamus (and then to S1). Name turns into 'medial lemniscus' when tracts reach the brainstem, where the dorsal root ganglion axons then synapse and cross to opposite side. Organized somatotopically.
Spinocerebellar tract
a set of somatosensory white matter tracts in the posterior/lateral spinal cord that carries information about joint position and muscle fiber tension from the spinal cord to the cerebellum; projections do NOT cross to opposite side. Organized somatotopically.
Superior olive
a small group of cell bodies (nucleus) in the middle section (pons) of the brainstem involved in the localization of sound by determining differences in the timing (medial superior olive) and intensity/level (lateral superior olive) of neural responses from each ear for a particular sound. - Medial Superior Olive - Lateral Superior Olive
Hemispatial neglect
a syndrome where patients are unaware of the world/themselves/objects/visual scene/etc. on one side of space, usually the left side from damage to right posterior parietal cortex
Gerstmann's syndrome
a syndrome where patients have finger agnosia (can't identify what their fingers/toes are), problems with left/right differentiation, and problems with calculation and writing, It is usually caused by damage to inferior part of dominant parietal cortex or can be developmental
Kinesthesis
ability to sense movement of body and limbs
Proprioception
ability to sense position of the body and limbs
Congenital analgesia
also known as congenital insensitivity to pain (CIP), is a set of rare conditions in which a person cannot feel (and has never felt) physical pain. Condition may be cause by 1) increased endorphins/natural opioids, or 2) mutation in sodium channel in pain receptors. Causes high risk of serious injury, illness, and death. - Insensitivity to pain means that the painful stimulus is not even perceived: a patient cannot describe the intensity or type of pain. - Indifference to pain means that the patient can perceive the stimulus, but lacks an appropriate response: they do not flinch or withdraw when exposed to pain.
Confabulation
basically: lying unintentionally. More technically: a disturbance of memory, defined as the production of fabricated, distorted, or misinterpreted memories about oneself or the world, without the conscious intention to deceive. Certain types of damage to the parietal lobes can cause neglect syndromes that are associated with confabulation. The patient has anosognosia - thus is not aware that he/she has a deficit (e.g., paralysis) - and instead comes up with random/untrue reasons for why he/she doesn't have an issue (like 'I just don't feel like moving' instead of 'I am paralyzed).
Anton's syndrome
blindness and anosognosia from dorsal occipital damage
Vertebral column
bony structure made of multiple vertebrae that protects the relatively shorter spinal cord. Spinal nerves project through small openings in the vertebral bones.
Lower motor neurons
bring the nerve impulses from the upper motor neurons out to the muscles. The cell bodies are in the spinal cord and send axons to innervate sets of muscle fibers. When lower motor neurons are damaged, 'function goes down.' When the lower motor neurons don't work, there is no way to send a signal to the muscles to tell them to contract. The muscles are flaccid (loose and floppy), and eventually atrophy (waste away) due to loss of neurotrophic (feeding) factors that the lower motor neurons also deliver to the muscle fibers.
Hypokinetic
characterized by decreased movement
Hyperkinetic
characterized by increased movement
Rapidly adapting fibers (RA)
fire at onset and offset of stimulation to provide info about the start and stop of a sensation; found in Meissner's corpuscles (upper dermis) and Pacinian corpuscles (lower dermis)
Slowly adapting fibers (SA)
fire continuously as long as pressure is applied to provide detailed/high acuity tactile info; found in Merkel's disks (upper dermis) and Ruffini cylinders (lower dermis)
Inner ear
from oval window to auditory nerve; includes oval window, round window, cochlea, auditory nerve fibers, and the semicircular canals of the vestibular system.
Middle ear
from tympanic membrane to oval window; includes the ossicles and drains out through the eustachian tube to the back of the throat.
Outer hair cells
hair-like cells on basilar membrane that are involved in amplifying sounds and improving frequency selectivity; only found in mammals. Although there are nearly 3x more outer hair cells than inner hair cells, outer hair cells do not directly transduce sound pressure waves to neural signals.
Glabrous skin
hairless skin (e.g., on palms, soles, lips, labia, penis); contains more specialized types of mechanoreceptors
Sensorineural hearing loss
hearing loss caused by damage to the sensory cells and/or nerve fibers of the vestibulocochlear nerve (auditory nerve / Cranial nerve VIII), the inner ear, or central processing centers of the brain. Seen in many forms of congenital and acquired deafness
Medial geniculate nucleus (MGN)
section of the thalamus that the auditory pathway connects through prior to reaching primary auditory cortex (A1). (Similar to how visual input connects through the lateral geniculate nucleus [LGN] of the thalamus before reaching primary visual cortex [V1]).
Stereocilia and Kinocilium
stereocilia are projections at the top of the hair cell that are attached to one another by structures which link the tips of one cilium to another. Stretching and compressing the tip links may open an ion channel and produce the receptor potential in the hair cell. The kinocilium is one larger, more stable cilium to which the stereocilium attach at the tips.
Skin
the largest organ in the body both in surface and in weight. The skin provides many functions, including protection (germs, trauma, UV, toxins), excretion (water, waste products like urea, ammonia, uric acid), endocrine processes (vitamin D production), regulation of body temperature and water loss, and sensation (tactile information). There are 3 layers of skin: epidermis, dermis, subcutaneous tissue
Primary auditory cortex (A1)
the main area of cortex which first processes auditory information in the brain, situated on the inferior surface of the lateral sulcus; contains core, belt, and parabelt subdivisions. Each subdivision contains multiple auditory field maps. - Tonotopy - Periodotopy
Dermis
the middle layer of skin below the epidermis that forms the true skin, containing blood capillaries, nerve endings, sweat glands, hair follicles, and other structures
Non-verbal auditory agnosia
the selective impairment in nonverbal (e.g., environmental sounds) auditory comprehension, , in the absence of verbal comprehension deficits, other aphasias, or defective basic hearing; may arise from lesions in/near Wernicke's area
Amusia
the selective inability to recognize musical tones or to reproduce them (agnosia for music). It involves loss of the ability to recognize musical notes, rhythms, and intervals and the inability to experience music as musical. Patients often describe music as being indistinguishable from the sound of pots and pans banging together. Amusia can be congenital (present at birth) or be acquired sometime later in life (as from brain damage).
Hemiplegia
total paralysis of the arm, leg, and trunk on the same side of the body, usually from lesions to M1
