Exam 2: Neurological Bases of Speech

4 lobes

frontal

temporal

parietal

occipital

largest lobe

frontal

how many frontal lobes

2

frontal lobes are separated by

central sulcus
lateral sulcus

central sulcus

divides frontal from parietal

lateral sulcus

aka sylvian fissure

divides frontal from temporal

frontal lobe cortexs

primary motor cortex

premotor cortex

prefrontal cortex

primary motor cortex

-Broadman area 4

-part of the precentral gyrus

-executes individual movements of different parts of the body (contralaterally)

-receives into from premotor area, sensory cortex, thalamus, cerebellum, and basal ganglia

motor homunculus

inverted representation (upside down)

proportional to the skills involved in performing the movement -speech area

primary cortex lesion

paralysis (motor) on the contralateral (opposite) side of the body

hands, feet, face

stroke in cerebral cortex are rarely big enough to effect an entire half of the body

premotor cortex functions

programming/planning motor activities of the primary motor cortex
receives input from sensory cortex, thalamus, basal ganglia

premotor cortex involvement

inferior frontal gyrus (typically the left) is involved with language processing

-brocas

-pars orbitalis

Broca’s area (fancy name and number)

pars opercularis 44

pars triangularis 45

what Brocas does w homoculus

sends motor programming plan for speech

Prefrontal cortex functions

like a CEO or supervisor

central executor

contains large amount of afferent and efferent pathways

appears to control higher mental functions (cognition)

prefrontal cortex “higher mental functions (cognition)” list

self-awareness

attention

initiation

planning

regulation of social behavior

inhibition

pragmatic skills

judgement

decision making

humor

personality

prefrontal lesion

-impaired cognition (attention, reasoning, judgement, problem solving, self-monitoring)

-inappropriate social behaviors

-apathy

-aphasia

temporal lobe landmarks

sylvian fissure= lateral sulcus

superior, middle, and inferior gyri

primary auditory cortex aka

heschl’s gyrus

41 

42

primary auditory cortex location

part of superior temporal gyrus

lies within sylvian fissure

not on the surface of brain

primary auditory cortex function

identifies and parses auditory stimuli

identifies sound location in space

primary auditory cortex organization

tonotopically:

interior part is concerned with reception of sound and low frequency (apex)

posterior is concerned with high frequency

cochlea is arranged with frequency

cochlea is (PNS/CNS)

PNS

Primary Auditory Cortex unilateral lesion

-partial deafness in both ears, greater loss in the contralateral ear

-affects auditory processing and phonemic discrimination

what happens when sound gets to the CNS

-at brainstem level most of the sound will go across to opposite side up to thalamus

-at brain stem level some of the sound will stay on the same side and travel to auditory cortex

-once at the auditory cortex, it will identify and segregate auditory stimuli and location in space

what happens if R auditory cortex is damaged

show partial deafness in both ears but greater deafness in L

what happens if L auditory cortex is damaged

show partial auditory deafness in both ears, greater loss in R

Auditory Association Cortex location

posterior to the primary auditory area in the superior temporal gyrus

auditory association cortex function

interpretation of sound

Wernicke’s area location

posterior two thirds of the left superior temporal gyrus

Wernicke’s area function

-receives spoken lang info from auditory and visual cortices

-comprehension of spoken and written lang

written info → wernicke’s process/steps

written

eyes

back of brain (primary visual cortex)

angular gyrus

wernicke’s (generate response)

Wernicke’s area lesion

impaired language comprehension, fluent and empty speech

no hemiparesis

hemiparesis

weakness on 1 side of body

Insula location

within the lateral sulcus (beyond Heschl’s gyrus)

Insula Function

visceral

taste

perception

vestibular functions

emotion and cognition

bilateral temporal lobe lesions

auditory agnosia

pure word deafness

Auditory Agnosia

-inability to recognize nonverbal sounds (meaning of sounds)

-normal hearing

agnosia

disorders of recognition

pure word deafness

-inability to recognize spoken words (meaning of speech)

-normal hearing

Primary somatosensory cortex location

post central gyrus

primary somatosensory cortex receives…

-and processes conscious sensory input (from contralateral side of the body)

-projection fibers from the thalamus (contralateral)

conscious sensory input includes

touch/tactile, temperature, pain, pressure

paper cut → what processes it

paper cut

receptors

CNS (spinal cord)

medulla (crosses from L to R

up to R thalamus

R primary somatosensory cortex (interpret what it is)

sensory homunculus

the opposite half of our body is represented as inverted

sensory homunculus sensitivity

not based on amount of skin but density of sensory receptors

primary sensory cortex lesions

contralateral sensory deficits

pain, temperature, tactile, pressure

parietal association cortex functions

of areas outside of primary sensory cortex

parietal association cortex center for…

associating information from different sensory modalities

parietal association cortex integration of…

body awareness

inferior parietal lobe connection

auditory, visual, somatosensory cortices

inferior parietal lobule integration

language functions, reading, writing, math

one of the last structures to fully mature in human child and may play key role in lang acquisition

inferior parietal lobule

right parietal lobe lesions

left side neglect

denial of a motor deficit

reduced emotional intonation

personality change

lesion at _____ of the brain you usually expect more motor issues

top

lesions at the _____ of the brain are much less likely to have motor issues

bottom

occipital lobe location and contents

-posterior/ inferior to parietal lobes

-primary visual cortex

-association visual cortex

smallest lobe

occipital

primary visual cortex description

thin cortex, granular type

primary visual cortex functions

-visual perception: discrimination, colors, patterns

-receives visual info from contralateral visual fields of both eyes

Primary visual Cortex Lesion

-cortical blindness

-more info later

Visual association cortex receives

afferent fibers from primary visual cortex and other cortical areas

visual association cortex function

-responsible for complex visual analysis

-recognizes the visual info to past visual experiences

visual association cortex lesion

visual agnosia

visual agnosia

inability to identify objects by sight

Primary motor cortex (main ideas)

voluntary, skilled movement, contralateral

Primary Somatosensory cortex (main ideas)

somesthetic sensation, contralateral

primary auditory cortex (main ideas)

input from both ears, insula

Primary visual cortex (main ideas)

visual perception

primary areas of cortex

primary motor cortex

primary somatosensory cortex

primary auditory cortex

primary visual cortex

association areas of cortex

premotor cortex

parietal association area

auditory association cortex

visual association cortex

premotor cortex (main ideas)

-plans/ initiates coordinated movement

-broca’s area; motor programming for speech

parietal association area (main ideas)

body image in space; language integration; math

auditory association cortex

wernickes areas, processing language

visual association cortex (main idea)

recognition and appreciation of visual stimuli

motor homunculus

motor homunculus

premotor cortex

prefrontal cortex

sensory homunculus

sensory homunculus

inferior parietal lobe

thalamus location

base of the cerebral hemisphere

thalamus (diencephalon)

a large, egg shaped nuclear mass

paired structures of gray matter

projecting neuronal fibers to different parts of the brain

makes up 80% of the mass of the diencephalon

diencephalon

term used to describe thalamus and other structures of the brain like the 3rd ventricle and the hypothalamus

the _____ is one of the main vesicles formed during early embryological development

diencephalon

thalamus function

-afferent info from entire body and other CNS

-major sensory relay station; Info converges at thalamus→ distributed to cortex and other parts of CNS

anterior part of thalamus is part involved in 

attention, memory, learning

medial part of the thalamus is part involved in

sensation (sensory integration necessary for abstract thinking and long term goal oriented behaviors

the limbic system regulates

emotion

motivation for survival behaviors

learning

memory

no _____ ______ on total # of limbic structures

universal agreement

not all ______ _______ are completely understood

limbic structures

thalamus connects thinking brain to the _______ and _____ brain

non thinking

older

regulates all visceral, endocrine, and sensorimotor functions

thalamus

limbic system structures

cingulate gyrus

amygdala

hippocampus

cingulate gyrus involved with

anxiety

obsessive compulsive behaviors

emotion information

processing

learning

cingulate gyrus description

curved fold covering corpus callosum

cingulate gyrus receives input from ______ and _______ ________

thalamus

cerebral cortex

amygdala control

drive, internal feelings (emotion) 

amygdala emotions examples

rage, escape, fear, aggression, sex related behaviors (erection and ovulation)