Primary sensory cortex sensory association



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CEREBRAL CORTEX




PRIMARY SENSORY CORTEX

SENSORY ASSOCIATION

CORTEX

ASSOCIATION CORTEX

MOTOR PLANNING

AREA

PRIMARY

MOTOR

CORTEX

GENERAL

Simple Sensory Discrimination

(Intensity, Quality)

Recognition of Sensation

Goal Selection, Planning, Monitoring;

Interpretation of Sensation;

Emotions, Memory Processing


Movement Composition,

Sequencing

Cortical Motor Output

SPECIFIC

Primary Somatosensory Cortex:

Location, shape, size, texture; major DC input;

See somatosensory Homunculus (largest cortical areas: fingers, lips, tongue)
Primary Auditory Cortex:

Loudness, pitch



Primary Vestibular Cortex:

Head movement, head position relative to gravity


Primary Visual Cortex:

Intensity of light (light & dark), shape, size, location, movements, 3-D



Somatosensory Association Cortex:

Stereognosis (recognition of objects)



Auditory Association Cortex:

Distinction b/w language, music, noise



Visual Association Cortex:

Motion, color, visual fixation (tracking)



Prefrontal

Essential for certain higher human functions

a) Goal-oriented behavior

b) Decision processing

c) Self-awareness

d) Personality

e) Contemplation of consequences of

one’s action


Parietotemporal

a) Sensory integration

b) Problem solving

c) Understanding language

(Wernicke’s Area)

d) Spatial rel’ships (Area opposite

Wernicke’s)

e) Cognitive intelligence


Limbic

a) Emotion

b) Mood (subjective feelings)

c) Affect (observable demeanor)

d) Motivation

e) Personality

f) Processing of some memory


Supplemental Motor Area:

a) Initiation of movement

b) Orientation of eyes and head

c) Planning bimanual

sequential movements
Premotor Area:

a) Controls trunk and

girdle muscles

b) Postural adjustments


Broca’s (Speech) Area:

a) Motor programming of speech

b) Grammar
Area Opposite to Broca’s:

a) Nonverbal communication

b) Emotional gestures

c) Adjusting tone of voice



Consciousness
initiates

movement;


Corticospinal tract;
See motor Homunculus

DAMAGE

AMORPHOSYNTHESIS:

Loss of awareness of a part or half of the body



HEMONYMOUS HEMIANOPSIA:

Complete destruction of PVC on one side will result in loss of vision in opposite half of both visual fields: retinal field loss on same side as lesion, BUT visual field damage is ALWAYS on opposite side



AGNOSIA:

Inability to recognize objects when using a SPECIFIC sense, even though discriminative ability with THAT sense is INTACT, i.e.



ASTEREOGNOSIS1

AUDITORY AGNOSIA2

VISUAL AGNOSIA3

PROSOPAGNOSIA4

Change in personality (socially indifferent, tactless);

Inability to follow an extended course of action;

Emotional lability;

Inability to think abstractly


WERNICKE’S APHASIA9b

ALEXIA7

AGRAPHIA8

AMNESIA5


a) To supplemental & premotor areas: APRAXIA:

inability to perform a movement or a sequence of movements despite intact sensation and motor output, and understanding the task


b) To Broca’s:

BROCA’S APHASIA9a

DYSARTHRIA6

AGRAPHIA8

See UMN
DYSAR-THRIA6

DEFINITIONS

1) ASTEREOGNOSIS: an object can be described, but not identified, DC pathway is intact

2) AUDITORY AGNOSIA: no recognition of sound; Left: no speech recognition; Right: no interpretation of environmental sounds

3) VISUAL AGNOSIA: inability to recognize objects in visual field although visual pathway is intact

4) PROSOPAGNOSIA: inability to identify people’s faces despite being able to correctly interpret emotional facial expression and being able to visually recognize other

items in environment



5) AMNESIA: loss of long-term memory: RETROGRADE: loss of memories PRIOR to trauma/disease; ANTEROGRADE: loss of memory FOLLOWING an event

6) DYSARTHRIA: lack of motor control of speech muscles

7) ALEXIA: loss of comprehension of written language (cannot read)

8) AGRAPHIA: loss of ability to write

9) APHASIA: impaired or absent communication by speech, writing, or signs (complete communication)

a) BROCA’S APHASIA: aka MOTOR APHASIA; difficulty expressing oneself using language, NO language output or may retain some HABITUAL

PHRASES, EMOTIONAL SPEECH (obscenities) when upset; usually AWARE of their difficulties, usually WRITING is as

IMPAIRED as speaking, abilities to UNDERSTAND language and to READ are SPARED

b) WERNICKE’S APHASIA: aka WORD DEAFNESS, language COMPREHENSION is IMPAIRED, produces spoken sounds but output is meaningless

(“word salad”); may REPEAT MEANINGLESS phrases; LISTENING to language is meaningless despite ability to hear

Normally; similar to trying to speak and comprehend a foreign language, SIGN LANGUAGE is INEFFECTIVE, alexia,

agraphia; often APPEAR UNAWARE of disorder



PARAPHRASIA (word substitution) in mild cases

c) CONDUCTION APHASIA: damage to connection b/w Wernicke’s and Broca’s; can speak and write in a way, but SKIPS or REPEATS words or

SUBSTITUTES one word for another (paraphrasias); similar to Broca’s in SEVERE form



d) GLOBAL APHASIA: MOST SEVERE form of aphasia; inability to use language in any form
CEREBRAL DOMINANCE
LEFT RIGHT

Comprehension and production of language

Dominant Nondominant

95% of R-hand dominant ind.

70 % of L-hand dominant ind. 15% of L-hand dominant individuals 15% in L-hand dominant ind.

(both hemispheres)

More cortical tissue



Math ability, Tasks involving spatial relations,

problem solving in logical drawing, recognition of human faces, sequential matter musical skills; solve problems in a holistic manner, not step-by-step

CORPUS CALLOSUM: great cerebral commissure (300 million fibers) connecting both hemispheres, informs one side what happens to the other

SPLIT BRAIN: each half capable of some independent function, but right usually mute, no verbal communication


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