Association Areas
ASSOCIATION AREAS
- Association areas form the “Inter-junction” for various cerebral cortex parts.
- They particularly connect motor & sensory areas.
- Mainly are associated with higher mental functions.
- Higher mental functions include speech, learning & memory and intellectual functions (insight, imagination etc.,)
SENSORY ASSOCIATION AREA:
- This area provides primary interpretation of perceived sensation.
Area included:
1. Brodmann’s area 3,1,2 –
- Includes somatosensory cortex.
- Perceives sensation of an object.
2. Brodmann’s area 5 –
- Referred as “Somatosensory association area”.
- Interprets the shape, size, & texture of sensation.
3. Brodmann’s area 17 & 18 –
- Includes primary visual cortex.
- Colors are perceived.
4. Brodmann’s area 19 –
- Referred as “Visual association area”
- Identification of visual objects.
5. Brodmann’s area 42 –
- Referred as “Auditory association area”.
- Interprets the meaning of heard sound.
MOTOR ASSOCIATION AREA:
- Includes, Premotor area (premotor cortex & supplementary motor area).
INTERHEMISPHERICAL DIFFERENCES:
- Right & left hemispheres are homologous & symmetrical regions of cerebral cortex on either side of brain.
- They are connected together by long association fibers carried by corpus callosum.
FUNCTIONS OF HEMISPHERES:
- Functional asymmetry usually exists between hemispheres.
- Most important functional asymmetry is exhibited by “Language”.
1. Left hemisphere:
- Referred as “Dominant/Categorical hemisphere”
Functions:
- Mainly represents language areas (Wernicke’s area & Broca’s area) –
- Both spoken & written language.
- Visual processing of written language.
- Auditory processing of spoken language.
- Language-related motor functions like speech, reading & writing.
- Detailed analytical abilities.
- Mathematical & scientific skills with reasoning.
- Complex motor planning activities.
- Mainly involves sequential analytical process & language.
2. Right hemisphere:
- Referred as “Non-dominant/Representation hemisphere”
Functions:
- Specialized for processing of complex geometric patterns.
- Auditory processing of music.
- Tactile recognition of complex spatial patterns & mental rotation of complex shapes.
- Mainly involves visuospatial orientation.
DISORDERS IN HEMISPHERES:
| RELATED TO CATEGORICAL/LEFT HEMISPHERE | RELATED TO REPRESENTATION/RIGHT HEMISPHERE |
| Aphasia | Astereognosis |
| Dyscalculia | Dysgraphia or agraphia |
| Anosognosia | |
| Agnosias |
Exam Important
ASSOCIATION AREAS
- Premotor area corresponds to Area 6.
- Brodmann’s area 17 corresponds to visual cortex.
- Processing of tactile stimulation occurs in Brodmann’s area 1,2,3.
- Neurophysiological defects present in right lobe involvement are Visuospatial defect, Anosognosia & Dysgraphia.
- Senseless, fluent speech indicates damage to the categorical hemisphere.
Don’t Forget to Solve all the previous Year Question asked on Association Areas
