Download - The Association Cortex
The Association Cortex
The Neocortex
The Association Cortices (Brodmann’s Areas)
space ,time, motion, planning, decision making, emotional reactivity, memory,recall, etc.
HOW DO WE KNOW THIS?????
Association Cortices Across Species
Basic Properties of the Association Cortex
• At least 1 primary source of INPUT and OUTPUT from other cortical or sub-cortical brain areas
Thalamus: Gateway of Neural Information
• If you recall….– vision (hearing) made possible through the
travel of neuronal information from the retina (cochlea) to the occipital (temporal) cortex via lateral (medial) geniculate leaflet
• Pulvinar Nucleus: Parietal Assocation Cortex
• Lateral Posterior: Temporal Association Cortex
• Medial Dorsal: Frontal Association Cortex
Basic Properties of the Association Cortex
• Connections to and from the association cortex on vertical (columnar) and horizontal (lateral) axes
Spatial Representation of Vertical Inputs to Association Cortex
Basic Properties of Association Cortex
• Cells with similar functions aligned radially (for the most part)
• Any functionally similar cell groups that are aligned horizontally are done so through interneurons
Basic Properties of Association Cortex
• Contralateral information travels via the corpus callosum or anterior commissure
Disruption: Dyslexia
Damage to Association Cortices
• Frontal• Parietal• Temporal• Lesions and Ischemic Damage
to these cortices result in neglect or agnosias– Difference: Neglect= “Don’t See
It” vs. Agnosia= “See it, but Don’t Know It”
Frontal Damage• Historical case study of Phineas Gage
(1800s) and his new polarizing personality
Deficits of Attention, Decision Making, and Gratification
• Anterior cingulate cortex• Neuropathology ofADD, for example
• Patients perform poorlyon Stroop Test
Deficits of Attention, Decision Making, and Gratification
• Orbitofrontal Cortex• Neuropathology ofOCD and antisocialpersonality disorder, for example
Deficits in Planning
• Dorsolateral Prefrontal
• Delayed Response Task is a measure of planning deficiency
Delayed Response Task in Monkeys
Parietal Damage• Contralateral Neglect Syndrome (Visuospatial
Deficit of “Not Seeing”)
Primarily due to damage of right parietal association cortex
Temporal Damage• Agnosias (“Seeing, but Not Knowing”)• Great leisurely, science reading on thesesyndromes by Oliver Sacks
-The Man Who Mistook His Wife for a Hat - The Island of the Colorblind
– Prosopagnosia– Appreceptive – Akinestopsia– Achromatopisa (*hereditary)
Prosopagnosia• The inability to differentiate and remember faces
due to damage of the inferior temporal lobe
Appreceptive Agnosia• An inability to differentiate and remember objects due to damage of the posterior right hemisphere
Akinestopsia• An inability to differentiate motion due to damage of the medial temporal cortex (“A LifeIn Still Frames”)
Achromatopsia• An inability to differentiate between colors(“A Life in Black and White”) due to a hereditarydeficit resulting in improper brain development
Deep Brain Stimulation• A brain pacemaker• Novel treatment strategyfor Parkinson’s and associative disorders likeOCD, ADD, and depression