Cerebral Cortex 4 Visual Association Cortex HigherOrder Visual

Cerebral Cortex 4

Visual Association Cortex • Higher-Order Visual Processing • Dorsal pathways to parieto-occipital association cortex – Where? • Ventral pathways to occipitotemporal association cortex – What?

Primary Visual Cortex Injury • Unilateral – Homonymous hemianopsia with macular sparing • Bilateral – Cortical Blindness – Anton’s syndrome • Anosognosia

Inferior occipitotemporal association cortex • What stream of visual analysis – Process color and visual form • Prosopagnosia – Bilateral injury to inferior occipitotemporal cortex – Can describe, but cannot identify – Generic recognition - intact – Specific recognition - impaired

Dorsolateral Parieto-occipital cortex • Where stream of visual analysis

Balint’s Syndrome • Simultanagnosia • Optic Ataxia • Ocular apraxia

Attention/Awareness • Brain regions – Brainstem reticular formation – Thalamus – Basal forebrain – Cerebral cortex

Memory • Three types of memory – Emotional – Declarative – Procedural

Emotional Memory • Memory of feelings • Memory for fear is in the amygdala • Brain regions not known for other emotions

Declarative memory • AKA conscious, explicit, cognitive memory • Memory for facts, events, concepts and locations • Requires attention during recall

Three stages • Immediate (sensory register) – 1 to 2 seconds – Memories can be easily displaced – Primary sensory and sensory association cortex • Short-term memory – Brief storage – Begins to be lost in 1 minute if not rehearsed • Long-term memory – Relatively permanent – Consolidation (ST LT)

Neuroanatomy of Declarative Memory Sensory Association Areas Anterior Temporal Lobe Parahippocampal Cortex Hippocampus Basal forebrain, including basal nucleus of Meynert Cerebral Cortex

Problems with Declarative Memory • H. M. – bilateral removal of medial temporal lobe including the hippocampus – Consolidation lost • Cannot form new long-term memories • No memory for events since the surgery • No memory for events less than one year before the surgery – Earlier memories intact – Can learn skills

Procedural Memory • AKA Skill, habit, nonconscious memory, implicit memory • Requires practice • Task can be done without conscious thought

Three stages of Procedural Memory • Cognitive – Beginning stages – Person thinks about what they are doing – cognitive – Step-by-step performance of task • Associative – Movements refined and more efficient – Less dependent on cognition

• Autonomous stage – Movements are autonomous, do not require attention or conscious thought – Other activities can be done at the same time • Walk and chew gum • Cook and talk

Procedural Memory • Location – Frontal cortex – Thalamus – Basal ganglia