Memory 2 PSB 5341

The Temporal Lobes and Declarative Memory The Diencephalon and Memory Processing –Diencephalon: Brain regions associated with memory and amnesia (outside the temporal lobe) Large lesion to anterior nucleus & dorsomedial nucleus of the thalamus in monkeys causes deficits in DNMS performance. Lesions to either structure alone, lead to milder deficits. Even milder deficits occur after lesions to mammillary bodies.

The Temporal Lobes and Declarative Memory The Diencephalon and Memory Processing –Korsakoff’s Syndrome Symptoms: Confusion, confabulations, severe memory impairment, and apathy –Alcoholics: Develop thiamin deficiency Leads to symptoms: Abnormal eye movements, loss of coordination, tremors –Treatment: Supplemental thiamin Thiamin deficiency: Structural brain damage

The mediotemporal lobe has important role in declarative memory or consolidation. Severe anterograde amnesia results after mediotemporal lobe lesions. Hippocampus itself important. In both animals & humans, the same stimulus elicits a different response when familiar than unfamiliar. Recordings from single cells from human hippocampus in Fig as part of surgery for epilepsy.

The Temporal Lobes and Declarative Memory Memory Functions of the Hippocampus –Role of the medial temporal lobes Declarative memory processing or consolidation

The Temporal Lobes and Declarative Memory Memory Functions of the Hippocampus –Spatial Memory and Place Cells Morris water maze

The Temporal Lobes & Declarative Memory Memory Functions of the Hippocampus –Spatial Memory, Working Memory, and Relational Memory Relational memory Highly processed sensory information –To hippocampus and nearby cortex

The Striatum and Procedural Memory Two elements of basal ganglia  Striatum –Caudate nucleus –Putamen Rodent Recordings and Lesions in the Striatum –Lesions to striatum: Disrupts procedural memory –Damaged hippocampal system: Degraded performance on standard maze task –Lesion in striatum: Impaired performance of the light task; Double dissociation

The Striatum and Procedural Memory Habit Learning in Humans and Nonhuman Primates –Striatum in humans plays a role in procedural memory

The Neocortex and Working Memory The Prefrontal Cortex and Working Memory –Primates have a large frontal lobe –Function of prefrontal cortex: self-awareness, capacity for planning and problem solving

The Neocortex and Working Memory The Prefrontal Cortex and Working Memory (Cont’d) –Imaging Working Memory in the Human Brain Numerous areas in prefrontal cortex are involved in working memory

The Neocortex and Working Memory Lateral Intraparietal Cortex (Area LIP) and Working Memory –Area LIP: Guiding eye movements –Delayed-saccade task

Concluding Remarks Learning and memory –Occur throughout the brain Memories –Duration, kind of information stored, and brain structures involved –Distinct types of memory –Different types of amnesia Multiple brain systems for memory storage Engrams in temporal lobe neocortex –Physiological basis? –Long-term memories: structural basis?