PSYCH 255 Human Memory PDF

PSYCH 255 Human Memory 1 MEMORY AND THE BRAIN 2 Learning Objectives Describe levels of analysis used in investigating the relationship between the brain and memory Describe how evidence from patients can be used to study memory, including the pros...

PSYCH 255 Human Memory 1 MEMORY AND THE BRAIN 2 Learning Objectives Describe levels of analysis used in investigating the relationship between the brain and memory Describe how evidence from patients can be used to study memory, including the pros and cons Describe methods of imaging and collecting data on brain structure and function. For each, describe its main mechanism (e.g., electrical activity, blood flow, radiation, etc.), its temporal and spatial resolution, and a possible question you could ask that the method would be useful for. 3 Levels of analysis Alzheimer’s Syndrome Amnesia Disease Cognition LTM WM Attention Neural Hippocampus Frontal Lobes System Signaling Pathway Monamine Dopamine Oxidase 4 Disease/Disorders e.g., patients with alcoholic Korsakoff syndrome May have multiple impairments Double dissociation LTM STM Patient 1 Normal Impaired Patient 2 Impaired Normal 5 Structural Imaging/Data Postmortem CT MRI 6 CT Computerized Tomography Multiple x-rays Each one a “slice” of the brain Measuring how well radiation passes through High spatial resolution Extremely poor temporal resolution Not used for direct tests of function 7 MRI Magnetic resonance imaging Measures blood flow High spatial resolution Poor to moderate temporal resolution (a few seconds) 8 Measuring Brain Function Anatomy is fairly easy to study Function is difficult Recording/Imaging EEG, CT, PET, fMRI Disrupt part of the brain Lesion, transcranial magnetic stimulation Directly stimulate part of the brain Electrical stimulation 9 EEG Electroencephalograph High temporal resolution Poor spatial resolution Non-invasive 10 PET Positron Emission Tomography Radioactively tagged contrast, picked up on x-rays Measures blood flow High spatial resolution Poor temporal resolution (~30 sec) 11 fMRI Functional magnetic resonance imaging Measures blood flow High spatial resolution Poor to moderate temporal resolution (a few seconds) 12 Technique Basis for Temporal Spatial Limitations technique resolution resolution EEG CT PET fMRI 17 Lesions Destroying a part of the brain Controlled destruction Accidental destruction H.M. Invasive, permanent 18 TMS Transcranial Magnetic Stimulation Temporary virtual lesions 19  MEMORY AND THE BRAIN – IMPORTANT STRUCTURES 20 Learning Objectives Describe the process of long-term potentiation Describe the role of the basal ganglia, cerebellum, hippocampus, and the amygdala in memory and learning Describe the role of the parietal, temporal, and frontal lobes in memory Describe the role of glutamate, GABA, dopamine, norepinephrine, and acetylcholine in memory 21 Basal Ganglia Habits Motor skill learning 26 The Cerebellum Cerebellum Fine muscle movement Balance Motor skill learning Procedural learning Pons Cerebellum Medulla 27 Hippocampus Consolidation of memories 28 Amygdala Basic emotional responses Fear, happiness, etc. Emotional learning Memory consolidation 29 Learning and the Hippocampus 30 Learning and the Brain Conditioning SM, WC, and RH SM had bilateral amygdala damage WC had hippocampal damage but an intact amygdala RH had damage to both the hippocampus and the amygdala 31 Normal controls – no damage Bilateral amygdala damage Hippocampal damage Damage to both the hippocampus and the amygdala 32 Parietal Lobes Sensory processing Spatial location Working memory 33 Temporal Lobes Auditory processing Storage of long-term memories 34 Frontal Lobe Frontal Lobe Selection of memories Prefrontal Cortex Higher-order functions Executive control Planning Reasoning Problem solving Working memory Inhibition Task flexibility 35 Hebb “neurons that fire together, wire together” Cell assemblies Neurons fire Synaptic Strengthened together Changes Connection 38 Long-Term Potentiation Synaptic transmission becomes more effective following a cell’s recent activation When an axon is repeatedly stimulated, the signals of neurons on the other side of the axon increase Transmission becomes more efficient Supports the idea that neurons that fire together wire together 39 Neurotransmitters Glutamate – formation of new synapses, LTP GABA – new memory formation Norepinephrine – memory consolidation Dopamine – positive reinforcement (conditioning) Acetylcholine – encoding new information 40