HM&L Exam 2 Study Guide PDF

HM&L EXAM 2 STUDY GUIDE Cellular and Molecular Mechanisms of Memory Durability of Long-Term Potentiation (LTP) S-LTP vs. L-LTP: -​ Short-Term LTP (S-LTP) is temporary and does not require new protein synthesis. -​ Long-Term LTP (L-LTP) lasts longer and requires protein synthesis for...

HM&L EXAM 2 STUDY GUIDE Cellular and Molecular Mechanisms of Memory Durability of Long-Term Potentiation (LTP) S-LTP vs. L-LTP: -​ Short-Term LTP (S-LTP) is temporary and does not require new protein synthesis. -​ Long-Term LTP (L-LTP) lasts longer and requires protein synthesis for maintenance. De Novo Protein Synthesis Hypothesis: -​ While initial LTP changes are supported by modifications, long-term maintenance requires translation of new proteins. -​ Supporting Evidence: Studies show that blocking translation after high-frequency stimulation (HFS) prevents L-LTP but still allows S-LTP. -​ Local mRNA translation in dendrites is crucial for sustaining LTP. Local mRNA Translation in Dendrites -​ Sutton & Schuman (2006): Dendrites were cut off from the soma, yet L-LTP still occurred. -​ This suggests local protein synthesis in dendrites can maintain LTP. -​ Bradshaw (2003): Blocking translation in dendrites prevented L-LTP, while blocking translation in the soma did not. -​ This reinforces the idea that mRNA translation in dendrites is necessary for LTP. Genomic Signaling Hypothesis -​ Why is it important? ​ Transcription factors (e.g., CREB) help produce the mRNA needed for L-LTP.  ​ Strong depolarization triggers a cascade that enhances transcription of key proteins. -​ CREB Activation Mechanisms: ​ Molecules activated at the synapse travel to the soma and phosphorylate CREB. ​ Calcium influx in the soma directly activates CREB (faster and more efficient). Key Molecules in LTP -​ BDNF: Released alongside glutamate. -​ Enhances local mRNA translation in dendritic spines. -​ Essential for LTP maintenance. -​ Arc: Quickly transcribed and translated after synaptic activity. -​ Helps stabilize synaptic changes by regulating actin. Synaptic Tag and Capture Hypothesis -​ How does it work? ​ Active synapses get a “tag” that allows them to capture plasticity molecules. ​ Strong stimulation provides both a tag and the ability to translate molecules. ​ Weak stimulation only provides a tag but can capture molecules from other synapses. -​ Why is this useful? ​ Allows efficient use of available plasticity molecules. ​ Helps integrate weak inputs into long-term memory. Encoding and Attention in Memory What Are Attention, Working Memory, and Encoding? -​ Attention: Focus on important information while ignoring distractions. -​ Working Memory: Short-term memory system that processes and stores information temporarily.  -​ Encoding: The process of taking in and organizing new information for long-term storage. Brain Regions Involved -​ Parietal Cortex: Combines sensory information (e.g., vision and touch). -​ Prefrontal Cortex (PFC): Controls focus, decision-making, and planning. -​ Anterior Cingulate Cortex (ACC): Helps switch attention and adapt to new information. Key Experiments -​ Wisconsin Card Sorting Task (WCST): Tests problem-solving and flexibility (related to the PFC, ACC, and parietal cortex). -​ Visual Paired Comparison Task (VPC): Tests recognition memory by measuring attention to new images. -​ Novel Object Recognition (NOR) Task: Tests how animals recognize new vs. familiar objects (perirhinal cortex & hippocampus). Types of Attention -​ Selective Attention: Focuses on one thing while ignoring distractions. -​ Inattentional Blindness: Failing to see something obvious because attention is elsewhere. -​ Selective Inattention: Ignoring stressful or unnecessary stimuli. Good or Bad? -​ Can be helpful for focus or harmful if it causes us to miss important details. Working Memory Components -​ Phonological Loop: Processes verbal info (e.g., remembering a phone number). -​ Visuospatial Sketchpad: Stores visual and spatial information (e.g., mental maps). -​ Central Executive: Controls attention and decides what’s important. -​ Episodic Buffer: Connects working memory to long-term memory. Schemas and Memory Organization -​ Schemas: Mental “folders” that group related ideas -​ Stronger schemas = better memory. -​ Assimilation: Adding new info to an existing schema. -​ Accommodation: Changing a schema to fit new info. Levels of Processing (Memory Strength) -​ Shallow Processing: Basic features (e.g., capital letters). -​ Intermediate Processing: Sound-based features (e.g., rhymes). -​ Deep Processing: Meaning-based understanding (best for memory!). Memory Strategies -​ Maintenance Rehearsal: Repeating information (good for short-term memory). -​ Elaborative Rehearsal: Connecting new info to existing knowledge (best for long-term memory). Working Memory and Cognitive Load The Atkinson-Shiffrin Model and Working Memory -​ Sensory Memory (SM): Holds raw sensory input briefly. -​ Short-Term Memory (STM): Holds small amounts of info temporarily. -​ Long-Term Memory (LTM): Stores information for extended periods. -​ Working Memory: Links SM and LTM, helping us process new info and retrieve old info. Multitasking and Task Performance -​ Multitasking is a myth—the brain switches between tasks, reducing accuracy and speed. -​ Leads to lower performance and increased fatigue. Task-Switching  -​ People think they’re multitasking, but they’re really switching between tasks rapidly. Example: Checking your phone while studying reduces focus. Automatic vs. Cognitive Tasks -​ Automatic Task + Automatic Task = Easy (e.g., walking + chewing gum). -​ Automatic Task + Cognitive Task = Possible (e.g., driving + music). -​ Cognitive Task + Cognitive Task = Hard (e.g., texting while driving). Cognitive Load Theory (CLT) -​ Intrinsic Load: Task difficulty (e.g., complex math problems). -​ Extraneous Load: Unnecessary distractions (e.g., noisy environment). -​ Germane Load: Effort to connect new info with existing knowledge. Element Interactivity -​ Low Interactivity: Simple tasks (e.g., memorizing a list). -​ High Interactivity: Complex tasks with multiple steps (e.g., writing an essay). Effects of Noise -​ Physical Noise (e.g., loud music). -​ Cognitive Noise (e.g., complicated instructions). -​ Too much noise makes learning harder! How Can Suzie Reduce Cognitive Load While Studying? -​ Extraneous Load: Remove distractions (quiet study space). -​ Intrinsic Load: Break difficult material into smaller sections. -​ Germane Load: Use old notes to connect new info. The Serial Position Effect -​ Primacy Effect: Remembering the first items on a list (long-term memory). -​ Recency Effect: Remembering the last items (short-term memory). -​ Von Restorff Effect: Unusual or different items stand out.