DO NOW • Briefly describe the three parts of the Atkinson-Shiffrin processing model IN YOUR OWN WORDS!
Memory Part II AP Psychology Ms. Desgrosellier 3.15.2010
MEMORY TEST • Get out a blank piece of paper. • DO NOT write down anything while looking at the next list. • You will have 30 seconds to memorize as much as you can.
MEMORY TEST • Milk, eggs, butter, fruit, cheese, mustard, soda pop, ice cream, bread, pizza
MEMORY TEST • Now write down everything you can remember. • What effects do we see?
Sensory Memory • Objective: SWBAT contrast two types of sensory memory.
Sensory Memory • iconic memory: a momentary sensory memory of visual stimuli. • A photographic or picture-image memory lasting no more than a few tenths of a second.
Sensory Memory • echoic memory: a momentary sensory memory of auditory stimuli • If attention is elsewhere, sounds and words can still be recalled within 3 or 4 seconds.
Working/Short-Term Memory • Objective: SWBAT describe the duration and working capacity of short-term memory.
Working/Short-Term Memory • Unless our working memory meaningfully encodes or rehearses information, it quickly disappears from our short-term store. • Research has shown that without active processing, short-term memories have a limited life.
Working/Short-Term Memory • Our short-term memory holds only about 7 items at a time (plus or minus 2). • Short-term recall is slightly better for random numbers than for letters.
Long-Term Memory • Objective: SWBAT describe the capacity and duration of long-term memory.
Long-Term Memory • Our ability for storing long-term memories is essentially limitless. • Research has shown that memories don’t live in just one place in the brain.
Long-Term Memory • Also, forgetting occurs as new experiences interfere with our retrieval and as the physical memory trace decays. • Research with hamsters showed that even stopping electrical activity in the brain did not erase memories.
Synaptic Changes • Objective: SWBAT discuss the synaptic changes that accompany memory formation and storage.
Synaptic Changes • Research using the Aplysia, the Californian sea snail, has focused on neurons because they have large, easily accessible nerve cells. • When learning occurs, the snail releases more of the neurotransmitter serotonin at certain synapses. • These synapses then become more effective at transmitting signals.
Synaptic Changes • Increases synaptic efficiency makes for more efficient neural circuits. • e.g. less prompting to release its neurotransmitter or increased number of neurotransmitter receptor sites.
Synaptic Changes • Increases synaptic efficiency makes for more efficient neural circuits. • long-term potentiation (LTP): an increase in a synapse’s firing potential after brief, rapid stimulation. Believed to be a neural basis for learning and memory.
Synaptic Changes • This has lead pharmaceutical companies to research on memory-boosting drugs.
Synaptic Changes • After LTP has occurred, passing an electric current through the brain won’t disrupt old memories. • The current will wipe out very recent memories.
Synaptic Changes • After LTP has occurred, passing an electric current through the brain won’t disrupt old memories. • This also happens in organisms after being hit in the head, people falling asleep, or athletes who are knocked out.
Synaptic Changes • After LTP has occurred, passing an electric current through the brain won’t disrupt old memories. • The information in short-term memory did not have time to consolidate into long-term memory.
Stress Hormones and Memory • Objective: SWBAT discuss some ways stress hormones can affect memory.
Stress Hormones and Memory • Stress hormones that are produced when organisms are excited or stressed make more glucose energy available to fuel the brain.
Stress Hormones and Memory • The amygdala (emotion processing clusters in the limbic system), boost activity in the brain’s memory-forming areas. • This can result in certain events being “seared” in the brain while other neutral events are left out.
Stress Hormones and Memory • Stronger emotional experiences make for stronger, more reliable memories. • Weaker emotions mean weaker memories.
Stress Hormones and Memory • Emotion-triggered hormonal changes help explain why we can long remember exciting or shocking events. • This is also helped by the fact that many people relive and rehearse these events.
Stress Hormones and Memory • When stress is prolonged (e.g. in abuse or combat situations), neural connections can be eaten away and the hippocampus can actually shrink.
Stress Hormones and Memory • Also, when stress hormones are flowing, older memories may be blocked. • e.g. blanking out when speaking in front of an audience.
Storing Implicit and Explicit Memories • Objective: SWBAT distinguish between implicit and explicit memory, and identify the main brain structure associated with each.
Storing Implicit and Explicit Memories • amnesia: the loss of memory. • Studied frequently in the study of memory. • Patients with amnesia can be classically conditioned, but they do all these things with no awareness of having learned them.
Storing Implicit and Explicit Memories • implicit memory: retention independent of conscious recollection. • Also called procedural memory. • The unconscious capacity for learning.
Storing Implicit and Explicit Memories • explicit memory: memory of facts and experiences that one can consciously know and “declare.” • Also called “declarative memory.
The Hippocampus • hippocampus: a neural center that is located in the limbic system and helps process explicit memories for storage.
The Hippocampus • Using brain scans while people are forming a memory, activity is seen in the hippocampus and certain areas of the frontal lobe. • The hippocampus is also activated during recall of words (explicit memory).
The Hippocampus • Damage to the hippocampus messes up certain types of memory. • You have two hippocampuses, just above each ear and about an inch and a half in.
What role does the synapse play in memory? What role does the hippocampus play? DO NOW (3.17.10)
The Hippocampus • Damage to the left hippocampus cause trouble remembering verbal information, but no issues recalling visual designs and locations. • Damage to the right hippocampus causes the reverse problem.
The Hippocampus • Subregions of the hippocampus activate for different tasks, like learning to associate names with faces, or using spatial mnemonics. • The rear area for spatial memory gets bigger in London cab drivers who has been navigating the city streets.
The Hippocampus • Monkeys and people who lose their hippocampus lost most of their recall for things learned during the preceding month, but older memories remain intact.
The Hippocampus • It seems to act as a “loading dock” for registering and temporarily storing elements of a remembered episode, like smell, feel, sound, and location. • Then older memories are shifted into long-term storage.
The Hippocampus • It is active during slow-wave sleep, as memories are processed and filed for later retrieval. • The greater the hippocampus’s activity during sleep after a training exercise, the better the next day’s memory.
The Hippocampus • Brain scans show that different memories activate different parts of the frontal and temporal lobes. • e.g. recalling telephone numbers and holding them in working memory activates a region in the left frontal cortex.
The Hippocampus • Brain scans show that different memories activate different parts of the frontal and temporal lobes. • e.g. recalling a party scene would more likely active a region of the right hemisphere.
The Hippocampus • This has helped prove that our memories are stored in more than one place. • Amnesia patients may remember fragments of memories, but have lost the ability to assemble them into a whole.
The Cerebellum • The cerebellum extends out from the rear of the brainstem. • It plays a key role in forming and storing the implicit memories created by classical conditioning.