1. Long-term Memory Explicit Memories (fact-based info, conscious retrieval) Semantic memories (memory of facts) Episodic memories (events) Implicit Memories (not consciously retrieved) Procedural memories (how to do things) Emotional memories (memory of emotional content)

2. CLO #7: Explain how biological factors may affect one cognitive process. (SAQ)

3.  Brain localization: Certain brain structures are responsible for certain types of memory functions  Brain structures that affect memory can be studied through animal studies, case studies (brain damaged patients) and brain-imaging technology  Much is still unknown about how memory is organized in the brain due to the brain’s complexity and difficulties in studying the working human brain.

4.  In the 1990s Kandel studied the sea snail aplysia. He picked it because it was a simple organism. He found that STM and LTM result in synaptic changes in the neural network.  His research showed that learning (forming memories) means growing new connections or strengthening connections between neurons.  Kandel went on to study synaptic changes due to memory in the hippocampus. In other words, what changes occur in the hippocampus when new memories are formed?

5.  Review: Animals have been studied in memory research experiments like the Rat Maze Study. Researchers lesion (cut away brain tissue) in certain parts of the brain until the animals cannot perform the memory task anymore.  Obviously, this cannot be done in humans, so instead we rely on case studies of people who already have damage to a certain part of the brain.

7.  Clive, an eminent English musician, was in his mid-40s when he was struck by a brain infection (herpes encephalitis). He was left with a memory span of only seconds – the most devastating case of amnesia ever recorded. In fact he had:  Anterograde amnesia (failure to store memories after a trauma)  and Retrograde amnesia (failure to store memories that have occurred before trauma)

8.  His episodic memory and some of his semantic memory were lost.  His procedural memory was still intact.  He could not transfer new info into LTM.  His ability to perceive new sensory info was unimpaired (but faded fast)  He can still play the piano and conduct music that he learned before his illness (this is implicit memory).  His emotional memory is intact (eg. He still loves his wife)

9.  MRI scanning showed damage to Clive’s hippocampus and some of the frontal regions. This indicates that retrograde amnesia can be tied to the hippocampus ALSO Implicit Memory must be linked to a structure other than the hippocampus.

10. HM suffered a traumatic head injury when he was 9 years old. He suffered from epileptic seizures, but at the time (1950s) there was no drug treatment for the seizures. The doctors decided to perform surgery and remove tissue from parts of the temporal lobe including the hippocampus.

11. After surgery he could recall info acquired early in life, but was unable to form new memories. He could hold a normal conversation, but could not recognize faces of people who visited him regularly. He could read and reread the same magazine without recognizing it. He suffered from anterograde amnesia.

12.  In 1997, HM was put into an MRI and the areas of his brain that were damaged in the operation were identified.  The damage was pervasive, but it did include the hippocampus, amygdala, and other areas close to the hippocampus.

13.  Based on the work of Kandel and Case Studies like Clive Wearing and HM, the hippocampus appears to have an important role in the formation of explicit memories.  Both Clive and HM had damage to the hippocampus yet could not form explicit memories, however both could form implicit memories.

14.  The amygdala seems to have a role in storing emotional memories.  According to one neuroscientist, LeDoux, certain memories have emotional significance which explains why memories based on emotional events are remembered better.  It also explains why people suffering from post-traumatic stress disorder have problems forgetting emotional memories.

15. CLO #10: Discuss the use of technology in investigating cognitive processes (Memory).

16.  Memory processes are localized  We know which parts of the brain are responsible for memory

17.  PET scans can measure important functions in the brain such as glucose consumption and blood flow.  They can also identify cellular changes in an organ or tissue.  PET scans can, therefore be used to detect brain tumors or memory disorders n Alzheimer’s patients. In some cases this detection comes even before patients were aware that anything was wrong with them.

18. Researchers at NYU have developed a brain-scan based computer program that quickly and accurately measures metabolic activity in the hippocampus. Using PET scans and this program, they have found a reduction in brain metabolism in the hippocampus in the early stages of Alzheimer’s.

19. In a longitudinal study, 53 healthy participants were followed for 9 to 24 years. They found that those who showed early signs of reduced metabolism in the hippocampus were associated with later development of Alzheimer’s.

20.  What other memory studies have used MRI’s to detect a relationship between memory and brain activity?

21.  Clive Wearing  H.M.

22. -Cognitive Processes -Physiology -Clive Wearing -HM