1. Session 5: Biological Factors & Cognition

3. 1. Human beings are information processors and mental processes guide behaviour 2. The mind can be studied scientifically 3. Cognitive processes are influenced by social and cultural factors

4.  Explain how biological factors may affect one cognitive process What the command term means: Explain: Give a detailed account including reasons or causes.

6.  Biological factors refers to the internal, physiological mechanisms of living organisms e.g. brain structure, hormones, neurotransmitters

7.  Not yet possible to have a complete understanding of the complexity of the biological foundations of memory, but research has provided some major insights into the biological nature of memory

8.  What do we already know about the relationships between biological factors and memory?  Think about:  Brain damage  Hormones

10.  Can be defined as the inability to learn new information or retrieve information that has already been stored in memory.  A condition in which people lose their ability to memorize/recall information.

11. ◦ Amnesia interacts directly with physiology because it is basically caused by damage in the hippocampus region of the brain. ◦ Studies demonstrating damage in the brain causing memory impairment illustrating how biological factors can influence cognitive processes

12.  Research method: case study  H.M first fell off a bicycle in childhood resulting in brain damage  Epileptic seizures started at age 10  At age 27 (1953) H.M had brain surgery to control his epilepsy and to stop seizures.  They removed tissue from the temporal lobe, including the hippocampus.  H.M. was studied extensively for 40 years.  After the operation, HM had anterograde amnesia – he was unable to create new memories. Nothing could be stored in his long-term memory (LTM). His childhood memories were intact.  MRI Scan Results (1997) – Brain damage was pervasive and included the hippocampus, the amygdala, and other areas close to the hippocampus.

13.  Did an MRI scan* of H.M.’s brain  Brain imaging was used because it allowed researchers to get a precise image of the brain damage  They were then able to identify where the damage was i.e. the removal of the hippocampus *MRI-Magnetic resonance imaging- a type of brain scanning technique

14. Conclusion:  The hippocampus is needed for memories to be transferred to long-term memory. Connection of study to question  The case of HM demonstrates how biological factors (brain damage) can affect cognition (memory). ◦ Brain damage in relevant areas caused memory impairment ◦ This study suggests that certain brain regions are responsible for the cognitive process of memory

15.  The hippocampus and areas around hippocampus play a critical role in converting memories of experiences from short-term to long-term memory  H.M. could retain memories of what happened BEFORE the surgery. This indicates that the hippocampus is a temporary rather than a permanent memory stories  H.M. could learn a few new procedural* memories which indicates that procedural memories are not stored via the hippocampus *procedural memory: memory for skills, actions and actions- “knowing how”

16.  The fact that H.M. (and other people with amnesia) had deficits in one part of the memory but not in others is evidence that the brain has several memory systems and that these are supported by distinct brain regions  Shows that memory processes are much more complex than originally believed  Although hippocampus is very important in the storage of new memories it is not the only part of the brain involved in the process

17.  Clive Wearing was a musician who got a viral infection - encephalitis.  This left him with serious brain damage in the hippocampus (biological cause), which caused memory impairment (effect on cognition)  He suffered from anterograde and retrograde amnesia  He could not transfer information from STM to LTM.  His memory lasted 7-30 seconds, and he was unable to form new memories.  Wearing still had the ability to talk, read, write, conduct and sight-read music (procedural knowledge)  Wearing’s episodic memory and some of his semantic memory were lost.  MRI scans of Wearing’s brain showed damage to the hippocampus and some of the frontal regions. Conclusion:  The case of Clive Wearing provides insight into the biological foundation of different memory systems, which is a cognitive process.  Wearing’s case highlights the interaction between biological factors and cognition as it establishes the link by illustrating the effect of physiological causes in the brain (brain damage occurring in hippocampus region, on the social and cognitive interactions of the individual.

20.  Produced by the adrenal cortex in response to physiological or psychological stress to restore homeostasis (the body’s normal balance)  Research has shown that excessive cortisol can hinder the brain in forming new memories or accessing existing memories

21.  Aim:  Aim: To investigate how levels of stress hormone cortisol interfere with verbal declarative memoryProcedure  Randomised, controlled, double blind experiment that ran for four days  Participants: self selected sample (recruited through advertisement) of 51 normal & healthy people aged 18-30 *double blind- neither participants nor experimenters knew which condition each participant assigned to

22.  Participants listened to a prose paragraph and had to recall is as a test of verbal declarative memoryResults  Group 1 showed worst performance on task  Group 2 showed no memory decrease  Shows that an increase in cortisol has a negative effect on memory Group 1 (high dose)Group 2 (low dose)Group 3 (control) Tablets containing 160mg of cortisol for 4 days (equivalent to cortisol levels in blood as a consequence of major stressful event) Tablets containing 40mg of cortisol for 4 days (equivalent to cortisol levels in blood as a consequence of minor stressful event) Placebo Tablets (tablets with no active ingredient)

23.  Controlled randomised experiment so possible to establish relationship between levels of cortisol (biological factor) and scores on verbal declarative memory test (cognitive process)

24. Followed group of elderly people for 5 years to study role of cortisol on memory Found that cortisol secretion was too high in about 30% of elderly population Those who were exposed to excessive cortisol secretion for 5 years showed memory impairment and atrophy (shrinking) of hippocampus Also found that memory impairment can be reversed if damage had not progressed to a “point of no return”

25.  Demonstrated that prolonged stress can damage neurons in the hippocampus but this can be reversed if normal levels of cortisol are restored  Long-term stress could cause irreversible damage