What is stress? Stress is any condition that disturbs the physiological or psychological homeostasis of an organism Two types of stress: External stress is an external condition that puts a strain on the homeostatic mechanisms of the body ○ Example: excessive heat Internal stress is when perceived demands exceed perceived ability ○ Example: unrealistic expectations
Positive and Negative StressPositive Stress (Eustress) Negative Stress (Distress) Stress is positive when it Hinders performance is essential for survival or aids performance Chronic stress The primal function of stress is survival Can cause physical Motivation and/or mental damage
Seyle’s General AdaptationSyndrome Three stage process that explains how individuals respond to stress First Stage – Alarm Reaction ○ Psychological ○ The body has become aware of the stress and prepares itself for the fight-or-flight response by releasing the hormones adrenaline and corticosteroid ○ Effects of the hormones include: increased heart rate, breathing rate, blood sugar level, and perspiration, and a decrease in digestion ○ Takes place in the Sympathetic System of the Autonomic Nervous System
Seyle’s General AdaptationSyndrome Second Stage - Resistance Stage ○ The body attempts to cope with the stress ○ If the stress continues for a long period of time, the body will attempt to remain alert to be prepared to deal with the stressor ○ The body cannot continue in this stage for a longed period of time because its resources will gradually be depleted ○ Takes place in the Parasympathetic System of the Autonomic Nervous System
Seyle’s General AdaptationSyndrome Third Stage - Exhaustion Stage ○ At this point, all of the body’s resources have been depleted and the body is no longer able to function normally ○ The symptoms that were caused in the alarm stage such as increased heart rate, breathing rate, blood sugar level, and perspiration, and a decrease in digestion may reappear ○ If the body experiences a prolonged exhaustion stage the immune system can be impaired and severe long term damage can result
Memory Memory is an organisms ability to store, retain, and recall information and experiences. There are many different models that explain what memory is and how it functions.
Information ProcessingPerspective There are three main stages in the formation and retrieval of memory First Stage – Encoding ○ Information is received, processed, and combined with other received information Second Stage – Storage ○ The creation of a permanent record of the encoded information is formed Third Stage – Retrieval ○ Stored information is recalled using a cue
Types of Memory Three types of memory Sensory Memory is memorization or the ability to look at an object and remember what it looked like ○ Brief – lasts only 200 to 500 milliseconds after the item is observed Short-Term Memory can be recalled for several seconds to even a minute after the information has been observed ○ Capacity is limited Long-Term Memory information from sensory memory or short-term memory that has been transferred to long-term memory through repetition or other means ○ Unlimited in capacity and duration
Hippocampus and Memory The portion of the brain most responsible for memory is the hippocampus Located in the medial temporal lobe of the brain Responsible for converting information in the short-term memory into the long-term memory, and inhibition and spatial perception It is not yet known what exact role the hippocampus plays in memory
The Effects of Stress onMemory Stress can affect various aspects of memory, brain structures, and physiological processes There have been many studies performed on both rodents and humans of how stress affects the hippocampus The hippocampus, which is a crucial component of memory, is highly susceptible to long-term stress than other portions of the brain Due to the hippocampus having a large quantity of corticosteroid receptors Stress hormones such as corticosteroid released over a long period of time damages the hippocampus
The Effects of Stress onMemory The damage to the hippocampus can include: reduced excitability of hippocampal neurons, inhibited creation of new neurons, and atrophy of dendrites The result is that certain hippocampal functions such as learning and memory are impaired and damaged due to stress Some of these effects can be reversed if the stress is discontinued Some of the effects are irreversible
Studies Studies done over two decades support the correlation between stress, the hippocampus, and memory impairment Patients that suffer from Post-Traumatic Stress Disorder have hippocampal atrophy People diagnosed with depression and hypercortisolemia (a condition where an individual has high amounts of circulating cortisol) have memory impairments due to hippocampus damage Patients that suffer from Cushing’s disease (a disease in which tumors in the adrenal gland cause excess secretion of glucocorticoids) have hippocampal atrophy and memory impairment Studies conducted on rats that were exposed to stress or given corticosterone displayed impairments in spatial memory
Our study The objective of the study was to determine if there is a correlation between stress level and memory performance. Consisted of 11 participants, all over the age of 18, and current college students Participants were instructed to complete an Undergraduate Stress Questionnaire to access their stress level Participants were provided with a page that contained a series of pictures and were asked to study them for 30 seconds At the end of 30 seconds, the pages were collected, and the participants were instructed to write down as many of the pictures that they could recall onto the answer sheet The hypothesis was that short-term memory performance of undergraduates would decrease according to stress level.
Assessment Stress levels were accessed by the number of items the participant checked on the Undergraduate Stress Questionnaire Memory test scores were accessed by the number of correctly recalled pictures
Results The results do not support nor reject the hypothesis Memory Test 16 14 Memory Test Score 12 10 8 6 4 2 0 0 10 20 30 40 50 60 Stress Level Score
Discussion Although there is a slight downward trend in memory test scores of the participants that had higher stress level scores towards the end of the graph, the results are inconclusive. It is predicted that with a larger sample of participants that the hypothesis could be proven correct. The study had many other variables that could have interfered with the data. The Undergraduate Stress Questionnaire did not take into account other life stressors, therefore the participants stress levels could have been inaccurately assessed It is difficult to assess an individual’s stress level because the amount of stress that a situation creates varies with each individual’s perception, therefore the stress levels again could have been assessed inaccurately Participants were not screened for any learning or memory disabilities or difficulties
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