3 stress as an example of a psychobiological process Flashcards
Stress
a psychobiological response produced by internal or external stressors perceived as challenging, or exceeding their ability or resources to cope
Distress and eustress
Distress: a form of stress characterised by a negative psychological state
Eustress: a form of stress characterised by a positive psychological state
Acute and chronic stress
Acute stress: a form of stress characterised by intense psychobiological symptoms in a brief duration
- Episodic acute stress: acute stress occurs over and over again
Chronic stress: a form of stress that endures for several months or longer
Cumulative stress: when multiple stressful events occur within a relatively short period of time
Stressor
a stimulus that produces stress
Internal and external stressors
Internal stressor: a stressor that originates within the individual
External stressor: a stressor which originates outside the individual from situations and events in the environment
Fight-flight or freeze response in acute stress
involuntary, physical adaptive response to a sudden threat (stressor) in readiness to:
- fight: confront the threat
- flight: escape the threat
- freeze: keep still/silent
occurs before brain’s visual info. processing interprets what is happening
Fight or flight reactions
Part 1: hypothalamus » activates sympathetic NS » stimulates adrenal glands (adrenal medulla) » secrete adrenaline & noradrenaline (stress hormones)
Part 2: hypothalamus » stimulates pituitary gland » release hormones to stimulate adrenal glands (adrenal cortex) » secrete cortisol (stress hormone)
Freeze reaction
- avoid detection & conserve energy until predator loses interest
- energy conserving actions of the parasympathetic NS dominate
Role of cortisol in chronic stress
- used to deal w stressor over a long time
- adrenaline & noradrenaline DON’T last long so HPA axis is activated
- energises body to increase blood sugar (metabolism)
- activates liver » releases glucose » activate muscles
- anti-inflammatory effect on the body
- leads to impaired immune system (e.g. diabetes)
Gut-brain axis
- bi-directional, multi-faceted communication b/w central & enteric NS
- gut disruptions affect our mood, emotional arousal, motivation, behaviour & cognitive abilities
Gut microbiota
- microorganisms (e.g. bacteria, viruses and fungi) present in an individual’s digestive tract
- microbiome can be affected by both internal & external factors (e.g. diet, infection, disease, age & lifestyle choice)
Links with stress
stress can disturb the GBA, gut microbiota composition & gut brain microbiome interaction, influencing development of:
- gastrointestinal disorders
- changes in psychological processes & behaviour
- vulnerability to mental health
- various other disorders
Selye’s General Adaptation Syndrome (GAS) as a biological model of stress
- aim: long-term effects on stress on rats
- findings: physiological arousal pattern in response to a variety of stressors was the same
- conclusion: stress is a condition that is non-specific
Stages of the GAS
Stage 1: Alarm reaction (immediate response)
- shock - decreased bodily arousal for a brief period of time
- counter shock - sym NS responses occur that mobilise the body to respond to stressor
Stage 2: Resistance (maximise resources to cope & adapt) - parasym NS activated but arousal lvl remains above normal, unncessary physiological processes shut down, cortisol released, immune system weakened
Stage 3: Exhaustion (vulnerable & weak) - physical wear & tear (e.g. extreme fatigue & if stress persists, death)
x-axis: time
y-axis: resistance to stress
Strengths and limitations of the GAS
strengths:
- recognises relo b/w chronic stress n illness
- recognises a predictable pattern of physiological repsonses associated w certain stages
limitations:
- conducted on rats so CANNOT generalise to human population
- DOESN’T recognise subjective nature of stress response
Lazarus and Folkman’s Transactional Model of Stress and Coping
stressor »
- primary appraisal: individual’s evaluation of the significance of a stressor & whether anything is at stake in the encounter, resulting in a decision that it is either:
irrelevant
benign-positive
stressful »
harm/loss —assess damage already done
challenge — assess opportunity for a positive outcome
threat — assess possible additional harm in the future »
- secondary appraisal: individual’s evaluation of their ability to control or overcome a stressful situation
coping resources are adequate » reduced stress or reappraisal
coping resources are inadequate » stress
Strengths of the Lazarus and Folkman model
- explains why individuals respond in diff ways to the same types of stressors
- acknowledges that stressors & the circumstances under which they occur can change over time
- allows us to change our thinking about a stressor & our response
Limitations of the Lazarus and Folkman model
- difficult to test thru experimental research bc of the subjective nature of stress responses
- we can experience a stress response w/o ever having thought about a situation (i.e appraisal isn’t essential)
- overlooks physiological responses to a stressor
Strategies for coping with stress
- Context-specific effectiveness
- Coping flexibility
- Approach and avoidance coping strategies
Context-specific effectiveness
in relation to coping, when there is a match or ‘good fit’ between the coping strategy that is used and the stressful situation
Coping flexibility
the ability to effectively modify or adjust one’s coping strategies according to the demands of different stressors
Approach and avoidance coping strategies
approach coping strategy: an effort to cope with stress by confronting the stressor and dealing directly with it and its effects
avoidance coping strategy: an effort to cope with stress by evading the stressor and dealing indirectly with it and its effects
