Psychology Chapter 3 - Stress as an example of a Psychobiological Process (copy)

Stress (4)

A psychobiological response involving increased physiological arousal produced by internal or external stressors. Can be adaptive or maladaptive.

Why is stress a psychobiological process?

Because it has both psychological and physiological components and consequences, involving changes affecting nearly every body system

Stressor

Stimulus that causes or produces stress and challenges our ability to cope.

The stress response

Used interchangeably with 'stress'; primary function primes us to deal with a stressor more effectively.

Is the physiological response to stress voluntary, and what are some examples of reactions that can occur?

Initial physiological reactions are involuntary and predictable. Noticeable ones like increased heart rate, fidgeting, fast speech; Less noticeable ones like increased blood pressure and secretion of stress hormones

Two categories of psychological responses to stress

Emotional - When stress makes someone feel a certain way. Occur when we don't have the chance to recover emotional equilibrium, e.g. anger, anxiety, hopelessness, negative attitude towards yourself or life

Cognitive - When stress influences someone's mental abilities, e.g. perceptions of circumstances and environment, abilities to concentrate or decide (possibly due to constant thoughts of stressor), or problem-solving

We have some degree of voluntary control over our psychological response (depending on the individual)

Internal vs external stressors

Internal - Originate within individual, such as personal problems causing concern over potential consequences, pain, hunger/thirst, fatigue, pregnancy, etc.

External - Originate outside the individual, such as having too much homework, being nagged by parents or being threatened by someone

Acute stress

Short term stress that is easy to bounce back from if managed well. Initially intense but if stressor is overcome the response fades quickly. Normal and adaptive in many situations with the help of adrenaline. If very intense acute stress involves an actual or perceived threat of loss of life, injury or assault, PTSD may occur.

Chronic stress

Long-lasting stress caused by ongoing demands or worries. It is less intense and initiated at the same time as an acute response. Stressor isn't overcome, so arousal is maintained. While it is adaptive and normal, prolonged chronic stress can cause serious physiological issues.

Culumalative stress

When stressors occur within a close span of time without time for recovery, leading to physiological arousal rising and staying high

What are the two models used for explaining the physiological response to stress?

1. Fight-flight-freeze response - Acute stress

2. General Adaptation Syndrome (GAS) - Chronic stress

The fight-flight-freeze response

An involuntary response to an event that is perceived as threatening, fearful or otherwise stressful, involving physiological changes produced by the sympathetic NS to put us in a state of preparedness to confront a threat, escape, or remain still to avoid detection. Response can occur before visual stressor perception (e.g. subconsciously jumping out of the way of an out of control car). Sudden, intense, and relatively short-lived

Why CAN all 3 responses in the F-F-F response considered adaptive?

Because depending on the situation, they each can enable us to deal with a threat or other stressor that's present and help minimise harm

What area of the brain detects stressors?

The amygdala, which sends the signal to the hypothalamus

Hypothalamus

Almond-sized gland above brain stem that functions as a command centre, communicating with the body through the nervous system. Also maintains homeostasis and connects nervous system to endocrine (hormonal) system

How is the body put in a state of immediate physiological arousal for a fight or flight response?

The sympathetic NS (activated by hypothalamus) has two mechanisms:

- Efferent nerves stimulate body at effector sites e.g. heart, liver, bronchiole in lungs

- Projections connected to adrenal medulla in adrenal gland stimulate adrenaline (and other hormones like noradrenaline) release

How is the body kept in a state of physiological arousal after the initial adrenaline release?

Hypothalamus stimulates the pituitary gland to initiate the HPA axis for additional stress hormone release (main one being cortisol) from adrenal cortex in adrenal gland.

Freeze response

(Tonic immobility) Highly aroused physiological state involving energy conservation (parasympathetic) and readiness for action (sympathetic) that occurs due to interaction of parasympathetic and sympathetic NS functions. Movement stops, heart rate and blood pressure drops, hypervigilance, possible orientating response

When is a freeze response adaptive

Is adaptive when it is used to conserve energy to run or to be less noticeable, but is maladaptive in many human situations, e.g. exam, public speaking

Adrenaline

Hormone that increases physiological arousal. Fast acting but slow to dissipate. Released from adrenal medulla into bloodstream during FFF response. Has a widespread effect (as it is a hormone)

Norepinephrine/noradrenaline

Adrenalin's sister chemical, most frequently used as a neurotransmitter in the brain instead of being released into the bloodstream like adrenaline.

Cortisol

Hormone released from the adrenal cortex during stress. Has same basic effects as adrenaline but less intense and can be sustained for longer. Slower to kick in, as it is mediated by various other hormones through the HPA axis

How does cortisol function as a part of our daily lives?

It's a normal part of our body's daily regulation. Typically it spikes in the morning and wears off during the day, but chronic stress leads to maintenance of cortisol for days or weeks.

Effects of cortisol

- Increase energy (through blood sugar levels and enhancing metabolism)

- Shuts off not immediately needed systems (e.g. reproduction)

- Anti-inflammatory effect by blocking white blood cell activity which can lead to slower wound healing and weakened immune system. This is still a normal part of cortisol's functioning as it helps redirect energy to the FFF response.

Effects of excessive cortisol due to long-term stress

- Impaired immune functioning and increased disease vulnerability

- Increased appetite and weight gain

- High blood pressure

- High blood sugar + diabetes

- Vulnerability to heart disease

- Delays ovulation

- Decreased serotonin

- Impaired cognition (e.g. memory formation, recall, learning issues and mental disorders)

How is cortisol characterised in a healthy stress response?

A quick spike in cortisol levels occur, before a rapid decline with the termination of the stressful event.

Short term physiological effects are beneficial and adaptive but prolonged activation of the stress response can be harmful to physical and mental health

HPA axis

Hypothalamic-pituitary-adrenocortical axis. Pathway through which cortisol is released into the bloodstream. Hypothalamus also responds to cortisol in a feedback loop. One of two activated pathways in the physiological stress response, slower than the sympathetic NS pathway.

The GBA

The gut-brain axis is a bidirectional (two-way), multi-faceted communication link between the Central and Enteric NS. It involves direct and indirect pathways connecting the cognitive and emotional areas in the brain to the gastrointestinal tract.

Gut microbiota

Living organisms within gut maintaining gut health and functioning. The GM and brain communicate through the GBA. GM affects our mental processes and behaviour, and it influences the production of serotonin and other neurotransmitters within the gut and broader NS.

Vagus nerve

The main nerve connecting the brain to the gut and other organs as part of the parasympathetic NS

The GBMA

Same as GBA but including microbiota as an essential part of the axis. A complex interconnected circuit with multiple pathways (ANS, endocrine system, immune system, HPA axis and other bodily systems). Therefore functions in these systems can be influenced by GBM activities.

Enterotype

Each individual's unique gut microbiota, composed of fungi, bacteria, viruses, etc.

How is the GM affected by age?

Gut microbiota diminishes with age

Gut dysbiosis

Unbalanced gut microbiome, either in number or type of microbiota

How does stress link with gut microbiota?

Growing evidence shows a bidirectional link between the two. Stress can disturb the balance of GM and GM can influence:

- susceptibility to stress

- physiological and psychological stress responses

- stress resilience

- recovery from stress-induced changes

Why is the gut sometimes referred to as the body's 'second brain?'

Because it is the only organ to function independent of the brain (in some respects).

Psychobiotics

Microbiota-targeted interventions like beneficial bacteria (probiotics) or support for such bacteria (prebiotics) that influence GBA communication

GAS

Hans Selye's General Adaptation Syndrome, a 3-stage biological/physiological model of stress. Study was conducted on rats who were put under extreme stress (torture)

3 key points of GAS

- Physiological stress response is non-specific

- Organisms move sequentially through three physiological stages in which their resistance to a stressor varies

- Generic symptoms of illness (e.g. fatigue, weight loss) can be put down to stress

What did the Hans Selye (GAS!) conclude that stress was?

He decided that stress is the body's physiological response to physical and psychological demands that represent the body's generalised efforts to adapt itself to new conditions.

Non-specific vs specific responses to stress (according to Hans Selye)

Non-specific - Sympathetic NS responses initiated, such as increased heart rate and breathing, and lowered digestion

Specific - E.g. running away from a vicious dog, fighting an attacker, immune system activation to fight invaders, or becoming frustrated with someone annoying.

3 stages of the GAS

Alarm reaction, resistance, exhaustion

First stage of the GAS

Alarm reaction - when the organism is first exposed to the stressor. Has two parts, shock and countershock. Results in a general defensive reaction to the stressor and a state of high alertness, tension, and readiness to respond.

Shock

1st phase of Alarm Reaction stage. The body's resistance to and ability to deal with the stressor initially fall below normal levels; parasympathetic dominance. Blood pressure, body temperature and muscle tone all decrease momentarily. Loss of fluid from body tissues.

Counter shock

Bodily rebound after 1st phase of Alarm Reaction stage. Physiological arousal through sympathetic NS is activated to prepare the body to act, and resistance to the stressor increases above normal levels. Stress hormones (adrenaline, noradrenaline, cortisol, etc) activate bodily functions that stimulate this arousal, and fight or flight response occurs.

Second stage of GAS

If the stressor persists, the body enters the Resistance stage. Intense arousal of alarm-reaction stage dissipates through parasympathetic NS, but activated cortisol means body maintains physiological arousal and stressor resistance at above-normal levels. Body is taxed to generate resistance, therefore unnecessary physiological processes are shut down to maximise resources to cope and ADAPT.

What physiological processes are shut down/slowed during the Resistance stage of the GAS?

Includes:

- Digestion

- Growth

- Sex drive

- Reproduction

- immune system (leading to decreased resistance to illness-based stressors)

Third stage of GAS

If the stressor isn't dealt with in resistance stage and stress isn't relieved, body enters Exhaustion stage. Some of the alarm rection changes may appear as the body can no longer sustain its resistance. Resources (e.g. stress hormones) are depleted and body's stressor resistance drops below normal level. Organism becomes vulnerable to physical and mental disorders, and even death.

Symptoms of exhaustion stage of GAS

- fatigue/sleep disturbances

- severe concentration loss

- anxiety attacks

- depression

- jumpiness

- crying spells

- permanent changes to bodily organs

- death

What majorly causes organ 'wear and tear' during resistance stage?

Immune suppression and effects of higher and more prolonged levels of cortisol in the blood stream.

Where does adrenaline map into the GAS?

We can map adrenaline and the fight-or-flight-or-freeze response onto the countershock stage of Selye's model, in addition to cortisol (while cortisol still best explains the resistance and exhaustion stages).

Explanatory power of the GAS model

- Provides a biological/physiological model of the stress response

- Explains our decreased immunity, greater susceptibility to colds, and other symptoms when experiencing the resistance stage and high levels of prolonged stress

- Specifies a non-specific stress response

Limitations of the GAS model

- Research was conducted on rats, not humans, and further emphasises why psychological aspect wasn't accounted for

- The rat's 'stress' was extreme - basically torture, and therefore this kind of true exhaustion is unlikely to occur in response to daily stressors.

- Assumes everyone has the same general automatic physiological responses to stressors

- Overlooks psychological aspect of stress response

Psychological factors that influence our stress response

Prior experience, attitudes, motivation, self-esteem, outlook on life, coping skills, etc

Transactional Model of Stress and Coping

Richard Lazarus and Susan Folkman's model explaining stress psychologically, involving an encounter (transaction) of an individual and their external environment. Involves two key factors that determine if something is stressful:

- The meaning of the event to the individual

- The individual's judgement of their ability to cope with it

When does stress occur according to Lazarus and Folkman?

When there is an imbalance between a person's appraisal of the demands of the situation and their estimation of their ability to meet those demands

Two parts of the transactional model of stress and coping

Primary appraisal - stimulus

Secondary appraisal - coping strategies

Primary appraisal

An evaluation of the significance and stakes of an event, i.e. the demands of a particular situation. Event appraised as being either irrelevant (doesn't affect us), benign-positive (affects us positively) or stressful (requires a response). If stressful, further appraisal occurs, where we decide if the stimulus is a harm/loss, threat or challenge.

Explanation of the 3 further appraisals of a stimulus after being appraised as stressful

Harm/loss - Stressor perceived to have already caused damage, so assessment of how much damage has been done occurs

Threat - An assessment that the stressor may cause harm/loss in the future

Challenge - Stressor perceived as an opportunity to change or grow, but will be taxing in some way

Distress vs eustress

Distress occurs from an appraisal of a stimulus that is harm/loss or threat. Eustress (good stress) occurs from an appraisal of a challenge.

Secondary appraisal

An evaluation of our ability to control, cope or overcome our situation. Undertaken if any perception of an event as stressful occurs. We perceive that we either have sufficient or insufficient coping resources. If insufficient, further stress occurs. If sufficient, stressor is reduced or eliminated, or reappraisal occurs.

Internal vs external coping examples

Internal - Strength, determination

External - money, support from others

Reappraisal

Sometimes a person will go on to cope, and hence reappraise previous 'decisions' at the primary and secondary level.

e.g. Person lost their job and they're very upset/worried

Primary = Harm / loss

Secondary = Inadequate resources

New strategy: decides to use network of friends to find a new job

Therefore, reappraisal of secondary = Adequate resources

Therefore, reappraisal of primary = Challenge

Explanatory power of the transactional model of stress and coping

- Emphasises the role of personal nature and individuality in the human stress response (explains why different people have different stress responses to the same stimuli)

- Developed on people

- Focuses on psychological determinants of the stress response, of which we have control

- Views stress as an interaction with the environment, of which the individual has an active role

- Allows us to change our thinking about a stressor

Limitations of the transactional model of stress and coping

- Lack of empirical evidence (difficult to test through experimental research due to subjective nature)

- Primary + secondary appraisals are not always undertaken in that order and can be simultaneous

- Emphasis on interpretation suggests we are always consciously aware that we find something stressful

- Overlooks physiological response to stressors

Coping

Involves cognitive and behavioural efforts to manage specific stressors that are appraised as taxing or exceeding the resources of the person in a stressful situation.

Coping strategy

Specific behavioural or psychological method that people use to reduce the stress produced by a stressor.

Context-specific effectiveness

Describes coping strategies that have a good match or 'fit' with the stressful situation

What 3 criteria are required for a coping strategy to have context-specific effectiveness?

It must suit the environment, stressor and individual.

Examples of context specific effective strategies

Studying for an exam - creating a study plan

Waiting for your ATAR - mental distancing/distraction

Exercise as a coping strategy

Cardiovascular exercise uses up cortisol, lowering effects of chronic stress. It also releases endorphins and helps to distract from the stressor and make someone feel productive. Also often involves going outside and interacting socially. Considered an approach strategy when the stressor requires an increase in physical fitness or a decrease in psychological stress.

Coping flexibility

The ability to effectively modify or adjust one's coping strategies according to the demands of different stressful situations. Includes abilities to:

- Select appropriate coping strategies

- Recognise where coping flexibility is required (i.e. recognise current strategy isn't working, discontinue it, and implement an alternative strategy)

Why is coping flexibility considered an adaptive personality attribute?

Because it enables us to adjust our thoughts, feelings and behaviours according to changing circumstances

High vs low coping flexibility

High coping flexibility - readily adjust their coping strategies if a particular strategy is proving to be ineffective

Low coping flexibility - consistently use the same type of coping strategies across different stressful situations, and persist in their use even when they are ineffective, e.g. substance use, perfectionism

Approach strategies

Efforts to confront a stressor and deal directly with it and its effects. Activity focused towards stressor and finding a solution that will eliminate its cause. Usually more effective than avoidance strategies

Avoidance strategies

Efforts to evade the stressor and deal indirectly with it and its effects. Activity focused away from the stressor and towards finding something to distract.

Alternative words used to describe approach vs avoidance strategies

Engagement vs disengagement with the stressor

Someone with good coping skills demonstrates...

- A sensitivity to the specific context (context-specific effectiveness)

- The ability to select and change strategies appropriately (coping flexibility)

- An orientation towards dealing with the underlying causes of a problem (approach strategies)

- A tendency to exercise regularly

Physiological stress response

Sympathetic NS and HPA axis