Human Physiology 101 #1

Physiology is the science of living things, it deals with the functions of all living creatures. Human physiology, specifically, is the study of the function and mechanisms of the human body.

Cell membranes

* It separates the intracellular fluids from the extracellular fluids/
* It functions as a semi-permeable membrane, permitting the passage of certain substances and not others.

Consists of:
* 55% proteins
* 25% phospholipds
* 13% cholesterol
* 4% other lipds
* 3% Carbohydrates



Phospholipids:
* Each phospholipid contains a 'head' and 2 'tails'.
* The head consists if a phosphate radical and is seen facing the outside and interior of the cell.
* The head is hydrophilic because it can mix and dissolve with water.
* The tails are formed of fatty acid radicals, they are insoluble in water but soluble in fats and are hydrophobic.
* The hydrophilic parts of the phospholipids are facing the outer and inner surfaces of the membrane so that they are in contact with the watery extracellular fluid and the aqueous cytoplasm interiorly.

Proteins:
* Several types of proteins are embedded in the membrane as globular units.
* Those on the surfaces are called peripheral proteins and some extend through the membrane, these are integral or trans-membrane proteins.

Membrane protein functions:
* Structural
* Passive channels, for passive transport of ions, they can be closed or opened by changing the shape of the protein molecule.
* Pump, for active transport of ions. They act as active carriers which can be Uniport or Co-transport.
* Receptors, uniting with a neurotransmitter or a hormone leading to physiological changes inside the cell.
* Enzymes, catalysing reactions at the surfaces of membranes, e.g. ATPase enzyme.
* Forming connections between cells
* Cell adhesion molecules, as in wound healing or tumour metastasis.
* Fixation of the cytoskeleton of the cells.

Psychology #13

Abraham Maslow:
Humanistic approach, view person’s behaviour in context of their environment and values. Self-actualization is the highest level of psychological development in which a person strives to realize his human potential, to achieve anything he is capable of.

Primary motives: biologically based motives like hunger, thirst and sex.

Acquired motives: learned motives like achievement, power etc.

Cultural experiences are not the only learned factor in food preferences, people develop personal likes and dislikes, guided by family, peers, advertising and innate factors.

The increasing number of obese people is evidence for psychological and social factors in eating and weight gain.

Sexual behaviour varies with age, gender, religion and culture.

Psychology #12

Competing motives might cause a conflict.

Conflict is the emotional state or condition that arises when a person must make a choice between two or more competing motives.

Arousal: is physical activation, including activation of the central nervous system, the autonomic nervous system, and the muscles and glands.

Arousal theory attempts to explain the link between behaviour and a state of arousal.

Yerkes-Dodson principle: performance is at its peak when arousal is at moderate levels, too much or too little arousal results in low performance levels.

Expectancy theories: explanations of behaviour that focus on people’s expectations about reaching a goal and their need for achievement.

Extrinsic motivation: comes from external environment in form of rewards or punishments, e.g. praise, high grades, payment etc. Increases self worth.

Intrinsic motivation: behaviour that has no apparent reward except the pleasure and satisfaction gained from the activity itself. Being completely intrinsically motivated in something is called flow.

Psychology #11

Motivation

Motivation is a condition; usually an internal one, that initiates, activates, or maintains an organism’s goal – directed behaviour.

4 parts to motivation:
1. It is an internal condition that cannot be directly observed, no one else knows about it.
2. Motivation is inferred to be the link between a person’s internal condition and external behaviour. People can’t see the motivation but they can see the resulting behaviour.
3. Motivation initiates, activates, or maintains behaviours.
4. Motivation generates goal – directed behaviour.

An instinct is a fixed behavioural pattern that occurs in all members of species and appears without learning or practice.

Drive: an internal aroused condition that directs an organism to satisfy some physiological need.

Drive theory focuses on need, a state of physiological imbalance that is usually accompanied by arousal. A need is a lack of some biological essential like food or water.

A motive is a specific (usually internal) condition, typically involving some form of arousal, which directs an organism towards a goal.

The ultimate goal of each organism is homeostasis – maintenance of a steady state of inner stability or balance.

Psychology #10

Observational learning:
organisms can learn new behaviour by observing and modelling the behaviour of others.

Key processes in observational learning:
1. Attention: individuals must attend to a model to learn from that model.
2. Representation: for observation to become learning, observers must represent the information in memory.
3. Behavioural production: converting the cognitive representation of the behaviour into action.
4. Motivation: an important process, individual needs to be motivated to produce the behaviour.

Observational learning is crucial in daily life in terms of gender role development and cultural views.

Psychology #9

Operant conditioning
This is the conditioning of voluntary behaviour by means of reinforcement and punishment. Behaviour occurs first and then it is reinforced or punished.

Reinforcement: A consequence that strengthens a response
A reinforcer is any event that increases the probability of a recurrence for a response that preceded it.

Positive reinforcement: Presenting a stimulus that will increase the likelihood of the behaviour recurring, e.g. giving a dog a biscuit.

Negative reinforcement: Also increases the likelihood of a stimulus recurring but by removal of an unpleasant stimulus, e.g. ‘taking medication’ to stop pain.

Primary reinforcement: has survival value for an organism, things like food, water, termination of pain etc. Food is a primary reinforcer for a hungry person.

Secondary reinforcement: a neutral stimulus with no value for an organism but it becomes rewarding when linked with primary reinforcement, e.g. an approving nod.

Shaping: gradual and selective reinforcement until the desired behaviour is correct, e.g. a parent who wants to teach a child to make their bed will start by rewarding even shoddy attempts by the child to make their bed but, then eventually rewarding only a well made bed.

Punishment: A consequence that weakens a response
Punishment: presenting an undesirable or removing a desirable stimulus in order to decrease the probability of the response occurring.

Positive punishment: adding something unpleasant to a situation
Negative punishment: removal of a pleasant stimulus e.g. not allowed to watch TV or removed from pleasant environment as in Time-out.

Primary punisher: any stimulus that is naturally unpleasant or painful.
Secondary punisher: any neutral stimulus that originally has no negative value for an organism but acquires punishing qualities when linked with primary punishers. E.g. the word ‘no’ or an angry expression.

Remember: negative reinforcement is the opposite of punishment.

Frequency of consequences
Schedule of reinforcement: pattern of presentation of a reinforcer over time.

2 main schedules are:
Continues reinforcement: reward given in every instance of desired behaviour – produces quickest learning. More effective in young children.
Partial reinforcement: reward is only some of the time – produces learning that lasts longer in the absence of reinforcement.

Psychology #8

Learning

Learning is the relatively permanent change in an organism due to experiences in the environment.

Concepts in the definition of learning:
Permanence (relatively, not completely permanent, organisms can forget)
Experience
Change
Overt behaviours- learned behaviour is expresses in this way usually.

3 basic concepts of learning
Classical conditioning, Operant conditioning and Observational learning.

Classical conditioning (Pavlovian)

Stimulus: detectable sensory input
Response: reaction of the stimulus
Reflex: automatic response to a stimulus that occurs involuntarily, without prior learning.

Conditioned behaviours are learned.

Before conditioning:
UCS (food) = UCR (salvation)
Neutral Stimulus (Bell) = No response

During Conditioning: repeated pairing
UCS (food) + Conditioned Stimulus (bell) = UCR

After conditioning:
CS (bell) = CR (salvation)

Classical conditioning is when a neutral stimulus is made to cause a response through repeated pairing with an unconditioned stimulus that naturally causes that response. Classical conditioning causes behaviour to change, so learning has occurred.

Conditioning is a method of developing, occurs extensively with infants.
Little Albert (white rat and frightening loud noise).

Strength, timing and frequency
- If the unconditioned response is weak, conditioning to a neutral response is less likely to occur.
- For UCS and NS to become paired, they must be paired close enough to be paired, approximately 1.5 seconds.
- Frequent pairing between UCS and NS are necessary.

Extinction and spontaneous recovery
If the conditioned stimulus continued to be present without the UCS (food), the conditioned response (salivating) may cease, this is extinction.
After extinction, the CR may reappear if the relevant stimulus is presented, this is spontaneous recovery.

Generalization: dog generalizes and responds to sounds similar to the bell
Discrimination: if 2 different tones presented, but food with only one of them, the dog would learn to discriminate.

Psychology #7

Visual illusions
1. Perception is a dynamic process of searching for the best available interpretation of the data received through the senses.
2. It is not a passive reflection of sensation received, but an active process of testing hypothesis received.
3. Sometimes that data received is ambiguous, so its interpretation can be erroneous (an illusion).
4. Visual illusions occur when info is passed to the brain and then it is either incorrectly or ambiguously interpreted.

Muller-Lyer illusion

The line between the outward arrowheads (A-B) appears to be longer than that between the inward pointing ones (C-D) but they are the same length.

Context and illusion

The context of the outer circles, larger in one case, smaller in the other, leads us to exaggerate the size of the centre circle in A and reduce the size of the centre circle in B, but they are in fact the same.

Illusions from ambiguous figures

The Necker cube, data is insufficient for our brain and unambiguous, so we are once looking down a cube and another time, up into it.

Figure ground illusions:
which one is the main image and which one is the background dilemma.

Psychology #6

Gestalt theories of perception
Kohler, koffka and Wertheimer
1. There exists in the mind an innate capacity for organising perception.
2. The ‘whole’ of perception was more than the sum of the parts.
3. Law of pragnanz (good form) psychological organization will always be as good as the prevailing conditions allow.

Proximity:

elements in close together will appear as belonging together.

Similarity:

elements that are similar appear to be grouped together.

Closure:

incomplete figure seen as a complete one.

Psychology #5

Perception
This is the process by which data from the environment around us is interpreted to allow us to make sense of it.

Sensation is the interpretation of data from the environment around us by the means of our senses. Horizontal

Perceptual constancies: we don’t just rely on what we see to know what it is.

Shape constancy:

Objects project different shapes on to our retinas from the angle they are viewed at.

Size constancy: for example, though the further away an object is, the smaller it is, we still know it’s real size.

Psychology #4

The humanistic approach

1. Take a phenomenological viewpoint, looking at the subjective conscience and experience of each individual.
2. Humans are unique, essentially good and have control over their destiny.

All people are born with an ‘actualizing tendency’, a motive that drives us to grow into mature individuals.

Maslow’s pyramid of needs (SEBSP)
1. Self actualization
2. Esteem needs
3. Belonging needs
4. Safety needs
5. Physiological needs

Main criticism is that terminology is not clearly defined.

What do psychologists do?

Pure research: Carried out to increase or knowledge of how organisms behave.

Applied research: Carried out to answer a question that has practical importance.

Some specific fields of psychology are Comparative, Developmental, Social, Individual differences, Clinical, Educational, Occupational and Counselling.

Psychology #3

The behaviourist approach

1. Environment and its constant interactions determine one’s behaviour.
2. Known as Stimulus response psychology (SR).

2 processes of conditioning
1. Classical conditioning: reflex response becomes associated with stimulus that does not usually activate that behaviour (dog salivating to bell).
2. Operant conditioning: learning of voluntary behaviour by reward or punishment. (little Albert and the fluffy toy).

Criticisms:
1. Mechanistic view of human beings, ignores biological factors
2. Passive beings at mercy of environment
3. Ignores free will, spontaneous and creative behaviour
4. Treats the symptoms of behavioural problems, not causes

The cognitive approach

1. Study mental processes and internal events that occur between stimulus and behaviour.
2. Mediators include perception, problem solving, memory, language and other thinking processes.
3. Believe human minds to be like a computer, absorbing information, then interpreting and retrieving it.

Criticisms:
1. Human as a computer analogy is offensive to many, humans forget, computers don’t, humans are emotional, computers are not etc.
2. Mostly lab studies that can’t be generalized to other settings.

Psychology #2

The physiological approach

1. Looks to biology as means of describing and explaining psychological function.
2. Assume what we think and feel is linked to our physiological make up.

Research: Selye’s General adaptation syndrome shows the physiology of a stress response in mammals. Genetic predisposition in schizophrenia. Neuro-syphilis leads to insanity.

Criticisms:
1. Psycho-physiological processes too complex to explain behaviour in any useful detail.
2. Over emphasis on physiology leads to reductionist explanations for psychology.

The psychoanalytic approach

1. Focuses on motivation and past experiences in the development of behaviour and personality.
2. The human personality is defined by the repressed contents of the unconscious mind.
3. We are born with instinctual biological drives that motivate and regulate behaviour; the most powerful is libido, the sexual drive.

Personality consists of 3 aspects.
1. Id - biologically determined and inherited instincts
2. Ego - works to satisfy the id’s needs but in a socially acceptable way
3. Superego – individual conscience and morality

Therapies:
1. Transference- patient’s feelings and thoughts are projected onto the therapist
2. Free association- patient says whatever comes into their mind and the therapist interprets it

Criticisms
1. Unscientific methods of study that can’t be proven or disproven.
2. Over emphasises the idea that motivation and behaviour is all driven by the need to satisfy biological drives.

Psychology #1

What is Psychology?

Psychology is defined as the science of behaviour and mental processes.

It looks at aspects of behaviour such as overt actions, social interactions, emotional reactions, perception, rationale and physiological reactions.

By studying these, psychologists can make inferences about mental processes.

The study of psychology allows us to correct and understand damaging behaviours, help people lead more fulfilling lives and solve other problems.

Gestalt psychology – argued that it is necessary to study the person’s total experience.

Scientific Thinking #5

Generalization:

- It is the logical process of transition from the particular to the universal, from the less to the more general knowledge.
- When we generalize we make inferences that bridge the logical gap between what we know directly from inward and outward observation and what we know indirectly.
- By using inductive reasoning and taking evidence from the particular to make inferences about the general, we can only have a good reason to believe the conclusion. It may still be false, even if the premises are true.
- Therefore, it is best to use deductive reasoning, which will guarantee a correct conclusion.
- However, it is more practical and logical to use inductive reasoning and the possibility of error is simply part of the imperfection of science.