IB Psychology: Biological Core (2025)

• The text is a psychology workbook focusing on the biological core concepts for the year 2025.

Introduction

• The IB Psychology course aims to understand behavior by answering the question, "Why did someone act in a particular way?".
• Achieving a complete understanding is impossible.
• Uncertainty is part of psychological study, requiring acceptance of the limits of current knowledge.
• Students are expected to do work on Canvas each week, to prepare for lessons and complete follow-up activities; additional work is required to support classwork.
• A new workbook is to be updated weekly alongside resources and the Oxford IB textbook, and the INTHINKING website.
• The class environment is intended to be safe and academically focused, encouraging discussion of controversial topics. The class will also have practical work, experiments, video viewings and films.

Biological Core

• One of the course's three core areas focuses on biological reasons for behavior like brain structure, neurotransmitters, hormones, and genes.
• Complex behaviors like love, hate, friendship, and prejudice result from multiple factors, requiring a holistic approach.

Biopsychosocial Model

• George Engel introduced a new medical model in 1977 that looked at medicine in a new way.
• A holistic approach is more likely to succeed.
• The biopsychsocial model is made up of three parts:
  • bio = biological factors
  • psycho = cognitive factors
  • socio = factors of upbringing, environment, and education

Structure of the Brain

• The brain is soft, having the consistency of jelly, and can easily be misshapen if left unsupported during autopsy.
• The difference between a healthy brain and one affected by Alzheimer's is that those affected are firmer, less supple, and have pockets of air.
• Localization of function that parts of the brain have are responsible for is partially correct.
• The nervous system facilitates communication using neurons; It consists of the spinal cord and brain.
• The cortex, a folded layer of neurons covering the brain, associates with functions and has developed through evolution. The cortex is associated with higher order functions including abstract thought and voluntary action.
• The cortex is divided into four sections called lobes.
  • The frontal lobes are associated with reasoning, planning, thinking and decision-making, voluntary action, complex emotions.
  • The parietal lobe is associated with movement, orientation, perception and recognition.
  • The occipital lobe is associated with visual processing.
  • The temporal lobes are associated with processing auditory information, memory and speech.
• It is mild localization when talking about elements being associated with a particular feature.
• For example, a lobe impacts functions, but it isn't alone; all brain structures do.
• Temporal lobes are involved in memory, but other brain regions also play a role.
• The cerebellum is associated with coordination of movement and balance.
• The limbic system is the evolutionary older subcortical structure, and sometimes called the 'emotional brain'; it includes multiple structures.
• The thalamus has sensory functions with nerves reaching it from all sensory organs before connecting to the cortex.
• The hypothalamus is 'below' the thalamus and involved in emotion, thirst, and hunger.
• The amygdala is involved in memory, emotion, and fear.
• The hippocampus is important for learning, memory and transferring short-term memory to a more permanent store, spatial orientation.
• The brain stem is below the limbic system regulating basic vital processes, connects to the brain via the spinal cord, and is similar to the entire brain in reptiles.
• The cortex is split into hemispheres by a deep furrow; the corpus collosum connects these. During extreme epilepsy this is split.

Brain Damage and Dementia

• Sports with blows to the head, like boxing, can cause brain damage.
• Football also causes brain damage and/or dementia.

Localization Research

• Earlier research showed that function had a strict localisation, this has since been revised.
• The Broca (1861) study by scientist is a case study known as Louis Leborgne, or “Tan."
• This study found he lost the ability to speak from age 30 onward.
• The ability to speak or write (language) was Leborgne's only disability.
• Broca's aphasia the loss of speech.
• Following Tan's death at 51, autopsy showed a lesion in the left hemisphere of the frontal lobe, known as Broca's area.
• Carl Wernicke discovered Wernicke's area in 1874; this area is responsible for written and spoken language comprehension and is in most people in the left temporal lobe.
• Wernicke's aphasia is general impairment of language.
• Individuals can speak fluently, but the result is without meaning.
• Loss of memory can be caused by illness or injury.

Brain Work

• Take the opportunity to look at the brain taken at four different elevations, and label all that you can on this age.

Personal Connection

• In order to find the effects personal connection has on patients, look at the alzeimer society's website.
• Dementia can affect memory.
• It can be hard for patients to put sentences together, and their vocabulary may be diminishing.
• Patients concept of time can lessen getting the time wrong.

Brain Mapping

• Wilder Penfield mapped areas of the brain using neural stimulation.
• By destroying epileptic seizure nerve cells, Penfield stimulated parts of the brain on conscious patients in order to discover the effect.
• Then, Penfield created a map of the sensory and motor cortex called the cortical homunculus.
• Functions aren't strictly localized

Induced Brain Damage

• Karl Lashley did an experiment on rats involving destruction of brain parts in order to test for behavior change.
• After teaching rats to run a maze without error, portions of their cortices were removed, and they were returned to the maze.
• They did not prove localisation and concluded that memory was distributed not localised.
• Principle of mass action: percentage of cortex destruction reduces performance not based on location.
• Equipotentiality: One part of the the cortex is able to take over part another parts section.
• Current neuroscience supports relative localisation and conditional localisation for some functions.
• The human brain has two parts joioned by the corpus collosum used to direct elctrical impusles. This is called lateralisation.
• Severing the connections at the corpus collosum creates separate brains.

Split Brain Research

• Roger Sperry and Michael Gazzaniga have been responsible for much of the key research in this area.

Conclusions

• Brain hemispheres operate independently.
• Where left eye (right hemisphere) observe and object; the left hand picked it up from behind. However, the centre of speech is in the left hemisphere, and subjects cannot describe what they saw and did.
• The right hemisphere can perform better on visual construction, visual tasks and emotions.
• Localisation can be weak or have different parts that make up a function. Localisations aren't static.

Neuroplasticity

• Remapping and redesignation can be the result of neuroplasticity.

What is Neuroplasticity

• The brain continues to grow throughout one's life.
• Changes can take place when synaptic connections are created and broken in between neurons , which results in the neural networks changing shape.
• Changes can be from genetic processes, injury, damage, or the process of learning.
• Neuroplasticity has different levels, from a single neuron (synaptic plasicity) to cortical remapping.
• "Neurons that fire together, wire together”
• "Neurons that fire out of sync, fail to link”
• There are three key studies that need to be considered.

Remapping of the Sensory Cortex

• Merzenich et al (1984) is where researchers studied the cortical representation of a monkey's hand using eight owl monkeys.
• Originally sensory inputs were mapped onto the cortex.
• Electrodes were placed in the cortext in order to repsond to stimulation. Each finger had responsible zones.
• Once the third finger was amputated the mapping process began after sixty-twa days.
• There were five areas responsible for the five fingers, with fingers next to each other from areas of the cortext next to each other. After the second mapping compensation occurred.
• With fingers one and five untouched, fingers two and four expanded and grew into the now removed area (threes). The take away is that it was concluded that cortical remapping took 62 days or less.

A Mechanism for Learning

• Draganski et al (2004) and Draganski et al (2006) looked to answer the question of whether the brain can really change its structure due to learning.
• Twenty-one subjects were divided into groups: a juggling group and a non-juggling group.
• The results are intriguing.
• Brain scans were taken before, mid and after completion of the experiment.
• It was to be expected that the scans from the two groups before the experiment were extremely similar due to the experiment co-hort not having juggled before.
• The juggling groups developed more grey matter specifically temporal areas connected to coordination and movement.
• Differences between groups were more pronounced in better trainers due to consistency and effort.

Further Evidence

• Gray matter continued to grow for Draganski (2006) as gray matter significantly increased in the posterior and lateral parietal cortex bilaterally.
• Maguire (2000) was a study on London cabbies comparing black cab drivers and a control group.
• This found that the posterior hippocampi were signifcantly larger for taxi drivers.
• Volumes of hippocampal impacted time as taxi drivers.

Effects of Poverty

• Understanding neuroplasticity requires the minimun accses to Merzenich, Draganski, and Maguire(both studies).
• Two very interesting studies on adults learning late in life found that neuroplasticity can develop well into old age.
• Also, learning and taxing the brain can hold off dimentia.
• Playing musical instruments has benefit. This may be due to both natures and nurture or predispositions.
• Other really interesting studies are: the effects of poverty and upbringing on the brain, Restricted physical movement of the arm and loss of use, and playing Super Mario to develop spatial navigation and strategic planning.
• Seligman and Maier (1968), look at learned helplessness, and researchers look at how it can be reversed to impact human behavior in depressing and victimes of domestic violence.
• There is inspirational ability between the passively and actively with people doing echo location from visual impairment.

Hormones and Behaviour

• Hormones are chemical messengers released by endocrine glands, traveling via blood vessels to target cells. They can reach places inaccessible to the nervous system's neurotransmitters.
• Hormones regulate long-term processes, metabolism, digestion, reproduction.
• Hormones may affect human behaviour. Although degree of control over functions like growth is negligible.
• The nervous system and endocrine system as systems are independent but interdependent, able to interact and influence each other.
• Adrenaline is both a hormone and a neurotransmitter. Hormones affect only the cells they were designed to.

Hormone Secretions

• Hormone location, secretion, and function:
  • Adrenal glands/Aldosterone = regulates salt, water balance, and blood pressure
  • Adrenal glands/Corticosteroid = controls key functions in the body
  • Pituitary gland/Luteinizing & follicle-stimulating = controls estrogen in women and testosterone in men
  • Pituitary gland/Oxytocin = stimulates contraction of uterus and milk ducts in the breast
  • Pituitary gland/Prolactin = initiates and maintains milk in breasts impacts sex hormone levels
  • Pituitary gland/Antidiuretic = affects water retention in kidneys- blood pressure
  • Pituitary gland/Thyroid-stimulating = stimulates the production and secretion of thyroid hormones
  • Pituitary glands/Adrenocorticotropic Controls production of sex hormones ACTH
  • Pituitary gland/Growth hormone GH = Affects growth and development
  • Kidneys/Renin and angiotensin = control blood pressure
  • Kidneys/Erythropoietin = affects red blood cells
  • Pancreas/Glucagon = raises blood sugar
  • Pancreas/Insulin = lowers blood sugar
  • Testes/Testosterone = develop and maintain male sexual characteristics and maturation
  • Pineal gland/Melatonin = releases melatonin during night hours
  • Hypothalamus/Growth hormone releasing hormone = regulates growth hormone release
  • Hypothalamus/Thyrotropin releasing hormone (TRH)= regulates thyroid stimulating hormone release
• Hypothalamus/Gonadotropin releasing hormone (GnRH) = Regulates LH/FSH production in the pituitary gland
• Hypothalamus/Corticotropin releasing hormone (CRH) = regulate adrenocorticotropin release in pituitary gland
• Adrenal glands/Epinephrine = ↑ heart rate, oxygen intake, and blood flow - Thymus/Humoral factors = helps develop the lymphoid system
• The hypothalamus is a bit like a command centre.
• The brain communicates with the body using the autonomic nervous system, which controls breathing, blood pressure, heartbeat, and the dilation or constriction of key blood.
• The autonomic nervous system has the sympathetic gas pedal systems that provide the body with a burst of energy, as well as the parasympathetic brakes from stress.

After Distess

• The amygdala sends a distress signal, then the hypothalamus activates the sympathetic nervous system by sending signals through the autonomic nerves to the adrenal glands.
• These glands respond by pumping epinephrine/adrenaline that then circulates and brings changes.

Oxytocin

• Essential, hormones do not influence behaviour directly, rather change the probability of a certain behaviour happening in response to environmental change.
• Oxytocin released establishes a stronger bond between mother and child, a released with every kiss or hug.
• Romero et al (2014): Human-animal experiment where humans and dogs tested the effect of oxytocin in a room. Interaction was evaluated.
• The experiment showed that oxytocin triggered more interaction in turn releasing more oxytocin, maintaining close social bonds in mammals.

Kosfeld et al (2005)

• Show that oxytocin increases trust in humans.
• One hundred twenty-eight males are involved in a economic with anonymity game assigned to either an oxytocin or placebo intranasal group.
• In the round the trustee makes decisions on how much to give based on an economics game. Whether one or both party's actually trust the other will result. This occurs once meaning a gamble for trust. The subject then can cash in after.
• Generally those with the oxytocin group were more trusting compared to control
• Kosfeld suggests possible alternation results and that it may or may not effect the increases of trusting other people.

Scheele et al (2012)

• The experiment's facet focused on whether to accept another broader definition regarding hormones.
• Study of eighty six hetero men broken single or in monogamous conditions. Subjects thyen had an attractive "experimented". Tested the distance.
• Result shows to where being oxytocin the men in relationship appeared to inhibit vs single. Those in relationship will have far more singles for the influence oxytocin.
• They say that if people made the subjects aware of their partner, where relevant will take over.
• If the results change its arguably very different.
• The inter group conflict could bring a pause where possiblility occurs regarding the pays a role to predict regarding disctrination and conflict.

The Prisoners' Dilemma

• This scenario tests how robberes will handle the bscene of an crime by seperating them into interogation and where depedeing an what happenes has effects of how they expect or could get worse by the police.
• Silent vs betrayal will be judged with numbers for years in prison
• It is shown both betray each other the result is a 2 year prison period. Betraying onw another is important and it's better
• If you want tp know aother exercise use descion analyis. or investigate the prizions demma on investopaida!

De Dreu et al (2012)

• De Dreu focused experiment had an another aspect: oxytocin had an underisable action to defence motivated, non coperation.
• A sample of one hundred and tweleve males had a double blind with subjects doing ad minister either the oxytocin or doing a plus through a sel spray.
• Individulas partnered with out team. the player was assigned into three person groups where they were competing against one team. they played a modified prisons demma.
• Fot is why the players have to to have a way to account when opposite were.
• It became known after the player the team's demonaion or the adaptable
• First the payer's if the had players for defence team it all come down from being in the condtion. The vulnerabilty was high however from the player.

De Dreu et al (2011)

• De Dreu 2002 says that confirmed he had previosuly made to seen. A years earilier he have seen also where an other ethinic that induced, which other grroup. If so this for example as the high groups will go to, is the not what. The study used to help elminiate and use some of the morail chocie such as for one trolly where and has people would decide. The suybvect was that the used the Duetck.