bio & behavioural sciences

Neuropsychology

The relationship between the brain and behaviour - specific mental functions and behaviour are linked to certain parts of the brain

Phrenology

The idea that you can learn about people's abilities/ personalities by examining the shape of the skull (proven wrong, but introduced the idea that different parts of the brain have different functions)

Lesion studies

Damaging or removing different parts of the brain and observing the effects on behaviour/ personality

Paul Broca

Examined the brain of a patient who could understand language but couldn't speak and found damaged regions later named after him and inferred to be linked to language production

Functionalism

Focuses on the purpose and function of the mind and mental processes.

Synapse

Point of communication between neurons or between a neuron and a different cell, which informs and shapes the brain and body's response to stimuli.

Nerve cells

Also known as neurons, they allow information to move throughout the nervous system via electrical and chemical signals.

Sensory neurons

Also known as afferent neurons, they transmit sensory information from receptors to the spinal cord and the brain. They handle the movement of signals to the central nervous system.

Motor Neurons

Also known as efferent neurons, they transmit information from the brain and spinal cord to the muscles and glands. They move information away from the CNS.

Interneurons

Most common type of neuron, found between other neurons and throughout the brain and spinal cord They connect neurons to each other and process information.

Central NS

Made up of the brain and the spinal cord, this is the part of the NS where the body's information is processed.

Peripheral NS

This is the network of nerves and ganglia outside the brain and spinal cord that connect the CNS to the rest of the body. It is made up of the somatic and autonomic nervous systems.

Somatic NS

Carries sensory information from the body to the brain and sends motor commands from the brain to the muscles. It is involved in both conscious and involuntary movement.

Autonomic NS

Regulates unconscious but necessary processes like breathing, blood flow, heart rate, etc. Made up of the sympathetic and parasympathetic NS.

Brain

Organ that allows us to perceive, interpret, and interact with the world.

Spinal cord

Communication pathway between the body and the brain that is involved in reflexes.

Sympathetic NS

Controls fight or flight response and preps the body to face a challenge or threat by increasing available energy and via processes like increasing heart rate, increasing delivery of oxygen to the tissues, & temporarily reducing the rate of non-essential functions.

Parasympathetic NS

Rest & digest. COnserves energy and carries out everyday functions like pupil constriction, slowing of heartrate, constriction of airways to normal diameter, stimulation of digestive activity, etc.

Dura mater

outer layer of the meninges, just beneath the skull

Arachnoid mater

Thin, weblike, fibrous layer between the dura and pia maters that is filled with cerebral spinal fluid which surrounds the brain and cushions it from injury, transports nutrients, removes waste, and maintains a stable environment for neurons.

Pia mater

Innermost layer of the meninges that is thin and delicate. It's directly connected to the brain as it lies on it, and it provides a pathway for blood vessels to help nourish the brain.

Forebrain

Also known as the prosencephalon, it splits into the telencephalon and the diencephalon. It contains structures like the cerebral cortex, the basal ganglia, the limbic system, the thalamus, and the hypothalamus. It is the larges portion of the brain by weight and volume.

Thalamus

Part of the forebrain through which most sensory info passes (except for smell). It helps organise and prioritise sensory input and is also involved in attention and awareness as it helps regulate how sensitive the brain is to sensory signals.

Hypothalamus

Part of the forebrain that helps maintain homeostasis by sensing when the body's conditions are no longer stable and enacting a response to re-establish stability. It also serves as a link between the NS and the endocrine system as it communicates with the anterior pituitary gland via the hypophyseal portal system. It is split into 3 parts: anterior (sexual behaviour), ventromedial (satiety centre), and lateral (hunger centre)

Posterior pituitary

Stores and releases hormones made by neurons in the hypothalamus, including examples like ADH (antidiuretic hormone) and oxytocin

ADH

Antidiuretic hormone. A hormone that helps the body conserve water by promoting the reabsorption of water when the body loses too much of it to the point that the blood becomes concentrated.

Oxytocin

Hormone released by the posterior pituitary at the direction of neurons in the brain. It stimulates uterine contractions during childbirth and promotes milk ejection during breastfeeding. It is also incolved in bonding and attachment.

Pineal gland

A structure in the diencephalon (a part of the forebreain/ prosencephalon). It releases melatonin, a hormone that helps regulate circadian rhythms. It also receives direct signals from the retina for coordination with sunlight.

Basal ganglia

A group of structures located in the forebrain that coordinate muscle movement by receiving information from the cortex and relaying it to the brain and spinal cord. Damage to these structures can cause Parkinson's disease, an illness characterised by tremors, muscle rigidity, etc.

Parkinson's disease

A chronic illness associated with destruction of portions of the basal ganglia. The neurons that produce dopamine decline, affacts movement and causing symptoms like tremors, muscle rigidity, poor posture maintenance, etc.

Limbic system

Network of interconnected structures in the forebrain (under the cerebral cortex) that regulates memory, emotion, and survival behaviours. It consists of structures like the septal nuclei, amygdala, hippocampus, and anterior cingulate cortex

Septal nuclei

Contains one of the primary pleasure centres in the brain and is involved in reward and reinforcement.

Amygdala

Responsible for determining if experiences are emotionally significant and plays a role in defensive and aggressive behaviours, including fear and rage.

Hippocampus

Involved with learning and memory processes. It helps cosolidate info to form long-term memories and can redistribute remote memories to the cerebral cortex. Damage can cause anterograde amnesia. It also contributes to spatial memories and memories of locations.

Anterograde amnesia

Inability to form new long-term memories.

Anterior Cingulate Cortex

Part of the limbic system that functions in higher order cognitive processes, including decision-making (it balances emotions and actions)

Cerebral Cortex

Part of the forebrain. It makes up the outer surface of the brain and is divided into 4 lobes.

Frontal Lobe

The part of the cerebral cortex located at the front of the brain, involved in executive functions, impulse control, and motor activity. Contains structures like the prefrontal cortex, the primary motor cortex, and Broca’s area.

Prefrontal Cortex

Part of the frontal lobe that guides complex behaviour and judgement and is involved in self-regulation.

Primary motor cortex

Part of the frontal lobe that initiates voluntary movement

Parietal Lobe

Part of the cerebral cortex that processes touch, pain, temperature, and pressure. It supports spatial awareness and orientation, and damage to it can lead to spatial neglect (one side of the world gets ignored). It also contains the somatosensory cortex

Somatosensory cortex

Part of the parietal lobe that receives sensory input from the body.

Occipital Lobe

Part of the cerebral cortex that processes visual information and interprets signals from the eyes.

Temporal Lobe

Part of the cerebral cortex that processes sound, memory, and language comprehension. It contains the auditory cortex (processes hearing), Wernicke’s area (language comprehension), and the Hippocampus (supports memory)

Contralateral control

The phenomenon whereby each hemisphere of the brain controls the opposite side of the body

Bilateral control

This is when both hemispheres contribute to a certain function. For example, hearing is bilateral (both hemispheres receive auditory input).

Lateralisation

When one hemisphere of the brain plays a larger role in a certain function of the brain

Left Hemisphere of the Brain

This hemisphere’s primary focus is language production as it contains Broca’s area, including grammar, syntax, and sequential processing. In terms of processing style, it enables for the detail-oriented, analytical, and step-by-step processing of fine features. It controls the right side of the body.

Right Hemisphere of the brain

The primary focuses of this brain hemisphere are spatial reasoning, facial recognition, emotional prosody (tone), and context. Its processing style is holistic as it helps us see overall patterns, and it helps with simultaneous processing and big-picture understanding. It controls the left side of the body.

Franz Gall

Creator of phrenology, the belief that you can learn about personalities/ abilities by examining the shape of the skull. Although he was wrong, he introduced the idea that different parts of the brain held different functions (localisation of function).

Pierre Fluorens

He carried out lesion studies where he damaged or removed different parts of the brain and observed the effects. These were some of the first experiments in the field of neuropsych.

Hermann Helmholtz

He measured the speed of a nerve impulse. His work showed that nervous system activity could be investigated with precise measurements.

William James

He helped develop functionalism, the idea that mental processes help humans adapt to their environment

John Dewey

He was a prominent psychologist who championed the idea that learning is an active process that happens via engagement, participation, and asking questions.

Charles Sherrington

His work inferred the existence of synapses. He investigated how information travels from one part of the body to another (eg: how does information flow when you touch a hot stove?)

Midbrain

Also known as the mesencephalon, this part of the brain is involved in movement, sensory processing, and response to visual/ auditory stimuli. It contains the inferior and superior colliculi which coordinate sensorimotor reflexes (inferior = auditory stimuli response & superior = visual stimuli response).

Hindbrain

also known as the rhombencephalon. This part of the brain splits into the metencephalon and the myencephalon (contains the cerebellum, pons, and medulla).

Cerebellum

Part of the hindbrain involved with refined motor movements; it fine tunes movements selected by the basal ganglia and helps with the coordination of movement.

Medulla Oblongata

Part of the hindbrain that controls the heartrate and vital reflexes (like breathing and blood pressure).

Pons

Part of the hindbrain that controls breathing and that makes communication within the brain possible. It is a bridge that connects the upper and lower parts of the brain.

Reticular formation

It is a network of neurons in the hindbrain that is involved with arousal (consciousness), and alertness. Damage to this network can lead to a coma.

Electrical Stimulation

This is when a specific area of the brain is activated so that the resulting behaviour or sensation can be observed.

Electroencephalography (EEG)

This is a technique that measures the electrical activity of the brain by recording signals from the scalp. Neurons communicate via electrical signals, so when a large number of them are active, it’s detectable through the scalp. It allows for tracking of brain activity in real time (high temporal resolution), but it’s limited as we can’t know where the activity is occurring in the brain (low spatial resolution).

Blood Flow Methods

These are methods used to image the brain that rely on the principle that more active regions of the brain receive more blood flow, so changes in blood flow indicated activity. As blood flow can be mapped with great precision, these methods can tell where exactly any observed activity is occurring in the brain. Some examples include rCBF and fMRI

Magnetic Resonance Imaging

A non-invasive, radiation free imaging technique that uses magnetic fields and radio waves to create clear images of different parts of the body, including the brain. It has high spatial resolution because the images it creates are quite clear and precise, but it has low temporal resolution of the brain because by the time the image is created, things might have changed, especially if one’s condition is fast-progressing.

Computed Tomography (CT)

This is a low-invasive, structural imaging technique that uses rotating x-rays and a computer to combine multiple “thin slice” images of the body into a good 3D image (more detailed than standard x-ray). This has less spatial resolution than MRI (less detailed images), but it is much faster and is thus used in emergency rooms.

Positron Emission Tomography (PET)

This is a function imaging technique whereby a small amount of radioactive tracer is put in the body. Since the most active parts of the brain have the highest metabolic activity, they will accumulate more of the tracer which is tracked to give us an image of which parts of the brain are in use during a task. This technique is moderately invasive and has low temporal resolution but moderate spatial resolution.

Magneto-encephalography (MEG)

This is a non-invasive, functional imaging technique that measures the magnetic fields produced by electrical signals from neurons. Because magnetic fields are less distorted as they pass through the brain and the skull, this technique provides a higher spatial resolution than EEG.

Neurotransmitter

A chemical used by neurons to send signals to other neurons, or to muscles, glands, and cells.

Agonist

Chemical that increases signaling along a pathway by activating a receptor or simulating/ mimicking the effects of the neurotransmitter that normally binds the receptor.

Antagonist

A chemical that decreases or prevents signaling along a pathway by blocking the receptors to which the neutransmitter would normally bind.

Adrenaline (aka Epinephrine)

A neurotransmitter that controls our fight or flight response. It is produced in stressful situations and takes actions like increasing heartrate & blood flow, leading to a physical boost and heightened awareness. It is a catecholamine (made from tyrosine). It is a neurotransmitter in the NS and a hormone in the bloodstream.

Noradrenaline (aka Norepinephrine)

Neurotransmitter involved with alertness, attention, and arousal. It also aids in constricting blood vessels to increase blood flow and assists the body in reacting to stress. It is a catecholamine (made from tyrosine). It is a neurotransmitter in the NS and a hormone in the bloodstream.

Dopamine

A neurotransmitter associated with feelings of pleasure, addiction, and with movement and motivation as well. People repeat actions and behaviours that lead to dopamine release. It is also a catecholamine (made from tyrosine) and is both a neurotransmitter and a neurohormone. Low levels are associated with diseases like parkinson’s, so medications to treat the disease increase dopamine levels and signaling.

Serotonin

Neurotransmitter that influences mood. It contributes to well-being and happiness and helps sleep and digestion. Its levels are affected by exercise. Medications used to treat anxiety and depression increase its signaling.

GABA (Gamma-aminobutyric acid)

This is an inhibitory neurotransmitter. It calms nerves that are firing in the CNS, and high levels of it improve focus while low levels cause anxiety. It also contributes to motor control and vision.

Glutamate

This is the most common neurotransmitter in the body. It is an excitatory neurotransmitter (it stimulates the firing of nerve cells) and is involved in learning, memory, and the creation of nerve contacts (synaptic plasticity). It also regulates development.

Acetylcholine

Neurotransmitter that activates muscle action in the body. It is also associated with learning, memory, attention, and arousal.En

Endorphins

Neurotransmitters released during exercise, excitement, and sex. They are associated with the feeling of euphoria and produce a sense of well-being and pain reduction.

The Endocrine System

Consists of organs (glands) that secrete hormones. This is a slower form of signaling than with neurotransmitters but it is more long-lasting and widespread.

Hormone

A signaling molecule in the body that is secreted directly into the bloodstream to distant target tissues.

Pituitary gland

Tiny organ at the base of the brain that acts as the master of the endocrine system and controls growth, metabolism, and other hormone'-producing glands. It consists of the anterior pituitary and the posterior pituitary.An

Adrenal glands

Two organs that sit atop the kidneys and help the body respond to stress via the adrenal medulla (which produces epinephrine and norepinephrine) and the adrenal cortex (which produces cortisol and aldosterone (BP & fluid)).

Thyroid gland

Organ that regulates metabolism by releasing hormones that control how the body uses energy

Parathyroid gland

Organs in the neck that regulate calcium, phosphorus, and magnesium levels in the body.

Pancreas

Gland in the abdomen that produces insulin (hormone that signals for the uptake of glucose into the cells when levels are too high) and glucagon (hormone that signals for the release of glucose from the cells when levels are too low)

Gonads

Primary reproductive organs (ovaries in women and testes in men) that secrete sex hormones

Family Studies

These types of studies compare related individuals to each other to look for genetic influence. The limitation is that they can’t separate genetic effects from shared environment (they can’t tell how much of a behaviour comes from genetics if these individuals also shared an environment).

Twin Studies

These types of studies compare identical (monozygotic single egg that splits) and fraternal (develop from two separate eggs) twins to assess genetic influence and concordance rates (the probability that both twins show the same trait or disorder). Greater similarity in identical twins compared to fraternal twins suggest a genetic contribution, especially when the twins are raised apart.

Adoption Studies

These types of studies compare similarities between biological and adoptive relatives. Resemblance to biological parents suggests genetics while resemblance to adoptive parents suggests environment.

Gastrulation

When an embryo organises itself into three primary germ layers (the ectoderm, mesoderm, and endoderm).

Neurulation

A process where the notochord stimulates the ectoderm, which lies above it, to fold over, creating a neural tube topped with neural crest cells.

Notochord

A structure that provides skeletal support and releases molecular cues that tell surrounding tissues how to develop. It forms from the mesoderm cells soon after gastrulation is complete.

Nervous System Development

Signals from the notochord in the mesoderm influence early NS development. After the notochord signals the ectoderm to fold over and make a neural tube, the neural tube then becomes the Central Nervous System (the brain and spinal cord). The neural crest cells then spread out throughout the body, differentiating into many different tissues.

Neural crest cells

Temporary, versatile stem cells in vertebrates that migrate throughout the body to form bones, nerves, and pigment cells.M

Multipotent cells

Cells that can develop into many different cell types depending on the signal they receive.

Teratogens

Any substance or exposure that interferes with fetal development. Examples of these include viruses & bacteria, pharmaceuticals, antiepileptic medications (spina bifida is a condition caused by antiepileptic meds where the neural tube doesn’t close properly), environmental factors, alcohol consumption, etc. Timing matters because the same exposure can have different effects depending on the stage of development at which it occurs.

Primitive Reflexes

Automatic, involuntary responses that appear early in life. Examples include Babinski, Moro, rooting, grasp, tonic neck, and stepping

Babinski

Stroking the sole of the infant’s foot causes the toes to splay outMo

Moro

An infant’s arms extend out and come back in when the infant feels unsupported or startled by a loud noise