Neuroscience, Sensation, Perception, and Genetics Lecture Notes

Vocabulary flashcards covering neuroscience, action potentials, nervous system organization, brain anatomy, sensation, perception, audition, vision, and behavioral genetics.

Dendrites

The parts of a neuron that receive neurotransmitters (NT).

Axon

The part of the neuron that sends the electrical impulse down the neuron.

Myelin Sheath

A structure that insulates the axon.

Terminal Buttons

The end of the axon that releases neurotransmitters.

Resting Potential

The polarized state of a neuron at rest, where the inside of the cell is $-70\,\text{millivolts}$ ($70\,\text{millivolts}$ more negative than the outside).

Threshold of an Action Potential

The point reached when a neuron's charge reaches $-55\,\text{millivolts}$, triggering an all-or-nothing action potential of $+35\,\text{millivolts}$.

Absolute Refractory Period

The phase during which potassium continues to flow out of the neuron, causing hyperpolarization where the electrical charge drops below $-70\,\text{millivolts}$.

Autonomic Nervous System (ANS)

A division of the peripheral nervous system (PNS) that controls internal, involuntary processes; subdivided into the sympathetic (fight-or-flight) and parasympathetic (slow it down) systems.

Somatic Nervous System (SNS)

A division of the peripheral nervous system responsible for voluntary movement.

Afferent Nerves

Nerves that bring information from the body to the spinal cord.

Efferent Nerves

Nerves that bring information from the spinal cord to the body.

Medulla

A hindbrain structure that controls vital functions such as heart rate, temperature regulation, and swallowing.

Pons

A hindbrain structure involved in arousal and sleep.

Cerebellum

A hindbrain structure responsible for balance and coordination.

Reticular Formation

A structure involved in arousal and sleep.

Tectum

A midbrain structure involved in visual and auditory reflexes.

Tegmentum

A midbrain structure involved in motor control and sensory relay that also produces dopamine.

Thalamus

A subcortical forebrain structure acting as a 'grand central station' where all incoming sensory information (except smell) stops before being directed to the appropriate area.

Hypothalamus

A subcortical structure responsible for regulating biological drives, such as hunger, thirst, and sex.

Pituitary Gland

The master gland of the endocrine system.

Basal Ganglia

Grey matter composed of soma cell bodies that is crucial for planning and voluntary movement.

Limbic System

A group of forebrain structures involved in motivation, emotion, learning, and memory.

Sulcus

A groove located between gyri on the cerebral cortex, with deep ones known as fissures.

Gyri

The ridges located on the cerebral cortex.

Frontal Lobe

A lobe of the brain containing the primary motor cortex and mirror neurons.

Parietal Lobe

A lobe of the brain housing the somatosensory cortex and mirror neurons.

Occipital Lobe

A lobe of the brain that houses the primary visual cortex.

Temporal Lobe

A lobe of the brain containing the primary auditory cortex (A1), the hippocampus, and the amygdala.

Corpus Callosum

The structure that connects the left and right hemispheres of the brain.

Brain Plasticity

The brain's ability to change and reorganize itself by creating new connections, forming new pathways, and adapting after learning or injury.

Homunculus

A visual representation of the body based on the amount of cortical space dedicated to each part, where sensitive body parts like hands, lips, and tongue appear larger.

Mirror Neurons

Neurons located in the frontal and parietal lobes that activate both when performing an action and when observing someone else perform it.

Long-Term Potentiation (LTP)

A process where repeated activity strengthens the connections between neurons.

Transduction

The process of converting physical signals from the environment into neural signals sent to the central nervous system.

Sensory Adaptation

A decrease in sensitivity to prolonged stimulation over time.

Absolute Threshold

The minimum amount of physical stimulation needed to detect a stimulus, measured at $50\%$ detection.

Just Noticeable Difference (JND)

The smallest change in a stimulus that can just barely be detected.

Trichromatic Theory

The theory that colour vision is based on three types of cones: S cones ($400\,\text{nm}$, violet/blue), M cones ($550\,\text{nm}$, greens), and L cones ($700\,\text{nm}$, red).

Additive Colour Mixing

The creation of colour by adding wavelengths of light.

Subtractive Colour Mixing

The creation of colour by removing wavelengths, such as when mixing paint.

Dorsal Stream

A visual pathway projecting to the parietal lobe that identifies where an object is located.

Ventral Stream

A visual pathway that identifies what an object is.

Change Blindness

The failure to see a change in your environment because you are focused on something else.

Inattentional Blindness

The failure to see something because you do not attend to it.

Ossicles

Three tiny bones in the middle ear (hammer, anvil, and stirrup) that vibrate in order and amplify pressure by $1000\times$.

Place Code Theory

An audition theory stating that different locations on the basilar membrane respond to different sounds, with low sounds registering at the tip and high sounds at the base.

Conductive Hearing Loss

Hearing impairment caused by damage to the eardrum or the ossicles.

A-Delta Fibers

Sensory nerve fibers responsible for transmitting fast, quick pain.

C Fibers

Sensory nerve fibers responsible for transmitting long, aching pain.

Gate Control Theory

The theory stating that when a pain signal arrives, interneurons in the spinal cord can distract from it and decrease pain perception by stimulating other haptic receptors.

Vestibular Sense

The sensory system dependent on fluid-filled semicircular canals that indicates body position in space.

Heritability

A statistic that measures how much the differences in a characteristic within a group are related to genetic differences versus environmental influences.

Epigenetics

The study of how environmental factors influence whether genes are expressed.

Monozygotic Twins

Identical twins who develop from one fertilized egg (zygote) that splits, sharing $100\%$ of their DNA.

Dizygotic Twins

Fraternal twins who develop from two separate fertilized eggs, sharing approximately $50\%$ of their DNA.