Behavioral Neuroscience Test 2 Study Guide

Flashcards covering key concepts in genetics, evolution, and sensory processing as outlined in the Behavioral Neuroscience study guide.

Natural selection

The process whereby organisms better adapted to their environment tend to survive and produce more offspring.

Sexual selection

A mode of natural selection where typically members of one gender choose mates of the other gender to mate with.

Artificial selection

The intentional breeding of organisms to produce offspring with desired traits.

Fragile X Syndrome

A genetic condition that causes a range of developmental problems including learning disabilities and cognitive impairment.

Down Syndrome

A genetic disorder caused by having an extra chromosome 21, leading to physical growth delays and intellectual disabilities.

Fetal Alcohol Syndrome

A condition resulting from alcohol exposure during pregnancy, leading to physical and cognitive abnormalities.

Huntington's Disease

A hereditary disease causing the progressive degeneration of nerve cells in the brain. HHT Gene

Teratogen

An agent or factor that causes malformation of an embryo.

Autosomes

Chromosomes that are not sex chromosomes; humans have 22 pairs of autosomes.

SRY gene

The sex-determining region Y gene; plays a critical role in male sex determination.

Myelination

The process of forming a myelin sheath around a nerve to allow faster propagation of electrical impulses.

Apoptosis

The process of programmed cell death that is a normal part of growth and development.

Cranial Nerves

Twelve pairs of nerves that emerge directly from the brain and brainstem, controlling various functions.

Prosopagnosia

A cognitive disorder characterized by an inability to recognize faces.

Trichromatic theory

The theory of color vision that proposes three types of cones in the retina, each sensitive to different wavelengths of light.

Cell migration

Directed movements of cells from location to another which is vital for feel development

Call Differentation

Unspecialized cells transforms into specialized cells

Mylination

Process of meylination wraps around axons and neurons increasing speed of action potential

Apoptosis

Is a natural process where cells in the body stop working and die

Synaptogenesis

New synapses and connections between neurons formed in the brain

Depletion

the genetic removal of a specific gene to study its effect on an organism's brain and behavior

Duplication

It is where a gene of DNA is copied, which can lead to the formation of new genes 

Translocation 

Translocation
is when a piece of one chromosome breaks off and attaches to another chromosome.

what is chromosal Inversion

A chromosomal inversion occurs when a segment of a chromosome breaks off, flips around, and reattaches in the reverse direction.

What are the 12 cranial nerves (in order)

The 12 cranial nerves are: Olfactory, Optic, Oculomotor, Trochlear, Trigeminal, Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Accessory, and Hypoglossal.

what do they control

• Olfactory (I) – Smell

• Optic (II) – Vision

• Oculomotor (III) – Eye movement, pupil constriction

• Trochlear (IV) – Eye movement (superior oblique muscle)

• Trigeminal (V) – Facial sensation, chewing

• Abducens (VI) – Eye movement (lateral rectus muscle)

• Facial (VII) – Facial expression, taste (front 2/3 tongue)

• Vestibulocochlear (VIII) – Hearing & balance

• Glossopharyngeal (IX) – Taste (back 1/3 tongue), swallowing

• Vagus (X) – Autonomic control of heart, lungs, digestion; speech

• Accessory (XI) – Neck and shoulder movement

• Hypoglossal (XII) – Tongue movement

Which are responsible for the eyes?

• Optic (II): Vision

• Oculomotor (III): Moves most eye muscles, constricts pupil

• Trochlear (IV): Moves eye downward/inward (superior oblique)

• Abducens (VI): Moves eye laterally (lateral rectus)

Cranial Nerves for Tongue and Throat Movement

• Glossopharyngeal (IX): Controls swallowing, gag reflex, and taste on the posterior tongue.

• Vagus (X): Controls speech and swallowing muscles, and carries sensory info from the throat and internal organs.

• Hypoglossal (XII): Controls tongue movement essential for speech and eating.
  

Cranial Nerve Associated with Migraines

• Trigeminal nerve (V) is closely associated with migraines. It transmits pain signals from the face and head and releases neuropeptides (like CGRP) that dilate blood vessels during a migraine.

Transduction

the conversion of physical energy (light waves) into neural signals. In the eye, photoreceptors (rods and cones) in the retina perform this function.

Prosopagnosia

A disorder causing inability to recognize faces, even familiar ones.

Caused by damage to the fusiform face area (FFA) in the temporal lobe, part of the ventral “what” visual stream.

Constancy (Color, Shape, Size)

• Constancy depends on contextual processing in the visual cortex and top-down cognition

Perceptual constancy is the brain’s ability to perceive an object as stable despite changes in sensory input.

• Color constancy: Perceiving colors as the same under different lighting.

• Shape constancy: Recognizing an object’s shape even when its orientation changes.

• Size constancy: Knowing that an object’s size remains the same even as distance changes.

1. Cornea

.

1. The clear outer layer that bends (refracts) light entering the eye.

2. Lens

2. Further focuses light onto the retina; changes shape for near/far focus (accommodation)

3. Iris

3. Colored part; controls pupil size to regulate light entry

Pupil:

4. The opening that allows light into the eye.

5. Retina

5. Light-sensitive layer containing rods and cones.

6. Fovea

6. Central area of the retina with dense cones, responsible for sharp vision

Optic Nerve:

Carries visual signals to the brain.

• Rods

• Specialized for low light (scotopic) vision, located in peripheral retina, highly sensitive but not color-specific.

• Cones

• Specialized for color vision, concentrated in the fovea;

Color Blindness

deficiency or absence of cone types (red, green, blue).

Trichromatic Theory

color vision is based on three types of cones, each sensitive to red, green, or blue light. The brain interprets color by comparing the activity of these three receptor types.

Opponent Process Theory

• color perception is controlled by opposing pairs: red–green, blue–yellow, and black–white. When one member of the pair is stimulated, the other is inhibited.

• Opposing pairs (R–G, B–Y, B–W

Thalamus & Occipital Lobe

Damage to the occipital lobe leads to cortical blindness—where eyes function, but perception fails. lateral geniculate nucleus (LGN) of the thalamus receives input from the optic nerve and routes it to the primary visual cortex (V1) in the occipital lobe.

Ventral Stream

Ventral Stream (“What” Pathway): Extends from the occipital to temporal lobe; identifies objects and faces

Dorsal Stream

• Dorsal Stream (“Where/How” Pathway): Extends to the parietal lobe; processes spatial location and movement.

Optic Chiasm

is the point where optic nerves from each eye cross so that visual information from the right visual field is processed by the left hemisphere, and vice versa

Myopia: Nearsightedness

image focuses before the retina due to a long eyeball

Hyperopia: Farsightedness

image focuses behind the retina due to a short eyeball

Saccades

rapid, jerky eye movements that shift the focus of gaze between points.

Vertigo

• The vestibular system works with the visual and proprioceptive systems to maintain balance. When signals conflict (e.g., motion sickness), vertigo occurs—demonstrating multisensory integration.

Pinna

• The visible part of the ear that collects and funnels sound waves into the ear canal.

Auditory Canal:

• Directs sound to the tympanic membrane (eardrum).

• Tympanic Membrane

• (Eardrum): Vibrates in response to sound waves.

Ossicles: Three tiny bones

• malleus (hammer), incus (anvil), and stapes (stirrup) — that transmit and amplify vibrations from the eardrum to the inner ear.

Cochlea

• A spiral-shaped, fluid-filled structure containing the organ of Corti, which holds hair cells (the sensory receptors for hearing).

Hair Cells:

• Convert (transduce) mechanical vibration into electrical impulses by bending, opening ion channels, and triggering neurotransmitter release to the auditory nerve.

Auditory Nerve (Cranial Nerve VIII):

• Carries neural impulses to the auditory cortex in the temporal lobe.

Primary Auditory Cortex (A1):

• Processes basic sound features (pitch, loudness).

This is where sound perception becomes meaningful—a convergence of sensory data and memory. The auditory cortex connects to the Wernicke’s area (language comprehension), illustrating how hearing enables linguistic communication.

Taste (Gustation)

Taste detects chemical molecules dissolved in saliva through specialized receptor cells in taste buds.

Taste Buds

Humans have approximately 5,000–10,000 taste buds, each containing 50–100 taste receptor cells.

Primary taste sensations in cranial nerves involved

• Primary Taste Sensations: Sweet, salty, sour, bitter, umami (savory).

• Cranial Nerves Involved:

  • Facial (VII) – anterior tongue

  • Glossopharyngeal (IX) – posterior tongue

  • Vagus (X) – throat and epiglottis