Infancy Test 2: Brain and Neural Development, Infancy test 2: Perceptual Development, Infancy test 2: Cognitive Development

What is heredity

The transmission of genetic information across generations, and how that genetic information translates to differences in physical characteristics and behaviour

What is DNA?

A long molecule called deoxyribonucleic acid found in the nucleus of cells.

What are chromosomes made of?

DNA and proteins coiled together

What is a gene?

A segment of DNA that has a specific location on a chromosome.

How many pairs of chromosomes do humans have?

23 pairs (46 total) sperm and egg cells each have 23

What are autosomes

22/23 pairs of chromosomes. and each pair has matching genes

What are the last pair of chromosomes

sex chromosomes. Female: XX and Male: XY

What is inheritance

how traits are passed from parents to their children through genes

What are alleles

different versions of the same gene. everyone has two for each gene, one from each parent

What does homozygous mean?

Both alleles are the same (e.g., both curly hair).

What does heterozygous mean?

The two alleles are different (e.g., one curly, one straight).

What is a dominant allele?

an allele that always shows up if present, even if there's only one

What is a recessive allele?

An allele that only shows up if the child gets two copies (one from each parent)

What is autosomal dominant inheritance?

A trait appears if just one dominant allele is inherited (e.g., freckles, dimples, Huntington's disease).

What is autosomal recessive inheritance?

A trait only appears if two recessive alleles are inherited, one from each parent (e.g., sickle-cell anemia, cystic fibrosis, attached earlobes).

What happens if a person has only one recessive allele

they are a carrier but don't show the trait

What is codominance?

Both alleles are dominant, so both traits appear together (e.g., blood type AB shows both A and B).

What is incomplete dominance?

The alleles blend, creating a mix of both traits (e.g., wavy hair is a mix of straight and curly).

What is passive gene-environment correlation?

Parents provide both genes and an environment that supports those genes (e.g., intelligent parents create a book-filled home).

What is evocative gene-environment correlation?

A child's traits influence how others respond to them (e.g., a friendly child gets more positive interactions).

What is active gene-environment correlation?

People seek environments that match their genetic traits (e.g., a musically gifted child takes music lessons).

What are gene-environment interactions (G×E)?

Genes make some people more sensitive to their environment.

Who are "Orchid Children"?

Children highly affected by their environment—thriving in good conditions but struggling in bad ones.

Who are "Dandelion Children"?

Children who can thrive in almost any environment, even under hardships.

What are the two types of cells in the nervous system

Neurons and Glia

What are neurons

allow information to pass around the brain

What are glia

support roles, making it possible for neurons to survive

What is a cell body

Contains the nucleus and keeps the neuron functioning.

What do dendrites do

Receive chemical signals from other neurons.

What does the axon do

Sends electrical signals from the cell body to the axon terminals. vary in length (from 1 mm to over 1 meter

What do axon terminals do

Convert electrical signals into chemical messages (neurotransmitters) to communicate with other neurons.

What is the myelin sheath

A fatty layer around the axon that speeds up electrical signal transmission.

What is the process of brain development?

1. Neurogenesis (cell proliferation)

2. Cell migration

3. Synaptogenesis (cell elaboration)

4. Myelination

5. Synaptic pruning (Culling)

What is Neurulation

process in early brain and spinal cord development where the neural tube forms.

This tube later becomes the brain and spinal cord. It happens in the first few weeks of pregnancy.

What is neurogenesis (cell proliferation)

Creation of new neurons from stem cells

When does neurogenesis occur

3rd-15th week of prenatal development, can also limitedly occur into adulthood

What is encephalization

brain growth outpaces body growth

how many neurons are their are in the adult cortex

14-16 billion

how many glial cells does the brain contain

61 billion

What are basket cells

brain cells that help control other brain cells. they wrap around them and help manage overall activity

What are chandelier cells

connect to the axon beginning of other neurons controlling their firing and regulating their activity

What are Martinotti cells

send signals to the branches (dendrites)

What is a genome

the entire set of DNA instructions found in a cell. Blueprint for the brain

What is cell migration

Neurons moving to their final locations

When does cell migration occur

4-6 weeks after conception

What is passive cell displacement

new cells are pushing old cells out (short distance)

What is active migration

cells activly move themselves to their final position (long distances

When is active migration done

during gestation at around 7 months in the tum

What happens during cell elaboration

neurons grow and connect and synaptogenesis and myelination occur.

What is the process of synaptogensis

synapses (connections between neurons) are produced due to the formation of axons and dendrites

When does synaptogenesis occur

20 weeks (4.5 months) after conception and continues into early adulthood. peak at 8 months in the womb

What is myelination

Neurons get covered with a fatty layer called myelin, which helps electrical signals travel faster and more efficiently.

when does myelination occur

5 months post-conception into adulthood

what is myelination crutial for

the development of observable behaviours

In what order do brain areas myelinate

Vision first, then language, then planning, decision-making, and self-control.

By what age is sensory and motor area myelination complete?

By age 4.

What is synaptic pruning (culling)

For efficient brain function, unused neurons die off and weak synapses are pruned

When does synaptic pruning occur

age 2- adolescence. strongest in adolescence

Two hemispheres of the brain: What does the left hemisphere represent

controls language, logic, and analytic thinking (eg speech and math)

Two hemispheres of the brain: What does the right hemisphere represent

Handles creativity, spatial ability, and recognizing emotions (eg music and faces)

What is the role of the brainstem

basic survival functions like breathing, heart rate, reflexes, and balance. pathway for information traveling between the brain and body

What is the role of the cerebellum

controls coordination, balance, voluntary movement, and muscle tone and may also play a role in memory.

What is the role of the occipital lobe

processing of visual information

What is the role of the temporal lobe

processing sounds, perception and recognition of objects, associated with memory and language (spoken and written

What are the two functional regions of the parietal lobe

First functional region and second functional region

What is the role of the first functional region in the parietal lobe

integrates sensory information like touch temperature and pain

What is the role of the second functional region of the parietal lobe

constructs a spatial awareness and navigation to represent the world around us

What is the role of the frontal lobe

higher-order thinking, including reasoning, planning, decision-making, and working memory. It helps with self-control and problem-solving.

What are the two processing streams of the brain

Dorsal stream and ventral stream

What is the dorsal stream

Processes "where and how" things are, including motion, object location, and guiding movements.

what is the ventral stream

processes "what" things are, including shape, color, object recognition, and long-term memory.

when are the modules for processing information like colour, orientation, depth, size functional by?

3 months after birth

When do saccades (rapid eye movement) activley appear

after 6 months

Mental rotation (the ability to mentally manipulate objects in space) activity reaches adult-like levels at

8-12 years

Pattern/object integration (integrate different parts of objects or pattern into a whole) develops fully at

12-14 years

See activity in the fusiform face area (FFA: temporal lobe region for facial recognition) at

2-3 months

Speech processing appears at

6 months

what develops slower the ventral or dorsal stream

the dorsal stream.. meaning spatial skills take longer to mature than object and face recognition.

What is plasticity

refers to the brains ability to change based on experience and adapt to different environments during development

What are the types of plasticity

Experience-expectant plasticity and experience-dependent plasticity

What is experience-expectant plasticity

The brain develops based on common human experiences (vision, language, social interaction) Example: if baby's vision is blocked (eg. by a lazy eye) normal depth perception may not develop

What is experience-dependent plasticity

Brain changes based on unique personal experiences (eg learning an instrument, growing up in a small town vs big city)

What is the process of vision and seeing

something is reflected onto the retina

Why does visual attention direct our resources

Because visual information is broken down into individual components (like colour and shape) and must be processed together.

What role does attention play in combining visual information?

It acts as the "glue" that joins the components together.

What are the two components of visual attention suggested by Cohen (1972)?

Attention-getting & attention-holding.

What two measures did Cohen (1972) use to assess attention?

Latency (time between stimulus and looking) & fixation duration (how long they looked).

How did checkerboard size influence attention?

Smaller size → took infants longer to look.

Bigger size → captured more attention.

How did the number of checkers affect looking time?

More checkers → longer looking time because more information had to be processed.

What are the two dissociated components of visual attention?

Size and number/quantity.

What did Richards (1985, 1991) measure in infants to study attention?

Heart rate changes during attention tasks.

What happens to an infant's heart rate when paying attention?

It decreases (decelerates).

what is visual pop out or bottom-up attention

aspect of selective attention in which items that are unique automatically catch our attention

What did Sireteanu & Rieth find about preferential looking and pop-outs

found that 10-12 month olds exhibited pop-out

What did Atkinson & Braddick find about preferential looking and pop-outs

found that 3.5-4.5 month olds also exhibited pop-out

What is the Visual Search Paradigm?

A task that measures eye movements to see how infants find a target among distractors, testing their ability to exhibit pop-out.

How did infants respond to more L's versus a + sign?

More L's → took longer; + sign → same reaction time regardless of quantity at 3 months.

What conclusion can be drawn from these findings?

Infants as young as 3 months can exhibit pop-out.

What did Bahrick, Walker, & Neisser (1981) study about selective attention in infants?

showed 4-month-old babies two overlapping pictures. Then, they split the pictures apart and watched which one the babies looked at.

What did it mean if infants looked at the novel stimulus

they had selectivley attended and chose one and ignored the other- showing that infants can focus on one thing while ignoring distractions