DevlPsych Test 2

Development of the Brain

Grows at an astounding rate early in life, increasing from 25% of its adult weight at birth to 75% by age 2

Brain Growth Spurt

Last Three prenatal months and first two years after birth. More than half of one's adult brain weight is added at this time.
-synaptogenesis proceeds rapdily during this time

Brain Cells

Human brain and nervous system consists of more than a trillion highly specialized cells that work together to transmit electrical and chemical signals across many trillions of synapses

Synapses

connective spaces between one nerve cell and another

Neurons

basic unit of the brain and nervous system. Cells that receive and transmit neural impulses. Produced in the neural tube of the developing embryo. All the nuerons a person will have are already formed by the end of the second trimester of pregnancy
-assume specialized functions. have the potential to serve any neural function, and the functions each serves depend on where it ends up

Glia

nourish the neurons and eventually encase them in insulating sheaths of a waxy substance called myelin. Glia are far more numerous than nuerons and they continue to form throughout life

Synaptogenesis

Formation of synaptic connections among neurons- proceeds rapidly during brain growth spurt. About half the neurons produced early in life also die early in life; surviving neurons form hundreds of synapses, many of which also disappear if then neuron is not properly stimulated.

Plasticity

The fact that its cells are highly responsive to the effects of experience. The brain has evolved so that it produces an excess of neurons and synapses in preparation for receiving any and all kinds of sensory and motor stimulation that a human being could conceivably experience.

Pruning

neurons that are stimulated less often lose their synapses and stand in reserve to compensate for brain injuries or to support new skills in plasticity

Plasticity in the Brains of Chimps

experienced atrophy of the retina and the neurons that make up the optic nerve. Atrophy was reversible if the animal's visual deprivation did not exceed seve months but was irreversible and often led to total blindness if the deprivation lasted longer than a year.

Brain Growth

At birth the most highly developed areas are the brain stem and the midbrain which control states of consciousness, reflexes, and vital biological functions

Cerebrum & Cerebral Cortex

surround the midbrain; areas most directly implicated in voluntary bodily movements, perception, and higher intellectual activations

Primary Motor Areas

control simple motor activities such as waving the arms; first area of the cerebrum to mature; by 6 months of age, the primary motor areas of the cerebral cortex have developed to the point that they now direct most of the infant's movements

Primary Sensory Areas

control sensory processes such as vision, hearing, smelling, and tasting' first area of the cerebrum to mature

Myelin Sheath

acts as an insulator to speed the transmission of neural impulses, thus allowing the brain to communicate more efficiently with different parts of the body

Myelinization

follows a definite chronological sequence that parallels the maturation of the nervous system. As neural pathways between the brain and the skeletal muscles myelinate the child becomes capable of increasingly complex motor activities such as lifting the head and chest. Some ares of the brain are not completely myelinated until the mid to late teens or early adulthood.
-increase attention span

Reticular Formation and Frontal Cortex

allow us to concentrate on a subject for lengthy periods; are not fully myelinated at puberty

Cerebrum

highest brain centre. Consists of two halves connected by corpus callosum

Corpus Callosum

band of fibres which connects two halves of cerebrum together

Cerebral Cortex

covers each of the hemispheres of the cerebrum. outer layer of grey matter that controls sensory and motor processes, perception, and intellectual functioning

Left Cerebral Cortex

controls the right side of the body. Controls centres for speech, hearing, verbal memory, decision making, language processing, and expression of positive emotions

Sensation

process by which sensory receptor neurons detect information and transmit it to the brain

Perception

interpretation of sensory input: recognizing what you see, understanding what is said to you, or knowing that the odour you've detected is

Learning

change in behaviour that meets the following three requirements
1. individual now thinks perceives, or reacts to the environment in a new way
2. change is clearly the result of a person's experiences, attributable to repetition, study, practice, or the observations the person has made, rather than to hereditary or maturational processes or to physiological damage resulting from injury
3. change is relatively permanent

Empiricist

believed that an infant was a tabula rasa (blank slate) who must learn to interpret sensations

Nativist

took the nature side of the nature/nurture issue, arguing that many basic perceptual abilities are innate

Enrichment Theory

claims that sensory stimulation is often fragmented or confusing. to interpret such ambiguous input, we must use our available cognitive schemes to add to or enrich it

Differentiation Theory

argues that sensory stimulation provides all we need to interpret our experiences. Our task as fledgling perceivers is simply to detect the differentiating information

Distinctive Features

characteristics of a stimulus that remain constant; dimensions on which two or more objects differ and can be discriminated

Preference Method

Simple procedure in which at least two stimuli are presented simultaneously to see whether infants will attend more to one of them than the others

Preference Method Shortcoming

If an infant shows no preferences among the target stimuli, it is not clear whether he or she failed to discriminate them or simply found them equally interesting

Habituation

process whereby a repetitive stimulus becomes so familiar that responses initially associated with it
-dramatically improves throughout the first year, related to the maturation of the sensory areas of the cerebral cortex

Dishabituate

Increase in responsiveness that occurs when stimulation changes
-change in respiration or heart rate. Should the infant fail to react, it is assumed that the differences between the two stimuli were too subtle for him to her to detect

Habituation vs Dishabituation Testing

Tests an infant's ability to discriminate two stimuli that differ in some way. Investigator first presents one of the stimuli until the infant stops attending or otherwise responding to it. Second stimulus is presented: if the infant discriminates this second stimulus from the first he or she will dishabituate

Evoked Potentials

change in patterning of the brain waves that indicates that an individual detects a stimulus
-electrodes are placed on the infant's scalp above those brain centres that process the kind of sensory information that investigator is presenting
-responses to visual stimuli are recorded from occipital lobe whereas sounds are recorded from the temporal lobe

High-Amplitude Sucking Method

method of assessing infant's perceptual capabilities that capitalizes on the ability of infants to make interesting events last by varying the rate at which they suck on a special pacifier

Sucking Method Meanings

should the infant detect this stimulation and find it interesting, he or she can make it last by displaying bursts of high-amplitude sucking. Once the infant's interest wanes and her sucking returns to the baseline level, the stimulation ceases. Second stimulus that elicits a dramatic increase in high-amplitude sucking would allow investigators to conclude that the infant has discriminated the second stimulus from the first.

Language and Habituation

infants who habituate rapidly during the first 6-8 months of life are quicker to understand and use language during the second year

Classical Conditioning

type of learning in which a neutral stimulus that initially has no effect on the child eventually elicits a response of some sort by virtue of its association with a second stimulus that always elicits the response

Unconditioned Stimulus (UCS)

stimulus that elicits a particular response without any prior learning

Unconditioned Response (UCR)

unlearned response elicited by an unconditioned stimulus

Conditioned Response (CR)

learned response to a stimulus that was not originally capable of producing the response

Conditioned Stimulus (CS)

Initially neutral stimulus that comes to elicit a particular response after being paired with a UCS that always elicits that response

Extinction

gradual weakening and disappearance of a learned response that occurs because the CS is no longer paired with the UCS or the response is no longer reinforced

Watson and Classical Conditioning

Proved that emotional responses can be acquired through classical conditioning procedures

Counter conditioning

therapeutic intervention based on classical conditioning procedures. Goal s to extinguish an undesirable response and replace it with a new and more adaptive one

Limitations of Classical Conditioning

In the first few weeks of life, is likely to be successful only for biologically programmed reflexes such as sucking. Neonates process information very slowly and require more time than an older participant to associate

Operant Conditioning

form of learning in which freely emitted acts become either more or less probable depending on the consequences they produce

Positive Reinforcer

any stimulus whose presentation, as the consequence of an act, increases the probability that the act will recur

Negative Reinforcer

any stimulus whose removal or termination, as the consequences of an act, increases the probability that the act will recur

Punisher

Any consequence of an act that suppresses the response and decreases the probability that it will recur

Positive Punishment

Punishing consequence that involves the presentation of something unpleasant following a behaviour

Negative Punishment

punishing consequence that involves the removal of something pleasant following a behaviour

Reinforcer

any consequence that strengthens a response by making it more likely to occur in the future

Operant Conditioning in Infancy

even babies born prematurely are susceptible to operant conditioning. Successful conditioning in very young infants is generally limited to the few biologically significant behaviours

Can Infants remember what they learned?

young infants might be better at behaviours they have performed that have proven to be reinforcing

Early memories

find it hard unless given explicit reminders.

Operant theorists and punishment

believe that it merely suppresses an undesirable response without teaching anything new. stress that it may engender anger, hostility, or resentment

Interpretation

this of this input rather than the sheer amount of anxiety he or she experiences, that determines the effectiveness of punitive controls

Observational Learning

results from observing the behaviour of other people.

Encode

process by which external stimulation is converted to a mental representation

Imitation

babies less than 7 days old were able to do this
-becomes much more obvious and more reliable between 8 and 12 months of age

Deferred Imitation

ability to reproduce the actions of a model at some point in the future- develops rapidly during the second year

Importance of Deferred Imitation

indicates that children are not only constructing symbolic representations of their experiences, but can also retrieve this information from memory to guide their reproduction of past events

Cerebral Lateralization

specialization of brain functions in the left and right cerebral hemispheres
-may originate during the prenatal period and be well under way at birth

PET scan

works by injecting a radioactive isotope into participant and watching blood flow/glucose levels for certain areas of the brain when presented with a stimulus

Subtraction method

actual locating principle of PET scan. Involves taking picture of neural activity at rest and when stimulated and comparing to locate stimulus area

PET advantages

Allows for participant to talk as well as move.

PET disadvantages

Requires the use of radioactive isotopes and has low temporal and spatial resolution