Developmental Psych 2

sensation

processing of basic info from the world through sense organs (ears, eyes, skin) to actual energy coming in

perception

process of organizing and interpreting sensory info into something meaningful

visual perception

majority of work, 40-50% cerebral cortex

acuity

ability to see "fine detail"

how you clearly can see things in the world

like high visual contrast

preferential looking tests

show two things, see which one baby looks at.

how is acuity tested in infants?

preferential looking tests

\-infants prefer to look at high contrast patterns i.e. black and white stripes vs something with less obvious of a difference

At what age is acuity at full adult level?

as sharp at 8 months, full at 6 years

what is contrast sensitivity?

-ability to distinguish between contrasting colors/patterns

how is contrast sensitivity tested?

tested by preferential looking\---infants prefer HIGH CONTRAST PATTERNS bc they have poor contrast sensitivity in FIRST 3 MONTHS

why do infants have poor contrast sensitivity in the first three months?

infants only catch 2% of light hitting the eye compared to 65% in adults

what is color vision like for infants?

\-very poor color vision in FIRST MONTH

after this, see color very well- prefer red and blue like adults

what are the main limitations for infants' vision in first 3 months?

\-underdeveloped cones: only catch 2% of light hitting eye- prefer high contrast patterns

* poor color vision (in first month no color)
* -poor visual scanning patterns (short jerky movements, trouble tracking moving objects)

where do infants look in a complex shape?

scanning restricted to area of high contrast

on face: often the eyes

pattern perception

integrating information into coherent and meaningful patterns and "wholes"

pattern perception: at what age can babies see illusionary figure?

7 months

(illusionary figure= discs arranged to look like a square is there but it's really not)

pattern perception: at what age can babies perceive form?

5 months

(example: point light walker example: moving dots in the way a human walks recognized as human form)

Infants ability to perceive faces

-even newborns don't have trouble with this: makes sense because recognizing faces is important for babies

pattern perception findings by Johnston

\-by 5 months babies see people the way adults do

\-prefer faces that are highly attractive, as judged by adults

\-no initial preference for facial expressions, but after 9-12 months, prefer smiling over angry

\-12 hours after birth, prefer mom's face

what is the MAIN finding of johnston's study on infants and face perception?

* really just need 3 dots in an eyes and mouth pattern to recognize
* -prefer this to a scrambled paddle face, prefer scrambled to blank

what is the ORE?

- the "other race effect"- by 3 months, infants find it easier to discriminate between faces from their own racial group

what is perceptual constancy

-objects appear to maintain shape and size despite constant changes in retinal image

when does perceptual size constancy develop?

\-developed by 1 MONTH

\-examp: understand that block is coming closer and moving away not growing and shrinking

* rule for this = built in

what is object segregation?

* knowing where one object ends and another begins: done automatically by visual system using cues:

\-color, shape, texture, gaps, and MOTION (common motion= most important cue), knowledge of gravity etc

Kellman and Spelke experiment

learned phenomenon by habituation

rod behind box experiment

4 months know single object behind box

what is the idea of common motion?

\-if objects move together, they are likely part of the same object

understand this at 4 months

must be developed

What did studies show about the development of depth perception?

\-depth perception is developed after a few weeks experience with new form of locomotion BUT

\-is formed dependent on type of locomotion (depth perc must be developed for both crawling and walking-doesn't carry over)

dependent of self locomotion

don't use what learned from previous stage to learn next stage

intermodal perception

integrating input from two or more sensory systems to perceive an object

types of intermodal perception

1\.) visual to auditory

* auditory localization; turning towards sound indicates they expect a sound to be associated with an object

2.) touch to vision

* being able to touch and not look at object, find the one they were playing with when they were able to see

perception guides motor action-evidence for this

* studies on reaching, tend to reach to middle of object (takes into account perception and motor skills)
* rely on feel of objects, vision not needed
* 3-4 months reaching is jerky and poorly controlled
* 4-8 months can grab object making noise in dark room
* 10 months open hand bigger for bigger object, make contact w moving object

when do children typically start walking?

~11-12 months

at what age do children start crawling?

\~8 months

* usually first form of self-locomotion

by what age can infants sit independently/ what is the effect?

~7 months, reaching becomes more stable, can reach farther etc

self-locomotion studies by Adolph

-things learned while crawling are not generalized to walking, same as depth perception.

WHY?

--mechanism behind learning seems to be guided by the perceptual info at each stage

\-- don't understand gaps between crawling and walking \= risky

Comprehension vs production

comprehension-understanding what others say

production-actually producing the language

What does the rule comprehension precedes production mean?

children understand words that people use before they include them in their speech

-4.5 months, recognize own name

-6 months, will look to mommy and daddy respectively

-12-14 months attend longer to normal word order and syntax

when are babies first words usually said?

between 10 and 15 months

what is generativity?

by using the finite set of words in our vocabulary, we can produce infinite number of sentences, expressing an infinite number of ideas

-must master native language first

phonological development

learning the sound system of language

what are phonemes?

which sounds are in your native language

-example: learning diff between beer and deer

semantic development

learning the meanings of words

what are morphemes?

smallest units of meaning in language

-example: cat vs cats have diff meanings

syntactic development

learning rules for combining words (Grammer)

what is syntax?

examp: dog bites man vs man bites dog

rules in language that specify how words from dif categories can be combined

\--- arrangement of words

when are infants sensitive to syntax?

by ~1 year

What does does it mean to say language is species-specific and species-universal?

--species-specific\= humans acquire language in normal course of development in their normal environment

--species-universal\= virtually all humans learn language

What are the two brain areas associated with language

- Broca's area

-Wernicke's area

Broca's area

controls muscles for speech production

-aphasia if problems are severely impaired

-more front left circle on cortex

Wernicke's area

"speech sense", comprehension

- if Wernicke's is damaged, can still speak but have trouble understanding

- back circle on cortex

where is language localized for Right handers?

left brain (90% are R)

What is the critical period hypothesis?

time when language develops readily and after age 5-puberty, language acquisition is much more difficult and less successful. sometimes beyond fixing

How does Genie demonstrate the critical period hypothesis?

Found in 1970, 18months-13years locked up.

-After found, language didn't develop more than a toddler, couldn't develop grammar, but had extensive vocab

-LOTS of intervention, but never FULLY developed language because was never introduced till ~12

What is the most crucial factor for second-language acquisition?

-age/time of exposure

-doesn't matter how many years- early exposure\= better outcomes from grammar understanding

-if 2nd language is learned in critical period, same localization as native language\= better

-left side of brain

holophrastic period

-the period when children begin using the words in their small productive vocal ONE WORD at a time

--"drink" to express the desire for a glass of juice

Janet Werker

-infants tested with speech contrasts used in native language vs those used in non native language

-can discriminate non native phonemes early in infancy but not later in infancy

-10-12months can discriminate all possible phonemes from native language

-ex; child does not know he is born in english language culture

why is parsing the speech stream necessary?

-figuring out when 1 words ends and another begins

-infants must learn by listening to lots of speech and recognize which sounds tend to follow each other then assume ones that frequently follow each other are words

examp: "pre" often followed by "tty"\= must be word

what is prosody?

-characteristic rhythmic and intonation patterns with which a language is spoken

--how the language sounds- timing, emphasis on certain words, phrases etc

when does babbling occur?

6-10months, average 7

-repeating syllable such as "dadada"

gesturing

using hand gestures before and during talking

foundation of language

to take sounds of the language that infants hear on a daily basis

telegraphic speech/telegraphic period

children's first sentences that are generally two word utterances missing essential elements

ex;read me, hurt knee

what are the most commonly learned types of word early on?

-nouns

What is Quine's problem?

how kids learn the meaning of words, how do you figure out what the words mean that you hear?

ex; walking with baby, bunny runs in front, you yell "gachruepihg" does it refer to something? if so, what?

whole-object bias

assume new word refers to whole object, not a part

-aid word learning