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n Early Term: Between 37 weeks 0 days and
38 weeks 6 days
Full Term: Between 39 weeks 0 days and
40 weeks 6 days
Late Term: Between 41 weeks 0 days and
41 weeks 6 days
Postterm: Between 42 weeks 0 days and beyond n Dr. Jeffrey L. Ecker, chair of the American
College of Obstetricians and Gynecologists’
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(ACOG) Committee on Obstetric Practice.

n n n n
Describe different “developmental job descriptions” of early infancy
– Describe different mechanisms of learning in infancy
Indicate two infant predictors of adolescent’s intelligence
Does rapidity of habituation predict future intelligence? Why do you think so?
What are the strengths and limitations of the habituation paradigm?
– Video resources
• Rovee-collier, infant brains, visual cliff, habituation
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n Body-Builder (O-9 weeks). n Inventory Control Officer (10-24 weeks) n Map Maker, Level I (25-40 weeks) n Map Maker, Level II (41-52 weeks)
– Rovee-Collier, 1996, “Shifting the focus from what to why”
Infant Behavior and Development
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n n
What I do and need
– Part-time work days and nights acquiring energy and minimizing energy expenditure. Variable hours.
–
–
–
Persistence required; strong suck and cry desirable.
Net energy income will be invested in fueling growth.
Around-the-clock protection and personal shopper service available.
Practical implications
–
–
Great at sucking and looking to control environment
But kicking requires too much energy
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n What I do and need
– Full-time days/occasional nights maintaining and controlling inventory of people and objects, what goes with what, and what happens when and in what order.
– Must be adept at soliciting caregiving and social interactions. Regular hours, benefits.
n Practical implications
– Can kick to show sophisticated memory for events and objects
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n
An infant’s foot was attached to a mobile.
n n
Initially, the infant would kick just by chance.
Each kick followed by the mobile’s movement. n n This movement was interesting to the infant, and reinforced the kicking behavior,
– increasing the likelihood that the infant would kick again.
Video
Real life example: https://www.youtube.com/watch?v=lPJiB-oGMN0
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n n
Level I (25-40 weeks)
– Full-time days, weekends; no nights. Regular hours.
–
–
Acquisition of preliminary cognitive map; some babbling, receptive language skills desired.
Beginning-level crawling a must.
Level II (41-52 weeks)
– Full-time days, weekends, no nights.
–
–
Regular hours. Self-starter. Navigational and receptive language skills required.
Must know when who and what are where, and how to get there.
• Rovee-Collier, 1996, Shifting the focus from what to why
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n
A parent’s smiling face will convince an infant to cross over the visual cliff before they have begun to crawl—social referencing.
Visual Cliff
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n Human infants with no crawling experience show no wariness of heights, but wariness becomes strong over the life span. n The crucial component of locomotor experience in this emotional change is developments in visual proprioception—the optically based perception of self-movement. n Precrawling infants randomly assigned to drive a powered mobility device showed significantly greater visual proprioception, and significantly greater wariness of heights, than did controls.
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n Classical Conditioning
– infant responds to a stimulus n Operant Conditioning
– Infant action changes the likelihood that an action will occur. n Habituation and Dishabituation
• http://www.cogs.susx.ac.uk/users/alisonp/dev1/lecture
2.html
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n n n
With repeated pairings of neutral stimulus and unconditioned stimulus, the infant begins to respond to the neutral stimulus.
– The neutral stimulus is referred to as a conditioned stimulus , and the response as a conditioned response .
Classical conditioning helps infants understand which events “go together,” to anticipate what happens next.
– Helps them learn to make sense of their environment.
Classical conditioning of reflexes
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n Sleeping infants presented with 'social'
(voice) or non-social stimulus (eg backward voice) followed by an airpuff to the eyelid.
n Infants increased learning across trials, regardless of stimulus type. n Infants conditioned to the 'social' stimulus showed increased learning compared to infants conditioned the non-social stimuli.
Reeb‐Sutherland, B. C., Fifer, W. P., Byrd, D. L., Hammock, E. A. D., Levitt, P., & Fox, N. A. (2011).
One‐month‐old human infants learn about the social world while they sleep.
Developmental Science, 14(5), 1134-1141. doi: 10.1111/j.1467-7687.2011.01062.x
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n A behavior followed by a stimulus that changes the likelihood of the behavior occurring again.
–
–
A stimulus that makes a behavior more likely to occur again is a reinforcer . Two kinds of reinforcers: n n presentation of a desired stimulus removal of an unpleasant stimulus.
A stimulus that makes a behavior less likely to occur again is called punishment .
n
Two kinds of punishment:
–
– removal of a desired stimulus presentation of an unpleasant stimulus.
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n n
Using operant conditioning, researchers can
“teach” infants to respond to a stimulus.
By varying the stimulus slightly, researchers can see whether infants perceive the variation.
– To discover which stimuli infants are able to perceive, and which stimuli infants prefer. n
Infants have a limited repertoire of responses--studies usually use sucking or head turn as the behavior which is reinforced.
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n n
A pacifier with which infants controlled, by sucking or stopping sucking, whether they heard the mother’s voice or another woman’s voice.
– Allowed the researchers to determine that infants were capable of perceiving the difference between the voices.
Testing infant hearing
–
–
Infants trained to turn their heads in response to a sound
Head turning is reinforced by the sight of toys which light up and become active when the infant turns.
– The sound is then produced more and more quietly, to determine what sounds the infant is able to perceive.
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n n
When infants smile or vocalize, parents often respond by smiling or vocalizing in return.
–
The parent’s response may reinforce the infant, increasing the likelihood that the behavior will recur.
Parents can be operant conditioned by their infants as well.
– When a parent is effective in soothing a crying infant, the infant stops crying. n This removal of an unpleasant stimulus (crying) reinforces the parent’s soothing technique, and the parent is more likely to use the same technique the next time the infant cries.
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“A new approach to reinforcement learning for control problems which combines value-function approximation with linear architectures and approximate policy iteration.”
Lagoudakis & Parr, 2003 22

n http://www.sciencedirect.com/science?_ob=ArticleURL&_
“use the reduction of uncertainty (information gain) as a reward signal. The result is an interesting form of learning in which the learner rewards itself for conducting actions that help reduce its own sense of uncertainty” n udi=B6T08-511R9KT-
1&_user=687815&_coverDate=11%2F30%2F2010&_rdoc=1&_fmt=high&_orig
=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000038378&
_version=1&_urlVersion=0&_userid=687815&md5=cd099de9f3a0e4a79f915ccd
365e8750&searchtype=a
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• Was presented to 93 premature infants for 60 sec.
o Infants who gazed at the pattern for more time had lower intelligence at 18 years if age.
o Infants who gazed at the pattern for less time had higher intelligence o Fixation duration in infancy and score on the intelligence test, r(91) = -.36, p < .0002.
o Why?
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n Three Theories
– Speed or efficiency of information processing n
Inhibition of responses to uninformative/familiar
– Sigman et al., 1991
– Fixation taps processing n Sigman, Cohen, Beckwith, 1997
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120 What conditions predict intelligence?
110
100
Inexact rendition of Sigman,
Cohen, &
Beckwith
(1997)
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N=25 N=24 N=22 N=20
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Long Infant
Fixation /
Low Maternal
Vocalization
Long Infant
Fixation /
High Maternal
Vocalization
Short Infant
Fixation /
Low Maternal
Vocalization
Short Infant
Fixation /
High Maternal
Vocalization
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o More maternal vocalizing at 1 month o Associated with vocalizations at 8 & 24 months and with socioeconomic status o Also predicts greater adolescent intelligence o R 2 = .22 for gazing and maternal vocalizations o Infants who gaze briefly and who were vocalized to more show especially high intelligence. o Interaction effect
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
n
‘Habituation and recognition memory in first year of life predict IQ between 1 and 8 years
–
–
Weighted (for N) mean correlation of .36
Raw median correlation of .45.
–
–
Similar for habituation & recognition memory.
Predictions consistently higher than for standardized infant tests of general development for nonrisk but not for risk samples. n
For nonrisk samples, predictions not consistently higher than predicting from parental education and socioeconomic status!
• A Meta-Analysis of Infant Habituation and Recognition Memory Performance as
Predictors of Later IQ Robert B. McCall, Michael S. Carriger Child Development , Vol.
64, No. 1 (Feb., 1993), pp. 57-79
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n A measure of learning and memory:
– habituation implies that the infant has encoded some of its properties & retained them.
n Habituation rate is linked to later achievement.
– Individual differences in speed of habituation relates to later IQ scores (Fagan & Singer, 1983).
• www.cogs.susx.ac.uk/users/alisonp/dev1/lecture2.html
n Bored faster

Brighter??
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
• http://www.youtube.com/watch?v=dlilZh60qdA from 1:30
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n n n
Habituation - gradual reduction in the strength of a response as the result of repetitive stimulation.
– When infants look at one stimulus for long period, they habituate, and look away more rapidly.
Dishabituation occurs when a new stimulus is presented, infants look at new stimulus longer
Enables infants to pay attention to new stimuli
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1.
2.
3.
–
SES-related disparities in MA
SES differences increase from 10mos to 2yrs
–
General contribution of genes & environment
Heritability higher at age 2
–
–
SES interacts with genes & environment
SES moderates genetic contribution to MA change
Increasing heritability of MA in infancy most n evident for high SES
Tucker-Drob, E. M., Rhemtulla, M., Harden, K. P., Turkheimer, E., & Fask, D. (2011). Emergence of a Gene
Fernandez
Science, 22 (1), 125-133.

Effect of genes on mental ability increases over infant development in high SES case
( Tucker-Drob, et al.. (2011)
Fernandez

n Assesses cognitive development in infancy.
n Composed of habituation-dishabituation items.
–
“a “novelty score” -- amount of fixation during the test phase devoted to the novel picture divided by the total fixation time to both the novel and familiar picture.” http://infantest.com/ftii.pdf
n n Used for research studies—index of the relative level of functioning in group being studied
–
Does not determine an individual child’s performance relative to that of the children in the norming sample – like in the Bayley
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n n
Infants may become distracted, tired, or bored.
It’s hard to motivate infants to perform at their best. n Interpretation of measurable dependent variables (e.g., looking time) is key
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n Research
– Exposure differences, prematurity differences n Identification of infants at risk for developmental delay in order to provide early intervention services.
n Scaled scores used at every age
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n n n n Permits observation of concepts noted by Piaget:
– A not B search error
– intentional, goal-directed behavior. n performance is compared with large group of infants on whom the test was normed.
•
•
•
Applied developmental research
1 through 3 ½ years
Extensively normed
•
•
Basis for early referral
Test-retest reliability http://www.youtube.com/watch?v=76SRamqYn0A&feature=related blue puzzle http://www.youtube.com/watch?v=kpx4AgO-Oxw&feature=relmfu yellow pegs http://www.youtube.com/watch?v=y1-ANMq1Cwo&feature=relmfu doll
Mullen Scales are alternate assessment
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A series of difficulty-graded items n One Year
– Mental n Making speech sounds and words
– n n
Fitting a piece in puzzle
Basic motor tasks
Motor n Standing, walking, & throwing n
Two & three year
–
–
Mental n n n
Uses multiple words in phrases
Completing puzzle
Counting & concepts
Motor n Runs, jumps, copies shapes
Cognitive performance becomes more verbal.
Children have to make verbal responses and understand more complex verbal instructions
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