Psych 311 - Psychophysical Development

OUTLINES

Chapter 5

Early Embryonic Development

Rev.1/19/03

I. Past placed little emphasis on child’s early psychological environment as a determinate of later behavior.

A. Freud – theory of psychosexual development

B. Observations

1. Infants separated from mothers exhibited symptoms including: Lack of appetite, pallor, loss of muscle tone, vomiting, diarrhea, and excessive sleep. *Condition called marasmus-wasting away.

2. Introduction of substitute mother revealed a significant improvement in health

C. Maternal Privation-loss of mother soon after birth-vs-Maternal Deprivation-when mother and infant are separated at a later time.

D. Cross-Species Fostering-young are raised from mother of different species.

II. Maternal Privation

A. Human Data

1. Humans infants living in institutions such as foundling homes experience exceptionally high mortality rates.

Example: Kesson (1965)- found that 45 out of 10,272 children admitted to foundling homes in Dublin survived between 1775 and 1800.

2. Psychological Consequences of Institutional Rearing

Example: Spitz (1945)- compared 61 infants living in a foundling home to 69 infants living in a nursery.—Foundling Home contained children given up by un-wed mothers whereas the nursery contained children of delinquent girls.

a. Environment

1) Foundling homes—little interaction with adults, few play things, most of the infants time is spent in cribs with extremely limited visual stimulation.

2) Nursery—infants were cared for by mothers or foster mothers, they were given toys, and the cribs allowed for visual stimulation.

b. Differences Between Groups

1) Developmental Quotient for foundling home babies was averaged at 72.

2) Developmental Quotient for nursery babies was averaged at 105.

3. Spitz (1946)

a. A study on 21 children who had not been adopted had to remain in the foundling home.

1) Youngest 2 years, oldest 4 years 1 month.

2) Mental development of the 21 children is extremely retarded compared to normal children ages 2-4.

3) Physical retardation also observed.

4) Inadequate perceptual experience not responsible for the deficits, but retardation was caused by a mother figure.

4. Pinneau

a. Criticized Spitz’s work

1) Said Spitz failed to mention whether foundling home infants suffered from congenital abnormalities.

2) Questioned the validity of the Hertzer-Wolf baby test that Spitz used provides quantitative assessments.

5. Provence and Lipton

a. Study of institutionalized infants.

1) Focused on issue of congenital abnormalities.

2) Established a strict set of criteria for subjects that were to be included.

a) Infants with an obvious handicap were excluded.

b) Used the Gesell Developmental examination.

3) The tests were of value because they provide a structured situation to observe children’s behavior.

b. Institutionalized vs. Family-reared Infants

1) Institutions more than Spitz’s foundling home as toys and cribs were available.

2) Still similarities-infants not encouraged to be motorically active, sensory stimulation was minimal, and there was little interaction with adult caretakers.

3) Retardation of the motor behavior was apparent. Deficit observed at 2 months involved how they responded to being held.

a) “They were not cuddly, felt like saw dust dolls, stiff or wooden.”

4) Three and four months of age, there were delays in head control, kicking activity, standing up and walking.

5) Institutionalized infants inactive and took little interest in its environment, only type of motoric behavior that did increase in activity was rocking.

6) Deficits observed in emotional reactivity, by the 2^nd month infants displayed little vocalization in response to people, exhibited fewer affective expressions and failed to seek adult when in distress.

7) Qualitative and quantitative impairment of sound production was observed. By the end not one infant uttered a single word, rarely cried. When they did they locked vigor.

c. Other Differences observed by Provence and Lipton and Institutionalized vs. Family-reared Infants.

1) Involve reactions to inanimate objects and discovery of the body.

2) After one and two years follow-up observations were made on some of the children in the foster homes.

a) Gains were made, but deficits were noted in emotional relationships, impulse control, play, thought, and action.

3) Goldfarb found similar results

a) Compared infants placed immediately into foster homes with those whose placement occurred after 3 years of institutionalization.

b) Children were between 10-14 years; those who had been institutionalized were deficient in language conceptual ability and unrepentant.

d. Mother’s Role

1) Provence and Lipton as well as Splitz argued that deficits in institutionalized children caused by lack of maternal care but viewed the role of the mother more objectively than Spitz did.

2) Mother primarily seen as an instructor.

3) Institutions described in research here do not foster normal development.

4) Was it lack of mother or perceptual deprivation that was responsible for the deficits?

6. Casler

a. Administered Gesell Development Schedule to sixteen institutionalized infants.

b. Formed eight approximate matched pairs determined by their scores.

c. One member of each pair was provided extra tactile stimulation by stroking their skin (not mouth, hands, or genitals).

d. Test then readministered scores of both groups declined, but infants who were stroked declined significantly less than their counterparts.

7. Dennis and Najarian (1957)

a. Found that institutionalized infants exhibited higher levels of mental retardation between 3 and 12 months

b. Infants had trouble taking the Cattell Infant Scale due to little experience in a sitting position and observing/manipulating objects

8. White and Castle (1964)

a. Experimented with rocking infants for 20 minutes a day, during days 6 and 36 of life, which increased time spent visually exploring environment while sitting upright

b. We can conclude that mom provides such stimulation: perceptual experience

9. Thompson and Grusec (1970)

a. They felt institutionalized infants were not a good representative of population because they were at risk prior to birth due to possible unwanted pregnancy, economic hardship of mom, and/or no prenatal care

B. Animal Data

1. Harlow (1958)

a. Studied maternal privation with macaque monkeys separating them from mom 6-12 hours after birth.

b. “Attached” to gauze pads on cage floor, and they became emotional when they were changed for sanitary reasons

c. This promoted his surrogate mother’s investigation

1) 2 “moms”: 1 wool, sponge, and terry cloth, one of wire mesh and left uncovered

2) 8 monkeys, 4 exposed to cloth mom with bottle attached, 4 to mesh mom with bottle

3) Time infant monkeys spent with cloth mom was significantly higher and concluded as a result of contact comfort rather than lactational state

4) When exposed to stimuli that provoked fear (drum beating teddy bear), differential responding occurred. They rushed to the cloth mother

5) When given the opportunity to press a lever to open a window, monkeys responded at higher rates when they saw the cloth mom, rather than the mesh mom

2. Reite et al (1978)

a. Reported separation from mother also leads to: decreased heart rate and body temperature, sleep disturbances, however, being separated from the surrogate mom yields fewer and less severe physiological changes than separation from birth mother

3. Harlow and Harlow (1962).

a. If isolated from birth they will exhibit behavioral abnormalities like self-clutching, body rocking and deficiencies in social behavior.

b. They don’t initiate or reciprocate in the grooming and play behaviors or peers and exhibit abnormalities in sexual behavior.

c. Males are sexually motivated while females show little interest in sex.

d. Parturient females either ignores young or subject them to physical abuse which occasionally lead to death.

4. Mason and Berkson (1975).

a. Provided 1 of the 2 groups of rhesus monkeys with a fur covered, lactating, surrogate mother.

b. The other group was given identical surrogates except for they were mobile.

c. It was found that 9 of the 10 raised with stationary surrogates developed rocking while none of the 9 subjects with mobile surrogates developed rocking.

5. Harlow and Suomi (1971).

a. Isolation reared parturient females that initially ignored babies eventually responded positively to the persistent attempts by infants over the course of months.

b. By month 4 these infants received less punishment and more nipple contact.

c. Isolates at 6 months old interacted with a normal adolescent for 2 hours a day, 3 days a week for a month then in pairs for the next 5 months. By 1 year a difference between isolated and normal infants was barely visible.

6. Rosenblum (1968)

a. Squirrel monkeys separated from mothers at birth and placed into social groups at 4 or 12 months old exhibited abnormal self-directed behaviors (excessive digit sucking), displayed normal sexual, maternal and social behaviors.

7. Dogs

a. Fox and Stelzner (1967)

1) Experimenter reared animals were least reactive toward other dogs; they were non-vocal, non-oral and initially non-aggressive. After social contact they became over-aggressive and rarely engaged in play behavior.

8. Rats

a. Thoman and Arnold (1968).

1) A problem taking away from the mother because they can’t be bottle-fed. Thoman developed a catheter, which delivered milk directly into the stomach.

2) Found that maternal privation alone or in combination with isolation doesn’t affect sexual behavior and the ensuing pregnancy.

3) Motherless rats exhibit maturational delay-eye opening occurs later than expected.

4) Offspring of motherless rats less likely to survive.

5) They also weigh less than those nurtured by mothers.

III. Maternal Deprivation

A. Human Data

1. Bowlby

a. Believed that maternal deprivation has transpired adverse affects on psychological development.

b. The psychoanalytic postulate that many adult disorders have roots in early life led Bowlby to concentrate on the impact of early loss on personality development.

2. Experiment

a. Bowlby compared 44 juvenile delinquents who had been caught stealing to 44 juvenile delinquents who had not been caught stealing.

b. 17 of the “thieves” had been separated from their mothers for 6 months or more within the first five years of life.

c. Only 2 of the non-thieves had been separated from their mothers

d. This investigation was criticized because people found it highly unlikely that maternal deprivation will lead to juvenile delinquency.

3. Bowlby, Ainsworth, Boston, and Rosenbluth

a. Another study conducted by Bowlby with 60 children who had been placed in a sanitarium for varying periods prior to the age of 4 to receive treatment for Tuberculosis.

b. Children only saw parents once a week for 3-hour periods.

c. Afterward, the children’s IQ was tested.

d. Only half of the children scored adequately during the administration of the test.

4. Other Options

a. The data could be a reflection of the particular institution in which the children reside.

b. The investigations have studied the institutions as well as, or instead of, maternal deprivation.

5. Spitz and Wolf

a. Called the immediate impact of deprivation anaclitic depression.

b. Comprised of weepiness, withdrawal, dejection, loss of appetite, and insomnia.

c. Maternal deprivation has also been implicated in the failure of hospitalized infants to thrive.

6. Bowlby and long-term affects

a. Believed loss of mother engenders frustration, which increases sexual and aggressive impulses.

b. Also believed that maternal deprivation prevents the establishment of close interpersonal relationships with others.

B. Data from animals

1. Seay, Hansen, Harlow (1962)

a. Observed the behavior of 6-month-old monkeys during a 3 week period of maternal deprivation.

b. Infants exhibit excessive vocalizations and disoriented locomotor behavior.

c. Attempted to break through a plastic barrier that separated them from mother.

d. Unsuccessful attempts were followed by lethargy and withdrawal.

e. Findings are similar to the protest and despair reactions of human children in response to maternal loss.

f. Also reported, Detachment reaction, active avoidance of the mother during the initial portion of the reunion period.

2. Spencer-Booth and Tinde

a. Found that infant monkeys and their mothers make immediate contact upon reunion.

b. The detachment reaction might be obscured in some species by the mother’s rapid retrieval of her infant.

3. Kaufman (1973)

a. The agitated behavior (vocalization and excessive locomotion) seen initially upon separation may serve to call attention to the infant there by facilitating the mothers search for it.

b. With the mothers continued absence, it is to the infant’s advantage to become inactive: inactivity would help conserve the infants energy and preserve it from being found by the predators.

c. Becoming inactive corresponds to the despair phase of the separation reaction.

4. Reite, Short, Seiler, and Pauley (1981)

a. Analyzed behavior of monkeys prior to and during a 10-day period of maternal separation and 4-days of reunion.

b. Young were raised in social groups containing 1 male and 4-8 females.

c. Many behaviors change markedly during separation and returns to baseline during reunion.

5. How long do the effects of maternal deprivation last?

a. The separated animals tend to spend less time away from their mothers and exhibit less locomotor activity; they are less likely to approach strange objects such as mirrors or balls.

b. Differences were still apparent about 2 years after separation experience

6. Lewis, Mckinney, Young, and Kraemer

a. Comparing the results of 5 experiments cautioned against the use of the maternally deprived animal as an experimental model of human depression.

b. Some human infants appear to be totally immune to the depressive effects of maternal separation.

7. Spenser-Booth and Hinde

a. Neither age at time of separation, sex, nor amount of contact with other group members during the separation period contribute to the individual differences.

b. The differences must derive from psychological factors intrinsic to the infant and from its relationship with the mother prior to separation.

8. Hinde and McGinnis

a. Contended that variation in post separation behavior is attributed to the mother- infant interaction seen before separation.

b. Infants from “tense” mother-infant dyads exhibit most distress.

9. Seitz (1959)

a. Separated cats 2 weeks of age

b. Cats were most anxious in novel situations and disturbed by, and slowest to recover from intense stimulation.

c. Cats were most persistent but also disorganized in their efforts to get food

d. Throughout life the cats were more suspicious, fearful, and aggressive both toward other cats and the experimenters.

e. Conclusion: A methodological factor renders the results (from Sietz’s) cats virtually uninterruptible- the findings may not have been due to maternal deprivation, but rather, to a nutritional factor associated with the hand- rearing procedure.

10. Nutrition serves a physiological regulator as well as permitted survival

a. Hofer (1970)

1) Reported a decline in heart and respiratory rates of 2-week old maternally deprived rats

a) Decreased more than 40% by 12 to 16 hours after separation

2) Decline in heart rate can be temporarily but completely reversed within a matter of minutes by placing as little as .5ml of a milk formula directly into the stomach

a) Respiratory rates could not be reversed as such

11. Rapidity with which the nutrient accelerates heart rate following its placement into stomach indicates that it acts prior to being absorbed into the circulatory system

a. Effect of nutrient is eliminated by the Beta-adrenergic blocker propanobl and by spinal cardio acceleratory pathways to the B-adrenergic synapses of the myocardium

12. Separating maternal from nutritional factors can lead to inconclusive data

a. Novakova(1966)

1) Studied the effect of maternal deprivation on the acquisition and retention of a conditioned response

a) Separate 1 group of rats from mothers on day 15

b) A second group was also weaned prematurely on day 15

(1) Mothers milk of this group were prevented from providing milk by cauterizing their teats

(2) Mothers were separated from young at 30 days

c) Third group nursed normally

2) At 8 months, the animals weaned early and deprived of their mother acquired a conditioned response more slowly than did the other 2 groups.

a) Also exhibited poorer retention of the response when retested 12 weeks later

3) Rats that lived with non-lactating mothers consumed more solid foods between days 16 and 20 of life than did maternally deprived rats

4) Concludes that maternal presence enhances intake of solid food

b. Hofer (1973) presented data indicating that certain behaviors are affected by the absence of the mother independent of her role in governing the nutritional status of the young

13. Vocalization is affected by separation

a. Young rats emit high frequency vocalizations in responses to separation (combined researchers)

1) In first few days of life-mainly associated with a decline in the infants body temperature

b. Infant rats are poikilothermic-unable to maintain body temperature

1) Thus, warming of the isolation chamber to about 36⁰ C prevents vocalization.

c. Later on, vocalizations are influenced by social factors

d. Rate of emission of ultrasound (detects vocalization) increases from 1 pulse/min to 12/min when pup is separated from mother and littermates and left in-home cage

1) Rate further increases to 25/min when places alone in an unfamiliar cage

2) Furthermore, when placed in contact with mother or littermate, vocalization rapidly decreases

14. Hofer, Shair, and Murowchick

a. 2 week old rats reared alone on day of birth and kept in cups floating in warm water also displayed an increase in rate of vocalization when placed in a novel environment

b. Contact with a warm object had no effect because mother usually leaves her young 1-20 times a day

c. Suggested that littermates function to prevent separation distress

d. Exhibit a reduction in vocalization when removed from cups

15. Physiological consequences of deprivation

a. Reite et al. (1981)

1) Monitored heart rate, body temperature and sleep patterns of young pig tailed monkeys

2) Found marked changes when removed from mother decrease in heart rate, decrease in body temperature and decrease in sleep

3) Concluded that it is difficult to predict an infant’s physiological reaction to separation

16. Endocrine System (pituitary-adrenal axis) - Mendoza, Smotherman, Miner, Kaplan, and Levine

a. endocrine system is reactive to maternal separation

b. assessed levels of cortisol in the plasma of infant squirrel monkeys prior to mothers’ removal, 30 min after removal, and during a separate removal-reunion session

1) Found that the degree of elevation is dependent on the conditions of separation.

2) monkeys placed in strange cages way from their mothers exhibited a greater rise in cortisol levels than those placed in cages adjacent to mothers

3) those left in familiar social groups in their home cages after removal of their mother displayed the smallest elevation

4) Familiar conspecifics and familiar surroundings ameliorate (decrease) the effect of maternal separation

c. Rats also exhibited a rise in levels of corticosterone when separated from mothers.

17. Hennessy and Weinberg

a. found an elevation in 18 day olds after 30 minutes of separation

b. elevations are exhibited by 10 day olds after at least 120 minutes of separation (Kuhn & Schanberg, 1988)

18. Cortisol and Corticosterone

a. hormones that facilitate the organism’s ability to cope with stressful situations and because their levels rise during separation, maternal deprivation has been viewed as a stressor

b. increased cortisol production is associated with the display of separation-elicited distress vocalization and agitated movement

19. Coe, Weiner, and Levine (1983)

a. reported frequency of distress vocalizations and plasma cortisol levels in squirrel monkey infants across a 6 hour separation period

b. Hennessy found that young continue to respond to separation hormonally but not vocally

c. Coe reported data causally relating the initial cortisol elevation to the display of behavior

1) before separated from mothers, infants were injected with metapyrone- a drug that blocks the adrenal response to separation

a) infants didn’t display the pacing and stereotyped movements-instead they were inactive

20. Ackerman, Hofer, and Weiner

a. Reported that rats separated from mothers a 15 days of age are 85% more prone to develop gastric ulceration in response to the application of stress on day 30 than those separated on day 21 or later.

21. Kuhn, Butler, and Schanberg (1978)

a. Removed 10 day old rats from their mothers and took blood samples 1, 2, or 6 hours later

b. Blood obtained from others either 15 minutes or 1, 2, or 4 hours after being returned to their mothers after a 2 hour separation

1) growth hormone exhibited a significant decline through deprivation period and returned to normal within 15 minutes after being returned to the mother.

22. Evoniuk, Kuhn, and Schanburg (1979)

a. 8 day old maternally separated rats were given 10 to 20 short, heavy strokes on the head and back area with a moistened camel hair brush once every 5 minutes for 2 hours

b. others were stroked gently, given a tail pinch once every 5 minutes or left alone

c. a fifth group of young were not maternally deprived

d. blood was obtained at the end of 2 hour period and serum growth hormone levels were determined

e. heavy stroking prevented the decline in growth hormone

f. stroking returns the hormone level to normal after it is lowered by 2 hours of maternal deprivation

23. Panksepp

a. endogenous brain opioids (endorphins) are involved in reactivity to separation

b. during periods of separation-opioid levels decline, inhibition in lifted and the organism experiences stress

c. naloxone – prevents opioid uptake and increases distress vocalization

IV. Cross species fostering

A. Conditions to be successful

1. Young must provide the adult with the requisite amount of tactile stimulation to cause milk letdown

2. Must be physically able to extract milk from alien nipple

3. Must be able to survive on milk that differs

B. Cross species fostering only between mice/rats

C. Denenberg, Hudgens and Zarrows 1964 initial experiment

1. Mice reared by rats in percents of rat young are less active and prefer the rat as a social stimulus

D. Denenberg Hudgens and Zarrows 1966

1. Rat-reared mice are less active on the first four daily open field tests, fought less among themselves

2. Later shown that rat-reared mice are sufficient stimulus to evoke attack from other aggressive mice

a. Mice exhibit defensive behavior

E. Rat mother responsible for changes in behavior

1. Changes seen in the mice result from ingestion of rat milk

2. Changes are induced passively by the rat mother’s emissions of particular stimuli, such as odors and sounds

3. Changes may occur actively

F. Passive influence

1. Neither open field activity nor aggressive behavior were assessed, the data suggests that the rat mothers influence depends on either the prevision of milk or behavior

G. Rat aunt experiment

1. Non lactation rats can be induced to behave maternally

2. Relative to mice reared only by mouse mothers, animals exposed to the rat aunt weighed more and were less active

3. Experiment strongly suggests that changes observed in mice raised by rat mothers are caused by behavior toward young rather then their milk

H. Dogs and cats

1. Unlike control dog, which appeared highly aroused barking tail wagging and pawing and jumping at the mirror the cat-raised dogs exhibited little reaction

2. Cat raised dogs were submissive towards other dogs

a. Frequently played with cat peers

V. Conclusion

A. Maternal privation is associated with more profound long term consequences than is maternal deprivation

B. Cross species fostering research has demonstrated that fundamental changes in behavior and in reactivity of the pituitary/adrenal system occur when mice were raised by rats.