Perceptual a d Motor Skillr, 1975,41, 709-710. @ Perceptual and Motor Skills 1975
CONTINGENCY AWARENESS IN PREMATURE INFANTS NORMAN SOLKOFF A N D CANDICE COTTON State University of New York at Buffalo Summary.-Infants of low birthweight were placed in an artificial contingency situation in which leg movement produced movement of an overhead mobile. When compared with 5 non-contingent controls, these 5 infants showed an increase both in frequency of kicks and in the amount of time spent focusing on the mobile. T o explain why normal infants under typical rearing conditions do not show awareness of environmental contingencies until about 3 mo. of age, Watson ( 2 ) postulates the existence of a "natural deprivation period" during which time, because of both short memory spans and long recovery periods for a rewarded response, infants are denied the opportunity of discovering how their behaviors affect the physical environment. In a test of this hypothesis, Watson and Ramey ( 3 ) demonstrated that in artificially created contingency situations, which take into account both an infant's scanning ability and his speed of motor response recovery, 8-wk.-old infants can learn that their responses are related to consistent environmental feedback. Experimental infants, whose head movements produced changes in a visual display (mobile) hung about 18 in. above their heads, had significantly greater pillow activations than did control infants for whom the mobile rotations were automatic and not related to their head movements or for whom the visual display remained stationary. In addition, the experimental babies were described by their mothers as more attentive and expressive. In the present research, a similar procedure was employed with infants of low birthweight whose barren and monotonous high-risk nursery environments deprive them of appropriate contingency experiences even more than full-term infants in a natural environment. Ten premature infants, five experimental and five control, with three girls and two boys in each group, were studied in the Intensive Care Nursery of the Buffalo Childten's Hospital. The mean birthweight of the experimental infants was 1880 gm. and of the controls, 1830 gm. Although Ss were randomly assigned to each group, the mean gestational age of the control babies was greater than that of the experimentals ( 3 6 vs 31 wk.). At the time of the initiation of the experiment, the mean CA (age since birth) of the experimental babies was 34 days and of the controls, 4 0 days, yielding a conceptual age of 36 wk. for the former group and 42 wk. for the latter group. N o infants with respiratory distress, convulsions, symptomatic hypoglycemia, recurrent apnea, or serum bilirubin levels above 13 mg. per 100 ml. were included. A mobile of 14 differently colored and variously shaped fish arranged in a circular pattern was suspended above the crib at about 2 to 3 in. over the infant's head. The infant was propped up by means of a blanket rolled up and placed under the mattress so that the mobile was almost at eye level and the bright nursery lights could be avoided. In the experimental condition, one end of a piece of string was attached to the mobile and the other end was tied to the infant's left ankle so that when the infant kicked his/her leg, the mobile would move. Arrangements for the control condition were similar except that the string was attached to the infant's ankle but not to the mobile. Instead, the mobile wzs moved randomly, by a nurse, during the recording periods. The mobile was introduced prior to each of the four daily, 15-min. recording periods
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and, so as to preclude the possibility of habituation, was removed on completion of each recording session. Recordings were made for five days, twice in the morning and twice in the afternoon, and at times when the infants were most alert. During each 15-min. observation period, three measures were recorded once every 3 0 sec.: (1) the infant's state as determined by ratings on a six-point scale ranging from 1 (deep sleep) to G (ctying) ( 1 ) ; ( 2 ) the frequency of kicks; ( 3 ) whether or not an infant was focusing on the mobile as determined by direction of gaze and eyes open. All recordings were made by the same two nurses who were the observers chroughout the duration of the experiment. They knew nothing about the hypothesis being tested having been told that we were simply interested in how premature infants responded to visual stimulation. Agreement between the two nurses was practically perfect on all of the recorded measures. Alertness was determined by the rather objective criteria established by Brazelton ( 1 ) in his Neonatal Behavioral Assessment Scale. Because of the small sample size, no formal statistical procedures were applied to the data, and all findings, although suggestive of rather interesting trends, must therefore be considered tentative. For both groups the mean number of kicks decreased over the five days, but the decrease was less for the experimental infants. The mean number of kicks with focus increased over time for the infants in the contingency situation, and decreased for the controls. The control infants who were older at the outset of the experiment had higher kicking base races than did the experimentals. Therefore, in the absence of statistical controls for base rate, it is not possible to determine whether these results were related to the contingency arrangements or the simple decline over time in the frequency of kicking of the control babies. Although on Day 1 of the experiment, the control infants demonstrated more eyesopen, focusing behavior, their performance remained fairly consistent over the five-day period. However, the experimental infants, who were about 1 mo. younger, showed a substantial increase in focusing behavior over the five days, evenmally reaching, but not surpassing, the initial level of controls. It seems then that the older controls who may have already been focusing at an optimal level, were not affected by the mere presence of a mobile, moved randomly by a nurse. On the other hand, infants in the contingency situation, who were younger, steadily increased focus time over the five-day experimental period. It seems therefore that within the limits imposed by the infant's sensory capacities, specially arranged contingency environments providing immediate feedback, can alter the behavioral repertoire of even premature infants. These findings, though difficult at present to interpret, confirm those obtained by Watson and Ramey ( 3 ) with older, full-term infants and suggest the importance of artificially creating contingency environments, especially for prematures, whose "natural deprivation period" is much longer than that for term infants. In this way, a group of infants most vulnerable to early stimulus deprivation will be provided with an opportunity to learn that their behaviors can produce immediate environmental feedback thereby creating a more varied and "interesting" stimulus world for them. REFERENCES 1. BRAZBLTON, T. B. Neonatal Behavioral Assessment Scale. London: Heinemann, 1973. (Spastics International Medical Publ., Monogr. 5 0 ) 2. WATSON,J. S. The development and generalization of "contingenq awareness" in early infancy: some hypotheses. Mmill-Palmer Qua~twly,1966, 12, 123-135. 3. WATSON, J. S., & RAMEY,C. T. Reactions to response-contingent stimulation in early infancy. Mewill-Palmer Quarterly, 1972, 18, 219-227. Accepted September 10, 1975.
CONTINGENCY AWARENESS IN PREMATURE INFANTS NORMAN SOLKOFF A N D CANDICE COTTON State University of New York at Buffalo Summary.-Infants of low birthweight were placed in an artificial contingency situation in which leg movement produced movement of an overhead mobile. When compared with 5 non-contingent controls, these 5 infants showed an increase both in frequency of kicks and in the amount of time spent focusing on the mobile. T o explain why normal infants under typical rearing conditions do not show awareness of environmental contingencies until about 3 mo. of age, Watson ( 2 ) postulates the existence of a "natural deprivation period" during which time, because of both short memory spans and long recovery periods for a rewarded response, infants are denied the opportunity of discovering how their behaviors affect the physical environment. In a test of this hypothesis, Watson and Ramey ( 3 ) demonstrated that in artificially created contingency situations, which take into account both an infant's scanning ability and his speed of motor response recovery, 8-wk.-old infants can learn that their responses are related to consistent environmental feedback. Experimental infants, whose head movements produced changes in a visual display (mobile) hung about 18 in. above their heads, had significantly greater pillow activations than did control infants for whom the mobile rotations were automatic and not related to their head movements or for whom the visual display remained stationary. In addition, the experimental babies were described by their mothers as more attentive and expressive. In the present research, a similar procedure was employed with infants of low birthweight whose barren and monotonous high-risk nursery environments deprive them of appropriate contingency experiences even more than full-term infants in a natural environment. Ten premature infants, five experimental and five control, with three girls and two boys in each group, were studied in the Intensive Care Nursery of the Buffalo Childten's Hospital. The mean birthweight of the experimental infants was 1880 gm. and of the controls, 1830 gm. Although Ss were randomly assigned to each group, the mean gestational age of the control babies was greater than that of the experimentals ( 3 6 vs 31 wk.). At the time of the initiation of the experiment, the mean CA (age since birth) of the experimental babies was 34 days and of the controls, 4 0 days, yielding a conceptual age of 36 wk. for the former group and 42 wk. for the latter group. N o infants with respiratory distress, convulsions, symptomatic hypoglycemia, recurrent apnea, or serum bilirubin levels above 13 mg. per 100 ml. were included. A mobile of 14 differently colored and variously shaped fish arranged in a circular pattern was suspended above the crib at about 2 to 3 in. over the infant's head. The infant was propped up by means of a blanket rolled up and placed under the mattress so that the mobile was almost at eye level and the bright nursery lights could be avoided. In the experimental condition, one end of a piece of string was attached to the mobile and the other end was tied to the infant's left ankle so that when the infant kicked his/her leg, the mobile would move. Arrangements for the control condition were similar except that the string was attached to the infant's ankle but not to the mobile. Instead, the mobile wzs moved randomly, by a nurse, during the recording periods. The mobile was introduced prior to each of the four daily, 15-min. recording periods
710
N . SOLKOFF & C. COTTON
and, so as to preclude the possibility of habituation, was removed on completion of each recording session. Recordings were made for five days, twice in the morning and twice in the afternoon, and at times when the infants were most alert. During each 15-min. observation period, three measures were recorded once every 3 0 sec.: (1) the infant's state as determined by ratings on a six-point scale ranging from 1 (deep sleep) to G (ctying) ( 1 ) ; ( 2 ) the frequency of kicks; ( 3 ) whether or not an infant was focusing on the mobile as determined by direction of gaze and eyes open. All recordings were made by the same two nurses who were the observers chroughout the duration of the experiment. They knew nothing about the hypothesis being tested having been told that we were simply interested in how premature infants responded to visual stimulation. Agreement between the two nurses was practically perfect on all of the recorded measures. Alertness was determined by the rather objective criteria established by Brazelton ( 1 ) in his Neonatal Behavioral Assessment Scale. Because of the small sample size, no formal statistical procedures were applied to the data, and all findings, although suggestive of rather interesting trends, must therefore be considered tentative. For both groups the mean number of kicks decreased over the five days, but the decrease was less for the experimental infants. The mean number of kicks with focus increased over time for the infants in the contingency situation, and decreased for the controls. The control infants who were older at the outset of the experiment had higher kicking base races than did the experimentals. Therefore, in the absence of statistical controls for base rate, it is not possible to determine whether these results were related to the contingency arrangements or the simple decline over time in the frequency of kicking of the control babies. Although on Day 1 of the experiment, the control infants demonstrated more eyesopen, focusing behavior, their performance remained fairly consistent over the five-day period. However, the experimental infants, who were about 1 mo. younger, showed a substantial increase in focusing behavior over the five days, evenmally reaching, but not surpassing, the initial level of controls. It seems then that the older controls who may have already been focusing at an optimal level, were not affected by the mere presence of a mobile, moved randomly by a nurse. On the other hand, infants in the contingency situation, who were younger, steadily increased focus time over the five-day experimental period. It seems therefore that within the limits imposed by the infant's sensory capacities, specially arranged contingency environments providing immediate feedback, can alter the behavioral repertoire of even premature infants. These findings, though difficult at present to interpret, confirm those obtained by Watson and Ramey ( 3 ) with older, full-term infants and suggest the importance of artificially creating contingency environments, especially for prematures, whose "natural deprivation period" is much longer than that for term infants. In this way, a group of infants most vulnerable to early stimulus deprivation will be provided with an opportunity to learn that their behaviors can produce immediate environmental feedback thereby creating a more varied and "interesting" stimulus world for them. REFERENCES 1. BRAZBLTON, T. B. Neonatal Behavioral Assessment Scale. London: Heinemann, 1973. (Spastics International Medical Publ., Monogr. 5 0 ) 2. WATSON,J. S. The development and generalization of "contingenq awareness" in early infancy: some hypotheses. Mmill-Palmer Qua~twly,1966, 12, 123-135. 3. WATSON, J. S., & RAMEY,C. T. Reactions to response-contingent stimulation in early infancy. Mewill-Palmer Quarterly, 1972, 18, 219-227. Accepted September 10, 1975.
