Schema formation and stimulus-schema discrepancy: A basic unit and its properties.

Research with 2-day-old neonates shows that they create mental representations-schemata-for their experiences and that this cognitive ability is hardwired and functional at birth. This research and studies with older infants indicate that both the formation and the expansion of schemata occur through moderate discrepancies, a concept that Jerome Kagan promoted conceptually and through his research. Discrepancy, as distinct from novelty, is insufficiently acknowledged in the literature on schema theory. The schema is both cognitive and affective and develops in unison in a curvilinear pattern with a gradual onset and exponential expansion. Optimal attentiveness and positive affect occur at the peak of formation and to moderate discrepancies. Redundancy beyond the optimal level produces decreasing interest and positive affect and increasing negative affect resulting in boredom and avoidance. These characteristics of schema development are difficult to study with older children and adults. Rumelhart (1980) regarded the schema as the "building block of cognition" and Kagan (2002) called its expansion through moderate discrepancies an "engine of change" implying widespread application for cognition and behavior throughout life. Kagan urged the search for structure (form) as opposed to function in cognition, and the curvilinear pattern of schema development and its characteristics, it is argued, is the structure he sought. Implications and select applications of schema development and expansion are presented. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Functional Play at 2 Years of Age: Effects of Prenatal Maternal Stress.

Toddler toy play evolves in a predictable manner and provides a valid, nonverbal measure of cognitive function unbiased by social behaviors. Research on prenatal maternal stress (PNMS) indicates that exposure to stress in utero results in developmental deficits. We hypothesized that children exposed to high objective PNMS from a natural disaster early in pregnancy would exhibit higher rates of stereotypical play and lower rates of mature functional play than their low-stress counterparts would. We examined the functional play abilities of 52 2-year-olds exposed to low or high objective PNMS from a natural disaster within a nonstructured play session. Toddlers exposed to high objective PNMS, subjective PNMS, or both exhibited less functional and more stereotypical toy play, with less diversity, compared to toddlers exposed to low PNMS. PNMS appears to affect functional play development in toddlers negatively. These results replicate delays in language and intellectual functioning observed in these toddlers using the Bayley Scales.

Glucose enhances newborn memory for spoken words.

The effect of a 2 g/kg glucose feed was compared with a water feed on retention of a spoken word in 2-4 days old infants in a between group randomized trial. Infants heard a word in 30-s trials until they demonstrated orientation (head turns towards the sound) and habituation. After a 100 s delay, infants who received glucose turned toward the word less often than infants receiving water (means 31.8 vs. 57.7%, t = 2.8, p < 0.01) implying that they remembered the word better. There were no differences between groups in measures of attention to or rate of learning of the word. Only infants who subsequently oriented towards a different word, indicating that they remained alert, were used in the data analysis. The results suggest that glucose enhanced memory for a spoken word in neonates.

A typical feeding enhances memory for spoken words in healthy 2- to 3-day-old newborns.

OBJECTIVE: The objective of this study was to determine whether healthy 2- to 3-day-old newborns have better memory of a spoken word after a typical feeding (breast milk or formula) than before a feeding and, if so, whether memory is related to blood glucose. METHODS: A naturalistic study was conducted in which delayed recognition memory of a spoken word was examined in 60 healthy 2- to 3-day-old newborns either 120 minutes after their previous feeding (preprandial) or 30 minutes after their last feeding (postprandial). In this procedure, infants initially turn their head toward a novel word (orientation) and with repeated presentations cease turning toward it (habituation). Mean number of trials to reach orientation and habituation criteria provides measures of attention and rate of learning, respectively. After a 100-second delay, the word is presented again. Infants either turn toward it, indicating that they have forgotten it, or remain habituated, indicating that they remembered the word. Percentage of trials with head turns toward the word after the delay is the principal dependent measure. RESULTS: The postprandial group was split at the median for blood glucose to define high- and low-glucose groups. All 3 groups showed similar rates of orientation and habituation. On reexposure to the word during postdelay trials, the preprandial group displayed less retention than the postprandial high and low groups. No correlation was found between memory and blood glucose levels. The postprandial high blood glucose level differed statistically from the preprandial level, whereas the postprandial low level did not. CONCLUSIONS: Memory for spoken words in newborns is better after a typical milk feeding than before a feeding. This feeding effect is specific to memory and does not include attention or rate of learning. Also, it is not necessarily associated with increased blood glucose. It remains to be seen whether feeding enhances memory for other types of stimuli and what implications this may have for development.

Stress during pregnancy affects general intellectual and language functioning in human toddlers.

Prenatal maternal stress has been shown to impair functioning in nonhuman primate offspring. Little is known about the effects of prenatal stress on intellectual and language development in humans because it is difficult to identify sufficiently large samples of pregnant women who have been exposed to an independent stressor. We took advantage of a natural disaster (January 1998 ice storm in Québec, Canada) to determine the effect of the objective severity of pregnant women's stress exposure on general intellectual and language development of their children. Bayley Mental Development Index (MDI) scores and parent-reported language abilities of 58 toddlers of mothers who were exposed to varying levels of prenatal stress were obtained at 2 y of age. The hierarchical multiple regression analyses indicated that the toddlers' birth weight and age at testing accounted for 12.0% and 14.8% of the variance in the Bayley MDI scores and in productive language abilities, respectively. More importantly, the level of prenatal stress exposure accounted for an additional 11.4% and 12.1% of the variance in the toddlers' Bayley MDI and productive language abilities and uniquely accounted for 17.3% of the variance of their receptive language abilities. The more severe the level of prenatal stress exposure, the poorer the toddlers' abilities. The level of prenatal stress exposure accounted for a significant proportion of the variance in the three dependent variables above and beyond that already accounted for by non-ice storm-related factors. We suspect that high levels of prenatal stress exposure, particularly early in the pregnancy, may negatively affect the brain development of the fetus, reflected in the lower general intellectual and language abilities in the toddlers.