Individual performance across motoric self-regulation tasks are not correlated for pet dogs

Inhibitory control, the ability to restrain a prepotent but ineffective response in a given context, is thought to be indicative of a species’ cognitive abilities. This ability ranges from “basic” motoric self-regulation to more complex abilities such as self-control. During the current study, we investigated the motoric self-regulatory abilities of 30 pet dogs using four well-established cognitive tasks – the A-not-B Bucket task, the Cylinder task, the Detour task, and the A-not-B Barrier task – administered in a consistent context. One main goal of the study was to determine whether the individual-level performance would correlate across tasks, supporting that these tasks measure similar components of motoric self-regulation. Dogs in our study were quite successful during tasks requiring them to detour around transparent barriers (i.e., the Cylinder and Detour tasks), but were less successful with tasks requiring the production of a new response (i.e., A-not-B Bucket and A-not-B Barrier tasks). However, individual dog performance did not correlate across tasks, suggesting these well-established tasks likely measure different inhibitory control abilities, or are strongly influenced by differential task demands. Our results also suggest other aspects such as perseveration or properties of the apparatus may need to be carefully examined in order to better understand canine motoric self-regulation or inhibitory control more generally.     

Differential rates of visual information processing in full-term and preterm infants

This study investigated the effect of increasing familiarization time on the visual recognition memory of 6- and 12-month-old full-term and preterm infants. Infants were given trials in which they viewed a shape for either 10-, 15-, 20-, or 30-sec familiarization and were then tested for visual recognition memory using the paired comparison technique. While the older infants showed evidence of recognition memory after less familiarization time than the younger ones, at both ages preterms required considerably longer familiarization than full-terms. The pattern of performance replicates our earlier finding of developmental lags in the visual information processing of 6-month-old preterms and extends these findings to 12-month-olds. These results suggest that there are persistent differences between preterm and full-term infants throughout at least the first year of life in this very fundamental aspect of cognition.     

Exploratory Behavior, Task Persistence, and Problem-Solving Ability Across the Second Year of Life

The present study focuses on individual differences in specific qualitative aspects of infants' exploratory behavior, task persistence, and problem-solving ability. Longitudinal questions concern the stability of these behaviors across the second year of life and the relationship between early exploration and task persistence and later problem- solving ability. Twenty-nine infants were observed at 12 months and again at 26 to 28 months of age. Behavior was observed on two exploratory and two problem-solving tasks, and a wide range of individual differences was found. The longitudinal results suggest stability between one and two years of age in terms of the cognitive sophistication of behavior rather than in correlations between identical index behaviors. Longitudinal stability was not found for task persistence. Also, infants who used more different schemes to explore at one year were found to be more successful and sophisticated in problem solving at age two. It is concluded that the quality and range of behaviors used during exploration have important developmental significance, rather than the use of any specific behavior, or persistent behavior, regardless of the degree of sophistication.     

Exploratory Behavior,Task Persistence,Across the Second Year of Life and Problem-Solving Ability

The present study focuses on individual differences in specific qualitative aspects of infants' exploratory behavior, task persistence, and problem-solving ability. Longitudinal questions concern the stability of these behaviors across the second year of life and the relationship between early exploration and task persistence and later problem- solving ability. Twenty-nine infants were observed at 12 months and again at 26 to 28 months of age. Behavior was observed on two exploratory and two problem-solving tasks, and a wide range of individual differences was found. The longitudinal results suggest stability between one and two years of age in terms of the cognitive sophistication of behavior rather than in correlations between identical index behaviors. Longitudinal stability was not found for task persistence. Also, infants who used more different schemes to explore at one year were found to be more successful and sophisticated in problem solving at age two. It is concluded that the quality and range of behaviors used during exploration have important developmental significance, rather than the use of any specific behavior, or persistent behavior, regardless of the degree of sophistication.     

Development of the ability to use recall to guide action, as indicated by infants' performance on AB

25 infants were tested every 2 weeks on the AB Object Permanence Task devised by Piaget, from the age when they first reached for a hidden object until they were 12 months. The delay between hiding and retrieval necessary to produce the AB error increased continuously throughout this period at an average rate of 2 sec/month, from under 2 sec at 7 1/2 months to over 10 sec by 12 months. All children displayed the AB error repeatedly over the months of testing. Large between-children differences in delay needed for the AB error were found at each age. Girls tolerated longer delays than boys. The characteristic pattern to the AB error did not vary over age or sex. Range of delay producing the AB error in any child was small. Errors disappeared when delays were reduced by 2-3 sec, and reaching became random or severely perseverative when delays were increased 2-3 sec above the level producing AB error. AB provides an index of the ability to carry out an intention based on stored information despite a conflicting habitual tendency.     

Abilities and neural mechanisms underlying AB performance

Schacter, Moscovitch, Tulving, McLachlan, and Freedman propose that infants may make the AB error because of immaturity of the memory system damaged in amnesia (e.g., the hippocampus). They contrast this with the proposal that infants may make the AB error because of immaturity of the frontal lobe system (Diamond; Diamond & Goldman-Rakic). Schacter et al.'s choice of subjects, however, did not permit a test of these 2 proposals, and characteristics of their task, such as length of delay, make comparison with infants difficult. Schacter et al. discuss sensitivity to proactive interference as a possible explanation for the AB error, but sensitivity to PI is more closely associated with frontal lobe damage than with amnesia. Schacter et al. associate perseveration with immaturity or damage to the frontal lobe; it is suggested here that this is better characterized as lack of inhibitory control. Tasks that are most likely to require frontal cortex function are those that demand both short-term memory and inhibitory control. AB is an excellent example of such a task.     

Prematurity stereotyping: effects on mother-infant interaction

The possibility that the self-fulfilling prophecy process can adversely affect the caregiving environment of premature infants was explored in this study. A portion of this process was investigated experimentally by assessing cognitive and behavioral reactions of 27 mothers to unfamiliar full-term infants who were labeled either full-term or premature. Infants who were described as premature were touched less and given a more immature toy to play with, were rated as smaller, finer-featured, and less cute, and were liked less than infants who were labeled full-term. In turn, infants labeled premature were less active during the interaction than infants labeled full-term. College students who later observed the videotapes made of the mother-infant interactions were able to accurately guess which label was assigned to the infants. The results of this study further support the existence of a prematurity stereotype and the impact of expectations on perceptions and behavior.     

Age-Related Effects of Study Time Allocation on Memory Performance in a Verbal and a Spatial Task

Past studies have suggested that study time allocation partially mediates age relations on memory performance in a verbal task. To identify whether this applied to a different material modality, participants ages 20-87 completed a spatial task in addition to a traditional verbal task. In both the verbal and the spatial task, increased age was associated with poorer utilization of study time, suggesting that age differences in study time allocation are qualitatively similar across material modality. Furthermore, age differences in how individuals allocated their study time partially mediated the age relations on memory performance in both tasks, indicating the importance of effective regulation of study time when learning information. Finally, age differences in study time allocation did not appear to be due to differences in awareness of performance. When a subset of participants was asked about their prior performance, awareness of previous performance was not associated with study time allocation on either task. Interestingly, asking participants about their prior performance tended to decrease recall performance. Overall, these results illustrate that how one allocates study time is related to subsequent memory performance in both a verbal and spatial modality, but knowledge about prior performance is not associated with study time utilization, and inquiring about past performance during study may disrupt rather than facilitate learning.     

Individual Differences in Infant Visual Attention: Are Short Lookers Faster Processors or Feature Processors?

Individual differences in the duration of infants' visual fixations are reliable and stable and have been linked to differential cognitive performance; short-looking infants typically perform better than long-looking infants. 4 experiments tested the possibility of whether short lookers' superiority on perceptual-cognitive tasks is attributable to attention to the featural details of visual stimuli, or simply to differences in the speed or efficiency of visual processing. To do this, the performance of long- and short-looking 4-month-olds was examined on separate discrimination tasks that could be solved only by processing either featural or global information. The global task was easier than the featural task, but as the amount of time allotted for infants to solve either type of task was decreased, short lookers' performance was superior to that of long lookers. These results thus lend support to a speed or efficiency of stimulus processing interpretation of infant fixation duration.     

Early home intervention with low-birth-weight infants and their parents

We investigated the effects of a year-long home intervention with a sample of preterm infants randomly assigned to 1 of 3 groups: a developmental intervention, a parent-infant intervention, and a no-treatment control group. A full-term no-treatment control was also used. Both intervention approaches focused on the parent-child unit, providing training for parents to improve observational skills, emotional support, and information about community resources. However, whereas specific tasks to facilitate the child's development were provided in the developmental intervention group, the quality of the parent-infant interaction was the target for treatment in the other group. All infants were assessed at 4, 8, 12, and 16 months of age corrected for prematurity. The results suggest that although both intervention approaches were effective in modifying some aspects of the home environment and, to a lesser degree, in improving infants' cognitive development, the parent-infant interaction approach seemed to have the greater impact. These findings confirm previous observations regarding the cognitive development of preterm and full-term infants during the first 18 months of life and demonstrate changes in behavior and behavior styles in both pre- and full-term infants as they become older.     

Reading and reading-related skills in children using cochlear implants: prospects for the influence of cued speech

We assessed the reading and reading-related skills (phonemic awareness and phonological short-term memory) of deaf children fitted with cochlear implants (CI), either exposed to cued speech early (before 2 years old) (CS+) or never (CS-). Their performance was compared to that of 2 hearing control groups, 1 matched for reading level (RL), and 1 matched for chronological age (CA). Phonemic awareness and phonological short-term memory were assessed respectively through a phonemic similarity judgment task and through a word span task measuring phonological similarity effects. To assess the use of sublexical and lexical reading procedures, children read pseudowords and irregular words aloud. Results showed that cued speech improved performance on both the phonemic awareness and the reading tasks but not on the phonological short-term memory task. In phonemic awareness and reading, CS+ children obtained accuracy and rapidity scores similar to CA controls, whereas CS- children obtained lower scores than hearing controls. Nevertheless, in phonological short-term memory task, the phonological similarity effect of both CI groups was similar. Overall, these results support the use of cued speech to improve phonemic awareness and reading skills in CI children.     

Infant temperament and subject loss due to crying during operant conditioning

Infants who failed to complete a 2-day operant-conditioning task were compared with a stratified random sample of those who did on measures of infant temperament and several demographic characteristics. A discriminant-function analysis revealed that female infants who cried differed from female infants who did not cry on measures of duration of orienting and latency to approach sudden or novel stimuli. Reliable prediction of crying and noncrying could not, however, be made for males. No sex differences emerged in the incidence of crying or in the number of sessions completed. Partially successful females (i.e., those completing 1 of the 2 sessions) could reliably be discriminated from those who cried during the first session on measures of age at testing and maternal ratings of smiling behavior. The results of this study suggest that, as with habituation studies, subject loss in operant-conditioning studies is influenced by individual differences among the infants which may or may not adversely affect external validity.     

Motion detection, letter position encoding, and single word reading

Recent research has shown that many people with dyslexia find it unusually difficult to detect flickering or moving visual stimuli, consistent with impaired processing in the magnocellular visual stream. Nonetheless, it remains controversial to suggest that reduced visual sensitivity of this kind might affect reading. We first show that the accuracy of letter position encoding may depend on input from the magnocellular pathway. We then suggest that when children read, impaired magnocellular function may degrade information about where letters are positioned with respect to each other, leading to reading errors which contain sounds not represented in the printed word. We call these orthographically inconsistent nonsense errors letter errors. In an unselected sample of primary school children, we show that the probability of children making “letter” errors in a single word reading task was best explained by independent contributions from motion detection (magnocellular function) and phonological awareness (assessed by a spoonerism task). This result held even when controlling for chronological age, reading ability, and IQ. Together, these findings suggest that impaired magnocellular visual function, as well as phonological deficits, may affect reading.     

Maternal Self-Efficacy: Illusory Control and Its Effect on Susceptibility to Learned Helplessness

66 mothers of 5-month-old infants participated in 2 simulated child-care tasks to examine differences in response to the performance demands of child care. Mothers first participated in a task in which they estimated their perception of control over stopping an audiotaped infant cry (illusion of control). 1 week later, they participated in another task to assess their ability to learn effective responses in stopping the cry (susceptibility to learned helplessness). Mothers with a high illusion of control differed from mothers with low or moderate illusory control by showing increased susceptibility to helplessness. Physiologically, mothers with low and moderate illusory control showed attenuated and "attentive" heart-rate responses to the impending cry, respectively. Mothers with high illusory control were "inattentive", with mothers of difficult infants in that group responding "defensively". Our data suggest that high illusion of control may be a maladaptive response to the performance demands of child care.     

Getting there faster: 18- and 24-month-old infants' use of function words to determine reference

Infants of 18 and 24 months acquiring English were tested in a preferential looking task on their ability to detect ungrammaticalities caused by manipulating a single function word in sentences. Infants heard grammatical sentences in which the determiner the preceded a target noun, as well as three ungrammatical conditions in which the was either dropped, replaced by a nonsense function word (el), or replaced by an alternate English function word (and). Both the 18- and 24-month-old infants oriented faster and more accurately to a visual target following grammatical sentences. The results suggest that by 18 months of age, infants use their knowledge of determiners in sentence computation and in establishing reference.     

Visual Attention Preference for Intermediate Predictability in Young Children

How do children allocate their attention? There is too much information in the world to encode it all, so children must pick and choose. How do they organize their sampling to make the most of the learning opportunities that surround them? Previous work shows infants actively seek intermediately predictable information. Here we employ eye-tracking and computational modeling to examine the impact of stimulus predictability across early childhood (ages 3–6 years, n = 72, predominantly Non-Hispanic White, middle- to upper-middle-income), by chronological age and cognitive ability. Results indicated that children prefer attending to stimuli of intermediate predictability, with no differences in this pattern based on age or cognitive ability. The consistency may suggest a robust general information-processing mechanism that operates across the lifespan.     

Differential Contributions of Development and Learning to Infants' Knowledge of Object Continuity and Discontinuity

Sixty infants divided evenly between 5 and 7 months of age were tested for their knowledge of object continuity versus discontinuity with a predictive tracking task. The stimulus event consisted of a moving ball that was briefly occluded for 20 trials. Both age groups predictively tracked the ball when it disappeared and reappeared via occlusion, but not when it disappeared and reappeared via implosion. Infants displayed high levels of predictive tracking from the first trial in the occlusion condition, and showed significant improvement across trials in the implosion condition. These results suggest that infants possess embodied knowledge to support differential tracking of continuously and discontinuously moving objects, but this tracking can be modified by visual experience.     

A cross‐sectional study of prosodic sensitivity and reading difficulties

In this cross‐sectional study, we explore the relationship between prosodic sensitivity (suprasegmental phonology) and phonological awareness (segmental phonology) and investigate whether a group of poor readers display significant suprasegmental phonological deficits in comparison to chronological age‐matched controls and younger, reading age‐matched controls. Phonological awareness assessments were administered along with a battery of prosodic sensitivity assessments drawn from recent literature. The results showed that poor readers were outperformed by their chronological age‐matched counterparts on all measures of prosodic sensitivity. A significant main effect of group was found on the revised stress mispronunciations task and the stress assignment task from the prosodic assessment battery, the former of which remained even after controlling for individual differences in receptive vocabulary and measures of phonological awareness. Significant relationships were also found between measures of prosodic sensitivity and phonological awareness (especially phoneme awareness). These findings emphasise the importance of both segmental and suprasegmental phonological skills in children's reading development.     

The Relations between Frontal Brain Electrical Activity and Cognitive Development during Infancy

The relations between changes in the scalp-recorded electroencephalogram (EEG) and the development of the ability to perform successfully 2 cognitive tasks attributed to frontal lobe functioning were examined in 13 infants from 7 to 12 months of age. Infants successful in performing the A-not-B task with increasingly longer delays across the second half of the first year of life showed changes in power in scalp-recorded brain electrical activity in the frontal region and an increase in anterior/posterior EEG coherence. Infants with rapid mastery of object retrieval did not differ in frontal EEG development from infants who exhibited the normal developmental progression in object retrieval performance. In a task examining inhibition of reaching to a novel toy, there were no differences in frontal EEG as a function of performance. Results from a cross-sectional sample revealed similar findings. These data confirm work with nonhuman primates on the importance of maturation of frontal cortex in the successful performance on certain tasks (A-not-B), but do not confirm nonhuman primate data on the importance of frontal cortex for other tasks (object retrieval). The data also suggest that the electroencephalogram may be useful as a noninvasive measure of central nervous system development during the first year of life.     

Locomotor Status and the Development of Spatial Search Skills

The principal objective of this experiment was to investigate whether previous reports of a relation between locomotor status and stage 4 object permanence performance generalized to performance on a different object localization task. A secondary objective was to evaluate the contribution of visual tracking as a mediating variable in the relation between locomotor experience and search performance. Precrawling (n = 20), crawling (n = 10), and creeping (n = 18) infants (M = 33 weeks old) were tested using a search task in which either they or the hiding containers were rotated 180 degrees before search was permitted. The results revealed that locomotor status was related to search performance following a displacement of the infant, but not following a displacement of the containers. Moreover, visual tracking of the correct container was not related to locomotor status, even though it was related to search performance. These findings suggest that the effects of locomotor experience on infants' search performance are quite specific and are mediated by a variety of factors that do not necessarily generalize across search tasks.