Biomedical subjects

Adele Diamond

Publications and source records attributed to Adele Diamond.

11 recordsLinked to original sources

PubMed2007

Interrelated and interdependent.

The possibilities for building and nourishing connections among the social, cultural, neuroscientific, biological, and cognitive sciences in the service of understanding children and their development are tremendously exciting. Crossing, and integrating across, disciplinary boundaries, especially those disciplines relating to biology/neuroscience, society/culture, cognition, emotion, perception, and motor function has greatly increased over the last decade and hopefully will increase exponentially in the future. All of these aspects of being human are multiply-interrelated and we need to make far more progress in understanding those interrelations.

Child↗

PubMed2006

Bootstrapping conceptual deduction using physical connection: rethinking frontal cortex.

The age at which infants can demonstrate the ability to deduce abstract rules can be reduced by more than half, from 21 months to 9 months. The key is to introduce a physical connection between the items to be conceptually related. I argue here that making the same change in how items are presented might also help some preschoolers with learning delays, especially some children with autism. I also suggest that the roles of premotor and ventrolateral prefrontal cortices in deducing abstract rules might have been misinterpreted behaviorally and anatomically. The crucial brain region may be the periarcuate, which partially overlaps both premotor and lateral prefrontal cortex. The cognitive ability made possible by this region might be something far more elementary than previously considered: the ability to perceive conceptual connections in the absence of physical connection.

Child↗

PubMed2006

Development of cognitive control and executive functions from 4 to 13 years: evidence from manipulations of memory, inhibition, and task switching.

Predictions concerning development, interrelations, and possible independence of working memory, inhibition, and cognitive flexibility were tested in 325 participants (roughly 30 per age from 4 to 13 years and young adults; 50% female). All were tested on the same computerized battery, designed to manipulate memory and inhibition independently and together, in steady state (single-task blocks) and during task-switching, and to be appropriate over the lifespan and for neuroimaging (fMRI). This is one of the first studies, in children or adults, to explore: (a) how memory requirements interact with spatial compatibility and (b) spatial incompatibility effects both with stimulus-specific rules (Simon task) and with higher-level, conceptual rules. Even the youngest children could hold information in mind, inhibit a dominant response, and combine those as long as the inhibition required was steady-state and the rules remained constant. Cognitive flexibility (switching between rules), even with memory demands minimized, showed a longer developmental progression, with 13-year-olds still not at adult levels. Effects elicited only in Mixed blocks with adults were found in young children even in single-task blocks; while young children could exercise inhibition in steady state it exacted a cost not seen in adults, who (unlike young children) seemed to re-set their default response when inhibition of the same tendency was required throughout a block. The costs associated with manipulations of inhibition were greater in young children while the costs associated with increasing memory demands were greater in adults. Effects seen only in RT in adults were seen primarily in accuracy in young children. Adults slowed down on difficult trials to preserve accuracy; but the youngest children were impulsive; their RT remained more constant but at an accuracy cost on difficult trials. Contrary to our predictions of independence between memory and inhibition, when matched for difficulty RT correlations between these were as high as 0.8, although accuracy correlations were less than half that. Spatial incompatibility effects and global and local switch costs were evident in children and adults, differing only in size. Other effects (e.g., asymmetric switch costs and the interaction of switching rules and switching response-sites) differed fundamentally over age.

Adolescent↗

PubMed2005

Attention-deficit disorder (attention-deficit/ hyperactivity disorder without hyperactivity): a neurobiologically and behaviorally distinct disorder from attention-deficit/hyperactivity disorder (with hyperactivity).

Most studies of attention-deficit/hyperactivity disorder (ADHD) have focused on the combined type and emphasized a core problem in response inhibition. It is proposed here that the core problem in the truly inattentive type of ADHD (not simply the subthreshold combined type) is in working memory. It is further proposed that laboratory measures, such as complex-span and dual-task dichotic listening tasks, can detect this. Children with the truly inattentive type of ADHD, rather than being distractible, may instead be easily bored, their problem being more in motivation (underarousal) than in inhibitory control. Much converging evidence points to a primary disturbance in the striatum (a frontal-striatal loop) in the combined type of ADHD. It is proposed here that the primary disturbance in truly inattentive-type ADHD (ADD) is in the cortex (a frontal-parietal loop). Finally, it is posited that these are not two different types of ADHD, but two different disorders with different cognitive and behavioral profiles, different patterns of comorbidities, different responses to medication, and different underlying neurobiologies.

Attention Deficit Disorder with Hyperactivity↗

PubMed2005

Not quite as grown-up as we like to think: parallels between cognition in childhood and adulthood.

Greater continuity in cognition between children and adults may exist than is usually appreciated. It was thought that after 3 to 4 years of age, the problem in switching on the dimensional-change card-sort task disappears. We show here, however, that if speed is used as the dependent measure, the effect of the first dimension is evident even in adults. Adults, like preschoolers, show difficulty in switching from a block of sorting by color or shape to a block of sorting by the other dimension. Notably, performance throughout the session was affected by the first dimension by which stimuli were sorted. We hypothesize that perhaps adults never fully outgrow any of the cognitive and perceptual biases of infancy and early childhood. Other examples of such biases that appear to still be present in adults are discussed. Conversely, the assumption that the optimal dependent measure for adults is the most sensitive measure for children is questioned.

Adolescent↗

PubMed2005

Preschool children's performance in task switching on the dimensional change card sort task: separating the dimensions aids the ability to switch.

Fifty-seven children (53% female) at 3 ages (2 1/2, 3, and 3 1/2 years) were tested on the standard Dimensional Change Card Sort (DCCS) task with integrated stimuli (e.g., a red truck) and on a separated-dimensions version where colorless shapes were presented on a colored background (e.g., a black truck on a red background). Roughly twice as many children successfully switched sorting dimensions when color was a property of the background than when color was a property of the shape itself. Children succeeded 6 months earlier in switching sorting criteria when the dimensions were separated. When evidence of both indecision and accuracy was taken into account, a clear and rich developmental progression emerged. These results support an inhibitory control interpretation of preschoolers' problems on the DCCS task. Diamond theorized that young children can have difficulty integrating features not part of a single object and separating features of a single object so that the object can be categorized first by one attribute and then by another. Preschoolers remain stuck in thinking about objects according to the objects' initially relevant attribute (attentional inertia; Kirkham, Cruess, & Diamond, 2003). To switch perspectives, the old way of thinking about the objects must be inhibited. Separating color and shape reduced the need for such inhibition; a truck was always a truck, and the background was always red.

Child, Preschool↗

PubMed2004

Developmental cognitive neuroscience: progress and potential.

Developmental cognitive neuroscience is an evolving field that investigates the relations between neural and cognitive development. Lying at the intersection of diverse disciplines, work in this area promises to shed light on classic developmental questions, mechanisms subserving developmental change, diagnosis and treatment of developmental disorders, and cognitive and neuroscientific topics traditionally considered outside the domain of development. Fundamental questions include: What are the interrelations between developmental changes in the brain (e.g. in connectivity, chemistry, morphology) and developmental changes in children's behavior and cognitive abilities (e.g. representational complexity, ability to sustain selective attention, speed of processing)? Why, and how, is learning enhanced during certain periods in development? How is our knowledge organized, and how does this change with development? We discuss preliminary investigations of such questions and directions for future work.

Aptitude↗

PubMed2004

Genetic and neurochemical modulation of prefrontal cognitive functions in children.

OBJECTIVE: The catechol O-methyltransferase (COMT) gene affects how long dopamine acts in the prefrontal cortex. The Methionine polymorphism, which results in a slower breakdown of prefrontal dopamine, is associated with better adult prefrontal cortex function. The authors investigated the relation between the COMT gene polymorphism and cognitive performance in children. METHOD: Children were tested on cognitive tasks that depend on the dorsolateral prefrontal cortex and seem to be sensitive to the level of dopamine there (dots-mixed task), depend on that neural region but appear insensitive to its dopamine content (self-ordered pointing), and depend on other neural systems (recall memory and mental rotation). After data collection, cheek swabs were obtained from all children. DNA was extracted and genotyped for the COMT gene with polymerase chain reaction. RESULTS: Children who were homozygous for the Methionine polymorphism performed significantly better on the dots-mixed task but not on others. CONCLUSIONS: The findings provide an existence proof that genotypic differences can relate to differences in cognitive performance in typically developing children. The authors achieved a level of specificity never previously attempted; the COMT polymorphism was found to be differentially related to performance on tasks linked to the same prefrontal region by whether cognitive requirements of the tasks were sensitive to the level of dopamine found. These results challenge accepted notions that since dopamine is important for some cognitive functions dependent on the prefrontal cortex, it is important for all. The differential sensitivity of distinct cognitive abilities to specific neurotransmitters may make possible targeted pharmacological interventions.

Adolescent↗

PubMed2004

Executive functioning in preschoolers: reducing the inhibitory demands of the dimensional change card sort task.

To investigate the role of inhibitory control in preschoolers' ability to switch sets, 3 conditions of the Dimensional Change Card Sort task ( Zelazo, Reznick, & Pinon, 1995) were tested. In Condition B (novel response options, standard stimuli) action inhibition was reduced, but the need for attentional inhibition was maintained. In Condition C (novel stimuli, standard response options) demands on both action and attentional inhibition were reduced. Performance in these was compared to that in the standard condition (A). Rule complexity was comparable across conditions. All 21 children who passed preswitch (average age 37 months) were tested on all postswitch conditions, order counterbalanced. Although reducing demands on action inhibition (Condition B) did not significantly improve performance, when demands on both action and attentional inhibition were reduced (Condition C) almost all children (95%) successfully switched sets (even children only 2 1/2 years old). Inadequate inhibition (of attention alone or both attention and action) appears sufficient to account for virtually all errors by preschoolers on this card sorting task.

Attention↗

PubMed2003

Early success in using the relation between stimuli and rewards to deduce an abstract rule: perceived physical connection is key.

Are spatial proximity (0.10-12.5 cm), temporal proximity (0-, 2-, and 5-s gaps), and/or perceived connectedness of stimulus and reward key to infants' ability to deduce an abstract nonmatching rule from reward feedback? In this investigation, 3 conditions of the delayed nonmatching to sample task were administered to infants 9, 12, and 15 months old, and 5 more conditions were administered just to 12-month-olds. Results showed that connectedness is key. In its presence, neither close spatial or temporal proximity was needed. In the absence of the perception that stimulus and reward were components of a single thing, even close spatial and temporal proximity were insufficient for infants in the 1st year to grasp the rule-based association between stimuli and rewards.

Age Factors↗

PubMed2002

Conditions under which young children can hold two rules in mind and inhibit a prepotent response.

The day-night task requires saying "night" to a picture of the sun and "day" to a picture of the moon. In this investigation of why young children fail at this task, systematic variations of the task were administered to 96 children, half 4 years old and half 4 1/2 years old. Training children on the strategy of chunking the 2 rules into I ("say the opposite"), thus reducing memory load, did not help their performance. What helped was reducing the inhibitory demand by instructing them to say "dog" and "pig" (not "night" and "day") even though memory of 2 rules and inhibiting saying what the pictures represented were still required. Here the response to be activated and the response to be inhibited were unrelated. When the correct response was semantically related to, and the direct opposite of, the to-be-inhibited response, children performed poorly. Inserting a delay between stimulus and response helped even though that delay was filled with distraction. Young children apparently need several seconds to compute the answer on this task. Often they do not take the needed time; when forced to do so, they do well.

Age Factors↗