Biomedical subjects

Michelle de Haan

Publications and source records attributed to Michelle de Haan.

9 recordsLinked to original sources

PubMed2006

Human memory development and its dysfunction after early hippocampal injury.

Cognitive memory involves long-term memories for facts (semantic memory) and personal experiences (episodic memory) that can be brought to mind. There is consensus that the hippocampus and related medial temporal lobe (MTL) structures are crucial for adult cognitive memory, but much less is known about their contribution to memory during infancy and childhood. We argue that the MTL is involved in memory from early in life, supporting recognition memory within the first postnatal months and recall memory within the first year. We propose that normal development involves a sequence in which a form of semantic-like memory emerges first, whereas the characteristics of episodic memory develop only later with progressive development of the hippocampus. Early bilateral injury to the hippocampus disrupts this normal pattern such that memory skills cannot develop beyond the stage of semantic memories. This review is part of the INMED/TINS special issue "Nature and nurture in brain development and neurological disorders", based on presentations at the annual INMED/TINS symposium (http://inmednet.com/).

Brain Injuries↗

PubMed2006

Brain and cognitive-behavioural development after asphyxia at term birth.

Perinatal asphyxia occurs in approximately 1-6 per 1000 live full-term births. Different patterns of brain damage can result, though the relation of these patterns to long-term cognitive-behavioural outcome remains under investigation. The hippocampus is one brain region that can be damaged (typically not in isolation), and this site of damage has been implicated in two different long-term outcomes, cognitive memory impairment and the psychiatric disorder schizophrenia. Factors in addition to the acute episode of asphyxia likely contribute to these specific outcomes, making prediction difficult. Future studies that better document long-term cognitive-behavioural outcome, quantitatively identify patterns of brain injury over development and consider additional variables that may modulate the impact of asphyxia on cognitive and behavioural function will forward the goals of predicting long-term outcome and understanding the mechanisms by which it unfolds.

Asphyxia Neonatorum↗

PubMed2005

The emergence of the social brain network: evidence from typical and atypical development.

Several research groups have identified a network of regions of the adult cortex that are activated during social perception and cognition tasks. In this paper we focus on the development of components of this social brain network during early childhood and test aspects of a particular viewpoint on human functional brain development: "interactive specialization." Specifically, we apply new data analysis techniques to a previously published data set of event-related potential (ERP) studies involving 3-, 4-, and 12-month-old infants viewing faces of different orientation and direction of eye gaze. Using source separation and localization methods, several likely generators of scalp recorded ERP are identified, and we describe how they are modulated by stimulus characteristics. We then review the results of a series of experiments concerned with perceiving and acting on eye gaze, before reporting on a new experiment involving young children with autism. Finally, we discuss predictions based on the atypical emergence of the social brain network.

Adult↗

PubMed2005

Deferred imitation of action sequences in developmental amnesia.

The aims of this study were to investigate whether patients with developmental amnesia (DA) associated with bilateral hippocampal volume reduction show an impairment in incidental nonverbal recall of action sequences, and whether the severity of this memory impairment is influenced by the sequence structure (causal vs. arbitrary). Like adult-onset cases of amnesia (McDonough, Mandler, McKee, & Squire, 1995), patients with DA did not differ significantly from their age-, sex-, and IQ-matched controls in spontaneous production of the sequences prior to modeling but recalled fewer target actions and action pairs than the control group after a 24-hour delay, independent of sequence structure. Unlike the patients with adult-onset amnesia, however, the patients with DA showed some memory for both types of sequences after a 24-hour delay. This difference in severity of memory impairment might reflect differences in extent of pathology and/or age at injury.

Adolescent↗

PubMed2004

Maternal personality and infants' neural and visual responsivity to facial expressions of emotion.

BACKGROUND: Recent investigations suggest that experience plays an important role in the development of face processing. The aim of this study was to investigate the potential role of experience in the development of the ability to process facial expressions of emotion. METHOD: We examined the potential role of experience indirectly by investigating the relationship between the emotional environment provided by mothers (as indexed by affective measures of their personality) and 7-month-olds' processing of emotional expressions (as indexed by visual attention and event-related potentials [ERPs]). RESULTS: For positive emotion, infants with highly positive mothers looked longer at fearful than happy expressions, and a subset of these infants who themselves also scored highly on positive temperament showed a larger negative central (Nc) component in the ERP to fearful than happy faces. For negative emotion, there were no detectable influences of maternal personality, although very fearful infants showed a larger Nc to fearful than happy expressions over the right hemisphere. CONCLUSION: To the extent that these variations in maternal disposition reflect variations in their expression of positive facial expressions, these results suggest that the emotional environment experienced by infants contributes to the development of their responses to facial expressions.

Adult↗

PubMed2003

Development of face-sensitive event-related potentials during infancy: a review.

Event-related potential (ERP) studies in adults have identified a number of components related to encoding and recognition memory of faces. Although behavioural studies indicate that even very young infants are able to detect faces and recognise familiar individuals, very few ERP studies document the neural correlates of these early abilities. In this article, we review four components (P1, N290, P400, Nc) and slow wave activity that are elicited while infants view faces. Where possible we draw links between these components and their possible equivalents to those observed in children and adults, and we highlight areas where further investigation is required. The theoretical importance of ERP studies of face processing in infants for debates about the origins and domain specificity of the adult cortical face processing system are discussed.

Child, Preschool↗

PubMed2002

Is face processing species-specific during the first year of life?

Between 6 and 10 months of age, the infant's ability to discriminate among native speech sounds improves, whereas the same ability to discriminate among foreign speech sounds decreases. Our study aimed to determine whether this perceptual narrowing is unique to language or might also apply to face processing. We tested discrimination of human and monkey faces by 6-month-olds, 9-month-olds, and adults, using the visual paired-comparison procedure. Only the youngest group showed discrimination between individuals of both species; older infants and adults only showed evidence of discrimination of their own species. These results suggest that the "perceptual narrowing" phenomenon may represent a more general change in neural networks involved in early cognition.

Adult↗

PubMed2002

Specialization of neural mechanisms underlying face recognition in human infants.

Newborn infants respond preferentially to simple face-like patterns, raising the possibility that the face-specific regions identified in the adult cortex are functioning from birth. We sought to evaluate this hypothesis by characterizing the specificity of infants' electrocortical responses to faces in two ways: (1) comparing responses to faces of humans with those to faces of nonhuman primates; and 2) comparing responses to upright and inverted faces. Adults' face-responsive N170 event-related potential (ERP) component showed specificity to upright human faces that was not observable at any point in the ERPs of infants. A putative "infant N170" did show sensitivity to the species of the face, but the orientation of the face did not influence processing until a later stage. These findings suggest a process of gradual specialization of cortical face processing systems during postnatal development.

Adult↗

PubMed2002

Developing a brain specialized for face perception: a converging methods approach.

Adults are normally very quick and accurate at recognizing facial identity. This skill has been explained by two opposing views as being due to the existence of an innate cortical "face module" or to the natural consequence of adults' extensive experience with faces. Neither of these views puts particular importance on studying development of face-processing skills, as in one view the module simply comes on-line and in the other view development is equated with adult learning. In this article, we present evidence from a variety of methodologies to argue for an "interactive specialization" view. In this view, orienting tendencies present early in life ensure faces are a frequent visual input to higher cortical areas in the ventral visual pathway. In this way, cortical specialization for face processing is an emergent product of the interaction of factors both intrinsic and extrinsic to the developing child.

Adult↗