Developmental Psychology 1 - Cognitive Development

Instructor: Patricia Gerván
Email: gervan.patricia@ppk.elte.hu
Term: 2025 Fall
Main Topics Covered: Knowledge of Objects, Knowledge of Numbers, Categorization, Statistical Learning, Habituation

Involves understanding properties and physical laws governing objects.
Infants possess an innate knowledge about objects, shaping their perception and attention.
Spelke provides a comprehensive overview of perceptual knowledge in infancy, highlighting the discrepancy between her findings and Piaget's original views.

Definition: The understanding that objects continue to exist even when they are hidden from view. This concept is central to Piaget’s theory, who believed infants do not grasp object permanence until about 8 months of age.
Initial Research Observations:
- Prior to 8 months, infants demonstrate a lack of object permanence largely due to their inability to mentally represent objects.
- Classic paradigm highlighted several shortcomings of Piaget's methodology, such as overreliance on motor ability, high task demands, unrepresentative samples, and lack of control in experiments.
Overt vs. Covert Behavior:
- Overt Behavior: Visible actions, such as an infant reaching for a hidden toy, easily measured but dependent on motor skills.
- Covert Behavior: Indications of internal mental processes. For example, an infant might look longer at an unexpected disappearance of a toy, suggesting understanding beyond their motor capabilities.

Baillargeon implemented innovative research methodologies:
- Ramp Study: Assessed infants’ responses to possible vs. impossible events
- Infants looked longer at contradictory events (e.g., a car rolling through an invisible obstacle), suggesting awareness of object permanence earlier than Piaget proposed.
- Short/Tall Carrot Test: Infants expected to see a tall carrot after it was hidden but did not, indicating their understanding of object permanence.
Results from Baillargeon’s studies:
- Indicate that object permanence exists as early as:
- 6.5 months (Baillargeon, 1986)
- 4 months (Baillargeon & DeVos, 1991)
- 3.5 months (Baillargeon & DeVos, 1991)

Concerns: Baillargeon’s studies may lack rigorous habituation standards.
A-not-B Task: Investigation into why infants do not reach for hidden objects before 8-9 months, demonstrating increasing delays affecting their abilities. Older infants tolerate longer delays without errors.
Exploring animal cognition further highlights that various species also exhibit differing levels of object permanence, suggesting a broader cognitive understanding of object permanence across species.

Object Coherence: The ability to perceive an object as a complete, singular whole, which is critical for understanding object permanence. Infants utilize visual cues to perceive cohesive objects.
Kellman and Spelke’s Study: Experiments demonstrated that infants perceive coherent objects inferred through movement rather than perceiving them as separate entities.
Study on Object Identity: Examined whether infants can deduce expectations about objects through their movements. Infants of differing ages display varying competencies in recognizing these expectations, revealing overarching cognitive development patterns.

Wynn’s experiments revealed that infants demonstrated core numerical understanding:
- 1 + 1 and 2 − 1 Conditions: Infants displayed surprise at unexpected outcomes, indicating early mathematical cognition.
- Core System 1 and Core System 2: Infants utilize distinct cognitive systems for numerical understanding, where Core System 1 covers large quantities and ratios while Core System 2 focuses on smaller, exact quantities.

Definition: A foundational cognitive ability that allows infants to detect patterns and regularities in their environments, aiding in various learning processes, including language acquisition.
Infants can differentiate stimuli through a statistical learning mechanism, which surfaces through observed ratios and relationships.

Studies (Eimas & Quinn, 1994) revealed that infants categorize based on perceptual features:
- Infants shown familiarized categories (e.g., cats vs. horses) displayed significant attentional biases towards novel animals within differing categories, indicating cognitive categorization skills.
Perceptual vs. Conceptual Categorization:
- Infants categorize based on appearance (perceptual) and functionality (conceptual). Studies indicated that as infants grow, they attain the ability to categorize based on more abstract and causal relationships, moving beyond mere visual recognition.

Understanding cognitive development in infants aids in recognizing the foundations of learning, reasoning, and problem-solving abilities, influencing educational strategies and interventions in early childhood.
The studies discussed underline the evolving nature of cognitive abilities and invite further exploration into mechanisms underlying childhood learning and developmental psychology.

Baillargeon, R. (1986). Object permanence in young infants: Evidence for at least two levels of understanding.
Diamond, A. (1985). The development of object permanence: Insights from research on infants.
Eimas, P. D., & Quinn, P. C. (1994). Studies on categorization in infants.
Kellman, P. J., & Spelke, E. S. (1983). Perception of partial occlusion in infant visual cognition.
Wynn, K. (1992). Addition and subtraction by human infants.
Xu, F., & Spelke, E. S. (2000). Large-number discrimination in 6- and 9-month-old infants.