Week 1-nativism-empiricism (1)

Introduction to Perception

• Nativism and Empiricism: Two contrasting philosophical perspectives on the origins of knowledge and perception.

Course Information

• Instructor: Zygmunt Pizlo

• Location: SSPA 2187

• Email: zpizlo@uci.edu

• OTA: Heliodoro Lemus

Definition of Perception

• Perception: Provides the observer with accurate information about the physical world.

  • Study of perception is termed Psychophysics, which focuses on the relationship between subjective experiences and the objective world.

Historical Context of Perception in Experimental Psychology

• Oldest branch of Experimental Psychology: The study of perception started with early philosophers like Alhazen in 1083.

• Trusting one's perceptions was crucial for experiments in disciplines like Physics and Astronomy.

The Challenge of Studying the Mind

• Scientific Study of the Mind: Complicated due to the private nature of mental events.

  • Psychologists focus on observable behavioral responses (e.g., button presses, verbal responses) rather than private thoughts, leading to the metaphor of the mind as a "black box".

Understanding Subject Perception

• Difficulty in knowing a subject's perception accurately.

  • Verbal descriptions may not align exactly with the observer's experience.

  • Example: Seeing a square does not guarantee the subject sees it as a square—different interpretations occur.

Visual Psychophysics

• Examination of how the visual system conveys accurate information concerning geometrical and physical characteristics.

• Key characteristics of interest: gravity, weight, distance, size, color, motion.

• Questions about whether these capabilities are innate or learned.

Developmental Studies in Depth Perception

• Thorndike, 1899: Research on depth perception in newborn chicks suggesting innate capabilities.

• Gibson & Walk, 1960: Investigated depth perception in human infants, highlighting the maturation of the nervous system post-birth.

  • Infants showed depth perception through experiments, indicating maturation is essential.

Visual Cliff Experiment

• Apparatus: A board over glass with differing patterns below illustrate depth perception in infants.

  • Child crawls toward the "shallow" side but avoids the "deep" side despite physical reassurance of safety.

Coordination in Newborn Sensory Systems

• Michael Wertheimer (1963): Suggested that visual, auditory, and motor systems are coordinated at birth.

Fechner’s Psychophysics

• Causal Chain of Events: Describes the flow from distal stimulus to perception involving:

  • Distal stimulus: The actual object in the environment.

  • Proximal stimulus: The retinal image formed.

  • Transduction: Conversion of stimulus into neural signals.

  • Brain Processing: Interpretation in the brain leading to percept.

Different Types of Events in Psychophysics

• Outer Psychophysics: Examines the relationship between physical characteristics of the real world and percept.

• Inner Psychophysics: Looks at the anatomical and physiological connections to perception (mind-body problem).

The Mind-Body Problem (Inner Psychophysics)

• Questions regarding the interplay between understanding perception and brain function:

  • What can we learn about perception through brain study?

  • What can studying perception reveal about the brain?

Exploring Representational Insight Problems

• Insight Problems: Required alteration of problem representation to solve (e.g., constructing shapes from matchsticks).

Fechner’s vs. Mach’s Paradigm

• Fechner’s Empiricism: Implies perception is directly caused by stimulus; influenced by John Locke.

• Mach’s Open-mindedness: Suggests alternatives to Fechner's strict empiricism, influenced by Leibniz’s philosophies.

Origins of Perception: Nativism vs. Empiricism

• Nativism: Ideas from Plato, Descartes suggesting some knowledge is innate.

• Empiricism: Philosophers like Aristotle and Locke claim experience is necessary for knowledge.

  • Implications for understanding perceptual mechanisms and cultural perspectives.

Case Studies on Object Recognition

• Hochberg & Brooks (1962): Study indicating innate recognition in children who had no exposure to 2D images but recognized line drawings after familiarization with 3D objects.

Experimental Studies of Touch and Visual Conflict

• Rock & Harris (1967): Investigated the conflict between visual and touch stimuli, concluding that vision often dominates.

Visual Adaptation Studies

• Rock & Harris (1967): Adaptation experiments revealing changes in positional sense rather than visual perception.

Implications of Visual Learning in Infants

• Hess (1956): Demonstrated innate visual direction and depth perception in chicks, not influenced by experience.

Müller-Lyer Illusion Findings

• Indicates the stability of perceptual processes against personal experience or learning.

fMRI Studies of Adaptation

• Linden et al. (1999): Analysis of how subjects adapt to visual distortions, showing differentiation between visuomotor adaptation and actual perceptual experience.

Child's Perception and Statistical Learning

• Spelke's Research: Infants exhibit an understanding of physical principles, including cohesion, continuity, and contact that allow boundary perception of objects.

Significant Findings in Infant Studies on Perception

• Infants recognize visual stimuli and maintain perceptual constancy across different viewing conditions, establishing foundations for understanding object permanence and motion.

Newborn Face Recognition Insights

• Slater et al. (2002): Infants display preference for mother's face, indicating early development of social recognition and visual preference.

Imitation Studies by Meltzoff & Moore

• Infants demonstrate the capacity for imitation of facial expressions, highlighting cognitive development and social interaction.

Intuitive physics in Infants

• Studies indicate infants' inherent understanding of physical properties such as solidity and gravity, underscoring the interplay between perception and cognitive development.