Biology and Behavior: Historical and Conceptual Foundations

Introduction

  • The mind-body connection is a significant topic in medicine.
  • The chapter explores the biological side of psychology, including:
    • The history of neuropsychology
    • The structure and organization of the human nervous system
    • Communication between the nervous and endocrine systems
    • The effects of genes and environment on behavior
    • Aspects of psychological development

A Brief History of Neuropsychology

  • Nineteenth-century researchers began linking behavior to physiology and brain anatomy.
  • Franz Gall (1758-1828):
    • Proposed that behavior, intellect, and personality are linked to brain anatomy.
    • Developed phrenology: well-developed traits expand the related brain area, causing skull bulges.
    • Phrenology was found to be false but spurred research on brain function.
  • Pierre Flourens (1794-1867):
    • Studied the functions of major brain sections using extirpation (ablation) on animals.
    • Extirpation: surgically removing parts of the brain and observing behavioral consequences.
    • Concluded that specific brain parts have specific functions, and removing one part weakens the entire brain.
  • William James (1842-1910):
    • Known as the father of American psychology.
    • Studied how the mind adapts to the environment.
    • Established functionalism: the study of how mental processes help individuals adapt.
  • John Dewey (1839-1952):
    • Another important name in functionalism.
    • His 1896 article criticized the reflex arc concept.
    • Believed psychology should focus on the organism as a whole adapting to the environment.
  • Paul Broca (1824-1880):
    • Demonstrated that specific functional impairments can be linked to specific brain lesions.
    • Studied a man unable to speak due to a lesion in a specific area on the left side of the brain, now known as Broca's area.
  • Hermann von Helmholtz (1821-1894):
    • Measured the speed of a nerve impulse.
    • Related nerve impulse speed to reaction time, linking behavior and nervous system activity.
    • Credited with transitioning psychology from philosophy to a quantifiable natural science.
  • Sir Charles Sherrington (1857-1952):
    • Inferred the existence of synapses.
    • Proposed that synaptic transmission was an electrical process (later found mainly chemical).