History and Evolution of Neuroscience

Energy Allocation of the Human Brain

The evolutionary condition where the brain consumes $25\%$ of bodily energy while accounting for only $2\%$ of body weight, enabled by cranial enlargement and jaw reduction.

Role of Fire in Brain Development

The use of fire to cook food, which shortened digestion time, required less circulatory demand by the intestines and liver, and freed up metabolic energy for the brain.

Erect Posture (Bipedalism)

The shift from quadrupedalism to standing on two legs, freeing the upper body to explore and stimulate the brain, thereby increasing brain mass, dendritic connections, and cerebral plasticity.

Prehistoric Trepanation (7000–2300 BC)

The practice of perforating the cranial vault, showing an early recognition of the brain as a vital organ affecting thought and behavior, evidenced by bone healing in skulls found in Denmark, India, and Peru.

Edwin Smith Papyrus

An Ancient Egyptian medical document containing the first known written appearance of the word "brain," describing the meninges and cerebrospinal fluid, even while the heart was still considered the seat of intelligence.

Hippocrates' Theory of Brain and Heart

The Ancient Greek medical view based on the balance of four humors (fire, air, water, earth) and the maxim to "do no harm," identifying the heart as the seat of intelligence and the brain as the organ of perception.

Plato's Body-Mind Dualism

The philosophical concept that the soul is confined by the physical body and must seek separation, asserting that health depends on maintaining an equilibrium between body and spirit.

Aristotle's Tripartite Soul

The concept dividing the soul into three forms: the vegetative soul (nutrition and sunlight), the sensitive soul (vegetative traits plus environmental responsiveness to pleasure and pain, seen in animals), and the intelligent soul (reasoning and higher cognition, seen in humans).

Aristotle's Cerebral Cooling Function

The belief that the heart is the seat of intelligence (psychic pneuma) and emotions, while the brain serves as a radiator to condense and cool emotional vapors, with temperament determined by this cooling capacity.

Galen's Cerebrum and Cerebellum Distinction

Anatomical observations based on sheep dissections showing that the anterior cerebrum is soft like a sponge to absorb sensations and memories, whereas the posterior cerebellum is firm to control muscles and movements.