1.1-1.2: Neuropsychology and Nervous System Organization

Franz Gall

had one of the earliest theories that behavior, intellect, and even personality might be linked to brain anatomy. He developed the doctrine of phrenology.

Phrenology

The basic idea was that if a particular trait was well-developed, then the part of the brain responsible for the trail would expand. This expansion would push the area of the skull tat covered that part of the brain outward and therefore cause a bulge on the head. Gall believed that one could thus measure psychological attributes by feeling or measuring the skull. Although this was shown to be false, it did generate serious research on brain functions and was the impetus for the work of other psychologists through the remainder of the 19th century.

Pierre Flourens

was the first person to study the functions of the major sections of the brain. He did this by extirpation (aka ablation) on rabbits and pigeons.

Extirpation or ablation

Various parts of the brain are surgically removed and the behavioral consequences are observed. Fluorens’ work led to his assertation that specific parts of the brain had specific functions, and that the removal of one part weakens the whole brain.

William James

known as the father of American psychology, studied how the mind adapts to the environment. His views formed the foundation for the system of through in psychology known as functionalism.

Functionalism

studies how mental processes help individuals adapt to their environments

John Dewey

is another important name in functionalism because his 1896 article is seen as its inception. This article criticized the concept of the reflex arc, which breaks the process of reacting to a stimulus into discrete parts. He believed that psychology should focus on the study of the organism as a whole as it functioned to adapt to the environment

Paul Broca

added to the knowledge of physiology by examining the behavioral deficits of people with brain damage. He was the first person to demonstrate that specific functional impairments could be linked with specific brain lesions. He studied a person who was unable to speak and discovered that the person’s disability was due to a lesion in a specific area on the left side of the person’s brain

Hermann von Helmholtz

was the first to measure the speed of a nerve impulse. He also related the measured speed of such impulses to reaction time, providing an important early link between behavior and underlying nervous system activity. Because he provided one of the earliest measurable links between psychology and physiology, he is often credited with the transition of psychology out of the realm of philosophy and into the realm of quantifiable natural science

Sir Charles Sherrington

first inferred the existence of synapses. Many of his conclusions have held over time - except for one. He thought that synaptic transmission was an electrical process, but we now know that it is primarily a chemical process.

Sensory (Afferent) Neurons

Transmit sensory information from receptors to the spinal cord and brain

Motor (Efferent) Neurons

Transmit motor information from the brain and spinal cord to muscles and glands

Interneurons

Are found between other neurons and are the most numerous of the three types of neurons. They are located predominantly in the brain and spinal cord and are often linked to reflexive behavior

Reflex Arcs

Neural circuits that control reflexive behavior linked to interneurons

Central Nervous System

Composed of the brain and spinal cord

Peripheral Nervous System

Made up of nerve tissue and fibers outside the brain and spinal cord; includes spinal and cranial nerves

31

The spinal nerves are the _____ pairs of nerves emanating from the spinal cord.

12

The cranial nerves are the _____ pairs of nerves emanating directly from the brain.

Central and Peripheral

The nervous system is divided into:

Somatic and Autonomic

The peripheral nervous system is divided into:

Sympathetic and Parasympathetic

The autonomic peripheral nervous system is divided into:

Somatic Nervous System

Consist of sensory and motor neurons distributed throughout the skin, joints, and muscles.

Afferent

Sensory neurons transmit information toward the CNS through _______ fibers

Efferent

Motor impulses travel from the CNS back to the body along ________ fibers

Autonomic Nervous System

Generally regulates heartbeat, respiration, digestion, and glandular secretions. It manages the involuntary muscles associated with many internal organs and glands. It also helps regulate body temperature by activating sweating or piloerection, depending on whether the body is too hot or too cold. These are automatic and independent of conscious control

Parasympathetic Nervous System

Conserves energy. It is associated with resting and sleeping states, and acts to reduce heart rate and constrict the bronchi. It is also responsible for managing digestion by increasing peristalsis and exocrine secretions

Acetylcholine

The neurotransmitter responsible for parasympathetic responses in the body

Parasympathetic

Functions of the _______ System:

• Constricts pupils

• Stimulates flow of saliva

• Constricts bronchi

• Slows heartbeat

• Inhibits release of glucose

• Stimulates bile release

• Inhibits adrenaline production

• Stimulates peristalsis and secretion

• Contracts bladder

• Promotes erection of genitals

Sympathetic Nervous System

Activated by stress. This can include everything from a mild stressor, such as keeping up with schoolwork, to emergencies that mean the difference between life and death. It is closely associated with rage and fear reactions, also known as “fight-or-flight” reactions. When activated, it:

• Increases heart rate

• Redistributes blood to muscles of locomotion

• Increases blood glucose concentration

• Relaxes the bronchi

• Decrease digestion and peristalsis

• Dilates the eyes to maximize light intake

• Releases epinephrine into the bloodstream

Sympathetic

Functions of the __________ Nervous System:

• Dilates pupils

• Inhibits salvation

• Relaxes bronchi

• Accelerates heartbeat

• Stimulates glucose production and release

• Inhibits peristalsis and secretion

• Secretion of adrenaline and noradrenaline

• Inhibits bladder contraction

• Stimulates orgasm

Fight-or-flight

Sympathetic nervous system is:

Rest-and-digest

Parasympathetic nervous system is: