Franz Josef Gall (1758-1828)
- Built on earlier work of Thomas Willis
- Was one of the first scientists to look at the brain as a complex organ
- Willis Observed that brain 2 kinds of substances, gray matter (outer surfaces of the brain) and white matter.
- Willis believed that the white matter contained spirits generated in the gray matter and correctly described blood vessels in the brain.
-Gall correctly identified commissures, that the two halves of the brain are interconnected by white matter. This helped explain why damage to one side would lead to effects on the other.
These findings laid the groudwork for the later discovery that the brain and spinal cord are composed of neurons.
-Gall was also one of the first comparative brain anatomists and developed phrenology. Believing that parts of the skull could properly identify different faculties and traits.
Used empirical observations to make deductions and proposed 27 faculties called organs.
Pierre Flourens (1794-1867)
- Aimed to use more rigorous scientific methods to understand brain functions
Ablation (Removal part of brain or lesions), then studied functions and regeneration.
Found that ablation of cerebellum=motor loss, and cerebral cortex=lost will
-Proposed that the cortex and cerebellum had specific functions (action proper) but they interacted to function as a whole (action commune)
- The proposed idea of brain plasticity
Paul Broca (1824-1880)
- A patient of Broca's named Tan had a lesion on the left frontal hemisphere which caused a lack of speech production, although comprehension was intact. Later Tan began losing sense of his right arm and leg.
Broca's aphasia: Loss of proudction of speech caused by damage to the left frontal hemisphere (Broca's Area) also known as motor aphasia
Gustav Fritsch (1837-1927) and Eduard Hitzing (1838-1907)
- Studied if brain responded to electrical stimulation i
- Shocking animals brains etc
David Ferrier
- Stimulated occipital lobe and found loss of vision.
- Also located the temporal lobe and sensory strip
Ideas emerged such as interconnected (association) areas and importance of white matter.
Carl Wernicke (1848-1905)
Described sensory aphasia also known as Wernicke's aphasia
- The ability to produce speech but not understand (receptive) language.
- Will repeat and have issues with comprehension, paraphasias
Shepard Ivory Franz (1874-1933)
- Found that cats that had previously solved a puzzle forgot the responses only when the frontal regions were ablated. Sometimes frontally ablated animals were able to relearn the escape response
Karl Lashley (1890-1958)
-Refuted localization and though that memories were contained within cortex widely.
-Said it was important the size of the ablation and the difficulty of the maze.
Built on Flourens's concept of action commune
Espoused Equipotentiality (Brain plasticity, neural regions take over)
Wilder Penfield (1891-1976)
- Located the region of the epileptic seizure through gentle stimulation and removed regions
Brenda Milner (1918-)
- Did work with HM
- HM had seizures and had medial temporal lobe severed and parts of hippocampus
- Seizures stopped but had severe anterograde amnesia (developing new memories)
- Had impared encoding and storage, declarative memory also impaired
- Findings showed that memory is a distinct cerebral function
- Showed that medial aspect of temporal lobe is important for memory
- Findings showed that hippocampus and temporal lobe stored memories.
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