Two overall views of brain-mind relationship: 1) Dualist: _________________________________________ ________________________________________ 2) Monist: _________________________________________ _____________ Two versions of monism: 1) Materialism: _____________________________________ _________________________________________________ _________________________________________________ 2) George Berkeley, Irish Bishop (1685-1753)_____________ _________________________________________________ _________________________________________________ Most neuroscientists assume a _____________ brain-mind relation. Why? Francis Crick (is famous for _______________________ ) He wrote “The Astonishing Hypothesis: The Scientific Search of the Soul” Are you monist or dualist? 1 Historic Overview of Mind-Brain Relationship Early clues of brain function: - As early as _____________, hominids bore holes into each other’s skulls (process called ____________). - Signs of healing: ____________________________________ ___________________. - Goal not clear: - However, writing from physicians of ancient Egypt (5000 years ago) suggests they believed that _____, not brain, was the seat of the soul and contained memory. 2 1 Views of the Brain in Ancient Greece - Most influential Greek scholar of 4th century B.C was ______________ (460-379), _______________________________. - Based on crude observations and dissections, ___________ not only believed that brain was an organ of sensation, but was also the seat of intelligence: - ____________ view disputed by __________ (384-322 B.C.). - _________ suggested that the heart was the center of intellect; he proposed that the brain was ________________________________ ________________________________________ Views of the Brain during the Roman Empire - Most influential figure in Roman medicine was the Greco-Roman physician _______ (A.D. 130-200), who embraced Hippocrate’s view. - He treated the injuries of gladiators and performed numerous animal dissections, especially sheep. - To him, sensations were registered and movements initiated by the movement of _______ to or from the brain ventricles via the nerves, which were believed to be hollow tubes, like the blood vessels. This was based on the prevailing theory that the body functioned according to a balance of four vital fluids, or _______. 3 Views of the Brain from the Renaissance to the XIXth Century - Galen’s view of the brain remained unopposed for nearly 1500 years - Emphasis is still on the ventricular localization of brain function by the great anatomist ___________________ (1514-1564). - Note the emphasis in his drawing of the __________ (large shape in the middle of the head). 4 2 - ____________ (1596-1650) proposed what theory of brain function? ______________________________ - According to his view, the brain functions on an _________ principle, such that environmental stimuli (sensations) can __________ produce motor responses. (defined differently today!) - Reflex comes from Latin reflectere “to bend back upon itself”. - He explained reflexes as ___________________________________ _____________________________________________________ - Note that he has only one nerve to and from the brain; there were no distinction between __________________________. - Thus, the brain of humans, like that of animals, were mechanical devices according to __________. 5 - To Descartes, what made humans different from animals? - According to Descartes, the soul controlled the body via the _____ _____, a gland centrally located just above the _______, covered by the _________. - The _____________, through its movements like a ______, could influence the muscles of the body, and receive external information via the sensory systems associated with the ventricular system (brain). This brain-mind relationship view is one of the best example of ___________. 6 3 Descartes’ view began to be refuted, in part because his model o f brain function was so _________________. - The discovery and experimentation with electricity in the late 1700’s allowed the Italian scientist ____________ and the German biologist ______________________ to discover that muscle tissue twitches in response to electrically stimulated nerves (even in decapitated frogs). - These discoveries finally displaced the notion that: ___________ __________________________________________________. 7 The lack of distinction between sensory and motor functions was also refuted by the Scottish physican ____________ and the French physiologist ___________________ around 1810. - They took advantage of the observation that nerve fibers divide just before joining the spinal cord (see below). - Remember the dorsal vs. ventral roots of the 31 pairs of spinal nerves? - They discovered that cutting the _______ roots produce sensory impairments while cutting the ______ roots produce motor deficits. - Gave rise to the notion that peripheral nerves are bundles of _____________________ that are either sensory or motor, but are generally mixed in peripheral nerves (we will see exceptions). 8 4 General Review of the Nervous System Nervous system - Central Nervous System (nucleus, nuclei, tracts) - ______ - ____________ - Peripheral Nervous System (ganglion, ganglia, nerves) - ___________________________ - ___________________________ - Afferent nerves - Efferent nerves - _________________________ (PNS) - _________________________ (SNS) - 12 pairs of ___________ (most somatic, some autonomic)9 Cells of the Nervous System Neurons - Example: a multipolar cell - __________ - ______ - _________ - ___________ Axon hillock Supporting Glial cells: - _______________ - ____________ - ___________ - ________ 10 5 Neurons communicate with each other at ___________________ Neuron A impulse Neuron B ____________ _____ ___________________ _____________________ ____________ ______________________ ___________ _______ Directions in the Nervous System: 11 CORTICAL ANATOMY Some facts about the Human Cerebral Cortex: Why is cortex referred to as gray matter? (clue, cell bodies vs.fibers) Surface area of cortex, which is constrained by a limited size skull, is maximized by ____________. Fissure - _______________________________. Sulcus - ________________________________ (plural - sulci). Gyrus - ________________________________ (plural: gyri). Pattern of cortical folding is fairly uniform from one person to the next, and is relatively symmetrical between the two hemispheres (but we will see some interesting exceptions). 12 6 Main Cortical Landmarks Fissures: - Longitudinal fissure: separates the ______________. - Lateral (Sylvian) fissure: furrow on the inferior surface of hemisphere, extending laterally between the _________________ lobes. It is separated in a posterior ramus (main part on the lateral surface), an anterior and ascending ramus, both projecting a short distance. - Transverse fissure: space between _______________________ (forebrain). - _____________: (sulcus of Rolando) Important landmark starts at superior aspect of hemispheres and descends along lateral surface at an angle, just short of the lateral fissure. Transverse fissure 13 The 4 Lobes of the Cerebral Hemispheres Frontal lobe: occupies entire area in front of _______________ and above the lateral sulcus on the lateral surface. Parietal lobe: Bounded anteriorly by _______________ and antero- ventrally by lateral fissure. Bounded posteriorly by imaginary line between pre-occipital notch and parietooccipital sulcus. Temporal lobe: Bounded dorsally by the _______________, and posteriorly by the imaginary line described above for parietal lobe. Occipital lobe: mostly on the _____________________________, and bounded from the parietal and temporal lobes as described above. Parieto- occipital sulcus Preoccipital notch 14 7 Space inside lateral fissure opens to the ______________________. Lateral view of the brain showing important landmarks: Frontal lobe: - superior, middle, and inferior frontal gyri, delimited by the superior and inferior frontal sulci. - precentral and central sulci delimit the precentral gyrus, forming the ________________________. - the anterior and ascending rami of the lateral fissure divide the inferior frontal gyrusinto the opercular (A), the triangular (B), and the orbital (C) portions. 15 Parietal lobe: - the central and postcentral sulci delimit the postcentral gyrus, forming the ___________________________. - the intraparietal sulcus divides the superior and inferior parietal lobules. - the inferior parietal lobule contains, dorsally, the supramarginal gyrus, and more ventrocaudally, the angular gyrus, two cortical regions implicated in ___________. Supramarginal gyrus Angular Superior gyrus frontal sulcus 16 8 Temporal lobe: - superior and inferior temporal sulci divide the lateral surface of temporal lobe into superior, middle, and inferior temporal gyri. - superior temporal gyrus dorsocaudally (floor of the lateral fissure) contains the transverse temporal gyri of Heschl, implicated in ______________________. - anterior to Heschl’s convolutions is the planum temporale, forming the ____________________. 17 Mid-sagittal View of Brain Occipital lobe: - calcarine and parieto-occipital sulci are readily apparent in mid- sagittal view, which demarcate the cuneus of the occipital lobe, containing the _____________________. - another area of interest in this view is the Cingulate gyrus. - the white appearing area in the middle of the brain is the ______ __________, which is the major fiber tract connecting the two ____________ of the brain. 18 9.