Brain and Behavior Chapter 1
Interview with Rodney Brooks Human as machine, machine as human: http://www.aaai.org/AITopics/html/show.html http://news.bbc.co.uk/olmedia/cta/progs/02/hardtalk/brooks19aug.ram
Organizational Principles Two hemispheres – left, right Each with four distinct lobes: Frontal – thinking, planning, control of movement Parietal – tactile sensation, body image, space Occipital – vision Temporal – hearing, learning and memory, emotion Each lobe has folds: Gyri (gyrus) – crests (flat areas) Sulci (sulcus) – grooves (areas folded in)
Organization (Cont.) Contralateral control: The left hemisphere controls the right side of the body. The right hemisphere controls the left side of the body. Sensory information from one side of the body is interpreted by the opposite brain hemisphere. Some brain functions are localized to a hemisphere.
Localization of Language Aphasia – a difficulty of language caused by brain injury (such as with stroke). Broca – described patients who can understand language but not speak. Results from damage to Broca’s area. Wernicke – described patients who can speak but not understand language. Results from damage to Wernicke’s area.
A Language Circuit Wernicke’s areas and Broca’s areas are part of a connected circuit for receiving and producing language. Wernicke predicted conduction aphasia – a disorder produced by breaking the connection between the two regions. Results in paraphasia – omitting and substituting parts of speech. Also, inability to repeat phrases.
Brodmann Areas Different areas of the brain with different functions have different kinds of neurons. Brodmann mapped the areas based on the kinds of cells found: Cytoarchitectonic method 52 functionally distinct areas identified by number.
Evolution and Neuroscience Darwin’s theory of natural selection states that modern species of organisms evolved from a common ancestor. Animal models can be used because there are important similarities with humans. Specialization for an environmental niche means there are also important differences. Today animal welfare is closely monitored.
Levels of Analysis The reductionist approach breaks the brain into smaller pieces for study: Molecular -- what molecules do Cellular – how molecules work together in cell Systems (vision, motor) – circuits that perform a common function Behavioral – how systems work together to produce integrated behaviors Cognitive – neural mechanisms of mental activity
Understanding Disorders An important goal of neuroscience is finding treatment, prevention, or cure for serious disorders: Alzheimer’s disease -- dementia Parkinson’s disease –voluntary motor movement Depression – 30,000 suicides per year Schizophrenia – disrupts cognition, personality Stroke Alcohol & drug addiction