Lecture 3: Neurons and the Brain PDF

Lecture 3: Neurons and Networks Cognitive Psychology 2135 Major Brain Areas Frontal Lobe- associated with reasoning, planning, parts of speech, movement, emotions, problem solving Parietal Lobe- associated with movement, orientation, recognition, perception of stimuli Occipital Lobe- associated...

Lecture 3: Neurons and Networks Cognitive Psychology 2135 Major Brain Areas Frontal Lobe- associated with reasoning, planning, parts of speech, movement, emotions, problem solving Parietal Lobe- associated with movement, orientation, recognition, perception of stimuli Occipital Lobe- associated with visual processing Temporal Lobe- associated with perception and recognition of auditory stimuli, memory, and speech Occipital lobe: vision Dorsal Pathway - actions, guiding locations, “how and where” systems - vision for catching, grasping Ventral Pathway - identification, naming, recognition, “what” Parietal lobe: visual processing, spatial processing, location Dorsal Pathway - actions, guiding locations, “how and where” systems - vision for catching, grasping, etc. Temporal lobe: Memory, language, words, object identification  Frontal lobe movement, cognitive control, planning, judgment, creativity 1) the motor strip 2) the premotor cortex 3) the prefrontal cortex  Subcortical structures Amygdala: Processes motivationally significant stimuli such as those related to reward and fear, regulates social functions. Hippocampus: forms new memories Hypothalamus: Regulates the autonomic nervous system (blood pressure, heart rate, hunger, thirst, sexual arousal) Thalamus: A sensory relay station  Neuronal Communication (a) pyramidal cell; (b) cerebellar Purkinje cell; (c) motor neuron; (d) sensory neuron (a) pyramidal cells about 67% of neurons in cerebral cortex, hippocampus, amygdala (b) cerebellar Purkinje cells many dendrites; found in cerebellum (c) motor neurons: control motor activity; some originate from cerebral cortex, others from brainstem & spinal cord (d) sensory neurons: central nervous system cells that are activated by sensory input from the environment (like touching a hot surface with your fingertips) also, glial cells: main function is considered as supporting the neurons  Communicative Neurons Cells that accumulate and transmit electrochemical activity in the nervous system Approximately 100 billion neurons in the human brain that are simultaneously active while processing information  Dendrites Branch-like processes extending from the cell soma Receive information from terminal boutons of adjacent neurons  Axons Long, thin tube extending from soma Varies in length (from a few millimeters to a meter) Provides the paths by which neurons communicate with one another: Transmit information  Terminal Boutons Ball-like structures located at the ends of axon branches Contain neurotransmitters Form synapses with other neurons  Synapses Near-contact gap separating the terminal bouton of one neuron and the dendrite (or soma) of the next neuron in the chain Synapses  Neurotransmitters Chemical that crosses the synapse from the terminal bouton of one neuron to alter the electric potential of the membrane of the next neuron - e.g., dopamine, serotonin, norepinephrine How one neuron communicates with the next  Neural Representation of Information All neural information processing takes place in terms of excitation and inhibition (turning other neurons on & off) - Individual neurons can respond to specific stimuli features - Single neurons cannot represent human cognition complexity - Human cognition is achieved through large, distributed, complex neural activity patterns A neural network Functional neuroimaging is possible because neurons generate an electrical impulse when they fire & neurons need oxygen that’s delivered by the circulatory system  Imaging techniques Physical - CAT scan Cerebral Blood Flow - PET, fMRI, fNIRS Electro/magnetic – EEG (ERPs), MEG  CAT Scan CT: Computerized Axial Tomography Uses x-ray Nonfunctional - picture of brain at a single point in time - not used for dynamic processes - used to identify areas that are damaged  PET - Positron Emission Tomography - measures blood flow - radiation decay of injected radioactive substance - not used much anymore  fMRI - functional Magnetic Resonance Imaging - measures blood flow caused by firing neurons - detects many neurons, not single ones  BOLD function Blood Oxygenation Level Dependent Blood flow increases as a function of neural activity ~20 sec. The fMRI signal depends on the difference in the magnetic properties of oxygenated and de-oxygenated hemoglobin  Motor imagery: imagine hitting a tennis ball Spatial imagery: visualize your house, going from room to room Motor imagery = "yes" Spatial imagery = "no"  Adrian Owen Talk https://www.youtube.com/watch?v=Hz133pdwbOA EEG Electroencephalography  ERPs Event Related Potentials Measures electrical activity after a stimulus is presented  N400 negative going wave that peaks about 400 ms after a stimulus has been used a ton for studies of cognition sensitive to word meaning and how a word fits into context i.e., the degree to which a word is predictable  Participants read sentences like these 1 word at a time: There was a nice gentle wind, so the boy went out to fly a DeLong, Urbach, & Kutas (2005) negative plotted up smaller N400 for "kite" than for "airplane" MEG Magnetoencephalography MEG uses the changes in magnetic field to rapidly localize activity in the brain fNIRS Functional Near-Infrared Spectroscopy Uses lasers to measure cerebral blood flow at the surface of the cortex Advantages/Disadvantages of Types of Functional Imaging  What to study for the exams? Lectures are important. Exams will emphasize what has been covered in the lectures, the slides, and text Convergence Figures and key terms in the textbook that are related to the lectures are also important Damage to the prefrontal cortex area leads to A. neglect syndrome. B. a variety of problems, including problems planning and implementing strategies. C. exclusively difficulties with memory. D. primarily language problems. Damage to the prefrontal cortex area leads to A. neglect syndrome. B. a variety of problems, including problems planning and implementing strategies. C. exclusively difficulties with memory. D. primarily language problems. Which of these structures modulates the strength of emotional memories and is involved in emotional learning? A. thalamus B. hypothalamus C. hippocampus D. pons E. amygdala Which of these structures modulates the strength of emotional memories and is involved in emotional learning? A. thalamus B. hypothalamus C. hippocampus D. pons E. amygdala