Covered in both lecture and booklearning objectivescheck your understandingChapter 1I Perceptual ProcessA. Stimuli (distal/proximal)1. the objects and events that are perceived and the physical phenomena they produce2. the object itself is the distal stimulus3. the light or sound reflecting the object is a proximal stimulus that makes contact with sensory receptorsB. Neurons 1. produce and transmit information carrying electrochemical signals2. neurons that are specialized to convert proximal stimuli to neural signals are sensory receptorsC. Directional processes1. Top-down information is an observers knowledge, expectations and goals affect on perception2. Bottom-up information is contained in neural signals from receptorsD. Perception1. receptors selectively sample the world2. more is sensed than what is perceived and more is perceived than what is sensed.a. the perception of depth, filling of blindspots, etc.3.brain makes best guess on what the real state of the world is4. rules for perception have been created based on what has been adaptive (natural selection)E. Three types of Questions1. How does the proximal stimulus carry information about the distal stimulus2. How is the proximal stimulus transduced3. What is the relationship between perceptual experience and the distal stimulusa. how perception differs from the real state of the object being experienced.II. Measuring SensationsA. Traditional Senses1. sight, smell, touch, taste and sound2. known as primary sensesB. Additional Senses1. Proprioception: limb position and movement 2. Nociception: pain quality. sharp vs. throbbing3. Thermoreception: heat, cold4. Balance: head orientation5. Body Movement: head acceleration/rotationC. Evolution of senses1. animals that have advantageous traits compete more effectively for resources and reproduce more.2. animals have evolved senses in response to their environment and lifestyle. (natural selection)a. birds can sense earths magnetic field, bees sense polarization property of lightCheck Your understanding: Why are people more sensitive to tones within the range produced by humans that outside of it, when we hear a larger range of tones than we produce?Heightened sensitivity to tones in the human range is an adaptive trait, allowing humans to differentiate and detect tones more accurately that are made by other humans.III Neurons and the BrainA. Law of Specific Nerve Energies1. the kind of perceptions we have depend on which neurons are activated, not on what is activating them2. photoreceptors will only transduce light, whether light is entering them or not.B. Neuron Doctrine1. perception depends on the combined activity of many specialized neurons, eachof which responds to specific aspects of a stimulus known as trigger features.C. Neuron Signals1. Cell body known as the soma2. dendrites form the receiving enda. reception can also occur on the soma and unmyelinated segments of axon 3. axon conducts signals to the axon terminals4. bundles of axons form nervesD. Action Potentials1. differences in concentrations of ions inside and outside of the cell give rise to thedifference in potential, known as membrane potential a. measured with single cell recording2. generated at the axon hillock3. resting potential within the cell is generally -70mVE. Activation of AP1. ion channels within the cell membrane are voltage gated2. open when membrane potential changes sufficiently3. the opening of sodium gates allows Na+ to flow into the cell due to the concentration gradient4. Sodium influx leads to a significantly more positive charge within the cell (depolarization)5. Sodium channels close, potassium channels open in response to depolarization6. potassium ions exit due to concentration until the neurons repolarizes at -70mVa. brief period of hyperpolarization7. sequences takes places in approx. 5 msF. Refractory Period1. results in one directionality within the cell2. refractory prevents recently opened gates from reopening for a period of time3. controls the neurons firing rate ( between 0 and 100 times per second)a. most neurons exhibit a baseline rate of random firing in the case that no stimulus is presentG. Transmission between Neurons1. synaptic vesicles release neurotransmitter signals that bind to receptorsa. binding produces ligand gated channel openings, changing membrane potentialb. binding doesn’t always produce AP, but multiple bindings can summate within a time frame, or within a certain location on a cell2. the cell producing the NT is the presynaptic membrane3. the cell receiving is the postsynaptic membraneH. Types of Neurotransmitters1. Excitatory NT depolarize the cell, increasing the chance for AP to occura. Excitatory postsynaptic potential: causes Na+ channels to open, cell= more positive 2. Inhibitory NT hyperpolarize the cell, reducing the chance for AP to occurb. Inhibitory Postsynaptic Potential: causes Cl- channels to open, cell=morenegativeIV The Human BrainA. Hemispheres1. the cerebral hemispheres divide the brain to left and right regions2. connected by a bundle of axons known as the corpus callosum3. bumps are known as gyrus, ridges are known as sulcusB. Lobes1. the frontal lobe is separated from the temporal lobe by the lateral sulcus and from the parietal lobe by the center sulcus2. occipital lobe is the back most region of the brain, separated from the parietal and temporal lobes by the parieto-occipital sulcusC. Other Anatomical features1. the cerebral cortex is the outermost layer of the braina. contains mostly gray matter (cell bodies of neurons)2. the interior layers are comprised primarily of white matter(myelinated axons)3. there are many subcortical structuresa. thalamus (important for perception) contains most neural signals originating from sensory organs and relays them to specific areas of the brain for processingCheck Your Understanding: 1. T/F, A neuron’s baseline firing rate is the firing rate evoked by a stimulus justabove thresholdFalse. Baseline firing rate is the rate a neuron fire at in the absence of stimulus2. How many Lobes make the brain? What are They?Moving from the top front, clockwise: frontal lobe, parietal lobe, occipital lobe, temporal lobeV Cognitive NeuropsychologyA. Modularity1. pertains to concepts used by Pierre Paul Broca in the case study of two patients with frontal lobe damage who could not produce spoken language2. the idea that the human brain consists of distinct modules to process and carry out