Exam 1 Study Topics PDF
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This document discusses the steps of visual perception, including stimuli, transduction, neural processing, perception, recognition, and action. It also covers aspects of motor activities, action potentials, and the roles of different brain areas (like FFA, PPA, EBA) in processing visual information. The document further expands on concepts like distributed representation and diseases of the eye, like presbyopia and myopia. It also describes the flow of visual information from the retina to the brain through the dorsal and ventral pathways.
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Exam 1 Study Topics Steps of the perceptual process and what they include ○ Stimuli - 1 Environmental stimuli Temperature clothes, fan of projector ○ Light is reflecte...
Exam 1 Study Topics Steps of the perceptual process and what they include ○ Stimuli - 1 Environmental stimuli Temperature clothes, fan of projector ○ Light is reflected and focused - 2 Directed attention plays key role in moving from many environmental stimuli to the attended (proximal) stimuli ○ Transduction - 3 Changing energy from one form to another Light → electric. Influence how we think Brains no access to the environment outside ○ Neural processing - 4 Moving from environment energy → neural firings → further processing in brain ○ Perception - 5 Conscious sensory experience ○ Recognition - 6 Ability to place objects in categories ○ Action - 7 Motor activities that occur in reference to the perceived and reorganized object ○ Elements and properties of action potentials (step-by-step process, ions involved, etc.) ○ “Grandmother” cell Highly specific type of neuron that fires in response to a specific stimulus, such as a persons grandmother ○ Modularity, including specific areas we discussed like FFA, PPA, EBA Definition:processes information through independent modules FFA Fusiform face area ○ Recognize faces PPA Responds best to spatial layout EBA Responds best to picture of full bodies ○ Distributed representation Occurs when a stimulus causes neural activity in a number of different areas of the brain, so the activity is distributed across the brain ○ Diseases of the eye Presbyopia inability of the eye to accommodate due to a hardening of the lens and a weakening of the ciliary muscles. Occurs as people age Myopia Inability to see distant objects clearly. Aka nearsightedness Hyperopia A condition causing poor vision in which people can see objects that are far away but do not see near objects clearly. Also called farsightedness ○ Accommodation In vision, bringing objects located at different distances into focus by changing the shape of the lens ○ Convergence Binocular cue for perceiving depth; the extent to which the eyes converge (meet) inward when looking at an object. The greater the inward strain, the closer the object ○ Dark/light adaptation the process by which our eyes adjust to darkness after being exposed to light ○ Double dissociations In brain damage, one person can function A but not B Another person can do function B but not A Shows that the two functions use different mechanisms and work independently from each other ○ Dorsal pathway Conducts signals from the striate cortex to the parietal lobe. AKA: the where, the how, or the action pathway ○ Ventral pathway Conducts signals from the striate cortex to the temporal lobe AKA: the what pathway; involved in recognizing objects ○ Lobes of the brain and its general organization Frontal Thinking Problem solving Decision making Parietal Touch Temperature pain Occipital vision Temporal Hearing Language Memory Brain has2hemispheres Different lobes work together to process information Cerebral cortex responsible for higher level thinking ○ Feature detectors (e.g., end-stopped neurons, simple cells, complex cells) Simple cells Basic shapes and edges Complex Motion and position changes End stopped cells Detect length Corners Edges Responds to bars of specific size or moving in a particular direction Ocular dominance columns ○ Definition Neurons in the visual cortex are organized into stripes, each responding more to input from one eye than the other Orientation columns A column in the visual cortex that contains neurons with the same orientation preference Location columns A column in visual cortex that contains neurons with the same receptive field locations on the retina ○ Hypercolumns In the striate cortex, unit proposed by Hubel and Wiesel that combines location, orientation, and ocular dominance columns ○ Different types of agnosias Agnosia Inability to ○ Flow of information through the LGN ○ Properties of the visual cortex (i.e., V1, V2, V3, etc.) Organization of the retinal layers ○ Vertical system Info goes to → photoreceptors → bipolar cells → retinal ganglion cells In periphery, many photoreceptors attach to little bipolar cells Attach to one ganglion (convergence) In fovea, one cone attach to one bipolar cell then attach to one ganglion cell ○ Horizontal system Attached to bipolar and photoreceptor cells Get info from photoreceptors → determine if fire or no fire of bipolar and ganglion Amacrine cells are attached to bipolar and ganglion cells and does the same action as horizontal cells just further down Specificity coding ○ Specific neurons → specific stimuli Sparse coding ○ Pattern of firing across groups of neurons code specific objects Population coding ○ Experience represented by pattern of firing across large number of neurons Disease of the eye ○ Macular degeneration Fovea and small surrounding area destroyed Make blind spot on retina Common in older people ○ Retinitis pigmentosa Genetic Rods destroyed first Foveal cones can be attacked Severe: may be blind relationship to measure perception ○ Absolute threshold Smallest amount of energy needed to detect a stimulus ○ Difference threshold Just noticeable difference Smallest difference between stimuli that a person can detect ○ Magnitude estimation Observer estimates intensity relative to a standard How much big or small it is Methods for measuring perception ○ Method of limits Stimuli shown in graduated scale, and participants must judge stimuli along a certain property that goes up and down Ascending and descending series Crossover point ○ Method of adjustments Stimulus adjusted by observer or experimenter till observer sees Repeat trials averaged for threshold ○ Method of constant stimuli Show observer stimuli, some high some low, in a random order ○ Magnitude estimation Participants put numerical estimates to the perceived strength of a stimulus Compare test stimulus to standard stimulus by assigning numbers Linear path Response expansion Response compression Types of distribution ○ Module Brain structure that processes info about specific stimuli Can be studied by brain imaging. ○ Distributed representation Idea that the brain represents info in patterns distributed across the cortex, not just one brain area Types of processing ○ Bottom up processing Processing from incoming stimuli Aka: data-based processing ○ Top down processing Processing based on perceivers previous knowledge Label these graphs Possible Essay topics . Define “top-down” and “bottom-up” processing and discuss how the “rat-man” demonstration is used 1 to exemplify the distinction between these two types of processing. . List seven steps from a stimulus in the environment to an action by the perceiving individual, 2 illustrating each step with an example. . Describe how information would be representedunder each of the following representational 3 schemes: specificity coding, population coding, and sparse coding. . Draw a graph (with appropriate axis labels)of the dark adaptation curve. Describe the methodology 4 used to isolate the rod component of the curve and the cone component. 5. What is the “blind spot”? Discuss two reasonswhy we are not usually aware of the blind spot. 6. Explain what Hubel and Wiesel’s research onsimple cells revealed about ocular dominance.
