Psych 120A Midterm.pdf

Psych 120A Midterm Names To Know William James ○ Founder of modern Psychology: distinction between primary and secondary memory Wilhelm Wundt ○ Introspection B.F. Skinner ○ Behaviorism Irving Biederman ○...

Psych 120A Midterm Names To Know William James ○ Founder of modern Psychology: distinction between primary and secondary memory Wilhelm Wundt ○ Introspection B.F. Skinner ○ Behaviorism Irving Biederman ○ Recognition-by-components (RBC) model; geons Donald Broadbent ○ Early filter model of attention Anne Treisman ○ Attenuation model of attention; feature integration theory Deutsch & Norman ○ Late selection model of attention Memory Mechanisms: ○ George Miller “Chunking” in short-term memory (7 +/- 2 capacity limit) ○ Atkinson & Shiffrin Modal model of memory ○ Baddeley & Hitch Multi-component model of working memory (phonological loop, visuospatial sketchpad, episodic buffer, central executive) Introduction to Cognitive Psychology Mental representations & processes ○ Mental representations: a set of objects that stand for another set of objects by virtue of having the same causal relational structure formed in the mind activated by objects/events in the world make it possible to think about objects/events in their absence ○ Processes: operations performed on mental representations coding, elaborations, etc creations, storage, retrieval, use for action, transformation ○ Cognitive offloading: the use of physical action to alter the information processing requirements of a task to reduce cognitive demand not allow ourselves to remember things we do not need to remember  not having to remember people's addresses or phone number bc we keep that in our phones Introspection vs. behaviorism (generally) ○ Introspection: the process through which one "looks within" to observe and record the conscious contents of one's own life Research tools to study human thoughts Concluded by Wilhelm Windt and Edward Bradford Limited research tool bc some thoughts are unconscious Very hard to use this tool and test its claims ○ Behaviorism: emphasized broad principles concerned with how behavior changes in response to different configurations of stimuli (including stimuli that's often called "rewards" and "punishments" Founded by BF Skinner Cognitive Neuroscience Neuron biology ○ Dendrites Detect incoming signals ○ Cell body/soma Contains the nucleus and cellular machinery necessary to keep the cell alive and functioning properly. ○ Axon Transmits signals to other neurons Incoming is to outgoing as dendrite is to axon. ○ Axon terminal Relays signals across synapses; Release the neurotransmitters of the presynaptic cell into the synapse Neuron A communicates with neuron B. The axon terminal of neuron A forms a synapse with the dendrite of neuron B. ○ Myelin sheath The layer of tissue, formed by specialized glial cells, provides insulation around the axons of many neurons and makes neurotransmission faster. ○ Synapse (chemical & electrical communication) Space where the axon terminal contacts the dendrite Communication between neurons is chemical, while communication within a neuron is electrical. Action potential ○ a signal that moves down its axon causing the release of neurotransmitters at the next synapse White vs. gray matter  ○ Gray Matter contains the cell bodies ○ White matter contains the axons In patients with MS white matter will be significantly decreased due to a lack of myelin Corpus callosum ○ Major white matter pathway that connects the two hemispheres of the brain and is a large commissure (Thick bundles of fibers that allow communication between the brain's hemispheres.) ○ A patient might elect to have split-brain surgery, which involves severing the corpus callosum Split brain patient experiments ○ Split brain patient’s brains have contralateral organization (left input is processed on the right, right input is processed on the left) Left hand → Right hemisphere → Left visual field Right hand → Left hemisphere → Right visual field the left hemisphere is better with language the right hemisphere is better with visuospatial Brain navigation ○ Medial, lateral, top-down Medial: towards the middle Lateral: towards sides Top-down: information flows from thoughts to lower-level processes like the senses ○ Anterior, posterior, superior, inferior, dorsal, ventral Anterior = Rostral (front) Posterior = Caudal (back) Inferior = Ventral (bottom) Superior = Dorsal (Top; Toward the head) What are the basic parts of the eye? ○ 1) cornea: transparent tissue at the front of the eye; important in focusing incoming light ○ 2) lens: transparent tissue at front of the eye; works with the cornea in focusing incoming light ○ 3) retina: Light sensitive tissue that lines the back of the eyeball What are photoreceptors? ○ Special cells in the eye's retina that are responsible for converting light into signals that are sent to the brain. 1) rods - night vision; sensitive to low light; unable to differentiate hues; poor 2) cones - color vision; can discriminate hues; high acuity Lobes  ○ Occipital, Temporal, Parietal, Frontal Occipital: For visual perception. Most likely to be used if you are visualizing your bedroom Bottom-Up Processing Temporal: Auditory + Speech function Parietal: Sensory perception, taste, hearing, sight, touch, and smell (5 senses) Top-Down Processing Frontal lobe: problem-solving, planning; motor cortex. Farthest from the cerebellum Major cortices ○ Primary visual (V1) Receive, segment, and integrate visual info Detects illusory contours ○ Somatosensory cortex Detect sensory information from the body Touch, temp, pain ○ Motor cortex Generate signals to direct movement to the body ○ Association areas Connect sensory and motor areas Organization of motor/somatosensory cortices (e.g. homunculus) ○ Motor output: the left hemisphere section controls the body's right side ○ Somatosensory (input): left hemisphere section receives input from the body's right side ○ Homunculus: distorted map of the body's stretched out across primary motor and primary somatosensory cortex. Hand/fingers, mouth,, and face most heavily represented. Neuroimaging methods & pros and cons for using each method and when ○ (Generally) how PET, MRI/fMRI work PET: Visualizes active brain areas via a small injection of radioactive tracer into the blood. Tracer reveals where blood is going, indexing areas that's active and need O2/metabolic supplies (indirect measures of brain activity Scans show brain areas that are currently consuming a particularly high level of glucose ○ Pros & Cons:  Relatively good spatial resolution, can aid in the diagnosis of disorders like Alzheimer's BUT poor temporal resolution, invasive, and expensive MRI: Studies brain anatomy; allows for body scans fMRI: Measures brain function; uses to see where brain is active during a cog task like memory processes; measures blood-flow based on oxygen signal which perturbs local magnetic field (an indirect measure of brain activity ○ Pros & Cons: Good spatial resolution, non-invasive, no/low risk, widely available BUT so-so temporal resolution (better than PET but worse than EEG), expensive, loud ○ Basics about EEG and TMS EEG: Records the electrical activity of the brain at the surface of the scalp (a more direct measure of the brain) ○ Pros & Cons: Good temporal resolution, non-invasive, inexpensive, portable formats available BUT poor spatial resolution, skull and brain tissue distort electrical fields TMS: Uses a strong magnetic pulse to produce a temporary disruption to the brain area, and thus brain function, where it is applied ○ Pros & Cons: Safe, non-invasive, and temporary, has causal evidence, good temporal resolution BUT relatively brief effects, greater impact on surface cortical areas, potential spread of activations, not effective on deeper brain regions ○ Single-cell recordings Records the moment-by-moment activation level of an individual neuron Measure the pattern of firing of individual neurons. A researcher wishes to determine exactly when a particular neuron is firing. A technique well suited to this purpose is single-cell recordings Pros & Cons:  ○ Great temporal and spatial resolution BUT only measure one neuron at a time; limited use studying humans Temporal vs. spatial resolution trade-off ○ Temporal Resolution (worst to best): PET (worst) → fMRI → EEG (best) ○ Spatial Resolution (worst to best): EEG (worst) → PET → fMRI (best) ○ EEG is the worst at spatial resolution but the best at temporal resolution Cognitive subtraction ○ Based on the logic that we can find two tasks (experimental and baseline) that differ in components, to find the effect of the experimental component; if two things interact, subtract the effect of the one thing to find the effect of the other thing; related to PET Visual Object Recognition Organization of human visual system ○ Relies of parallel processing (going on simultaneously) Retina (first) optic nerve Lateral Geniculate Nucleus Primary visual cortex (V1) V1-> V2-> V4-> IT (Inferior temporal) Center-surround cells ○ In the center = excitation and higher firing ○ In the surround = causes inhibition of firing rather than excitation Receptive fields ○ The line of space that is important in vision Outside receptive field = Low rate of neural activity Dorsal stream vs. ventral stream ○ “What” / “Where” pathways Dorsal stream = “where” pathway Optic Ataxia Ventral stream = “what” pathway Visual agnosia and having trouble identifying objects Double dissociation ○ Lesion in brain structure 1 impairs function A but not function B, and a lesion to brain structure 2 impairs function B but spares function A Stronger evidence for functional independence ○ Example: Optic ataxia  Condition of impairment of visually guided reaching despite normal object recognition; can tell what the object is but not where it is Visual agnosia (patient D.F.) Ability to name objects but not to recognize them or describe any of their traits; DF had damage to ventral stream ("what" pathway) and couldn't describe any object aspects Difficulty identifying common objects in plain view. Face processing ○ Face processing is holistic because the relationship or configuration of features is important for recognition ○ Face inversion effect It is much harder to recognize faces when they are displayed upside down Inversion disrupts the relationships between facial features, which is why it is harder to recognize inverted faces compared to inverted objects ○ FFA (Fusiform Face Area) Area of the brain that 'recognizes faces'; Not just for recognizing faces, this area lights up when we look at anything we have expertise on ○ Prosopagnosia Loss of the ability to recognize faces even though vision is normal Can identify traits of a person but not understand who the person is and their relationship to them Not even recognize themselves "I see faces, but I can never be sure of the identity of a person based on his or her face" Gestalt principles (examples of each) ○ Simplicity We tend to look at objects in its simplest form. Ex: Instead of seeing something as a complex multi edged shape, we break it down in terms of simple shapes that we already know: so we say that the drawing consists of a circle with a triangle to its side instead of as one whole new object. ○ Good continuation Elements arranged on a line or curve are perceived to be more related than elements not on the line or curve Ex: When you tend to see a cylinder as having a continuous green bar behind it rather than two rectangles behind it. ○ Proximity Things that are close to one another are perceived to be more related than things that are spaced farther apart  Ex: We group the circles that are close together in a column that is separate from the other column of circle that are further away ○ Similarity We tend to group things that we perceive as similar to each other (shape, color, etc) Ex: We group all the individual squares in 1 group and then we group all the circles together in another group ○ Closure Incomplete objects will tend to be perceived as wholes Ex: Illusory contours ○ Figure-ground Elements are perceived as either figures (distinct elements) or ground (which figures rest) Ex: When you look at the black foreground it looks like a vase, but when you look at the white background it looks like 2 faces Theories of object recognition ○ Template theory Our mind has mental templates for all possible objects We overlay the visual input onto several templates until one matches. HOWEVER, We would need to have a huge database of templates, and we would need templates of all possible viewpoints ○ Recognition by components (RBC) / geon theory There are 36 geons We identify things by breaking them down into geon components. HOWEVER, difficult to extract geons from real images, too many geon candidates for another object, deriving structural representations can be difficult, etc. Ex: Ice cream is a sphere on top of a cone Evidence in favor of the 2 theories ○ Template: Able to recognize things by recognizing its template first. ○ RBC: Able to recognize items more easily if everything else is invisible with the constitutional geons still being present. Critiques of the two theories ○ Both theories do not include a mechanism for contextual influences on object recognition Template: Able to recognize things without having a template per se.  RBC: Can't determine many geons in an object; doesn't account for context. Top-Down vs. Bottom-Up Processing (Always using both) ○ Top-Down When prior knowledge biases the bottom-up interpretation of a pattern of sensory stimulation (concept driven) Ex: Imaging a face ○ Bottom-Up When we allow the stimulus itself to shape our perception by relying on our senses rather than prior experiences or schemas (data driven) Visual/Perceptual Constancy ○ Shape Consistency Correct adjustment for shape of an object even when retinal image changes depending on viewing angle ○ Size Consistency Adjustment for distance of an object when perceiving size even when retinal image size changes ○ Brightness/Lightness Consistency Correct perception of brightness of object regardless of actual luminance conditions Brightness illusion/The Effect of Contrast ○ Our brain does not directly perceive the true brightness of objects in the world but instead compares the brightness of a given item with others in its vicinity. ○ Perceptual constancy Hearing the same word in many different people's voices