Study Guide

Gestalt Grouping Principles (e.g., similarity, good continuation):

1. Similarity Throw a bag of M&Ms on a table and your mind will immediately start to group them by color. Red will be one group, green another, and yellow a third. We're inclined to group elements that look like each other. 2. Proximity The principle of proximity states that we tend to perceive elements as a group when they are close to each other 3. Good continuation Ever notice how your eyes like to travel along lines, following and flowing with them? Our mind has a tendency to follow paths and group elements that are aligned with each other. This is the principle of continuity. 4. Closure Given the chance, our mind will opt for simplicity. Since a whole is easier to process than multiple parts, we'll fill in the gaps or connect the dots to complete implied shapes or images. 5. Simplicity our mind perceives everything in its simplest form

Lesions:

A lesion is damage to a part of the brain that results in destruction to the neurons. Lesions can come from natural sources (like brain injury or disease) but can also be deliberately caused. Lesion in hippocampus = memory problems Lesion in occipital cortex = problems w/ sight

Automatic vs. Controlled processing:

Automatic processes: unconscious practices that happen quickly, do not require attention, and cannot be avoided. Controlled processes: intentionally done while we are consciously aware of what we are doing

Unilateral neglect:

Damage to the right parietal lobe Cannot attend to the left side of space However, some experiments suggest that the deficit is actually object-based Two-part account 1. Spatially defined bias in preparation for stimuli Once presented, target object defines focus Neuroscientific support Attention to space activates dorsal attention system Attention to particular objects activates ventral attention system

Basic functions of Prefrontal Cortex, hind brain, and midbrain

Hindbrain: Top of spinal cord Key life functions Heartbeat & breathing rhythms Posure, balance, alertness Cerebellum: largest region of hindbrain Movements & balance Spatial reasoning Sound discrimination Sensory integration *also includes the pons and medulla Midbrain: Coordinating movement, especially eye movements auditory pathways Regulating pain experiences Forebrain: Surrounds the midbrain & hindbrain *cerebral cortex: outer surface of forebrain Roughly 3mm thick Approx. 80% of brain Divided into 3 hemispheres by longitudinal fissure Consists of 4 lobes and subcortical structures Divided into lobes by fissures

Cocktail party effect:

Information from the unattended channel can be noticed Catches your attention Examples: our own name, words of high personal significance

Introspection:

Introspection Observing and recording your own thoughts and experiences Required systematic training Problems with introspection Some thoughts are unconscious Thoughts are not directly observable or measurable It is generally impossible to know if self-report accurately reflects the conscious experience Behaviorism sought to overcome the limitations posed by introspection From introspection and behaviorism, experimental psychologists learned that: Introspective method for studying mental events are not specific However, we need to study mental events in order to understand behavior

Neuron and its parts:

Neuron: building block and transmission lines of the nervous system Dendrites: detect incoming signals Cell body: contains the nucleus and cellular machinery Axon: transmits signals to other neurons *Synapse

Word superiority effect:

People are shown either a word (for example, "DARK") or a single letter (for example, "E") They are then given a choice between two letters and are to indicate which letter the prior display contained (in the first example, the question might be "Did the display contain an E or a K?") Responses are more accurate when the original stimulus was a word, compared to when it was a single letter

Primary motor and sensory cortex:

Primary motor cortex: is the area that provides the most important signal for the production of skilled movements. Electrical stimulation of this area results in focal movements of muscle groups on the opposite side of the body, depending on the area stimulated. Sensory cortex: the sensory cortex is a section of the cerebral cortex which is responsible for receiving and interpreting sensory information from different parts of the body

Recognition by Components - theory of object recognition:

Process of object recognition is complex The importance of features Recognition begins with features - the small elements that result from the organized perception of the form Features Building blocks Commonalities for variable objects Play a role in visual search Ex. CAN SEE IF AN OBJECT IS IN A LIST Integrative agnosia Difficulty in judging how multiple features bound together in objects Parietal lobe damage Ex. can see a triangle, but CAN'T if triangle is part of something else Word recognition Object recognition begins (according to many accounts) with feature detection How are these features bound into complete objects? Factors influencing recognition Brief presentation of stimuli (approx. 20-30ms) Tachistocscope: a device used to present stimuli for precise amounts of time "Tachistoscopic presentations" with modern computers Post-stimulus mask: interrupts continued processing Ex. TREE → XJDKEL *words better known are more recognized *words used often are more recognized *words seen recently are more recognized Receny priming

Contralaterality:

Property of the brain such that one side of the body is controlled by the opposite hemisphere of the brain: the left hemisphere controls the right side of the body, and the right hemisphere connects the left side of the body.

Rods vs. Cones:

Rods: black and white (many more than cones) Cones: produce color - need light

Identify parts of the eye:

Rods: black and white (many more than cones) Cones: produce color - need light Blind spot theory: point at which the optic nerve leaves the eye Cornea: protects the eye and the first place where light enters; bends light to focus Iris: ring of muscle tissue that makes color part of eye around pupil; controls size of pupil Pupi: the adjustable opening in the center of the eye through which light enters Lens: transparent structure behind the pupil that changes shape to focus images on the retina Retina: light sensitive; contains rods/cones and layers of neurons that start to process visual info Fovea: the central focal point in the retina, around which the eye's cones surround it

Change blindness:

The inability to detect changes in a scene despite looking at it directly

Synapse:

end of axon, gap, receiving membrane of next neuron a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter.

Selective Attention:

refer to the skill through which one focuses on one input or one task while ignoring other stimuli Sometimes the effects of selective attention are so strong that we fail to see stimuli that are directly in front of our eyes Summary of selective attention Both facilitating desired input and inhibiting unwanted input Attention directed both to an object and to space Flexibility of early and late attention Attention not a single process or particular mechanism

Binding problem:

the features of object that are processed separately in different areas of the brain. The saliency of an object can cause an area of the brain to fire more often because it is able to capture one's attention more. Elements that help solve the binding problem Spatial position Overlap map of "what forms are where" with map of "what colors are where" and so on Neural synchrony The brain seems to register synchronized firing as a cue that attributes to a single object Attention In the absence of attention, conjunction errors are common

Agnosia:

the loss of the ability to recognize objects, faces, voices, or places. It's a rare disorder involving one (or more) of the senses. Agnosia usually affects only a single information pathway in the brain.

Data-driven/Conceptually-driven processing (i.e., Bottom-up/Top-down processing):

- Bottom-up processing: "Data-driven," or stimulus-driven effects Smaller things building up an explanation for perceptions that start with an incoming stimulus and working upwards Process of sensation For example, there is a flower at the center of a person's field. The sight of the flower and all the information about the stimulus are carried from the retina to the visual cortex in the brain. The signal travels in one direction - Top-down processing: "Concept-driven," or knowledge-driven effects Process of perception One area in which this has been demonstrated is reading and letter identification. Experiments have shown that when briefly presented with either a single letter or a word that contains that letter and then asked to identify which letter or word they had seen, participants could more accurately identify the word than the letter. Example: Stroop effect - in this task, people are shown a list of words printed in different colors. They're then asked to name the ink color, rather than the word itself. For instance, you are presented with a paragraph written with difficult handwriting. It is easier to understand what the writer wants to convey if you read the whole paragraph rather than reading the words in separate terms

Neuroimaging techniques and what are they good for, what are they not good for (e.g., TMS, fMRI, MRI, PET, EEG):

Data from neuroimaging Imaging techniques Structural imaging Computerized axial tomography (CT) scans Magnetic resonance imaging (MRI) scans Functional imaging Positron emission tomography (PET) scans Functional magnetic resonance imaging (fMRI) scans Data from electrial recording Electroencephalogram (EEG) Records electrical communication within neurons Firing of action potential in a neuron Action potential triggered by chemical communications from one or more other Used to study: Broad rhythms (sleep stages) Event-related potentials (ERPs) The power of combining techniques Every method has strengths and limitations EEG: Strength: temporarily locating neural activity (when?) Weakness: spatially locating neural activity (where?) PET and fMRI: Strength: spatially locating neural activity (where?) Weakness: temporally locating neural activity (when?) CT and MRI scans: detect brain structures, not activity Researchers can overcome limitations by combining techniques Problem: most neuroimaging techniques used to study brain activity and structures provide correlational data Transcranial magnetic stimulation (TMS) Magnetic pulses activate neurons Produces temporary lesions Provides casualdata

face processing (viewpoint dependence)

Experiment 1, using "shape only" representations, showed that all the views used (full-face, three-quarter and profile) were equally well recognized when all had been learned. Performance was better when the same views were presented in an animated sequence, rather than at random, suggesting that structure-from-motion provides useful information for recognition. When stimuli were presented inverted, performance was worse and there were differences in the recognizability of views, demonstrating that the familiarity of upright faces affects generalization across views. Experiments 2 and 3 investigated generalization from single views and found performance to be dependent on learned view generalization from learned full-face fell off with increasing angle of rotation. With shape only stimuli, three-quarter views generalized well to each other, even when inverted, but for profiles generalization was equally bad to all unlearned views. This difference may be explained because of the particular relationship of the profile to the axis of symmetry

Lobes of the brain and their functions:

Frontal lobe - bigger decision making Parietal lobe - movement & locating self in space Occipital lobe - vision processing Temporal lobe - hearing and language

Early vs. Late selection in Attention:

It could be that participants literally do not perceive the stimulus In other words, a limit of perception It could also be that participants perceived the stimulus but immediately forgot it In other words, a limit of memory Early selection hypothesis: Only the attended input is analyzed and perceived Unattended information receives little or no analysis It is never perceived Late selection hypothesis: All inputs are analyzed Selection occurs after analysis Only the attended input reaches consciousness The early selection hypothesis and the late selection hypothesis are both true (depending on the exact circumstances) Late selection - stimuli that are not attended to can nevertheless have effects on perception Early selection - electrical brain activity for attended inputs differs from activity for unattended inputs within 80 ms There is evidence that attention can change activity in the lateral geniculate nucleus (LGN), thus influencing perception

How light information is transformed to neural activity (pathway of stimulation):

Light enters the eye and passes through the optically active components to reach the retina. These components pass through all layers of the retina to stimulate the outer segment of the photoreceptors in the photoreceptor layer. The impulse crosses both the outer limiting membrane and the photoreceptor synapses in the outer plexiform layer. Here, they are modified by the accessory cells of the retina (bipolar, amacrine, and horizontal cells) before they move on to the proximal end of the ganglion cells. Once activated, the ganglion cells pass the action potential to their distal axons, which travel in the nerve fiber layer of the retina. Eventually, the axons converge to form the optic nerve.

Ponzo Illusion (review your ZAPS)

Otherly known as size/distance illusion Ponzo illusion demonstrates how the brain often relies on depth perception to guess at the properties of an object that it cannot directly sense. When asked to adjust the length of the bottom line to match the length of the top line, most people over-adjust, making the bottom line longer than the top the oblique (slanted) vertical lines provide the brain with distance cues by making the image appear three-dimensional This means that, when given two horizontal lines that are actually exactly the same length, the brain will perceive the top line as longer Quiz: 1. A psychological scientist asks study participants to indicate whether the green line at the front corner of the wall pictured here is longer than, shorter than, or equal in length to the green line at the back corner of the wall. Participants regularly say that the front line is shorter than the back line (even though the two are perfectly equal in length). The participants' brains are using ___________ to guide perception. Context clues about depth 2. The process we call perception involves our eyes sensing objects in the world and our brain interpreting the information that our eyes sense. Keeping this definition in mind, which of the following is a true statement about the Ponzo illusion? The brain leads us to perceive something that is not true 3. A real-life visual illusion is the "moon illusion." When the moon is close to the horizon, the full moon seems larger than it does when high in the sky. Rationally we know that the moon does not change size according to its position in the sky. Based on what you have learned about optical illusions, why do you think the moon illusion occurs? When the moon is near the horizon, objects on the earth which are near the moon on your retina, lead to a misperception of depth & size - the brain discerns the low moon as closer and thus BIGGER than the moon high in the sky.

Expectation vs. Repetition priming (studies that relate to these concepts):

Posner and Synder (1975) found two kinds of priming related to attention Repetition priming: Stimulus-based Requires no effort or cognitive resources Example: hearing your name on an unattended channel Expectation-driven priming: Effortful and deliberate Explaining the costs and benefits: Photo in phone pictures Black is goal-related Blue is stimulus-related (repetition priming) Gray - both types of attention Stimulus-base priming (ex. Repetition priming) does not have a cost, but expectation-based priming does. Limited-capacity system: expectation-based priming requires some of our limited mental resources Posner and colleagues (1980) asked participants to detect letters Press a button as soon as the target appeared while focusing on a central fixation mark Letters presented to the left or right of the mark Prior to each trial: Neutral cue to signal the start of the trial, or Arrow indication location of the upcoming letter (with 80% accuracy) Posner and colleagues (1980) asked participants to detect letters Press a button as soon as the target appeared while focusing on a central fixation mark Letters presented to the left or right of the mark Prior to each trial: Neutral cue to signal the start of the trial, or Arrow indication location of the upcoming letter (with 80% accuracy)

Capgras Syndrome:

Relatively rare, but can result from damage to different areas of the brain Fully able to recognize people in the world (husband, wife, parents, friends) but utterly convinced these people are NOT who they say they are Feel that the REAL individual has been kidnapped, etc. Emotional processing is disrupted, leading to an intellectual identification without a familiarity response SYMPTOMS: impaired vision, paranoia DAMAGE TO THE AMYGDALA & TO THE FRONTAL LOBE

Priming:

Selection via priming: Selection as a form of priming: The perceives tries to anticipate the attended channel This anticipation leads the perceiver to prime the detectors needed for the (now expected) input Even with anticipation, some high-frequency or salient information is already primed Two types of priming: Posner and Synder (1975) found two kinds of priming related to attention Repetition priming: Stimulus-based Requires no effort or cognitive resources Example: hearing your name on an unattended channel Expectation-driven priming: Effortful and deliberate Explaining the costs and benefits: Photo in phone pictures Black is goal-related Blue is stimulus-related (repetition priming) Gray - both types of attention Stimulus-base priming (ex. Repetition priming) does not have a cost, but expectation-based priming does. Limited-capacity system: expectation-based priming requires some of our limited mental resources

Split-brain patients - what can they report and why/how? - Review your ZAPs!:

Severed corpus callosum Was a last-resort treatment for severe cases of epilepsy Severely limits communication between hemispheres Evidence for some hemisphere specializations of functions These "split-brain patients" can, for the most part, lead relatively normal lives. However, a classic experiment run by Michael Gazzaniga and his colleagues, revealed that the split-brain operation does change how these patients process information. What CAN they report? When a word is presented to the right visual field, the patient's left hemisphere can easily process the word (since most of our language abilities reside in the left hemisphere), direct the patient to say the word aloud, and cause the right hand to find the object behind the screens. HOW/WHY? Right hemisphere seems to have enough language capability to comprehend simple words of concrete objects, it does not have the phonological (speech) capabilities to allow the word of the object to be spoken. Thus, while the right hemisphere may be able to "read" the word and therefore direct the left hand to pick up the correct object, the patient isn't able to state the name of the object. Quiz Questions: 1. The word banana appears on the left screen, and the split-brain patient is told to use her left hand to select the object named on the screen. Will she be able to fetch the banana? Yes 2. The word banana appears on the left screen, and the split-brain patient is told to use her right hand to select the object named on the screen. Will she be able to fetch the banana? No 3. The word banana appears on the right screen, and the split-brain patient is told to use her left hand to select the object named on the screen. Will she be able to fetch the banana? No 4. The word banana appears on the right screen, and the split-brain patient is told to use her right hand to select the object named on the screen. Will she be able to fetch the banana? Yes

Where are the limits?

Summary of divided attention and practice Tasks require resources, and you cannot use more resources than you have Some resources are task-specific and others are task-general. If two tasks make demands using the same resource, the result will be interference Practice increases the automaticity of a task, resulting in a need for fewer cognitive resources Posner & Synder's 4 characteristics: (1) The process occurs without intention, without a conscious decision (2) The process is not open to conscious awareness or introspection (3) The process consumes few if any resources; that is, it consumes little if any attention (4) The process is very rapid, usually within 1 second

Functions of Thalamus, Corpus Callosum, Hippocampus:

Thalamus: sensory relay station Hypothalamus: simple motivated behaviors (eating, drinking, sex) Limbic system: Amygdala: emotional processing Hippocampus: learning and memory Corpos collosum: The two hemispheres in your brain are connected by a thick bundle of nerve fibres called the corpus callosum that ensures both sides of the brain can communicate and send signals to each other

Inattentional Blindness:

The failure to see a prominent stimulus, even if one is staring right at it Inattentional deafness: the auditory corollary Inattentional numbness: the haptic corollary Some researchers propose that people actually fail to remember what they experienced, rather than failing to perceive it *usually seen in the lab In real-world example: Can't find the ketchup in the refrigerator

Fusiform Face Area (FFA) and its involvement in object recognition:

The fusiform face area (FFA) is particularly responsive to faces High levels of activation can also be produced by tasks requiring subtle distinctions, however. Differences between distinguishing faces versus distinguishing within familiar categories FFA NOT JUST USED FOR FACIAL PERCEPTION ALSO USED FOR EXPERTS IN SPECIFIC THINGS Ex. Car expert uses the FFA to see different makes & models of cars

Where vs. What pathways in visual processing:

The what system Identification of visual objects Occipital-temporal pathway Damage: can lead to visual agnosia The where system Location of visual objects and guiding of actions Occipital-parietal pathway Damage: can lead to problems with reaching for seen objects

Cell phones & Driving (basic findings):

With no cell phone use - your fraction of lights missed is LOWER With cell phone use - your fraction of lights missed is HIGHER With no cell phone use - your reaction time is roughly 520 ms (LOWER) With cell phone use - your reaction time is roughly 580 ms Driving while talking to a passenger in the car - your success in simple highway navigation is roughly 85% Driving while talking on the phone - our success in simple highway navigation is roughly 50%

Stroop effect (review ZAPS):

a task designed to measure conflicts between two sensory inputs that is perhaps the mostly widely used and important of all cognitive tests Congruent trials: words and colors match. Incongruent trials: words and colors do not match. semantic interference - being distracted by the meaning of words Quiz: Based on the ideas presented in this ZAPS lab, under which of the following conditions do you think participants would be able to most quickly name the color in which the stimuli are written or drawn? Colored blobs Imagine you are a web designer working on an interactive website. You need a symbol to indicate to users that they will start a timed task. Based on the ideas presented in this ZAPS lab, which of the following symbols would be most effective for this purpose? Green go sign

Prosopagnosia:

also called face blindness, is a cognitive disorder of face perception in which the ability to recognize familiar faces, including one's own face (self-recognition), is impaired, while other aspects of visual processing People with face blindness have normal visual acuity. They can differentiate between shades of colors, identify patterns, and see in 3D as well. They do not have any problems with memory or comprehension and have normal intelligence

What is the route to automaticity?:

describes tasks that are well-practiced and require little or no executive control Dangers of automaticity Action slips - errors in which a person performs a behavior/response that is different from the behavior/response intended

Dichotic listening task:

different audio inputs presented to each ear via headphones Attended channel - listen to the input (ex. The message presented to the ear) Shadowing - repeat out loud the information from the attended channel Unattended channel - ignore the other input (ex. The message presented to the right ear) *only listen to an attended channel, BUT may notice "voice" of unattended channel