Midterm 3 Flashcards
Describe the Mental Lexicon
The mental lexicon is a mental store of information that includes semantic (word meaning) information, syntactic (how we combine words) information, and word form (sound patterns and spelling) information.
What is the Neighborhood effect?
We are slower to identify words with a large auditory neighborhood (more that differ on only a single phoneme)
What is auditory neighborhood?
The number of similar sounding words (differ from target by a single phoneme; late/rate/hate)
What is phoneme:
Smallest unit of sound that makes difference in meaning (L and R late vs. rate)
Describe Semantic Networks of Knowledge/Words
Our knowledge of words is organized into a semantic network, where words that are more closely related are represented more closely together in this network
What is the evidence behind Semantic Networks of Knowledge/Words
Evidence from studies of semantic priming; if subjects have to make a decision about a list of words, they are faster at making a decision about a word if the previously presented word is semantically related (“car” primes “truck”, but not “cloud”)
How are Semantic Networks organized?
Semantic Networks are categorically organized; words can be categorized by certain semantic properties (living, non-living)
Can brain damage destroy a particular category of words within the mental lexicon?
Yes; evidence from Category-Cpecific Word Deficits
Describe the Category-Specific Deficits
Warrington studied patients who had Category-Specific deficits for conceptual/semantic knowledge about certain categories of words: patients were fine at pointing to/naming pictures of living things, but they had great difficulty in pointing to/naming non-living, man-made objects like tools, other patient showed the opposite pattern (double dissociation)
How is Category-Specific deficit different from Visual Agnosia?
Can tell you that 2 objects are the same (i.e., can match 2
pictures of telephones), but don’t have access to what that object is for (not a problem of object recognition – deficit is in conceptual knowledge)
Describe Damasio et al. findings about Category-Specific Deficits
Locations of brain lesions are correlated with selective deficits in naming people (mostly anterior temporal lobe), animals, or tools (mostly posterior temporal lobe) anterior to posterior gradient for living to non-living things
Describe the similar pattern to Damasio in PET study of healthy subjects
Naming people activated mostly temporal pole (anterior portion of temporal lobe), naming animals activated middle portion of inferior temporal gyri, and naming tools activated mostly posterior portions of the inferior temporal gyrus
Why do we see this differentiable gradient of brain damage leading to different category-specific deficits?
Sensory-functional explanation
Describe the Sensory-functional explanation
Category-specific deficits due to brain damage can be attributed to differences in the processing of sensory/perceptual information vs processing of functional information
What is the compromise of the Sensory-functional explanation?
Organization of information within semantic memory network is a distributed network of specialized clusters
What is sound?
Pressure waves caused by vibration that vary in frequency
How does our speech system solve problems of speech perceptions?
Our speech system can solve these problems of speech perception by relying on higher order cues; prosody (tone of voice), syllable stress, and formant frequencies (complex sound waveforms that carry the most critical information about speech)
Describe Eric Ramsey and the results of the study conducted on him?
Eric Ramsey was in a vegetable state; can think of/imagine speech sounds, but cannot produce them; Kennedy and Guenther implanted electrodes in left premotor cortex (speech planning area) and measured activity; then they built a decoder that translates neural activity into formant frequencies, and output can drive a speech synthesizer
What is the key idea behind Kennedy and Guenther’s study?
Speech output areas represent intended speech sounds in terms of formant frequencies
What is aphasia?
Deficits in language comprehension or production following brain damage or disease
What is primary aphasia?
Problems in language due to direct disruption of language processing system
What is secondary aphasia?
Problems in language due to memory problems
Describe Lichtheim’s Classical Model of Language Processing
There is an auditory area that stores information about words sounds that you hear (Wernicke’s area) and another area for speech programming (motor) area that involves the motor component of word output, necessary for speaking (Broca’s area); these two are connected by a fiber tract; damage to these 2 areas result in different aphasias
What is Broca’s Aphasia, and who is Patient Tan?
Broca aphasia is a non-fluent aphasia in which the output of spontaneous speech is markedly diminished and there is a loss of normal grammatical structure. Patient Tan had Broca’s Aphasia; labored speech, repetition of words, can’t produce a full, fluent sentence. TMS to Broca’s area can disrupt fluent speech
Does damage to Broca’s area result in Broca’s aphasia?
No, not always. Damage to other white matter and subcortical structures is also important
What is Wernicke’s Aphasia?
Problems in word comprehension and producing meaningful sentences. Fluent speech but nonsensical sounds and/or sentences. Making up words
Does damage to Wernicke’s area result in Wernicke’s aphasia?
No, not always. There has to be damage to the surrounding posterior temporal lobe regions, or damage to white matter paths that connect this area to other parts of the brain.
Is Broca’s area = output and Wernicke’s Area = comprehension true?
No, it is too simplistic of a distinction. To some degree both areas are involved in both output and comprehension.
What is the Classical Economist’s approach to decision-making?
People are rational and should make the choice with the greatest expected outcome
What is Psychologist’s approach to decision-making?
People don’t behave rationally because there are psychological factors at play - they use certain heuristics or have biases when processing decisions
What is Neuroeconomics?
Combines classical economic theory, psychological theory, and neuroscience
What regions in the brain are correlated with Value Representation?
Two regions show a linear increase with subjective value: Striatum and Orbitofrontal Cortex
What do dopamine neurons in the striatum respond to?
“Reward Prediction Neurons”. Dopamine Response = Reward Occurred - Reward Predicted
Describe the Striatal-related monkey experiment
In the experiment, monkeys are either given an unexpected reward or trained to associate a light with a reward a few seconds later. Result 1: When a monkey receives a reward without an expectation of reward, the neurons fire. Result 2: Monkey is trained to associate a flash of light with a reward. when the light is turned on, the dopamine neuron fires. The dopamine neuron does not respond to the reward. Result 3: Same as result 2, but there is no reward, the dopamine neuron drops below baseline firing
What is the prediction error?
The discrepancy between the expectation or prediction of reward and receiving the actual reward
Summarize the Striatum
Striatum plays a key role in coding prediction error, allowing learning from feedback to influence future choices (across at least the domains of value and social reputation learning)
Describe the Orbitofrontal Cortex
OFC is an important structure for emotional decision making
Describe Patient Elliot
Damage to OFC; displayed dampened, dull emotional responses to situations; can generate solutions to social problems and consider the consequences, but can’t decide which solutions are most likely to be effective or which ones to choose
Describe Damasio’s Somatic Marker Hypothesis and OFC’s role
Our emotional response (physiological arousal) to a situation are “somatic markers” that can guide our decisions (“go with your gut”). OFC helps associate situations and somatic (bodily) changes - support from Iowa Gambling Task
Describe the Iowa Gambling Task
OFC patients continue to choose pile A (riskier pile), and do not show SCR (skin conductance) response from pile A. Suggests that failure to generate somatic marker impairs ability to learn from the task
Describe how Iowa Gambling Task supports Damasio’s Somatic Marker Hypothesis
Suggest that failure to generate somatic marker impairs the ability to learn from the task
Describe the evidence against Damasio’s Somatic Marker Hypothesis
Patients with spinal cord injuries don’t have physical feedback, and thus have no somatic markers; however, they learn the Iowa Gambling Task just fine - don’t need a physiological response to learn
How is the OFC related to Reward Value/Weighing Value?
OFC may track the relative value of choice; value in relation to social/emotional context, to previous value for the same choice, value relative to internal states, preferences, and long-term goals
What is the evidence behind OFC and Value?
Greater activity in OFC as pleasantness increases; OFC increases as pleasantness of temperature increases, water taste increases (different experiments)
Describe the Striatum and OFC
Striatum = prediction error, evidence from monkeys and humans; OFC = relative value of choice, somatic marker hypothesis and updated view
What are Explicit Attitudes?
Belief that we consciously hold and express
What are Implicit Attitudes?
Belief that we have that we may not be aware of
How are Explicit Attitudes measured?
Modern Racism Scale; participants signify agreement with prompts like: discrimination against Blacks is no longer a problem in the US or over the past few years, Blacks have gotten more economically than they deserve
How are Implicit Attitudes measured?
Eyeblink Startle Response and Implicit Associations Test (IAT)
What is the Implicit Associations Test
The IAT measures the strength of associations between
concepts (e.g., Black and White) and evaluations (e.g., Good
and Bad); Making a response is easier when closely related items share the same response key
Describe the Conscious and Unconscious Processing of Race study and the findings
White young adults are given an MRI task: view a series of Black and White faces. Some are subliminal, and others are supraliminal. Findings were there’s more amygdala activity for Black faces, and more activity for Black faces that aren’t consciously processed (subliminal)
Describe the Dorsolateral PFC (relates to activation due to Black faces that are supraliminal)
dlPRC = Cognitive Control of Emotion; Regulates implicit attitudes in a manner consistent with explicit attitudes - regulating racial bias
Describe the Anterior Cingulate (relates to activation due to Black faces that are supraliminal)
Anterior Cingulate = Conflict Detection; Detects need for regulation of implicit attitudes - monitoring for racial bias
How is the Amygdala related to implicit race bias and judgments?
Amygdala activation is related to both the expression
of implicit race bias and judgments of trust
What were the findings of the trust game?
In economic games, implicit race bias is related to decisions to trust - the higher the pro-white bias, the more you invest with White partners relative to Black partners. Race bias in decisions to trust persist even when there is a clear personal cost
What is the fundamental attribution error?
Overweighing dispositional explanations for behavior (personality)
How does the fundamental attribution error relate to linking race bias to decisions?
The stronger the Pro-White implicit bias, the stronger the
attribution bias for negative actions by Black actors
Can we take advantage of our understanding of
the neural circuitry of implicit race bias to enhance
our understanding of race interactions?
Learning about others - there may be a ‘preparedness’ to associate negative outcomes with outgroup members, that may be harder to change with new information. Contact with others may alter perceptions of ‘ingroup’ and mediate this effect
Decisions about others - our decisions to trust and attributions about the cause of negative behaviors are influenced by implicit
race attitudes
How might we change race bias in the brain and behavior?
Through experience with others - amygdala activity does not correlate with implicit bias for familiar outgroup faces, like it does for unfamiliar outgroup faces
Approach to a situation - different neural circuitry is used when thinking about individual traits vs. group membership
Social context - IAT scores are less extreme when the experimenter was Black than White. White juries are more likely to deliberate before a guilty verdict of a Black man if there was at least one Black man on the jury
Awareness of implicit bias
What is the first evidence that suggests the Orbitofrontal Cortex role in social cognition?
Phineas Gage - piece of iron pierced his skull and it went through OFC and other parts of frontal cortex; drastic changes in personality - impatient, rude, used lots of profanity, and often abounded future plans that he made
What are four ways to study social cognition?
Faux Pas Tax, Teasing Task, Engaging in Personal Conversations, and Social judgments based on facial expressions
Describe the Faux Pas Task
Read narratives where social faux pas (embarrassing/rude remark) is committed; Healthy controls can correctly identify the faux pas, but OFC patients do poorly (don’t detect the faux pas) - have trouble putting together the whole sequence of events properly and taking context into account when making social judgment
Describe the Teasing Task
Make up nickname for an experimenter; Healthy controls don’t like this, make up positive nicknames, and then apologize; OFC patients enjoy the task, make up negative nicknames, weren’t embarrassed, etc. (note: If they’re not embarrassed, then there’s no reason to change)
Describe the Engaging in Personal Conversations Task
Engage in conversation where experimenter asks personal questions (while being videotaped); OFC patients are more likely than healthy controls to introduce impolite, inappropriate, and personal conversation topics (unaware of their behavior in the moment); however, THEY DO HAVE SOCIAL KNOWLEDGE. They know its inappropriate to discuss intimate/emotional topics; When they watch the video, they report greater embarrassment that other controls; Because they are unware in the moment of their inappropriate behavior, they do not generate emotional feedback that would allow them to change behavior
Describe the Social Judgement based on Facial Expressions task
Shown photos of 10 unfamiliar faces with various expressions (angry, disgusted, fearful, happy, sad, neutral) -indicate the extent to which they would ask this person for directions; OFC patients and controls performed similarly for neutral faces, but OFC patients were much more likely to rate a face as approachable than other controls, even though they could recognize a foreboding face
What is the self-referent effect?
When presented with a word list, we remember more words if we process them in relation to the self (e.g., Does this word describe you?) versus if you process them relative to others (e.g., Does this word describe the President?)
What study is related to Self-Referential Processing?
Encoding task: Make yes/no judgments concerning self (does this word describe you), other (does this word describe George Bush), and printed format (is this word in uppercase or lowercase letters)
What were the findings of the encoding task and what did it reveal?
Left inferior frontal cortex showed greater activity for both self and other judgments (require deeper processing) than for printed format judgments and Medial PreFrontal Cortex showed greater response (less reduction in activity) for self-judgments than for other and printed format judgments… Revealed, processing self-relevant information is a special process
What is the Medial PreFrontal Cortex a part of?
Medial Prefrontal Cortex is part of the default network; when we don’t have a specific task to do, MPFC activity increases
What is the default network?
Network of regions decrease in activity during attention-demanding cognitive tasks (require externally-focused attention), and increase in activity during rest (that involve self-focused attention)
What is our “sense of self”?
Our sense of self is NOT merely a collection of autobiographical memories - people do not recall episodes from their life when they have to decide whether a trait applies to themselves, but we use our memory to retrieve specific episodes when making judgments of others. Personality traits are true across most of our lives - Patient K.C. could accurately describe his own personality (after the accident), which changed after the onset of amnesia, which shows we can acquire new semantic information about oneself
Why is the Right Temporal-Parietal Junction important?
Right Temporal-Parietal Junction (rTPJ) is important for Theory of Mind (understanding the mental states of others); rTPJ is involved is reasoning about other people’s mental states
How is rTPJ assessed?
Assessed using the False Belief Task; rTPJ shows greater activity when individuals engage in false belief task compared to other control tasks
What is Synaptogenesis?
Formation of synapses: Synapses form long before birth (prior to week 27), doesn’t reach peak density until after birth (first 15 months), goes “from inside out” - deep (midbrain) to superficial layers (cortex), at the same time, neurons are growing longer dendrites, extending their axons and undergoing myelination
What is Synaptic elimination?
Pruning - elimination of synapses following synaptogenesis. Lasts for more than a decade; considered to reflect “fine tuning” of neural connectivity, removing redundant or non-functional connections
What is Critical Period?
Time window in which appropriate environmental input is essential for learning to take place, and this learning is hard to reverse in the face of the later experience
What is Filial imprinting?
Ducklings identify their parent by forming an attachment to a moving object seen in a particular time window (15 hours to 3 days) – hard to form attachments to new “parents” after this time; However, subsequent research suggests that timing of window is flexible (e.g., if no moving object is seen) and can be changed gradually; Suggests a sensitive period (more flexible than critical period)
Describe Critical Period for language acquisition
Critical period for language acquisition is thought to end during adolescence, after puberty (Lenneburg, 1967); However, different aspects of language may have different sensitive periods (e.g., discriminating between phonemes is set at infancy, whereas accents are more fluid during infancy but become harder to change in adulthood)
Describe the Adolescent Brain and their disposition to risky behavior
In addition to slow development of frontal lobes, the limbic regions (responsible for emotional arousal and sensitivity to reward) develop more quickly - heightened emotional reactivity + underdeveloped impulse control = risky adolescent behavior
Describe the amygdala in the adolescent brain and how its tested
Tested using “Go/No-go task”: Participants see a series of faces, and are asked to make a “go” response (i.e., press a button) to fearful faces or a “no-go” response (i.e., don’t press button) to neutral faces. Adolescents have heightened amygdala responses, regardless of whether they’re responding to a fearful face or not
Describe aging in relation to the brain
Aging is associated with declines in speed of processing, working memory processes, and long term memory … but it’s also associated with increases in acquired world knowledge
What regions of the brain decrease in volume with age?
Hippocampus, caudate nucleus, cerebellum, and lateral PFC show reductions with age
What regions of the brain don’t show reductions with age?
V1 and entorhinal cortex (the gateway for information entering and leaving the hippocampal formation)
What is the self-initiated encoding task and its findings?
Remember a bunch of words from a list. Older adults significantly under-recruit LIFC (i.e., less activity in this region) during the task, compared with young adults; However, if you give them a support strategy (e.g., an effective semantic coding task that requires deeper encoding), then they show same levels of LIFC activity as young adults.
Additionally, Younger adults selectively recruit the left frontal area, not the right. However, older adults have nonselective recruitment of frontal resources (i.e., more equally recruit both left and right frontal regions); With strategy support (i.e., deeper semantic encoding), both younger and older adults show improved memory performance, but older adults still show non-selective recruitment of bilateral frontal areas
Is non-selective recruitment in older adults adaptive and
compensatory, or a sign of breakdown?
Older adults who do well on tasks show more bilateral activation, whereas older adults who do poorly show more lateralization. Thus, non-selective recruitment seems to be a compensatory adaptation
What is the new view of brain plasticity?
The adult human brain is plastic and changes in response to experience; it is also capable of neurogenesis (formation of new neurons). Neurogenesis is now well established in several brain regions, especially the hippocampus
Describe cortical grey matters life trajectory
Cortical grey matter in frontal, parietal, and temporal regions shows an inverted U (peaks and then declines)
Describe white matters life trajectory
White matter shows increases throughout development
What are two things aging is associated with?
Under-recruitment and non-selective (bilateral) recruitment of frontal lobes
Describe the study that examined exercise and the hippocampus and the findings
120 older adults were randomized into 2 groups: Aerobic exercise group and stretching control group. 6 months later, came back to perform spatial memory task. Exercise group shows a selective increase in anterior hippocampal volume with aerobic exercise (anterior hippocampus is associated with associative and spatial memory tasks)
Summarize the effects of exercise
Structural imaging shows that exercise increases the volume of grey and white matter in the prefrontal cortex. Evidence that higher physical activity levels are associated with reduced risk of Alzheimer’s disease
What is consciousness?
Involves having access to information: the ability to report on the context of mental experience without knowing about the processes that build up to that context/experience. Also involves some aspect of sentience
What are the three frameworks of conscious?
Conscious awareness requires attention
Conscious vs unconscious processing in the brain (network approach)
Disorder/dissociations of consciousness
Describe the studies that support “Attention is the gateway to consciousness”
Change blindness and inattention blindness - if you don’t pay attention to it, you’ll miss it. Attentional blink: look for the numbers amongst letters - people usually notice and report the first number, and subsequently miss the second numbers
Describe Conscious vs Unconscious Processing
Whereas unconscious experience (even of high-level, semantic tasks) can happen in posterior regions of the brain, conscious experience is associated with widespread activity that includes more anterior parts of the brain such as the frontal and parietal lobes; Conscious processing requires engagement of the fronto-parietal attention network
Describe binocular rivalry and its findings
Perceptual experience of switching between two images (house and face); when your attention/conscious experience is on the face, more activity in FFA; if conscious experience is of the house, then more activity in PPA
Describe unresponsive wakefulness state (UWS) or minimally conscious state and current understanding
UWS: No sustained, reproducible, purposeful, or voluntary behavior. No evidence of language comprehension or expression
Minimally Conscious: Purposeful behavior (limited). Can follow commands (limited). More continuous improvement
In the medical arena, scientists are still trying to understand whether people in unresponsive wakefulness state (UWS) or minimally conscious state have any remaining consciousness at all
Describe the Trace Conditioning paradigm
(Rats). Play a tone, introduce a delay for several seconds, then shock. Patients will only acquire a standard conditioning response (i.e., increased SCR) if they become aware that the tone and shock are linked (not merely implicit learning… involves some aspect of explicit, conscious learning). Individuals in a UWS do show trace conditioning effect, but anesthetized patients do not suggests that people in a UWS might have some level of awareness of what is going on around them
Describe visual imagery in Unresponsive Wakefulness State patients and limitations
Visual imagery often evokes similar brain activity to actual perception; Ask individual in scanner to imagine 2 activities: playing tennis (activates SMA), vs. walking through house (activates PPA); UWS patient activates the expected regions during visual imagery, similar activity compared to controls; Not just an automatic response (don’t show same activity when just hearing the word without imagining anything).
However, not all UWS patients show modulation of brain activity based on instructions, and only 1 patient could actually use this activity as a mode of communication (e.g., “Imagine playing tennis to say yes, imagine walking through your house to say no”)
What is Wernicke’s area?
Speech comprehension brain area in superior temporal gyrus (junction between parietal and temporal lobes). Wernicke’s Aphasia:
What is the symbol grounding problem?
The symbol grounding problem concerns how it is that words get their meanings. If words are defined by other words, one must know the meaning of some words in advance.
What is the Hub-and-Spoke Model
Sensory and motor informations of a concept are processed by different modality-specific brain regions (spokes). These regions interact with a semantic hub, located in the lateral temporal lobes, which represents the concept in a unified and amodal manner.
Describe Levelt’s Discrete Stages Model
Speaking occurs in a sequence of non-overlapping stages. 1) Lexicalization (choosing semantic concept) 2) Lemma Retrieval (access syntactic properties) 3) Lexeme Retrieval or Phonological Encoding
Describe Interactive Models of Language
Interactive models of language processing reject the unidirectional flow of information in the Level stage model: activation at later stages able to influence what happens at earlier stages, because there is some parallel processing
Describe Dell’s Interactive Stages Model
Similar stages to Levelt’s but includes bidirectional or interactive activation
Describe Category-Specific Deficits study
Warrington found that some patients had little or no difficulty pointing to or naming pictures of living things, but had great difficulty pointing to or naming man made objects such as tools. Other patients showed the opposite pattern (i.e., double dissociation). These patients had category-specific deficits in conceptual/semantic knowledge, but others have category-specific naming deficits with intact conceptual knowledge.
Why are category-specific deficits in comprehension and naming observed?
Warrington & Shallice (1984): Differences in processing of sensory perceptual information (most relevant for distinguishing among living things) vs. functional information (most relevant for distinguishing nonliving things, e.g., manmade objects such as tools)
What are the problems to Ward’s theory of why there are category-specific deficits in comprehension and naming observed?
Patients with selective deficits for living things don’t have more difficulty answering sensory vs. functional questions about animals or objects.
Some patients who have difficulties with sensory properties don’t show expected category-specific impairments.
What are two special problems of Speech?
Lack of sharp boundaries (Written words/sentences have sharp physical boundaries, but spoken words/sentences don’t) and segmentation (Spoken sentences often lack clear boundaries between words because they are frequently coarticulated (i.e., ends and beginnings are united).
What is the role of the Striatum?
The striatum plays a key role in coding prediction errors allowing learning from reward feedback to influence future choices
Describe the OFC (what damage leads to and why)
OFC damage leads to a range of social/emotional problems resulting from poor choices. Deficits are related to difficulty updating/changing the reward value of choices, and/or incorporating social/emotional context in valuation of choices
What is your sense of self?
Summaries of our Personality Traits; Things that are true about us across most of the events in our lives and not tied to any single life event
