Understanding Emotions: Components, Neural Systems, and Responses

School
University of Toronto**We aren't endorsed by this school
Course
PSY B55
Subject
Psychology
Date
Dec 12, 2024
Pages
22
Uploaded by GrandDeer3719
LEC 9 EMOTION10.1 What is an Emotion?Definition of Emotion:Emotions are multifaceted responses to external or internal stimuli.They consist of:Neural circuits (partially dedicated systems).Observable responses (behavioral and physiological).Subjective experiences or "feelings."Characteristics of Emotions:Emotions are valenced(positive or negative) responses to external stimuli and/or internalmental representations that:Involve changes cross multiple response systemsDistinct from moods, they’re longer-lasting and have identifiable objects or specific triggers.Moods are a long-lasting diffuse affective state characterized by enduring subjective feelings without an identifiable object or triggerEmotions are often tied to specific stimuli, and can be unlearned responses to stimuli which can be intrinsic (e.g., first taste of sugar) or learned responses with acquired emotional value (e.g., fear of a dog that bit you).Can be influenced by cognitive appraisals—interpretations of how stimuli relate to personal goals.Viewed as the result or consequence of the emotional stateAn “emotion” constitutes an internal, central (as in central nervous system) state.This state is triggered by specific stimuli (extrinsic or intrinsic to the organism).This state is encoded by the activity of particular neural circuits.Activation of these specific circuits gives rise to externally observable behaviors, and to separately (but simultaneously) associated cognitive, somatic, and physiological responsesEntails (at least) three following components:Physiological reaction to a stimulusA behavioural responseA feelingNeural Encoding:Emotions involve central nervous system circuits.These circuits activate specific behaviors and simultaneously produce subjective feelings.Encountering a stimulus/event that threatens us triggers stressStress–A fixed pattern of physiological and neurohormonal changesThese changes disrupt homeostasis, and immediately activate the hypothalamic-pituitary-adrenal (HPA) axis and release stress hormones, such as cortisol. Cortisol increases blood gluclose levels and decreases inflammatiry responses10.2 Neural Systems Involved in Emotion ProcessingWhen emotions are triggered by an external event or stimulus (e.g., a crying baby), our sensory systems play a role
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With an internal stimulus, such as an episodic memory (e.g., remembering your first kiss), our memory systems are involved. Autonomic Nervous System:The physiological components of emotion that produce physical feelings (e.g., the shiver up the spine and the dry mouth that people experience with fear) involve the autonomic nervous system (ANS), a division of the peripheral nervous system.ANS: Made up of the sympathetic and parasympathetic nervous system, where the two systems work in combination to achieve homeostasis. The sympathetic nervous system promotes the fight or flight responseGetting your body ready to act in stressful or dangerous situations like speeding up your heart rate or making you breathe fasterThe parasympathic system promotes the rest-and-digest responseHelps your body relax and recover, like slowing your heart rate or helping you digest foodHypothalamus:Control center for ANS, helps release hormones that trigger stress responsesHPA (hypothalamus, pituitary gland, adrenal glands)Hypothalamus sends signal called CRF which goes to pituitary gland and release another signal called ACTH in your bloodstream, which reaches the adrenal glands and releases cortisol to handle stressWhen enough cortisol is in your bloodstream, it sends a message to the hypothalamus to stop the stress response process to avoid overreacting–Negative FeedbackEmotions are tightly connected to your body’s arousal system, which keeps you alert and ready to respond to situations.The reticular activating system (RAS)in your brainstem acts like a switchboard, sending signals to wake you up and keep you focused.These systems—ANS, HPA axis, and RAS—work together to create the physical and behavioral responses we associate with emotions, like a racing heart when you're scared or calm breathing when you're relaxed.The Limbic System:Historically thought to be the "emotional brain," the limbic system (including the amygdala, hippocampus, and hypothalamus) is central to emotional responses.Maclean’s Limbic System believed brain evolved in laters, the older areas that handle basic survival emotions, and newer areas that manage complex social emotions like love or empathyHowever, modern research identifies a more distributed network of brain areas involved in emotionLocationist View of Emotions:Early models assumed each emotion (e.g., fear) had its own specific brain circuit.This view suggests these circuits evolved because they helped survival and are shared by other mammals.Amygdala:Processes emotional salience, particularly fear.Influences memory consolidation of emotional events.Orbitofrontal Cortex (OFC):Critical for integrating sensory input with emotional valence.Damage to the OFC (e.g., in Phineas Gage’s case) leads to impulsivity and poor emotional regulation.Insular Cortex:Linked to disgust and recognizing bodily states associated with emotions.
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Prefrontal Cortex (PFC):Regulates emotional responses and supports decision-making.10.3 Categorizing EmotionsPaul Ekman (1960’s)Found that cultures express these six basic emotions: Anger, fear, disgust, happiness, sadness, and surprise in similar ways Basic Emotions (Universal):Anger, fear, disgust, happiness, sadness, and surprise Are innate, universal, and short lastingCultural “rules” can shape how emotions like pride and shame are expressedCharacterized by specific facial expressions, as identified by the Facial Action Coding System (FACS).Duchenne (1862) studied facial muscles by electrically stimulating them in a patient with facial numbness and showed how different muscle contractions create emotional expressionDarwin (1872)Argued that facial expressions of emotion are similar to animalsBelieved emotions evolved for specific purposes like survival and each emotion has a unique physiological expressionComplex Emotions:Involve combinations of basic emotions, context, and cultural factors (e.g., shame, guilt).Complex emotions last longer–sometimes months or a lifetime–and involve multiple layers of feelingsEmotion complexes–more involved than basic emotions (like jealousy)Jealousy is a mix of emotions like anger, fear, and sadness.Shaped by personal experiences, relationships, and context, making it harder to define and categorize compared to basic emotions.Dimensional Theories of Emotion:Emotional reactions to stimuli can be characterized by two factors:Valence:Pleasant–Positive (e.g., happiness) vs. Unpleasant–negative (e.g., fear).Arousal:High (e.g., excitement) vs. low (e.g., calmness). Intensity of the internal emotional response Emotions can drive us to approach (engage), or withdraw (avoid)Can feel both positive and emotions at the same time, showing emotions are more complex than just being good or badPositive feelings are linked to more dopamine in the brainNegative feelings are linked to more norepinephrine10.4 Theories of Emotion GenerationEmotion Generation is an attempt to explain: Physiological Reaction (racing heart)Behavioural Reaction (fight or flight response)Subjective Experiential feeling (I’m scared)James–Lange Theory:
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Emotions are a direct result of physiological changes (e.g., "I feel afraid because my heartraces").Your body’s response comes first and the emotions happen only after our body reacts to something and you notice and interpret those changes Your sense organs relay information about a stimulus that triggers a reaction, youhave a physiological response (sweating etc.) which produces a behavioural response (running), you interpret these changes in cognition (my heart’s beating fast and i’m running=afraid), and produce subjective emotional feeling (i’m scared)Cannon–Bard Theory:Emotions (fear) and physiological responses (your body’s reaction) occur simultaneously but independently.Thalamus in the brain sends emotional signals to the neocortex for emotions, and the body for physical reactionsAppraisal Theories:Emotions result from evaluations (appraisals) of how events relate to personal goals.Cognitive appraisals shape emotional responses (e.g., interpreting nervousness as excitement). Cognition (appraisal) evaluates if something’s harmful or beneficial, which produces emotion and behavioural responsesLeDoux's Dual Pathways to Emotion:Two emotion systems in your brainFast Pathway (Defesive Circuits):Direct route from sensory thalamus to amygdala, allowing rapid emotional responses.Reacts to threats without thinking, increasing survival chancesAutomatic and hadwiredSlow Pathway:Involves cortical processing for more detailed appraisals and regulation.Involves thinking and conscious awareness of feelingsDepend on learning and experience10.5 The AmygdalaRole in Emotional Processing:The amygdala detects emotional salience and processes fear.Damage to amygdala leads to a lack of fear and risky behaviour because the emotional importance of stimuli isn’t recognized It enhances memory for emotional events by interacting with the hippocampus.Emotional learning and memoryconnecting sensory inputs with emotional significanceAttention and decision makingSignals from the amygdala prioritize emotionally relevant stimuliImplicit Emotional Learning:Amygdala helps you unconsciously associate certain stimuli with fear or dangerCitical for linking sensory stimuli to emotional responsesFear conditioning occurs through associations between neutral stimuli and aversive outcomes (e.g., blue square paired with shock).Amygdala damage disrupts the ability to form these associations.Explicit Emotional Learning:
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Involve conscious knowledge, such as learning that a situation is dangerous based on verbal informationRelies on hippocampus but amygdala is necessary for showing emotional responses The amygdala also supports conscious associations between emotions and stimuli.Hippocampus works with amygdala to store explicit emotional memoriesExperimental Evidence:Amygdala Damage:Patients with damage show reduced skin conductance response in fear-conditioning experiments, even though they experience emotions.10.6 The Influence of Emotion on LearningEmotional Memory Enhancement: Emotional content (especially negative stimuli) boosts memory consolidation.Emotional or exciting events are remembered more vividly than ordinary eventsAmygdala strengthens memory retention by working with the hippocampus, especially during emotional arousalFlashbulb memories: Vivid memories of where you were and what you were doing during significant eventsAmygdala helps these memories feel more vivid, even if some details fade over timeArousal-dependent modulation:Amygdala doesn’t directly create memories but enhance their retention by influencing the hippocampus during emotional eventsCan enhance memory for significant events if they’re related to an emotional experienceIf the amygdala is damaged, emotional events are forgotten as quickly as neutral onesNeuroimaging Studies:fMRI studies show increased amygdala activity for emotionally charged images.Emotional memories are more likely to be remembered than neutral ones.Mechanistic Insights:Disruption of amygdala function (via damage or transcranial magnetic stimulation) diminishes this memory boost.10.7 Interactions Between Emotion and Other Cognitive ProcessesAttention:Emotional stimuli capture attention more effectively, particularly negative stimuli.The amygdala plays a role in prioritizing such stimuli.Naturally more aware of and pay attention to emotional stimuliAmygdala plays a key role in enhancing attention for emotional stimuli which improves perception and attentionAmygdala works works with visual cortex to prioritize emotionally significant stimuli before we’re fully aware of themDecision-Making and Somatic Marker Hypothesis:
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Proposed by Antonio Damasio, this theory suggests that emotional "gut feelings" guide decision-making.Emotional reactions in the body act as “markers” to guide decision-makingThe orbitofrontal cortex (OFC) helps associate these body signals with past experiences, aiding in future decisionsVentromedial Prefrontal Cortex (vmPFC):Generates somatic markers—bodily states linked to emotions that influence decisions.Damage to the vmPFC impairs risk evaluation, as demonstrated by the Iowa Gambling Task:Healthy participants learn to avoid risky decks.vmPFC-damaged patients fail to associate risky decks with penalties, continuing poor choices.Emotion and Moral Decision-Making:Emotions influence how we make decisions even when logic and reason seem more appropriateDual-systems theory:Suggests that emotion and logic compete in decision-making, but they also work togetherEmotional reactions often help guide better decisionsTasks like the Trolley Problemshow that vmPFC activity increases during emotionally salient moral decisions (e.g., pushing someone to save others).vmPFC damage reduces emotional aversion to personal moral dilemmas, leading to moreutilitarian choices.Emotions influence decisions by assigning values to outcomesEmotional responses such as fear or regret guide choices and help avoid negative outcomesOribitofrontal cortex and amygdala collaborate to integrate emotional and rational thinking10.10 Cognitive Control of EmotionEmotion Regulation:How we manage our emotions–what we feel, when we feel, and how we express itAntecedent-focused regulation:Managing emotions before they fully form by changing your focus, and the way you view a situationResponse-focused regulation:Controlling emotions after they form by suppressing the emotional responseEmotion Regulation Strategies:Suppression:Reducing emotional responses/expressions (e.g., trying not to react to anger).Reappraisal:Changing how a stimulus is interpreted to reduce emotional impact(e.g., viewing a stressful event positively).Neural Mechanisms:Prefrontal Corted (PFC):Helps regulate emotions by controlling activity in deeper emotional brain areas like the amygdalaPFC activity increases during reappraisal to downplay or amplify emotions
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Regulation depends on prefrontal regions, including:Dorsolateral Prefrontal Cortex (dlPFC):Supports cognitive reappraisal.Ventromedial and Orbitofrontal Cortices:Integrate emotional and cognitive information.Amygdala:Processes the emotional importance of stimuliactivity decreases when negative emotions are reduced and increases when negative emotions are amplifiedExperimental Findings:Viewing negative images and trying to reduce their emotional impact decreases amygdalaactivation.Conversely, enhancing emotional interpretation increases amygdala engagement.Integration with Lecture NotesAmygdala and Emotional Memory:The lectures highlight experiments (e.g., emotional vs. neutral pictures) consistent with the amygdala’s role in memory enhancement.Fear Conditioning:The notes emphasize the amygdala’s critical role in forming fear associations, as seen in both the textbook and lecture examples.Decision-Making and Emotion:The Somatic Marker Hypothesis aligns with lecture discussionson the Iowa Gambling Task and vmPFC’s role in processing risk.Moral Decision-Making:Trolley Problem scenarios reinforce the vmPFC’s influence on integrating emotion and logic.Emotion Regulation:Lecture insights into cognitive strategies (e.g., reappraisal) complement the textbook’s findings on amygdala and prefrontal interactions.LEC 10 LANGUAGE11.1 The Anatomy of Language and Language DeficitsPrimary Language Areas:Broca’s Area:Located in the left inferior frontal gyrus.Key for speech production, syntax, and grammar.Damage results in Broca’s Aphasia:Difficulty speaking fluentlyEffortful speech lacking grammar, but retaining comprehensionSpeech of patients contain content words and leave out function words that have only grammatical significance and comes in uneven burstsAggramatic Aphasia:Basic and overlearned grammatical forms are produced and comprehended Wernicke’s Area:Found in the left superior temporal gyrus.Essential for language comprehension.Damage leads to Wernicke’s Aphasia:Speech remains fluent but nonsensical ("word salad")Comprehension is impaired.
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Difficulty understanding spoken or written language and sometimes cannot understand language at all, but speech is fluentSemantic Paraphasia:Error in speech production, using the wrong wordArcuate Fasciculus:White matter tract connecting Broca’s and Wernicke’s areas.Damage causes Conduction Aphasia:Patients struggle to repeat spoken phrases despite intact comprehension and speech.Visual Word Form Area (VWFA):Located in the left fusiform gyrus.Processes written words and supports reading fluency.Damage results in Pure Alexia, an inability to read even single words.Left Hemisphere:Dominates language processing in most people.Critical for producing and understanding language.Right Hemisphere:Supports prosody (rhythm and intonation).Processes metaphorical and nonliteral language.Additional Deficits:Aphasia: Broad term referring to the collective deficits in language comprehension and production that accompany neurological damageDysarthia: Speech problems caused by the loss of control over articulatory musclesAnomia:Form of aphasia characterized by inability to name objects or retrieve specific wordsApraxia of Speech:Difficulty forming correct speech sounds due to motor planning deficits.Often co-occurs with Broca’s aphasia due to overlapping damage in the insula.11.2 The Fundamentals of Language in the Human BrainA word in spoken language has two properties: a meaning abnd a phonological loop (sound based) formA word in written language has an orthographic (vision-based) formMental lexicon:A mental store of information about words that includes semantic information (meanings)syntactic information (how words combine to form sentences)details of word forms (spellings and sound patterns)Organized efficiently to enable quick retrieval of words durig speech or comprehension:Morphemes: Smallest meaningful units in language (e.g., "un-" in "undo").Frequency: Commonly used words are retrieved faster (e.g., "people" vs. "fledgling").Lexical Neighborhoods: Words that differ by one phoneme or letter are grouped(e.g., "bat", "cat", "hat").Semantic Similarity: Words with related meanings are linked (e.g., "dog" and "bark").
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Lexical access:the stage(s) of processing in which the output of perceptual analysis activates word-form representations in the mental lexicon, including their semantic and syntactic attributes.Process of identifying a word’s representation in the mental lexiconMatching phonological or visual input to stored representationsLexical selection:the stage in which the representation that best matches the input is identified (i.e., selected).Selecting the correct word from the mental lexiconLexical integration:the final stage, in which words are integrated into the full sentence, discourse, or larger context to facilitate understanding of the whole message.Integrating its meaning into the broader context of a sentenceNeural Substrates of Mental LexiconSemantic Paraphasia: Errors in speech production, using the wrong wordShow word meanings are stored in related networks in the brainDyslexia: Errors in readingThis indicates that reading and speech share the same mental lexicon.Progressive Semantic Dementia:Patients lose the ability to assign specific meanings to objects, often naming them broadly (e.g., calling a horse "animal"). This occurs due to damage in the left temporal lobes, which store conceptual knowledge.Name a category when asked to name a picture Can still understand and produce synaptic structure of sentencesSemantic Network HypothesisThe brain organizes meanings in a connected network. When parts of the network are damaged, related concepts become confused or generalized:Category-Specific Deficits:Living Things(e.g., animals) rely on visual features (e.g., color, shape).Due to lesions in the inferior and medial temporal cortex, near regionsfor visual object recognition.Human-Made Objects(e.g., tools) are defined by their functions (e.g., how to use a hammer).Due to lesions in left frontal and parietal areas, involved in motor and action-related processing.Challenges to the Semantic Network HypothesisSome researchers argue that the brain organizes meanings differently:Animacy vs. Inanimacy:Living and nonliving things are processed in separate systems because of their evolutionary importance.For example, distinguishing animals might rely more on perceptual features (e.g., size, fur) while identifying tools focuses on their use (e.g., actions).Evidence from Brain Imaging:Studies in healthy participants confirm findings from patients:Living Things:Activates areas for visual processing, such as the fusiform gyrus and occipital lobe.Human-Made Objects:
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Activates areas for motor functions, like the premotor cortex and middle temporal gyrusThese findings suggest that living and nonliving objects engage different brain regions based on their defining features.Specific vs. General NamingGeneral Naming:Involves simpler features (e.g., a tiger is an "animal").Requires less detail retrieval.Specific Naming:Requires more precise features (e.g., a tiger is "large," "has stripes").Patients with anterior temporal lobe damagestruggle with this because these regions help retrieve detailed features.Timing of Semantic ProcessingWithin 100 ms: Visual cortex activates basic features (e.g., shape, color).150–250 ms: Temporal cortex processes more detailed meanings.Around 300 ms: Specific object identification occurs, requiring integration of features.11.3 Language Comprehension: Early StepsLanguage comprehension involves understanding both spoken words and written text, which require different neural processes due to the nature of their input modalities:Spoken Language: Acoustic signals must be decoded.Written Language: Visual symbols must be mapped to phonological and semantic meanings.Auditory Processing (Spoken Language):Depends on auditory pathwaysBegins in the primary auditory cortex and transitions to Wernicke’s area for decoding spoken words.When we hear speech, the sound is analyzed and translated into a phonological (sound-based) codeThis code helps us find the matching word in our brain’s “dictionary” (mental lexicon), and once we identify the word, we access its grammar, meaning, and context Phonemes:Basic units of sound that differentiate meanings (e.g., /k/ in "cat" vs. /b/ in "bat").English has about 40 phonemes, though this varies across languages.Wernicke’s Area: Critical for understanding the meaning of wordHierarchical Speech Processing:Initial stages process general auditory features (e.g., pitch, intensity).Later stages specialize in identifying speech sounds and their meanings.Visual Processing for Reading (Written Language):Depends on visual processing areasWhen we read, the first step is recognizing orthographic units (letters or symbols)Symbols are marched to orthographic forms stored in the mental lexiconLetters are either directly linked to words in the mental lexicon or converted into their sounds (phonological forms), and then accesses words meanings and grammatic rules like for spoken wordReaders translate written symbols into their corresponding sounds and meanings
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This process engages:Visual Word Form Area (VWFA):Critical for recognizing word forms and distinguishing real words from pseudowordsLeft occipotemporal cortex crucial for recognizing letters and wordsVWFA communicates with language related regions like Broca’s area (speech production) Activated for letter and word recognition.Integrates information from both visual fields for unified word processing.Dual Route Model of Reading:Phonological Route:Sounding out words (grapheme-to-phoneme conversion).Lexical Route:Accessing whole words from the mental lexicon.Reading Disorders:Developmental Dyslexia:Impaired reading fluency and decoding due to reduced VWFA activation.Pure Alexia:Severe reading deficits due to direct VWFA damage, affecting word recognition.Shared and Unique Processes in Spoken and Written ComprehensionShared Mechanisms:Both modalities ultimately rely on the mental lexicon for word meanings.Semantic and syntactic integration occurs in similar brain regions.Differences:Temporal Processing: Spoken words are processed sequentially over time.Spatial Processing: Written words are processed as a whole or in parts, spatially.Neural Substrates of Early Language ComprehensionSpoken Language:Primary Auditory Cortex: Processes sound features.Superior Temporal Cortex:STG handles basic speech sounds.STS identifies phonological patterns and begins linking them to words.Written Language:VWFA(Visual Word Form Area): Recognizes written word forms.Occipitotemporal Cortex: Specialized in processing orthographic symbols.11.4 Language Comprehension: Later StepsLanguage comprehension involves more than recognizing individual words. Later steps integrate syntactic (sentence structure) and semantic (meaning) information to create coherent understanding of sentences and larger narratives.Semantic Integration:Refers to understanding the meaning of the words in the context of sentences or storiesUnderstanding a sentence requires combining words into a structure that assigns roles like subject, object and verbAmbiguities arise when multiple meanings or structures are possible. Context resolves these ambiguities.Brain combines the meaning of the word with context provided by surrounding words or sentencesProcess involves two types of representations: Lower-level representations: Basic sensory input, like hearing the word "bank."
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Constructed from sensory input Higher-level representations: Context from the sentence or story.Constructed from the context preceding the word to be processedImportant to determine the right sense or meaning of words in the context of a sentenceThe N400 brain wave reflects how we process word meanings:Brainwave associated with detecting semantic mismatchesIt activates when a word doesn’t fit semantically, like in "He spread the warm bread with socks."It is strongest when a word conflicts with the context of a sentence or story.The N400 is generated in the left temporal lobe, where the brain processes meaning.Links word meanings into coherent thoughts.Disruptions (e.g., in Wernicke’s aphasia) lead to garbled communication and impaired comprehension.Syntax and Grammar:Syntax involves the structure of sentences, such as grammar rules and how words fit together to convey meaning.Brain assigns roles to words in sentences in real time. This helps derive meaning even when semantics are unclear or nonsensicalYour brain builds sentence structures dynamically, rather than relying on pre-stored templates.The P600 brain wavereflects syntactic (grammatical) processing:Linked to syntactic reanalysis or error detectionIt activates when a sentence has a grammatical error or unexpected structure.Example: "The eggs would eat toast" triggers a P600 because eggscannot logically be the subject of eat.Like the N400, the P600 helps identify errors, but it focuses on structure rather than meaning.Broca’s area is essential for understanding and producing grammatically correct sentences.Damage results in agrammatism, where function words are omitted in speech.Role of the Right Hemisphere:Supports understanding of context, metaphors, and broader discourse elements.Damage impairs abilities to interpret non-literal meanings and social nuances.When a sentence has more than one meaning, the right hemisphere helps resolve subtle nuances and overarching context.The right hemisphere processes the emotional undertone of language, such as sarcasm or empathy.11.5 Neural Models of Language ComprehensionHagoort’s Model: Memory, Unification and Control:Divides language into three key componentsMemory:Knowledge of language we’ve learned and stored Includes phonological (sound), morphological (word structure), and synctactic (sentence structure) units
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Encoded in temporal lobe, which stores and retrieves language-specific knowledgeUnification:Combining language elements (sounds, meanings, grammar) to create full sentences or ideasHeavily relies on Inferior Frontal GyrusSemantic integration (meaning) Broddmann areas 47 and 45Synctactic integration (grammar) Areas 45 and 44Phonological integration (sounds) Area 44 and nearby regionsControl:Managing language use in real-world interactionsSupports real-time communication tasks (like conversation turn-taking) and managing multiple languagesHappens in brain areas involved in cognitive control that helps focus attention and supports decision-making and flexibilityMultiple pathways connect these regions, ventral pathway (for understanding words), dorsal pathway (for sentence structure and speech)Network-Level Language Processing:Involves interactions between:Frontal Areas:Support syntax, planning, and speech production.Temporal Areas:Decode auditory and written input.White Matter Tracts (e.g., Arcuate Fasciculus):Enable communication between production and comprehension areas.Functional MRI shows strong connectivity between Broca’s and Wernicke’s areas duringlanguage tasks.Right Hemisphere Contributions:Pragmatic language processing (e.g., sarcasm, irony).Discourse processing to extract the overall meaning of conversations.Social interpretation of intent and behavior.Damage can lead to literal interpretations and difficulty in grasping social subtleties.Integration with Lecture Notes1.Aphasias:Lecture examples of Broca’s (Leborgne’s “tan” case) and Wernicke’s aphasias reinforce distinctions in fluency and comprehension deficits.Conduction aphasia highlights the functional importance of the arcuate fasciculus, as described in both sources.2.Reading Models:The Dual Route Model aligns with lecture discussions of phonological vs. lexical routes, emphasizing VWFA’s critical role in fluent reading.Dyslexia and pure alexia examples in lectures connect to VWFA disruption and its cascading effects on language processing.3.Right Hemisphere Contributions:Lecture examples of impaired pragmatics and discourse in patients with right hemisphere damage complement textbook descriptions of its role in context and social processing.4.Testing for Language Dominance:
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Wada test and fMRI studies are consistently highlighted as effective tools for mapping language laterality.LEC 11 COGNITIVE CONTROL12.1 Anatomy of Cognitive ControlCognitive control, also known as executive function, involves processes that enable goal-directed behavior by using perceptions, knowledge, and goals to guide actions and thoughts.Relies on the prefrontal cortex (PFC) to regulate attention, memory, and emotions.Key Functions:Involves planning, monitoring, inhibiting habitual responses, and adapting to unforeseen challenges.Requires the ability to sustain focus on goals over extended periods while ignoring distractions.Core Abilities:Working Memory:Maintaining goal-relevant information.Inhibition:Suppressing inappropriate responses or distractions.Cognitive Flexibility:Adjusting behavior in response to changing circumstances.Planning:Breaking complex goals into prioritized steps.Problem-Solving:Applying reasoning to overcome novel obstacles.PFC:The prefrontal cortex coordinates processing across wide regions of the central nervous system (CNS). It contains a massively connected network that links the brain’s motor, perceptual, and limbic regions Extensive, reciprocal projections connect the prefrontal cortex to almost all regions of theparietal and temporal cortex, and to prestriate regions of the occipital cortex. Subregions of the PFC:Dorsolateral PFC (dlPFC):Involved in working memory and decision-making.Ventromedial PFC (vmPFC):Processes emotions and social cognitionOrbitofrontal Cortex (OFC):Regulates emotional responses and decision-making under uncertainty.Inferior Frontal Gyrus:Supports semantic retrieval.Anatomy:The prefrontal cortex (PFC)is the primary region associated with cognitive control.LPFC, FP, OFCThis control system works in concert with more posterior regions of the cortex to constitute a working memory system Recruits and selects task-relevant information.
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Involved with planning; simulating conse-quences; and initiating, inhibiting, and shifting behavior.Lateral Prefrontal Cortex (LPFC): Handles task-relevant information and working memory.Frontal Pole: Involved in abstract reasoning and managing complex behaviors.Orbitofrontal Cortex (OFC): Associated with evaluating rewards and decision-making.Medial Frontal Cortex (MFC): Monitors ongoing behavior and regulates control intensity.Plays an essential role in guiding and monitoring behavior. It works in tandem with the rest of the prefrontal cortexMonitoring ongoing activity to modulate the degree of cognitive control needed to keep behavior in line with current goals. Evolutionary Insights:The PFC is larger in humans compared to other species, indicating its critical role in advanced cognitive functions like planning and reasoning.12.2 Cognitive Control DeficitsDeficits in cognitive control often result from damage to the frontal lobes and manifest in various psychological and behavioral disorders.Frontal lobe lesions impair decision-making, memory organization, and social rule adherence.Reduces ability to plan, inhibit impulses or adjust strategiesBehavioral Symptoms:Perseveration: Repeatedly performing the same action or response despite its inappropriateness.Repeat wrong actions despite being correctedImpulsivity: Acting without planning or consideration of consequences.Unable to make decisions, plan actions, or understand the consequences of their actionsUnable to organize and segregate the timing of events in their memory, remember the sources of their memories, and follow rulesDisregard social normsStimulus-Driven Behavior: Responding automatically to environmental cues without context consideration.Without clear goals, their actions become reactive to their surroundings rather than intentional.No longer have a purpose of their actionsExample: Patients might use objects inappropriately due to lack of inhibition (e.g., hammering a nail when not appropriate).Utilization Behaviour:A condition where patients act automatically on environmental cues without considering context or goals.Extreme dependency on prototypical responses for guiding behaviourThey automatically act on familiar objects in their environment without context.
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An example is using a syringe inappropriately because they associate it with its typical use.Conditions and Disorders:Psychiatric disorders like depression, schizophrenia, and ADHD are linked to cognitive control deficits.Addictions impair the PFC, reducing impulse control and promoting harmful habits.A hallmark of drug or alcohol addiction is the sense of a loss of control. Suggests that disruption of PFC function underlies the charac-teristic problems addicts have in inhibiting destructive behaviors and appropriately evaluating the relevance of behavioral cues Case Study:W.R., a patient with extensive PFC damage, exhibited lack of emotional response to life changes, poor goal execution, and passivity. This highlights the PFC’s role in sustaining motivation and purpose.12.3 Goal-Oriented BehaviorGoal-oriented actions are guided by expected outcomes and the understanding of causal relationships between actions and rewards. It requires processes that enable us to:Maintain our goalFocus on the information that is relevant to achieving that goalIgnore or inhibit irrelevant informationMonitor our progress toward the goalShift flexibly from one sub-goal to another in a coordinated wayTypes of Actions:Goal-Oriented Actions: Based on evaluating possible outcomes to achieve a specific goalDeliberate and driven by a clear reward/purposeAction-outcome relationshipExample: Studying for an exam to achieve good grades.Habitual Actions: Stimulus-driven and automaticAction that’s no longer under the control of a rewardAutomatic and triggered by familiar stimuli/past experiencesExample: Turning on the car radio automatically without evaluating its functionality.Cognitive Control and WMRequires working memoryMaintenance of information that provides an interface linking perception, long-term memory, and action that enables goal-oriented behaviour and decision makingCritical when behaviour isn’t stimulus drivenWe need to integrate current perceptual information with stored knowledge from long term memory to carry out our decisionsMaintains focus on goals, inhibits distractions, and adapts actions based on context.Helps aligns actions with goals by maintaining focus on relevant information, ignoring distractions, and adaptabilityPrefrontal Cortex Dynamics:The prefrontal cortex (PFC) is crucial for linking our current environment (what we see) with stored knowledge (what we know).
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A working memory system requires a mechanism to access stored information and keep that information active. The prefrontal cortex can perform both operations. LPFC sustains task-relevant information.Sustains information that is relevant for achieving that goal across the delay periodCritical region for maintenance and manipulation of information in the working memoryOperates along three gradients:Ventral-Dorsal: Deals with "what" (content) and "how" (action)Organized in terms of maintenance and manipulation and reflects generalorganizational principles (ventral and dorsal)Anterior-Posterior: Handles task complexity, with more abstract tasks requiringthe frontmost regions.More abstract representations engage anterior regionsLess abstract engage posterior regionsThe point where abstract intentions are translated into concrete movement (PMC)Lateral-Medial: Integrates external info (lateral) and personal/emotional info (medial) Lateral regions of the PFC integrate external info tha’s relevant for current goal-oriented behaviourMedia regions allow info related to motivation and potential reward to influence goal-oriented behaviourThe PFC helps keep task goals active and interacts with other brain regions to retrieve relevant knowledge.The interaction between PFC and other brain regions integrates long-term memory with current goals.Working memory facilitates dynamic goal representation, enabling flexible responses to changes in context.Working memory, like a "mental blackboard," temporarily holds information we need to achieve goals.12.4 Decision MakingDecision-making processes involve selecting actions based on available options. It involves weighing potential outcomes, assessing risks, and evaluating rewards to achieve goals.Neuroeconomics bridges neuroscience and economic theories to understand decision-making.Normative vs. Descriptive Theories:Normative Theories: Define how decisions shouldbe made to achieve optimal outcomes.Based on logic and probability theory (calculating the best choice)Descriptive Theories: Focus on what people actuallydo, often highlighting inconsistencies or suboptimal behaviors.Human decisions often deviate from logical models due to biases, emotions, or incomplete informationDecision making relies on specific brain regions to process rewards, risks, and consequencesClassification of decisions:Action–outcome decisions:
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Decision involves some form of evaluation (not necessarily conscious) of the expected outcomes. Stimulus–response decisions:After we repeat that action, and if the outcome is consistent, the process becomeshabitualModel-based:Means that the agent has an internal representation of some aspect of the world and uses this model to evaluate different actions. Involves planning and constructing a mental model of the environmentActions are chose by simulating potential future outcomes to identify the best optionModel free:Relies on habits and reinforcement learningActions are chosen based on previously learned reward values without considering the underlying structure of the environmentBrain Mechanisms in Decision Making:Prefrontal Cortex (PFC):The prefrontal cortex plays a critical role in integrating reward values and potential consequences.Central hub for decision making and goal-oriented behaviourBefore making a choice, the brain evaluates the value of each option based on Reward (Payoff): How much will you gain?Probability: How likely is the reward?Effort (Cost): What will it take to achieve it?Context: Situational factors like time or energy levels.Preference: Personal likes and dislikes.PFC uses different brain areas to compute aspects of valueMedial Prefrontal Cortex: Evaluates outcomes and adjusts strategies dynamically.Processes and rewards and evaluates choicesLateral Prefrontal Cortex: Maintains goal-related information and monitors potential conflicts.Helps focus on goals and inhibit distractionsOrbitofrontal Cortex: Processes rewards and evaluates their significance Evaluates the emotional value of choices and predicts outcomeVentromedial Prefrontal Cortex:Evaluates probabilities and potential rewardsParietal Cortex:Contributes to decision-making by integrating sensory and numerical informationAmygdala:Adds emotional weight to decisions, particularly those involving risks or rewards.Anterior Insula: Processes feelings of uncertainty or potential lossDopamine:A key brain chemical, helps us guide choices and learn and adjust behaviors based on rewardsTracks rewards and feed back and helps predict outcomes based on past experiencesGuides decisions by reinforcing actions that led to positive outcomes
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Prediction Error: Dopamine signals the difference between expected and received rewards.When an outcome differs from expectations, dopamine levels adjust future behaviourPositive outcomes increase dopamine, encouraging repetition.Negative outcomes decrease dopamine, discouraging the same action.Processes of Decision MakingValuation of Options:Decisions require estimating the value of each option.The brain integrates information from past experiences, current goals, and expected outcomes.Reward Prediction Errors:The brain adjusts expectations when actual outcomes differ from predictions.Positive outcomes increase motivation; negative outcomes encourage change.Effort vs. Reward Trade-off:Decisions often involve balancing effort with expected rewards.Example: Choosing between an easy task with a small reward or a challenging task with a high rewardImmediate vs. Delayed Gratification:Temporal discounting: The brain tends to prioritize immediate rewards over larger, delayed rewards.Example: Eating junk food now versus maintaining a diet for long-term health.Biases in Decision MakingLoss Aversion:People are more sensitive to potential losses than equivalent gains.Avoiding things that could lose money even if it has high potential returnsFraming Effect:Choices are influenced by how options are presented.Preferring surgery with a 90% survival rate over a 10% death rateOverconfidence:Overestimating one’s ability to predict outcomes.Availability Heuristic:Decisions are influenced by recent or easily recalled experiences.Choosing not to fly after hearing about a plane crash even if it’s unlikely12.5 Goal Planning: Staying on TaskGoal planning involves maintaining focus on a desired outcome while navigating distractions or multitasking. Three components are essential for successfully developing and executing an action planGoal must be identified and subguals developedIn choosing among goals and subgoals, consequences must be anticipatedRequirements for achieving subgoals must be determinedRetrieval and selection of Task relevant informationGoal-oriented behavior requires selecting task-relevant information and filtering out task-irrelevant information.
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The prefrontal cortex (PFC) plays a central role in retrieving and prioritizing information that aligns with current goalsSelective Attention: Filtering out irrelevant stimuli to maintain focus.Working Memory: Storing and manipulating goal-relevant data.Lateral Prefrontal Cortex (LPFC): Crucial for actively maintaining task-related information.Anterior Cingulate Cortex (ACC): Monitors performance and detects conflicts when priorities compete.PFC has been conceptualized as a dynamic filtering mechanismReciprocal projections between the PFC and posterior cortex provide a way for goals, represented in the PFC, to maintain task-relevant information that requires long-term knowledge stored in the posterior cortexAs the goals shift, the filtering process will make salient links to representations associated with the color.Multitasking:Multitasking involves switching attention between tasks or managing multiple streams of information simultaneously.Challenges of Multitasking:Increased cognitive load.Decreased efficiency due to the brain’s limits on parallel processing.Brain's Strategy:Sequential processing: Tasks are not done simultaneously but switched betweenrapidly.Involvement of the dorsolateral PFC to coordinate task-switching.Research Insight:Studies show that multitasking reduces accuracy and increases response times compared to single-task focus.Prolonged multitasking may lead to cognitive fatigueBenefits and Costs of Goal-Based Selection:Advantages:Ensures focus on high-priority goals.Minimizes distractions by suppressing irrelevant information.Drawbacks:Effort-intensive, leading to mental fatigue.Over-suppression can hinder creative thinking or flexibility.Neurobiological Evidence:Successful task completion is linked to strong activity in the PFC, particularly during periods of sustained attention.12.6 Mechanisms of Goal-Based SelectionGoal-based selection is a critical cognitive process that enables individuals to prioritize task-relevant information while filtering out distractions.The ability to stay focused on tasks and achieve goals by amplifying relevant inputs and inhibiting irrelevant ones is mediated by the prefrontal cortex (PFC) in conjunction with other brain regions.Prefrontal Cortex (PFC)The PFC interacts with sensory areas (e.g., visual cortex) to amplify relevant inputs.Acts as the brain's "dynamic filtering mechanism" that facilitates:
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Enhancement: Amplifies relevant information to improve sensitivity to task-related inputs.Inhibition: Suppresses irrelevant or distracting inputs.Evidence:Studies of patients with PFC lesions demonstrate impaired filtering abilities, leading to heightened sensitivity to irrelevant stimuli and difficulty maintaining task focus.Goal-based behavior relies on a network of interactions between the prefrontal cortex andother brain regions:Lateral Prefrontal Cortex (LPFC): Supports working memory and task-specific filtering.Maintains goal-relevant informationAnterior Cingulate Cortex (ACC):Monitors for conflicts and adjusts attention.Posterior Cortex:Supplies long-term memory and perceptual knowledgeDynamic Interplay:Goals stored in the PFC dynamically activate specific memory or sensoryrepresentations in the posterior cortex to align with current tasks.Dynamic Filtering:The prefrontal cortex acts as a filter and selectively enhances important information whilefiltering out irrelevant stimuliDynamic, meaning it adjusts based on the changing needs of the task of environmentMechanisms:Facilitatory Control: Enhances sensitivity to task-relevant stimuli.Inhibitory Control:Suppresses distracting or irrelevant information (e.g., Stroop test).Frontal Lobe Dysfunction:Lesions in the prefrontal cortex impair inhibitory control, leading to heightened distractibility and reduced task efficiency.Damage to the prefrontal cortex reduces the ability to inhibit inappropriate actions, leading to impulsive behavior.Evoked response studies show:Healthy brains enhance relevant sensory signals.Damaged frontal lobes fail to suppress irrelevant stimuli effectively.Inhibitory Control in Action:Goal-based selection includes the ability to stop or inhibit actions that conflict with current goalsBeing able to cancel a planned actionRequires distinct neural mechanisms including the right inferior frontal gyrus(action inhibition) and subthalamic nucleus(supports rapid stopping of motor actions)Stop Signal Paradigm:Demonstrates the brain’s ability to cancel pre planned actions.Inhibiting pre planned actions (e.g., stopping a swing in baseball) These structures enable rapid adjustments when errors are anticipated.Improving Cognitive Control through Brain TrainingCognitive tasks design to challenge and improve mental flexibility, working memory and attention control
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Evidence suggests video games improve aspects of cognitive control, like task switching and response inhibition.Long-term retention of cognitive control improvements has been observed after intensive training.Training on action-based games leads to measurable improvements in:Reaction timesAttention and focusTask- switching (e.g., reduced switch costs in task performance).Task Switching:The brain transitions between tasks by suppressing old goals and activating new ones.Switching requires cognitive flexibility and working memory, heavily relying on the PFC.Switching costs: mental delay when switching between tasksIntegration with Lecture Notes1.Cognitive Control Processes:Lecture objectives highlight goal maintenance (working memory), flexibility, inhibition, and planning, which align with textbook discussions.2.Working Memory:Dopamine's role in improving signal-to-noise ratios and the PFC’s integration with sensory streams for goal-directed behavior matches lecture details.3.Inhibition and Emotion Regulation:Think/No-Think Paradigm and its PFC-hippocampus interactions are central to both sources.Frontal lobe injuries disrupting emotional control (e.g., OFC lesions) align with lecture examples of heightened frustration and impulsivity.4.Plasticity and Counterfactual Thinking:Counterfactual thinking ("what-if" scenarios) is emphasized in both sources as essential for learning and flexibility, impaired by PFC damage.5.Environmental Dependency Syndrome:Described in lectures as reliance on external cues due to impaired goal-directed behavior, consistent with textbook descriptions of utilization behaviors.6.Supervisory Attentional System (SAS):Key model linking habits, routines, and goal-directed control in novel or complex scenarios, deeply discussed in both sources.
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