Higher Cognition James H. Baños, Ph.D. Department of Physical Medicine and Rehabilitation

Overview The Damaged and Undamaged BrainThe Damaged and Undamaged Brain Principles of OrganizationPrinciples of Organization Principles in Action: Domains of CognitionPrinciples in Action: Domains of Cognition

The Damaged and Undamaged Brain

“The deficits observed after a brain lesion don’t tell you what the lesioned portion of the brain did. They tell you what the rest of the brain is still capable of doing.” - John Gabrieli - John Gabrieli

The Damaged and Undamaged Brain Neural processing rarely occurs in a simple linear or sequential fashionNeural processing rarely occurs in a simple linear or sequential fashion Instead, it often occurs in continuous “loops”Instead, it often occurs in continuous “loops” Like a water faucet that is always running.Like a water faucet that is always running.

The Damaged and Undamaged Brain The nervous system thrives on balance and homeostasis of neural processes within these loopsThe nervous system thrives on balance and homeostasis of neural processes within these loops Damage often upsets balance/homeostasis in a processDamage often upsets balance/homeostasis in a process A “normal” process runs unchecked or fails to run at allA “normal” process runs unchecked or fails to run at all Like other neurologic symptoms, many neurocognitive symptoms can be thought of in “hyper” and “hypo” termsLike other neurologic symptoms, many neurocognitive symptoms can be thought of in “hyper” and “hypo” terms Ex: muscle tone, reflexes, basal gangliaEx: muscle tone, reflexes, basal ganglia

Principles of Organization

Where to Begin? Left vs. RightLeft vs. Right Anterior vs. PosteriorAnterior vs. Posterior Hierarchical ProcessingHierarchical Processing Cortical vs. SubcorticalCortical vs. Subcortical

Hemispheric Specialization

Don’t think in terms of hemispheric “dominance”Don’t think in terms of hemispheric “dominance”

Hemispheric Specialization Left HemisphereLeft Hemisphere SpeechSpeech Reading/writingReading/writing PraxisPraxis Verbal memoryVerbal memory Processing detailProcessing detail Right HemisphereRight Hemisphere ArousalArousal Self-awarenessSelf-awareness Spatially directed attentionSpatially directed attention Emotion/affectEmotion/affect Nonverbal memoryNonverbal memory Visuospatial processingVisuospatial processing Processing “gestalt”Processing “gestalt” Nonlanguage soundNonlanguage sound MusicMusic

Hemispheric Specialization Left Hemisphere: “Classic” Clinical PresentationLeft Hemisphere: “Classic” Clinical Presentation Right hemiparesisRight hemiparesis AphasiaAphasia ApraxiaApraxia

Hemispheric Specialization Right Hemisphere: “Classic” Clinical PresentationRight Hemisphere: “Classic” Clinical Presentation Left hemiparesisLeft hemiparesis Poor arousalPoor arousal Left neglectLeft neglect Unawareness of deficitsUnawareness of deficits Flat affectFlat affect

Anterior vs. Posterior

PosteriorPosterior Processing of information about the environmentProcessing of information about the environment Sensory gatingSensory gating Unimodal and multimodal sensory associationsUnimodal and multimodal sensory associations Constructing a unified “representation” of the environment across sensory modalitiesConstructing a unified “representation” of the environment across sensory modalities

Anterior vs. Posterior AnteriorAnterior Planning and formulating cognitive and behavioral goalsPlanning and formulating cognitive and behavioral goals Acting on hypothetical representations of the environmentActing on hypothetical representations of the environment Incorporating behavioral relevance, reinforcement value, and emotion into cognition and behaviorIncorporating behavioral relevance, reinforcement value, and emotion into cognition and behavior

Hierarchical Processing SMAPremotor PrimaryMotor PrimarySomatosensory UnimodalAssociation Multimodal Association Cortex PrimaryVisual UnimodalAssociation PrimaryAuditory UnimodalAssociation AnteriorPosterior

Cortical vs. Subcortical Subcortical structuresSubcortical structures InitiationInitiation CessationCessation ModulationModulation ControlControl

Cortical vs. Subcortical ThalamusThalamus Not just a “sensory relay”Not just a “sensory relay” Cortico-thalamo-cortical loops modulate:Cortico-thalamo-cortical loops modulate: ConsciousnessConsciousness ArousalArousal VigilanceVigilance Foundation for higher attentional processesFoundation for higher attentional processes “Cortical tone”

Cortical vs. Subcortical Basal gangliaBasal ganglia InitiationInitiation CessationCessation MaintenanceMaintenance Similar role in motor and cognitive functionSimilar role in motor and cognitive function

Cortical vs. Subcortical Cortical-Basal Ganglionic LoopsCortical-Basal Ganglionic Loops Cortex Striatum Pallidum s. nigra Thalamus SMA Putamen Vl-GPiCl-SNr VLoVLm Motor FEF Caudate(body) Cdm-GPiVl-SNr VAmcMDpl Oculomotor

Cortical vs. Subcortical Cortex Striatum Pallidum s. nigra Thalamus DLPFC dl-Caudate(head) ldm-GPivl-SNr VApcMDpc DorsolateralPrefrontal LOFC vm-Caudate(head) mdm-GPirm-SNr VAmcMDmc LateralOrbitofrontal AC VS rl-GPi, VP rd-SNr pm-MD AnteriorCingulate

Cortical vs. Subcortical Basal Ganglia: Motor SymptomsBasal Ganglia: Motor Symptoms Hyperkinetic disorders (too much movement)Hyperkinetic disorders (too much movement) Slow writhing movementsSlow writhing movements Quick jerking movementsQuick jerking movements Repetitive abrupt movementsRepetitive abrupt movements Hypokinetic disorder (too little movement)Hypokinetic disorder (too little movement) Difficulty initiating motor movementDifficulty initiating motor movement Motor impersistenceMotor impersistence RigidityRigidity Reduced eyeblinkReduced eyeblink

Cortical vs. Subcortical Basal Ganglia: Cognitive SymptomsBasal Ganglia: Cognitive Symptoms “hypercognitive”“hypercognitive” PerseverationPerseveration IntrusionIntrusion “Hypocognitive”“Hypocognitive” Poor cognitive initiationPoor cognitive initiation Poor recall (failure to initiate recall processes)Poor recall (failure to initiate recall processes) Loss of cognitive set (cognitive impersistence)Loss of cognitive set (cognitive impersistence) Diminished semantic search effectivenessDiminished semantic search effectiveness

Cortical vs. Subcortical Basal Ganglia: Emotionally Guided BehaviorBasal Ganglia: Emotionally Guided Behavior “hyper”“hyper” Obsessive-compulsive behaviorsObsessive-compulsive behaviors Addiction, gamblingAddiction, gambling Mania (in some disorders such as Huntington’s Disease)Mania (in some disorders such as Huntington’s Disease) Affective LabilityAffective Lability “Hypo”“Hypo” AvolitionAvolition Flat affectFlat affect

Cortical vs. Subcortical CerebellumCerebellum Cerebrocerebellum CortexPlanEffectors “Reality” Cerebellum Feedback

Cortical vs. Subcortical Cerebellar SignsCerebellar Signs MotorMotor AtaxiaAtaxia DysmetriaDysmetria CognitiveCognitive “Cognitive Ataxia”“Cognitive Ataxia” “Dysmetria of Thought”“Dysmetria of Thought” Emotionally Guided BehaviorEmotionally Guided Behavior Affective labilityAffective lability Psychiatric symptomsPsychiatric symptoms

Putting it Together… Motor/Sensory Cognition Common View:

Putting it Together… Sensorimotor Cognition EmotionallyGuidedBehavior Reality: PurposefulEffortful Automatic

Principles in Action: Domains of Cognition

Domains of Cognition Motor and Sensory Aspects of CognitionMotor and Sensory Aspects of Cognition LanguageLanguage AttentionAttention Executive FunctionExecutive Function

Motor and Sensory Aspects of Cognition SMAPremotor PrimaryMotor Multimodal Association Cortex Hemiparesis

Motor and Sensory Aspects of Cognition SMAPremotor PrimaryMotor Multimodal Association Cortex Akinesia, Bimanual dyscoordination

Motor and Sensory Aspects of Cognition SMAPremotor PrimaryMotor Multimodal Association Cortex ? Apraxia

Motor and Sensory Aspects of Cognition Apraxia -- Inability to correctly perform learned skilled movements, not due to impaired basic motor function, impaired cognition, or impaired comprehensionApraxia -- Inability to correctly perform learned skilled movements, not due to impaired basic motor function, impaired cognition, or impaired comprehension Lesion: Inferior parietal lobule, corpus callosum, SMALesion: Inferior parietal lobule, corpus callosum, SMA

Motor and Sensory Aspects of Cognition SMAPremotor PrimaryMotor Multimodal Association Cortex SMAPremotor PrimaryMotor Cortex CorpusCallosum ? Alien Hand

Motor and Sensory Aspects of Cognition PrimaryVisual VisualAssociation Multimodal Association Cortex PrimarySomatosensory SomatosensoryAssociation PrimaryAuditory AuditoryAssociation VisualLossSomatosensoryLossAuditoryLoss

Motor and Sensory Aspects of Cognition PrimaryVisual VisualAssociation Multimodal Association Cortex PrimarySomatosensory SomatosensoryAssociation PrimaryAuditory AuditoryAssociation ? ??

Motor and Sensory Aspects of Cognition Agnosia -- Impairment of object recognition in the presence of relatively intact basic perception and languageAgnosia -- Impairment of object recognition in the presence of relatively intact basic perception and language Visual Object AgnosiaVisual Object Agnosia Prosopagnosia (agnosia for faces)Prosopagnosia (agnosia for faces) Tactile AgnosiaTactile Agnosia Auditory AgnosiaAuditory Agnosia

Motor and Sensory Aspects of Cognition PrimaryVisual VisualAssociation Multimodal Association Cortex PrimarySomatosensory SomatosensoryAssociation PrimaryAuditory AuditoryAssociation ?

Motor and Sensory Aspects of Cognition Hemispatial NeglectHemispatial Neglect Visuospatial Integration DeficitsVisuospatial Integration Deficits

Motor and Sensory Aspects of Cognition

Language

Broca’sWernicke’s AssociationCortexAssociationCortex Expressive(non-fluent)Receptive(fluent) LanguageAssociation“Pure”Language

Broca’sWernicke’s AssociationCortexAssociationCortex Expressive(non-fluent)Receptive(fluent) LanguageAssociation“Pure”Language

Wernicke’s AphasiaWernicke’s Aphasia Fluent speech (but doesn’t make sense)Fluent speech (but doesn’t make sense) Impaired comprehensionImpaired comprehension Impaired repetitionImpaired repetition Linguistic analog to a primary sensory deficitLinguistic analog to a primary sensory deficit Can’t decode words or associate meaningCan’t decode words or associate meaning

Language Broca’sWernicke’s AssociationCortexAssociationCortex Expressive(non-fluent)Receptive(fluent) LanguageAssociation“Pure”Language

Broca’s AphasiaBroca’s Aphasia Non-fluent speechNon-fluent speech Intact comprehensionIntact comprehension Impaired repetitionImpaired repetition Linguistic analog to a primary motor deficitLinguistic analog to a primary motor deficit Can’t produce the components of language outputCan’t produce the components of language output

Language Broca’sWernicke’s AssociationCortexAssociationCortex Expressive(non-fluent)Receptive(fluent) LanguageAssociation“Pure”Language

Transcortical Sensory AphasiaTranscortical Sensory Aphasia Fluent SpeechFluent Speech Impaired comprehensionImpaired comprehension Intact repetitionIntact repetition Linguistic analog to agnosiaLinguistic analog to agnosia Can decode the word but can’t make associations to meaningCan decode the word but can’t make associations to meaning

Language Broca’sWernicke’s AssociationCortexAssociationCortex Expressive(non-fluent)Receptive(fluent) LanguageAssociation“Pure”Language

Transcortical Motor AphasiaTranscortical Motor Aphasia Non-fluent speechNon-fluent speech Intact ComprehensionIntact Comprehension Intact RepetitionIntact Repetition Linguistic Analog to an ApraxiaLinguistic Analog to an Apraxia Broca’s area can produce speech, but lacks associations necessary to assemble the componentsBroca’s area can produce speech, but lacks associations necessary to assemble the components

Attention “Attention” is a generic term“Attention” is a generic term Refers to a family of processesRefers to a family of processes Attention is fluid and constantly changingAttention is fluid and constantly changing

Attention “Anything short of omnipresence creates the need to choose which of many suitable internal and external events will be granted access to narrow portals of consciousness and action” “Anything short of omnipresence creates the need to choose which of many suitable internal and external events will be granted access to narrow portals of consciousness and action” -- M. Mesalum

Attention Aspects of AttentionAspects of Attention ArousalArousal General level of responsivityGeneral level of responsivity OrientationOrientation Realignment of sensory organsRealignment of sensory organs Selective AttentionSelective Attention Processing of one stimulus over anotherProcessing of one stimulus over another Divided AttentionDivided Attention Simultaneous processing of stimuliSimultaneous processing of stimuli Attention SpanAttention Span Holding of information with rehearsalHolding of information with rehearsal “Working Memory”“Working Memory” Mental manipulation of information in attention spanMental manipulation of information in attention span

Attention Modulation of attention is an “anterior” functionModulation of attention is an “anterior” function It is mediated by cortical basal ganglionic loopsIt is mediated by cortical basal ganglionic loops Some attentional shifts are automaticSome attentional shifts are automatic Some must be initiated and maintainedSome must be initiated and maintained Salience and relevance must be balancedSalience and relevance must be balanced Unwanted shifts must be inhibited (“stimulus pull”)Unwanted shifts must be inhibited (“stimulus pull”)

Executive Function Dorsolateral FrontalDorsolateral Frontal Planning/goal formationPlanning/goal formation OrganizingOrganizing SequencingSequencing Set shiftingSet shifting Abstract thinkingAbstract thinking Orbital FrontalOrbital Frontal InhibitionInhibition Behavioral modulationBehavioral modulation Cognitive modulationCognitive modulation Evaluating relevance/rewardEvaluating relevance/reward

Executive Function Impaired initiation:Impaired initiation: Failure to generate ideas/courses of actionFailure to generate ideas/courses of action Impaired inhibition:Impaired inhibition: Impulsive cognitive approachImpulsive cognitive approach You think it, you do itYou think it, you do it You think it, you say itYou think it, you say it

Executive Function Impaired set-shiftingImpaired set-shifting Perseveration/decreased mental flexibilityPerseveration/decreased mental flexibility Inability to shift to a more appropriate strategy when you get feedback that the current strategy is ineffectiveInability to shift to a more appropriate strategy when you get feedback that the current strategy is ineffective Impaired PlanningImpaired Planning Difficulty sequencing multiple actions to achieve a goalDifficulty sequencing multiple actions to achieve a goal Difficulty seeing more than one “move” ahead in the gameDifficulty seeing more than one “move” ahead in the game Difficulty generating multiple “if-then” alternate courses of actionDifficulty generating multiple “if-then” alternate courses of action Difficulty assessing consequences of various choicesDifficulty assessing consequences of various choices

Executive Function Impaired Abstract ReasoningImpaired Abstract Reasoning Literal or “concrete” thinking styleLiteral or “concrete” thinking style More likely to think in terms of objects and actions rather than conceptsMore likely to think in terms of objects and actions rather than concepts

Executive Function Executive Function is also…Executive Function is also… “Personality”“Personality” Point of convergence for cognitive, emotional, and motivational aspects of behaviorPoint of convergence for cognitive, emotional, and motivational aspects of behavior

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