early spect studies

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Early SPECT StudiesEarly SPECT Studies

David Ingvar and Niels LassenDavid Ingvar and Niels LassenDaniel Weinberger and Karen Daniel Weinberger and Karen

Berman Berman

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Ingvar and LassenIngvar and Lassen

Normals

Patients (Hypofrontality)

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Frontal FunctionsFrontal Functions• Fluency of thought and speechFluency of thought and speech• Emotional attachmentsEmotional attachments• Social and moral judgmentSocial and moral judgment• Volition and driveVolition and drive• Planning and identifying goalsPlanning and identifying goals• Formulating abstract conceptsFormulating abstract concepts

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Weinberger and BermanWeinberger and Berman

Normals

Patients

Number WCS

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PET StudiesPET Studies

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Normals: Remembering Normals: Remembering WordsWords

•Increased Increased blood flow in blood flow in frontal frontal operculum, operculum, thalamus, thalamus, cerebellumcerebellum

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Patients: Remembering Patients: Remembering WordsWords

•Failure to Failure to activate activate regions used regions used by normalsby normals•Decreased Decreased frontal flowfrontal flow

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Using PET to Study Using PET to Study AnhedoniaAnhedonia

• Examine changes in blood flow in Examine changes in blood flow in response to visual emotional response to visual emotional stimulistimuli

• Comparison of pleasant vs Comparison of pleasant vs unpleasant picturesunpleasant pictures

• Examine the final stage in Examine the final stage in emotional processing—attributionemotional processing—attribution—which is the interface between —which is the interface between cognition and emotioncognition and emotion

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UnpleasantUnpleasant

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PleasantPleasant

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Activations in Normals: Activations in Normals: Visual StimuliVisual Stimuli

• Subtraction images: Subtraction images: Unpleasant minus pleasantUnpleasant minus pleasant

• ““Unpleasant” activations: areas Unpleasant” activations: areas of increased flow are redof increased flow are red

• ““Pleasant” activations: areas of Pleasant” activations: areas of increased flow are blueincreased flow are blue

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““Unpleasant” ActivationsUnpleasant” Activations

•Extrastriate and Extrastriate and visual cortexvisual cortex•CerebellumCerebellum•AmygdalaAmygdala

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““Pleasant” Activations:Pleasant” Activations:

•Medial, orbital, Medial, orbital, and dorsolateral and dorsolateral prefrontal cortexprefrontal cortex

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Interpretation:Interpretation:Emotion Attribution in NormalsEmotion Attribution in Normals• The system that assigns The system that assigns

positive emotional valence to positive emotional valence to stimuli is primarily prefrontalstimuli is primarily prefrontal

• Pleasure attribution in human Pleasure attribution in human beings activates beings activates phylogenetically younger phylogenetically younger “higher” cortical regions“higher” cortical regions

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Randomization Randomization Analysis of PET DataAnalysis of PET Data

• A non-parametric statistical method A non-parametric statistical method that is robust to differences in variancethat is robust to differences in variance

• Displays areas where patients differ Displays areas where patients differ from controlsfrom controls

• Blue: flow is decreased in patients Blue: flow is decreased in patients during unpleasant stimuliduring unpleasant stimuli

• Red: flow is increased during Red: flow is increased during unpleasant stimuli (?compensatory?)unpleasant stimuli (?compensatory?)

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Unpleasant Pictures: Unpleasant Pictures: Areas of Decreased FlowAreas of Decreased Flow

•ThalamusThalamus•Extrastriate Extrastriate visual cortexvisual cortex•HippocampusHippocampus

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Unpleasant Pictures: Unpleasant Pictures: Areas of Increased FlowAreas of Increased Flow

•InsulaInsula•Putamen/ Putamen/ accumbensaccumbens•Superior frontalSuperior frontal

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Focusing Visual AttentionFocusing Visual Attention

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Remembering FacesRemembering Faces

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Recalling Complex NarrativesRecalling Complex Narratives