Northwestern University Bilateral semantic processing: Inferences in language, insight in problem solving Mark Jung-Beeman Northwestern University Department of Psychology Neuroscience Institute Cognitive Brain Mapping Group \

Northwestern University Drexel University Bilateral semantic processing: Inferences in language, insight in problem solving Northwestern University Drexel University Zoe Clancy John Kounios Jason Haberman (UCDavis) Debbie Green Sandra Virtue (Depaul U) Jennifer Frymiare (U Wisc) Stella Arambel (deceased) Jessica Fleck Dianne Patterson Richard Greenblatt Todd Parrish Paul Reber Bar-Ilan University Terri Swan Miriam Faust Karuna Subramaniam Nira Mashal Ed Bowden Research sponsored by NIDCD/NIH

Bilateral semantic processing: Inferences in language, insight in problem solving OUTLINE: • Drawing inferences from stories -- bilateral comprehension • Three bilateral component semantic processes (to start) • Insight -- bilateral, parallel processing during problem solving

Semantic activation - “Wernicke’s area” Bilateral Activation, Integration, and Selection model of semantic processing Semantic activation - “Wernicke’s area” Bottom-up lexical-semantic activation: index of semantic representations (pMTG) Semantic integration - anterior Sup. Temp. Gyrus Compute semantic overlap - detect or generate (aSTG) Semantic selection - Inf. Frontal Gyrus Select among competing activated concepts (IFG)

Bilateral semantic processing: Inferences in language, insight in problem solving OUTLINE: • Drawing inferences from stories -- bilateral comprehension • Three bilateral component semantic processes (to start) • Insight -- bilateral, parallel processing during problem solving

Problems with view that language is purely a LH function General anatomical symmetry RH damaged patients - some language problems Recovery from aphasia, hemispherectomy, callosotomy Neuroimaging - always some RH signal, some tasks RH>LH Some tasks lvf-RH better than rvf-LH

Brain bases of comprehension of natural language Natural language, stories, discourse • Higher level semantic processing (plus all lower levels) As language input more complex (and natural): • More anterior temporal lobes • More bilateral processing

Brain bases of cognitive processes when people draw inferences from stories Causal bridging (coherence) inferences “Before going to the wedding, John was sitting around in his jeans, so he went to his bedroom to find some clothes.”

Brain bases of cognitive processes when people draw inferences from stories Causal bridging (coherence) inferences “Before going to the wedding, John was sitting around in his jeans, so he went to his bedroom to find some clothes. He came out wearing his tuxedo, which had belonged to John's father, but looked like new.”

Brain bases of cognitive processes when people draw inferences from stories Causal bridging (coherence) inferences “Before going to the wedding, John was sitting around in his jeans, so he went to his bedroom to find some clothes. He came out wearing his tuxedo, which had belonged to John's father, but looked like new.” CHANGE

Brain bases of cognitive processes when people draw inferences from stories We know people make such causal inferences We know a lot about other types of inferences that people make - types of text, motivation, knowledge, capacity We still don’t know much about component processes that support this seemingly complex behavior

RH semantic processing and inferences RHD patients have difficulty drawing inferences • Answer questions about inferable events less accurately than control subjects; intact on explicitly stated facts (Brownell et al., 1986; Beeman, 1993) • Do not show inference-related priming; control subjects do (Beeman, 1993)

Proposed component processes of inference generation 1) Activation / integration (detect overlap) 2) Selection 3) Incorporation / integration (map overlap) Hemispheric cooperation RH activates information that may support inferences. Weak activation not reach consciousness. I interpret these results as providing support for multiple component processes involved in drawing inferences. Optimally drawing inferences requires hemi coop’n… in which the RH

Time course of inference related semantic activation in both hemispheres during story comprehension. “Before going to the wedding, John was sitting around in his jeans,1 so he went to his bedroom to find some clothes.2 After a few minutes,3 he came out wearing his tuxedo,4 which had belonged to John's father5, but was still fashionable and looked like new.” - CHANGE (1) and (2): Predictive inference. (3): Transition. (4): Coherence or bridging inference. (5): Resolved and incorporated.

Left visual field Right visual field Left Hemisphere Right Hemisphere

Priming: Inference faster than Unrel “Before going to the wedding, John was sitting around in his jeans,1 so he went to his bedroom to find some clothes.2 After a few minutes,3 he came out wearing his tuxedo,4 which had belonged to John's father5, but was still fashionable and looked like new.” Brain and Language, 2000 Priming: Inference faster than Unrel This graph shows priming….

Asymmetric dynamic semantic fields: relatively coarser coding in RH; better selection in LH Left Hemisphere Right Hemisphere RULER foot foot TOES CUT Large but weakly activated; Diffuse, including secondary and less relevant concepts - hard to select, output Small but strongly activated; Focused on dominant or contextually relevant concepts - easy to select, interpret, output

RH coarse semantic coding: Increased likelihood of semantic overlap for distant semantic relations foot foot pain glass CUT CUT pain glass

Semantic activation - “Wernicke’s area” Bilateral Activation, Integration, and Selection model of semantic processing Semantic activation - “Wernicke’s area” Bottom-up lexical-semantic activation: index of semantic representations (pMTG) Semantic integration - anterior Sup. Temp. Gyrus Compute semantic overlap - detect or generate (aSTG) Semantic selection - Inf. Frontal Gyrus Select among competing activated concepts (IFG)

RH Middle & superior temporal gyrus involved in computing semantic integration Deriving theme from paragraphs (St. George et al.) Generating best ending (Kirchner et al.) Generating inferences? - moderately related sentence pairs (Mason & Just) Metaphoric over literal sentences (Bottini et al.) Detecting temporal/emotional inconsistency (Ferstl) Generating insight solutions (Jung-Beeman et al; Kounios et al)

Brain activity when people draw inferences on-line, as indexed by fMRI Three ways to contrast inference versus no-inference conditions: - Text: infernce versus no-inference; strong vs. weak constraint - Individual differences: high versus low Working Memory - Behavioral measures: recall of inferences General Results: Bilateral activity in pMTG; aSTG; IFG - modulated by constraint, WM, time

Brain activity when people draw inferences on-line, as indexed by fMRI … John was going to a wedding, but he had been sitting around the house in his jeans, so he went to his bedroom to find some clothes. Soon he came out wearing his tuxedo, * … Explicit: …went to his bedroom to change his clothes. Soon he came out wearing his tuxedo ,* … - High baseline, ongoing stories; small input difference

Semantic integration at moment of implied events: Predominantly RH aSTG

Semantic integration at event point: Bilateral anterior Superior Temporal Gyrus L R Post Ant L R L R Lower (ns) threshold, selected for LH STG

Semantic activation and integration at coherence break (“tuxedo”): Predominantly LH STG

Semantic selection: High versus low working memory High WM (reading span) subs show stronger, earlier evidence of semantic selection of inferences (St. George et al; many behavioral) • Completion requires selection, incorporation

Semantic selection: Inferior frontal gyrus Selecting some concepts over competitors • Usually IFG in LH (Thompson-Schill et al; Barch; Friston) Some instances, RH IFG (Seger 2000; Friederici et al., 2000; Jung-Beeman et al.)

Semantic selection: Inferior frontal gyrus Selecting some concepts over competitors • Usually IFG in LH (Thompson-Schill et al; Barch; Friston) Some instances, RH IFG Unusual verb generation (cake -> “decorate”) (Seger 2000) Repair grammatical errors (Friederici et al., 2000) Utilize unintended meaning of ambiguous words in sentence (Jung-Beeman et al.)

Semantic selection: fMRI signal in IFG (LH > RH) at coherence break in High WM subs only (Fig: High WM > Low WM)

Replication and extension: Working memory and predictability Unpredictable inferences: LH activation, IFG, pSTG • searching for connections Predictable inferences: Bilateral activation, IFG, pSTG • building on connections Higher WM (n=13) > lower WM (n=13): • facile comprehension

Successful integration versus continued activation: STG in High vs. Low WM subs at coherence break, Predictable inferences RH IFG High WM subs show bilateral (stronger in RH) Low WM show LH only RH pSTG p<.001

Replication and extension: Working memory and predictability Unpredictable inferences: LH activation, IFG, pSTG • searching for connections Predictable inferences: Bilateral activation, IFG, pSTG • building on connections Higher WM (n=13) > lower WM (n=13): RH activation, pSTG, IFG, and a little aSTG • facile comprehension

Successful integration versus continued activation: STG in High vs. Low WM subs at coherence break, Predictable inferences RH aSTG High WM subs show bilateral (stronger in RH) Low WM show LH only, no aSTG p<.005

Replication and extension: Working memory and predictability Unpredictable inferences: LH activation, IFG, pSTG • searching for connections Predictable inferences: Bilateral activation, IFG, pSTG • building on connections Higher WM (n=13) > lower WM (n=13): RH activation, pSTG, IFG, and a little aSTG • facile comprehension

Conclusions about inferences Semantic integration builds up as story hints that some event might occur: anterior STG; RH (?) At coherence break: integration and activation (STG), especially in LH completing the inference requires selection (IFG) RH contributes to facile inferencing/comprehension, not just kick in when demands are high

Current projects, Future directions Shift semantic distance for integration --> shift hemi asymmetry Closely tie to behavioral markers of inference activation, selection, incorporation Recall of inferences √ Priming of inferences Successful integration versus effort of difficult integration Incorporation (recall study)

Recalled inferences If inferences recalled, must have been incorporated Working Memory correlates with total recall Recall of inferences NOT with recall of episodes w/o inferences Contrast fMRI signal of recalled infs versus recall episode, no infs

L R Post Ant L R Inferences recalled versus Episode recalled, inf not recalled L R Post Ant L R L R R R Bilateral pMTG, stronger in RH RH aSTS, bilat IFG p<.005 , positive only

So what? Knowing where processing occurs informs and constrains what and how it occurs

Bilateral semantic processing: Inferences in language, insight in problem solving OUTLINE: • Drawing inferences from stories -- bilateral comprehension • Three bilateral component semantic processes (to start) • Insight -- bilateral, parallel processing during problem solving

Semantic activation - “Wernicke’s area” Bilateral Activation, Integration, and Selection model of semantic processing Semantic activation - “Wernicke’s area” Bottom-up lexical-semantic activation: index of semantic representations (pMTG) Semantic integration - anterior Sup. Temp. Gyrus Compute semantic overlap - detect or generate (aSTG) Semantic selection - Inf. Frontal Gyrus Select among competing activated concepts (IFG)

Why does the RH code more coarsely? Asymmetries in neural microcircuitry

Given topographic mapping of brain, broader input/output fields => coarser semantic coding Left Hemisphere Right Hemisphere RULER foot foot TOES CUT Large but weakly activated; Diffuse, including secondary and less relevant concepts Small but strongly activated; Focused on dominant or contextually relevant concepts

RH coarse semantic coding: Increased likelihood of semantic overlap for distant semantic relations foot foot pain glass CUT CUT pain glass

Why a separate area for semantic integration? Could form associations in “activation” area BUT Higher level relations, correlated co-occurrence, indirect Ability to extract, attend to, & manipulate relations Analogous to individual areas within vision (e.g., motion)

Why anterior STS/STG for semantic integration? Again, neural architecture

Patchy organization and multisensory integration (Beauchamp 2004) L R Post Ant L R

Why anterior STS/STG for semantic integration? Again, neural architecture More anterior = longer intrinsic conxns, better to integrate across patches RH = longer than LH

Important clarifications Not an “inference area” Semantic integration - participates in many functions Not specific to categories of inferences - varies with demand Tight comparison not reveal whole network Just areas that differ when storied imply versus explicitly state events RH and LH cooperate

Bilateral semantic processing: Inferences in language, insight in problem solving OUTLINE: • Drawing inferences from stories -- bilateral comprehension • Three bilateral component semantic processes (to start) • Insight -- bilateral, parallel processing in problem solving

Brain bases of insight during problem solving: Aha! and antecedents Most problems solved with mix of analytic and insight processing • Distinct computations, distributed across hemispheres, allows two approaches to proceed simultaneously (partially interactive) • Hemispheric components, task shielding/switching

Archimedes and the crown King’s crown - gold, or silver Archimedes knew gold and silver differed in density Archimedes knew weight, but couldn’t geometrically measure to obtain volume (and compute density)

Archimedes and the crown Why has story persisted so long?

Archimedes and the crown Why has story persisted so long? • Resonates with our own experiences of solving insight problems solving problems with insight

Archimedes and the crown Solvers reach impasse (dead-end) - couldn’t measure Must reinterpret some aspect of problem Volume by water displacement Unconscious processing important If not thinking of crown, how recognize importance of water? Solution accompanied by “Eureka!”

Insight component processes? Insight solutions associated with Switching to new strategy or associations (“restructuring”) Semantic integration -- solvers see connections that previously eluded them Right hemisphere?

Solving problems with insight Characteristics of both “insight problems” and solving processes similar to characteristics of discourse and comprehension processes for which the Right Hemisphere (RH) seems to make contributions Drawing inferences, understanding the gist Getting jokes, metaphors, connotations 2ndary word meanings

Solving problems with insight Solvers reach impasse (dead-end) Must reinterpret some aspect of problem Unconscious processing important Solution accompanied by “Aha!”

Short insight problems: Remote Associates Test: The RAT (Mednick, 1962) RAT Compound Remote Associate Problems Bowden & Jung Beeman, 1998 child tennis scan lame strike same

brain match RAT Compound Remote Associate Problems Bowden & Jung Beeman, 1998 child tennis scan lame brain match strike same

Aha! experience Solution appears sudden and obvious As soon as you think of solution, you “just know” it works for all three words Comes as a whole, not part by part (vs strategic, step-by-step testing, etc)

Event-related fMRI design Insight solutions versus noninsight solutions Very “tight” comparison Not reveal whole network of problem solving Highlights just components that are uniquely engaged (or at least emphasized) for insight solutions

Insight effect in RH anterior Superior Temporal Gyrus: FMRI signal for insight > noninsight solutions. L R Post Ant L R L coronal R axial sagittal p < .005, cluster > 500 mm3

RH aSTG: Singal change across the active region Signal change for insight Insight effect and noninsight solutions (Ins - non) Percent Signal change Percent signal change Time (sec)

“Best” cluster within each hemisphere!!

Parallel study with 128 channel EEG Temporal specificity Processing specificity - frequencies

Gamma band insight effects

Insight solving conclusions Insight solutions associated with increased activity in RH aSTG Binding and conscious accessibility (gamma) over RH aSTG Preceded by visual gating (alpha) - RH temp/ occipital areas

Insight solving conclusions Insight solutions associated with increased activity in RH aSTG Binding and conscious accessibility (gamma) over RH aSTG - Lexical or semantic integration Preceded by visual gating (alpha) - RH temp/ occipital areas - Sensory gating indicates cognitive control?

Replication plus… more areas New data set: improved N, scanner, protocol RH aSTG (distant semantic integration) Anterior Cingulate (monitoring response competition, switching) Posterior Cingulate - same? Hippocampus/parahippocampal gyri - memory, reorgnzn?

Insight effect in RH Superior Temporal Gyrus: FMRI signal for insight > noninsight solutions. L R Post Ant L R L coronal R axial sagittal p < .001, cluster > 1000 mm3 ant and post STG

NONinsight effect in LH Inf. Frontal Gyrus: FMRI signal for NONinsight > insight solutions. LH IFG - dominant semantic retrieval or selection - turns on at problem onset - off at solution, esp’y Insight RH IFG - unusual retrieval / selection - off at problem onset - on at solution (I>NI, ns) sagittal p < .005, cluster > 1000 mm3

General vs specific mechanisms - Visual Aha!

Visual Aha! effect in RH anterior Mid Temporal Gyrus: FMRI signal for insight > noninsight recognition L R Post Ant L R L coronal R axial sagittal p < .01, cluster > 500 mm3

Visual Aha! effect in RH anterior Mid Temporal Gyrus: FMRI signal for insight > noninsight recognition L R Post Ant L R L coronal R axial sagittal p < .01, cluster > 500 mm3

Visual Aha! effect in RH Angular Gyrus: FMRI signal for insight > noninsight recognition L R Post Ant L R L coronal R axial sagittal p < .01, cluster > 500 mm3 Also: RH Sup Frontal Gyrus

Visual Aha! effect in Bilateral M. Occipital Gyri: FMRI signal for NONinsight > insight recognition L R Post Ant L R L coronal R axial sagittal p < .005, cluster > 500 mm3

Visual Aha! conclusions NOT just for verbal problems Similarities - shared mechanisms (not “insight”, but…) Insight: top-down, cognitive control, integration RH -- unconscious, weak but mutually constraining, integration Recognition comes as a whole, not part by part Noninsight: bottom-up Some differences - Angular Gyrus somewhat surprising

General vs specific mechanisms - Visual Aha!

Insight solving conclusions Insight solutions associated with increased activity in RH aSTG Binding and conscious accessibility (gamma) over RH aSTG Preceded by visual gating (alpha) - RH temp/ occipital areas

Insight solving conclusions Insight solutions associated with increased activity in RH aSTG Binding and conscious accessibility (gamma) over RH aSTG - Lexical or semantic integration Preceded by visual gating (alpha) - RH temp/ occipital areas - Sensory gating indicates cognitive control?

Insight solving conclusions Insight solutions associated with Semantic integration -- solvers see connections that previously eluded them When “the light goes on…”

Semantic activation - “Wernicke’s area” Bilateral Activation, Integration, and Selection model of semantic processing Semantic activation - “Wernicke’s area” Bottom-up lexical-semantic activation: index of semantic representations (pMTG) Semantic integration - anterior Sup. Temp. Gyrus Compute semantic overlap - detect or generate (aSTG) Semantic selection - Inf. Frontal Gyrus Select among competing activated concepts (IFG)

Insight preparation Do different mental states influence how you solve problems? Brain activity during a “rest period” (fMRI) or at a “Ready?” prompt (EEG), prior to getting a problem Problems solved with insight versus without insight

Preparation for Insight Is there a general form of preparation for insight that begins before a problem is presented? We examined neural activity during the 2 sec immediately before each problem was presented. Compared neural activity preceding problems solved with insight to activity preceding problems solved without insight.

t Noninsight: More neural activity over right occipital cortex. More attention to the visual stimulus? Insight: More neural activity over left temporal cortex and medial frontal cortex. Medial frontal cortex is involved in control and mobilization of cognitive resources. Left temporal cortex represents concept. Preparing to retrieve solution from area likely to have the strongest activity. Fits hemispheric theory. Not area where insight occurs.

Conclusions Two forms of preparation. Noninsight: Increased visual attention to displayed problem. Insight: Mobilization and control of cognitive resources; activation of temporal lobe semantic regions; suppression of irrelevant thoughts.

Summary Insight is different from ordinary problem solving. Insight involves a sudden, discrete, awareness of the solution to a problem. Insight involves different neural structures and mechanisms. Insight is the result of a special form of preparation involving cognitive regulation by medial frontal region.

Is insight really sudden? Part II: Antecedents of insight Positive mood facilitates insight and creative problem solving (Isen et al.)

Insight and mood Positive mood associated with increased creativity Better access to more distant associations Increased cognitive flexibility Anxiety associated with decreased creativity narrower focus of attention

Positive mood and insight Positive mood enhances (anxiety impedes): Total solution rate % solved with insight Insight-like preparatory activity in ACC

Positive mood modulates prep activity in ACC Insight >Non Prep activity Pos Aff>Neg in prep activ Convergence

General vs specific mechanisms - Visual Aha!

Thank you!