How Does Negative Emotion How Does Negative Emotion Cause False Memories?Cause False Memories?

C. J. Brainerd, L. M. Stein, R. A. C. J. Brainerd, L. M. Stein, R. A. Silveira, G. Rohenkohl, & V. F. Silveira, G. Rohenkohl, & V. F.

ReynaReynaCornell University, Cornell University, Pontifical Catholic Pontifical Catholic University of Rio Grande do SulUniversity of Rio Grande do Sul , , &&

University of Santa Cruz do SulUniversity of Santa Cruz do Sul

Emotion, Memory Distortion, and Emotion, Memory Distortion, and Memory Evidence in CrimesMemory Evidence in Crimes

- The bulk of criminal evidence (investigations & trials) The bulk of criminal evidence (investigations & trials) consists of memory reports (e.g., oral interviews, written consists of memory reports (e.g., oral interviews, written narratives, telephone conversations, e-mails, eyewitness narratives, telephone conversations, e-mails, eyewitness identifications, interrogations, depositions, trial testimony)identifications, interrogations, depositions, trial testimony)

- A common feature of such reports is that emotional A common feature of such reports is that emotional content is involved: content is involved:

- Criminal events are inherently emotionalCriminal events are inherently emotional- Memory reports are often given in circumstances that are fraught Memory reports are often given in circumstances that are fraught

with emotion (police interviews, interrogations, sworn testimony)with emotion (police interviews, interrogations, sworn testimony)

-- Hence, whether and how emotional content distorts Hence, whether and how emotional content distorts memory is a fundamental question when it comes to the memory is a fundamental question when it comes to the reliability of evidence reliability of evidence

Basic Scientific Distinctions About Basic Scientific Distinctions About Emotional ContentEmotional Content

- The 2-dimensional model of emotional contentThe 2-dimensional model of emotional content- It’s valenced (has a definite positive/negative, pleasant/unpleasant It’s valenced (has a definite positive/negative, pleasant/unpleasant

quality)quality)- It’s physically arousing rather than calmingIt’s physically arousing rather than calming

- Data: Variations in valence and arousal affect memory Data: Variations in valence and arousal affect memory performance differently (cf. Kensinger, 2004)performance differently (cf. Kensinger, 2004)

- Variations in valence and arousal have different brain signaturesVariations in valence and arousal have different brain signatures- Valence = LVLPFC, MPFC, & RVLPFC activationValence = LVLPFC, MPFC, & RVLPFC activation- Arousal = L & R amygdale activationArousal = L & R amygdale activation

-- Recent work has stressed that specific emotions (anger, Recent work has stressed that specific emotions (anger, sadness) may have unique semantic content [but that’s a story sadness) may have unique semantic content [but that’s a story for another day]for another day]

Classic Ideas About How Emotion Classic Ideas About How Emotion Affects Memory for EventsAffects Memory for Events

- Dr. Johnson effect (“When a man knows he is to be hanged in a Dr. Johnson effect (“When a man knows he is to be hanged in a fortnight, it concentrates his mind wonderfully.”)fortnight, it concentrates his mind wonderfully.”)

- Scientific version: Negative content focuses attention on Scientific version: Negative content focuses attention on target events, improving verbatim memory and suppressing target events, improving verbatim memory and suppressing false memoryfalse memory

- Go with the flow (e.g., Storbeck & Clore, 2005)Go with the flow (e.g., Storbeck & Clore, 2005) - Positive content enhances meaning extraction, increasing Positive content enhances meaning extraction, increasing

false memory but leaving true memory unchangedfalse memory but leaving true memory unchanged

- So, classic ideas add up toSo, classic ideas add up to- Memory enhancement by negative emotionMemory enhancement by negative emotion- Memory distortion by positive emotion Memory distortion by positive emotion

- But, notice that these ideas are just about valence – arousal is But, notice that these ideas are just about valence – arousal is missing in actionmissing in action

Fuzzy-Trace Theory & EmotionFuzzy-Trace Theory & Emotion- Dual-trace theory of false memoryDual-trace theory of false memory

- Verbatim traces of actual events: They support true memory and Verbatim traces of actual events: They support true memory and suppress false memory.suppress false memory.

- Gist traces of meaning content: They support false memories of Gist traces of meaning content: They support false memories of meaning-sharing events and true memories.meaning-sharing events and true memories.

- FTT’s take on emotionFTT’s take on emotion - Valence is mainly a gist dimension, in 2 senses: Positive or negative Valence is mainly a gist dimension, in 2 senses: Positive or negative

valence is a concept in itself (“my junior prom was the pits”) but valence is a concept in itself (“my junior prom was the pits”) but valence may also stimulate memory for other meaning content. valence may also stimulate memory for other meaning content. [Think of it on analogy to semantic orienting tasks.][Think of it on analogy to semantic orienting tasks.]

- Arousal is mainly a verbatim interference manipulation. (Sorry, Dr. Arousal is mainly a verbatim interference manipulation. (Sorry, Dr. Johnson.) Heating up the amygdale generates off-task noise that Johnson.) Heating up the amygdale generates off-task noise that impairs verbatim memory for actual events. [Think of it on analogy impairs verbatim memory for actual events. [Think of it on analogy to dual-task deficits.] to dual-task deficits.]

- Negative valence stimulates semantic processing, relative to positive or Negative valence stimulates semantic processing, relative to positive or neutral, producing stronger gist memories.neutral, producing stronger gist memories.

- So, memory distortion is maximized by negative valence.So, memory distortion is maximized by negative valence.- Caveats about the elderly and about children will be needed later. Caveats about the elderly and about children will be needed later.

How is Emotion-Induced Memory How is Emotion-Induced Memory Distortion Studied in the Lab?Distortion Studied in the Lab?

- Separate emotion from study/test materials Separate emotion from study/test materials via mood induction before study; administer via mood induction before study; administer neutral study/test materialsneutral study/test materials

- Storbeck & Clore (2005); Bauml & Storbeck & Clore (2005); Bauml & Kuhbandner (2007); Corson & Verrier (2007)Kuhbandner (2007); Corson & Verrier (2007)

- Put the emotion in the study and test Put the emotion in the study and test materials, as it is in crimes (e.g., Budson materials, as it is in crimes (e.g., Budson et al., 2006; Brainerd et al., in press)et al., 2006; Brainerd et al., in press)

- Today’s experimentsToday’s experiments

Today’s ExperimentsToday’s Experiments

- 2 experiments2 experiments- 1 in Portuguese (Brazilian undergrads)1 in Portuguese (Brazilian undergrads)- 1 in English (American undergrads)1 in English (American undergrads)

- Basic design: Basic design: - Study several “emotional” DRM listsStudy several “emotional” DRM lists- Respond to conjoint recognition testsRespond to conjoint recognition tests

Today’s ExperimentsToday’s Experiments

- Emotional DRM listsEmotional DRM lists- First 15 forward associates of a negative First 15 forward associates of a negative

word (e.g., word (e.g., hungry, lie, thiefhungry, lie, thief), a neutral word ), a neutral word (e.g., (e.g., fruit, teacher, windowfruit, teacher, window), or a positive ), or a positive word (e.g., word (e.g., baby, god, hugbaby, god, hug))

- Associates are presented as study words Associates are presented as study words but the generating word is notbut the generating word is not

- Generating words appear on memory tests Generating words appear on memory tests as false memory probesas false memory probes

- Arousal is controlled across the 3 valence Arousal is controlled across the 3 valence typestypes

Today’s ExperimentsToday’s Experiments

- Conjoint recognition testsConjoint recognition tests- Test probes: true (Test probes: true (school)school), false (, false (teacherteacher), ),

unrelated (unrelated (lakelake – measures response bias) – measures response bias)- Questions: verbatim = word on the list? gist Questions: verbatim = word on the list? gist

= related to a word on the list? verbatim + = related to a word on the list? verbatim + gist = either a word on the list or a related gist = either a word on the list or a related word?word?

- Math model: extracts measures of verbatim Math model: extracts measures of verbatim and gist memory, for both true and false and gist memory, for both true and false items, from this 3 x 3 matrixitems, from this 3 x 3 matrix

Combined Data (Signal Detection) of Combined Data (Signal Detection) of the Brazilian and U.S. Experimentsthe Brazilian and U.S. Experiments

-2.5

-2

-1.5

-1

-0.5

0

0.5

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1.5

2

Valence

d'/C

d' true

d' false

C true

C false

NeutralPositive Negative

Combined Data of the Brazilian and Combined Data of the Brazilian and U.S. ExperimentsU.S. Experiments

0

0.4

0.8

1.2

1.6

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Positive Neutral Negative

Valence

d' d' true

d' false

What the Data (What the Data (dd′′) Show About ) Show About Valence-Induced Memory DistortionValence-Induced Memory Distortion

- False memory is elevated by negative valence, False memory is elevated by negative valence, relative to neutral valence.relative to neutral valence.

- False memory is lowered by positive valence, False memory is lowered by positive valence, relative to neutral valence.relative to neutral valence.

- Net memory accuracy (Net memory accuracy (dd′′ true - true - dd′′ false false) is ) is increased by positive, relative to neutral.increased by positive, relative to neutral.

- Net memory accuracy is decreased by Net memory accuracy is decreased by negative, relative to neutral.negative, relative to neutral.

- When valence is negative, memory is net When valence is negative, memory is net inaccurate: The sign of inaccurate: The sign of dd′′ true - true - dd′′ false is false is negative.negative.

Valence Effects on Verbatim and Valence Effects on Verbatim and Gist MemoryGist Memory

0

0.1

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Postive Neutral Negative

Valence

p

False gist

False verbatim

True gist

True verbatim

Modeling Data: What Valence Does Modeling Data: What Valence Does to Gist and Verbatim Memoryto Gist and Verbatim Memory

- False memory probesFalse memory probes: : - Gist support for false items increases as we move Gist support for false items increases as we move

from positive to neutral to negative.from positive to neutral to negative.- Verbatim suppression of false items decreases as Verbatim suppression of false items decreases as

we move from positive to neutral to negativewe move from positive to neutral to negative

- True memory probesTrue memory probes: : - Gist support for true items increases from positive Gist support for true items increases from positive

to neutral, but not from neutral to negative.to neutral, but not from neutral to negative.- Verbatim support for true items varies only slightly Verbatim support for true items varies only slightly

across the 3 valence conditionsacross the 3 valence conditions

The Story So Far for Negative The Story So Far for Negative ValenceValence

- It increases false memory hugely and decreases net It increases false memory hugely and decreases net accuracy (because true memory does not increase accuracy (because true memory does not increase nearly enough to compensate).nearly enough to compensate).

- This is mainly a gist-memory effect. Negative valence This is mainly a gist-memory effect. Negative valence is an especially good gist that is preferentially is an especially good gist that is preferentially processed.processed.

- The distortion effects are valence-specific: Positive The distortion effects are valence-specific: Positive valence actually reduces false memory and increases valence actually reduces false memory and increases net accuracy. net accuracy.

The Story So Far for Negative The Story So Far for Negative ValenceValence

- Arousal now needs to be folded into Arousal now needs to be folded into the valence picturethe valence picture

- We’re working on itWe’re working on it- CEL norming projectCEL norming project- It looks like arousal amplifies gist It looks like arousal amplifies gist

processing (increasing false memory) processing (increasing false memory) when valence is positivewhen valence is positive

Two Caveats About Vulnerable Two Caveats About Vulnerable PopulationsPopulations

- Older adults, who are frequent victims of certain types of crimes:Older adults, who are frequent victims of certain types of crimes:- Display positive gist-processing preferences, rather than the Display positive gist-processing preferences, rather than the

negative preferences of younger adults (Mikels, Carstensen).negative preferences of younger adults (Mikels, Carstensen).- So, it is likely that negative distortion effects will morph into positive So, it is likely that negative distortion effects will morph into positive

ones in late adulthood.ones in late adulthood.- Recent data from our labs and Mikel’s lab confirm this prediction. Recent data from our labs and Mikel’s lab confirm this prediction.

- Children, who are also frequent victims of certain types of Children, who are also frequent victims of certain types of crimes:crimes:

- Display lower levels of false memory when distortion depends on Display lower levels of false memory when distortion depends on extracting the gist of experience (Brainerd, Reyna, & Ceci, 2008).extracting the gist of experience (Brainerd, Reyna, & Ceci, 2008).

- So, it is likely that negative distortion effects will be absent or greatly So, it is likely that negative distortion effects will be absent or greatly attenuated in children and emerge with development.attenuated in children and emerge with development.

- Recent data from our labs confirm this prediction.Recent data from our labs confirm this prediction.