Lecture 9: The Self

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Lecture 9 The Self
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Who am I?
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The Self has a profound effect upon all domains
of our life our relationships and interactions
with others, our careers, our thoughts, our
feelings, our choices - the list is endless.
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Conceiving a Notion of the Self
Major Issue Can the self be located in the
brain? Philosophy The irreducibility of
self Cognitive Neuroscience All cognition the
result of neural activation.
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A cognitive neuroscience approach to studying the
self
Because you are a unique individual, the
particular multifaceted aspects of the self that
define you are present in your brain alone.
And in order for you to remain who you are from
minute to minute, day to day, and year to year,
your brain just somehow retain the essence of who
you are over time. In the end, then, the self is
essentially a memory, or more accurately, a set
of memories. Joe Le Doux (2003) Annals of the
NY Academy of Sciences.
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What is the self?
Damage to different neural structures leads to an
altered Self
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Overview

• What is the Self?
• Is it subserved by a special process?
• 3. Is it subserved by a specific brain region?

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What is the self?
Kihlstrom Klein (1997) state the self
represents our own knowledge of ourselves, and
therefore should be considered in terms of the
manner in which knowledge is represented.
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What is the Self ? The Self as Self-Knowledge

• A Concept
• (The self is actually a fuzzy set of
  context-specific selves).

• A Narrative
• (which we construct, rehearse and relate
  to others).

3. An Associative Network (episodic and semantic
memory) Self-Semantics
4. An Image (a percept-based representation of
face, body and gestures) Self-Recognition
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What is the Self ? The Self as Self-Knowledge
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What is the self?
The Self and Memory Am I beautiful? Is George
Bush stupid?
Memory advantage for traits encoded in relation
to the self (Symons Johnson, 1997). However
only for traits and non-intimate other
comparisons.
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Is self-referential processing special?
The Self-Referential Effect in Memory
The self is a unique cognitive entity with
special mnemonic powers (Rogers et al., 1977).
Reflected by automatic organization elaboration
of information. It is powerful, but ordinary
(Greenwald Banaji, 1989) the memory
enhancement afforded to self-referential
processing can be explained as an extension of
the Levels of Processing effect (Tulving).
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Is self-referential processing special?
Levels of Processing Effect Deep (or
meaning-based) processing produces better
subsequent memory than shallow (or surface-based)
processing.self-referential encoding deep
processing
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Is self-referential processing special?
LOP differences associated with activation
in Left Prefrontal Cortex (LPFC)
If nothing special about self then just greater
activation in LPFC.
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Overview

• What is the Self?
• Is self-referential processing special?
• 3. Is it subserved by a specific brain region?

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Is it subserved by a specific brain region?
Candidates areas
Lateral Prefrontal Cortex associated with higher
order cognitive functions (memory retrieval,
decision making etc.)
Medial Prefrontal Cortex associated with
self-regulation and inhibition (Phineas Gage).
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Is self-referential processing special?
Kelley et al. (2002) JoCN.
Used Rapid Event-Related Design
Deep Encoding
Shallow Encoding
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Is self-referential processing special?
Kelley et al. (2002)
Showed a self-referential effect in trait memory.
Left Inferior Prefrontal
No difference between Self and Bush in region
associated with Level of Processing effect.
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Is it subserved by a specific brain region?
Kelley et al. (2002)
MPFC
Significant difference in MPFC for
Self. Self-Referential processing linked to a
specific brain region.
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Explaining MPFC Activity Why deactivations?
Cortical maps therefore show differences in
DEACTIVATION in this region.
High metabolic resting rate. Spontaneity of
self-referential processing during rest.
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Is MPFC Activity Related to Memory?
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Summary of Self-Reference Effect in Memory

• 1. Not a Level of Processing effect.
• 2. Greater activation in MPFC.
• Evidence for Special Cognitive Entity Specific
  Brain Region.
• BUT.
• Strongest effect for item memory when traits
  used
• the referent other is non-intimate.
• Traits may already be highly organized in
  relation to
• the self.
• May therefore just be measuring LTM differences.

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Does Self-Referential Encoding Enhance Other
Types of Memory?
Source Memory relies on organization and
elaboration but not linked to existing knowledge.
Can look for converging evidence in support of
a special self underpinned by specific brain
region using source memory methodology.
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Can Ask the Same Questions

• Is self-source processing special?
• Is it subserved by a specific brain region?
• similar to that for item memory - MPFC

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Is self-source processing special?
Turk et al. (2005) JoCN Suppl.
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Is self-source processing special?
Significant Self-Source Memory Advantage
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Is it subserved by a specific brain region?
Does MPFC Modulation Predict Subsequent Memory?
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Summary of Self As Semantic Knowledge

• Is self-referential processing special? YES
• Self Reference Effect for Item and Source
  Memory.
• Not Linked to Levels of Processing in the Brain.
• Is it subserved by a specific brain region? YES
• Common neural substrate for both item and source
  encoding (MPFC).
• Activation predicts subsequent memory.

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• What are we measuring in MPFC?
• In trait studies we are more likely to endorse
  positive traits than negative traits as being
  self relevant (Taylor Brown, 1988).
• Therefore, MPFC activation could reflect
• Self-referential processes.
• Item valence (positive vs. negative)
• An interaction between a. b.

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Moran et al. (in press) JoCN.

• Subjects responses with 4-point
• Likert scale to assign self-relevance
• to the trait word
• Not at all like me
• Through to
• 4. Most like me.

lazy
1250ms
750ms
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Results
MPFC
MPFC
vACC
MPFC activation linked to self-relevance. vACC
activation linked to valence. Greater for
positive, self-relevant items.
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Do you have to directly self-reference to
activate MPFC?
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Are You Like Me?
How pleased?
Use knowledge about self to infer the mental
states of similar others
How symmetrical?
How pleased?
How symmetrical?
Mitchell et al. (2005) JoCN.
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Similar v. dissimilar targets
Mitchell et al. (2005), JoCN.
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Summary of Evidence for MPFC Involvement in
Self-Referential Processing
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Sumary Evidence that the self is a special
cognitive entity. Self-Reference Effect in
Memory. Not just a LoP effect. Evidence that
self-referential processing engages a distinct
neural system in the ventral portion of the
medial prefrontal cortex. This region
differentially processes relevance (MPFC) from
affect (vACC). Caveats General problem with
methodology Directed question. Shouldnt self
be engaged for unconscious processing as well
(Mitchell et al., 2005)?
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References Johnson et al. (2002) Brain,
125. Kelley et al. (2002) JoCN, 14. Kihlstrom
Klein (1997) Annals of NY Academy of Sciences.
Vol. 818. Macrae et al. (2004) Cerebral Cortex.
Vol. 14 Mitchell et al. (2005) JoCN, 17. Moran et
al. (in press) JoCN. Rogers et al. (1977)
JPSP. Schmitz et al., (2004) NeuroImage,
20. Symons Johnson (1997) Psychological
Bulletin. Turk et al. (2005) JoCN Supplemental
(conference abstract) Vogeley et al. (2004) JoCN,
16.