12 January 2015, Monday
6:30 pm – 7:30 pm
Theater T4, Meng Wah Complex, HKU
By Prof. Glyn HUMPHREYS,
Department of Experimental Psychology, Oxford University, UK
Distinguished Visiting Scholar, The University of Hong Kong
http://sol.edu.hku.hk/understanding-self-self-bias/
2. Id, superego & ego: ego a form of moderation
between desires and social context, to serve
the purpose of the individual
Physical, mental, spiritual aspects of the self
Physical aspects could be transferred to
objects associated with the self
3. These different aspects of the self have been difficult to
study without relying on subjective opinion
Different – more indirect - approach
Study the way the self biases judgements which can
be measured objectively
Then to study what characterises self biases in judgements
4. Self bias effects
There is considerable work showing that humans
show a bias towards information related to
themselves
Memory (Conway et al., 1996)
Trait evaluation (Klein et al., 1989)
Face recognition (Keenan et al., 1999)
7. However it is unclear what factors drive these effects
(what aspects of the self are important? visual
familiarity?)
It is unclear what type of process may be affected
(enhanced perception?)
The relations between the effects and basic
underlying processes (e.g., reward, emotion) remain
unexplored.
8. We have tried to examine these issues using new
simple procedures developed to assess the
associative learning of self bias
Procedures can be used for various associations
other than the self [reward, emotion]
Procedures can be used to look at exactly what
processes are changed by being associated with the
self
Work aims to tell us
– what characterises the self in self bias effects?
- what processes are affected?
- how does this relate to factors such as reward
and emotion?
9. Here I will introduce the self-association procedure to
show that self-bias effects are robust and stable
across individuals
Effects depend on a specific neural circuit
Effects reflect the self as a form of ‘glue’ for
integrating information
Effects can be distinguished from biases reflecting
reward and emotion – though influenced by both
Self-biases reflect the ‘self’ as a hub through which
we integrate incoming information
21. Self-bias in individuals – trait-like measure
Stability: test - retest
Individuals who show a strong self bias do so
across different occasions
Self-bias – even in such simple tasks – is a personal
characteristic
Linked to how individualistic the person is on
questionnaire measures
22. Part 2: Brain mechanisms of the effects
Participants performed the self-association match
task in the scanner
How do brain states change to generate the effect
(Sui, Rotshtein & Humphreys, 2013, PNAS)?
23. vmPFC classically associated
with self processing
LpSTS linked to the ventral
attentional network
Linking of self to socially
salient signal
Strength of connections
related to the strength of the
self advantage
24. Activity in the classic
dorsal attention control
network
Consistent with attention
needed for the more
difficult task
25. Opposite roles
in two neural
networks
Self tagging - a neural circuit of
vmPFC LpSTS
Self tagging - a neural circuit of
vmPFC LpSTS
Other-tagging - the frontal-parietal
control network
Other-tagging - the frontal-parietal
control network
Networks compete to determine behaviour
26. Part 3: The nature of self bias
1.The self as perceptual and memorial glue
27. A redundant trial
Redundancy gains occur when we have to
verify the presence of a target, performance is
enhanced when two targets are present relative
to when only a single target appears.
Redundancy gains occur when we have to
verify the presence of a target, performance is
enhanced when two targets are present relative
to when only a single target appears.
A trial with single item
28. A personal association task -
self vs. friend
A personal association task -
self vs. friend
Identical redundant
stimuli
A trial with single item
Same person
redundant stimuli
Sui & Humphreys, in press, APP
Sui, Yankouskaya, & Humphreys, in press,
JEPHPP
29. Self advantage
Formal analyses of these effects provide powerful
constraints on how they occur – e.g., whether there
is enhanced perceptual integration.
Formal analyses of these effects provide powerful
constraints on how they occur – e.g., whether there
is enhanced perceptual integration.
30. 1 = no capacity limits <1 limited capacity
>1 = super capacity
The self has super-capacity ‘super glue’
32. The self as ‘glue’ for memory
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1. Match to the label
2. Recall all items
What happens to the items from the relevant categories?
What happens to the irrelevant items?
33. Self advantage for relevant and irrelevant items
Self association as glue
34. Self bias is linked to greater integration of
stimuli in perception and in memory
The self as perceptual and memorial glue
Are these effects related to reward or emotion?
35. Part 4: Self-, reward-, and emotion-biases
£8£0.5
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36. Self-, reward-, and emotion-biases
Effect of brain lesionEffect of brain lesion
Are these the same
phenomenon?
Self as high reward or
positive emotion?
37. January 19, 2015Presentation title, edit in
header and footer
(view menu)
Page 37
Damage to left circuit – change the self advantage
Damage to right circuit – reduce attentional control &
increase the self advantage
What happens to the effects of emotion and reward?
38. The left frontal lesion
associated with three
types of hyper-biases
Frontal lesion of the executive control
network
40. The left insula and
vmPFC lesion associated
with hypo-self and
hyper-emotion
Lesion of self representation
41. The neuropsychological data suggest that
self, reward and emotion biases are not the
same phenomenon
This conclusion also supported by results
where one factor is pitted against another
Self to low reward, stranger to high reward
etc.
43. Conclusions:
Part 1: Self-bias occurs in simple association learning.
Self bias acts like an individual trait
Part 2: Self bias is supported by a neural network
independent of the attentional network
Part 3: Self bias is sensitive to a self-reference frame and
it reflects super-integration in perception and memory
Part 4: Self-bias is not driven just by reward or emotion valence
44. Conclusions:
Association with self-representation is a cognitive enhancer
in perception and memory
Harnessing self-bias effects may be an effective means
of improving memory and perception
Self bias may reflect a basic aspect of human cognition
and perception – to produce enhanced attention to self
relevant stimuli
46. GA – patient who suffered herpes simplex encephalitis – severe
amnesia
We assessed if his amnesia could be reduced
by having him make personal associations with stimuli –
objects assigned as belonging to him or sister
48. Overall points:
Techniques of this type may have provide a new means of
exploring perception in a social context
Self bias modulates even basic perceptual processing –
perception not isolated (Fodor, 1983)
Self bias may reflect a basic aspect of human cognition
and perception – to produce enhanced attention to self
relevant stimuli
49. Overall theoretical & methodological points:
Techniques of this type may have provide a new means of
exploring perception in a social context
Self bias modulates even basic perceptual processing –
perception not isolated (Fodor, 1983)
Self bias may reflect a basic aspect of human cognition
and perception – to produce enhanced attention to self
relevant stimuli
51. To what extent do these effects of the self
reflect more basic processes – such as the
self being linked to high reward (Northoff &
Hayes, 2011)
Used the tagging paradigm with stimuli
varying in reward
£15 £5 £1
52. Effects of reward & contrast
Effects mimic those of self
association
If we pit self against reward?
54. Conclusions:
After <15 learning trials, neutral shapes can be tagged
with social significance
This changes the perceptual salience of the stimulus
- self-associated shapes gain in perceptual salience
There is also a change in the neural response to tagged shapes
The self-bias effect does not seem ‘merely’ to reflect
differential familiarity or reward
55. Overall points:
Techniques of this type may have provide a new means of
exploring perception in a social context
Self bias modulates even basic perceptual processing –
perception not isolated (Fodor, 1983)
Self bias may reflect a basic aspect of human cognition
and perception – to produce enhanced attention to self
relevant stimuli
56. Self-, reward-, and emotion-biases
Effect of brain lesionEffect of brain lesion
Control data
58. Part 2: Automaticity and brain circuits
How automatic are these effects?
Vary the probability with which the match pairs appear
(Sui et al., APP, 2014)
Can you reduce self bias if the self only appears
rarely?
Self: Mother: Stranger 1: 3: 3
Self: Mother: Stranger 3: 1: 3
Self: Mother: Stranger 3: 3: 1
59. Performance plotted relative to when there were
equal probabilities of occurrence
Faster as probability varies
Slower as probability varies
60. What happens on low probability trials?
No cost for the self condition, costs on
performance for mother and stranger
conditions
61. What happens on high probability trials?
Mother & Stranger
Self & Mother
Self & Stranger
Only self gains
62. On low probability trials substantial costs for low frequency
‘other’ stimuli (relative to same frequency baseline) – effects
of expectancy to high frequency
Yet NO costs for self
On high probability trials, benefits for 2 high frequency
‘others’
Substantial benefits for self but NOT for paired ‘other’
Low probability trials - self advantage is automatic
High probability trials - self expectation is dominant
70. Activity in the classic
dorsal attention control
network
Consistent with the more
difficult task
71. On mismatch trials you can examine activity linked to the
self shape, the self label or neither
Relations between brain activity and behaviour
72. Effect on perception: change the contrast of the shape
Effects of social
association modulates
effects of stimulus contrast
on perceptual sensitivity
Evidence for a perceptual
locus
Is this effect stable – like a trait measure?
73. Effects of social significance can be
established in simple perceptual matching
tasks
Effects modulate perception (redundancy,
stimulus contrast)
Effects stable across individuals over time
74. Part 3: Brain mechanisms of the effects
Participants performed the self-association match
task in the scanner
How do brain states change to generate the effect
(Sui, Rotshtein & Humphreys, 2013, PNAS)?
75. vmPFC classically associated
with self processing
LpSTS linked to the ventral
attentional network
Linking of self to socially
salient signal
76. Dynamic causal model:
Stronger intrinsic
connectivity
from vmPFC
LpSTS, the
more efficient
performance for
matching self trials
77. Activity in the classic
dorsal attention control
network
Consistent with the more
difficult task
78. Opposite roles
in two neural
networks
Self tagging - a neural circuit of
vmPFC LpSTS
Self tagging - a neural circuit of
vmPFC LpSTS
Other-tagging - the frontal-parietal
control network
Other-tagging - the frontal-parietal
control network
Sui, Rotshtein, & Humphreys, 2013,
PNAS
79. Conclusions:
Self-matching affected by a neural circuit
connecting self representations (vmPFC)
attentional responses to sensory signals (LpSTS)
Strength of connections within this circuit
determine the efficiency of behaviour to self-
associated stimuli
Self-attention network distinct from the classic
fronto-parietal attentrional network
80. Mevorach et al. (2006, Nature Neuroscience)
People respond faster to whichever level is more salient,
and they show less interference from the other (distractor)
level
81. These effects of perceptual saliency have been
linked with neural control centres in posterior parietal
cortex
Evidence from fMRI studies where the magnitude of
interference from salient distractors in manipulated
(Mevorach et al., 2009, JCoN)
82. Target low saliency & distractor high saliency –
target high saliency & distractor low saliency
Cluster along the left IPS shows increased
response when high saliency distractors need
to be rejected Left IPS works harder to reject
such distractors?
Are there similar behavioural and
neural effects with social saliency?
83. 4 experiments
Experiment 1 – demonstrating performance
with neutral shapes
Experiment 2 – demonstrating the pattern of
performance when perceptual saliency of the
shapes is varied
Experiment 3 – demonstrating effects of social
saliency
Experiment 4 - fMRI
88. Can these effects be mimicked by manipulating social
rather than perceptual salience?
Hexagon self, square friend, circle other
Task = identify the shape at the target level as being you
or friend
91. Does self association change the brain’s
response to stimuli
Run the local-global experiment in the scanner
92. Overlap of neural response to social saliency and
perceptual saliency
Editor's Notes
In contrast to the first results, there are also different effects of self and reward.
We look at the individual difference
Neural circuit involves increased functional connectivity between vmPFC and pSTS
This circuit is distinct from the fronto-parietal attentional control network – two may be opposed in generating behaviour
Redundancy gain - when we have to verify the presence of a target, performance is enhanced when two targets are present relative to when only a single target appears.
There is evidence that these redundancy gains can reflect enhanced perceptual processing of stimuli, an effect that is modulated by whether the stimuli are coded as part of a common object representation (Mordkoff & Danek, 2011).
Most studies have assessed redundancy gains based on simple perceptual properties of stimuli (e.g, their color or orientation) and we have sparse evidence on whether higher-level processes modulate the effects.
Redundant self stimuli alone both violated the independent race model and were processed with super-capacity. In contrast, the redundant high reward stimuli did not show race inequality and were associated with limited capacity processing. The data advance our theoretical understanding of self bias both by demonstrating that it can be distinguished from effects of reward, and by suggesting that self-bias can result from the enhanced integration of stimuli associated with the self.
separat
imaging
separat
imaging
Neural circuit involves increased functional connectivity between vmPFC and pSTS
This circuit is distinct from the fronto-parietal attentional control network – two may be opposed in generating behaviour