Cognitive control, hierarchy, & the rostro-caudal
organization of the prefrontal cortex
David Badre
Department of Cognitive & Linguistic Sciences
Department of Psychology
Brown University
What does neural systems level data tell us?
• Complex actions can be represented hierarchically
Sandwich for lunch
Make sandwich
Slicing bread
Pack sandwich
Spreading
Etc…
Mayonnaise
• Action hierarchy may not require a hierarchical system
Action and the Frontal Lobes
• Frontal lobe dysfunction
Inability to organize or plan a sequence of behaviors
(Shallice and Burgess, 1991)
Vulnerability to action slips
(Schwartz et al., 1998)
Rostro-Caudal Axis of the Frontal Cortex
• Perception-Action cycle (Fuster, 1997; 2001; 2004)
• Human Neuroimaging Evidence
Relational complexity
(Christoff & Gabrieli, 2000; Christoff et al., 2003)
Temporal organization of behavior
(Koechlin et al., 2003; Koechlin & Jubault, 2006;
Koechlin & Summerfield, 2007)
Fuster, 2004
Talk Outline
• FMRI evidence of hierarchy along rostro-caudal PFC
• Disruption of PFC hierarchy
• Learning at different levels of PFC hierarchy
Prefrontal Cortex and Cognitive Control
Cognitive control processes represent contextual information to
bias relevant representations over competitors.
Hypothesis 1: Manipulate control by varying competition
Hypothesis 2: Regional differences in PFC are determined by
the level of abstraction of competing action
representations.
Cue Cue
Cue 1Response
Cue 12
Response
Cue 21
Response 1 Response 2
Cue 2
Response 2 Response 1
Level 1: Competition among Responses
1
Badre and D’Esposito, JOCN, 2007
2 3
4
Level 1: Competition among Responses
3 Response Levels
1
1 Response
(no competition)
1
2
2 Responses
1
2
3
4
4 Responses
Level 1: Competition among Responses
.8
4 Responses
2 Responses
1 Response
PSC
.4
0
-.4
1 2 3 4 5 6 7 8 9 1011 12
TR
Badre and D’Esposito, JOCN, 2007
Level 2: Competition among Features
Features
1 - Positive
2 - Negative
1
Badre and D’Esposito, JOCN, 2007
2
Level 2: Competition among Features
3 Feature Levels
1 Feature
2 Features
4 Features
Level 2: Competition among Features
4 Features
2 Features
1 Feature
PSC
.2
.1
0
-.1
1 2 3 4 5 6 7 8 9 1011 12
TR
Level 3: Competition among Dimensions
Dimensions
Orientation
Texture
Shape
Size
1 - Match along relevant dimension
2 - Mismatch along relevant dimension
1
Badre and D’Esposito, JOCN, 2007
2
Level 3: Competition among Dimensions
3 Dimension Levels
Orientation
1 Dimension
Orientation
Texture
2 Dimensions
Shape
Size
Orientation Texture
4 Dimensions
Level 3: Competition among Dimensions
PSC
4 Dims
2 Dims
1 Dim
.6
.4
.2
0
-.2
1 2 3 4 5 6 7 8 9 1011 12
TR
Badre and D’Esposito, JOCN, 2007
Level 4: Competition among “Contexts”
Recent Instructions
Size
Texture
Shape Orientation
3 Context Levels
100% mapping 50% mapping 25% mapping
Badre and D’Esposito, JOCN, 2007
Sustained
Adj iPSC
Level 4: Competition among “Contexts”
.08
.04
0
0
.5
.25
Mapping Frequency
Interim Conclusions
• FMRI evidence of hierarchy along rostro-caudal PFC
– Hierarchical system in PFC engaged by competition in action system
– Hierarchy ranked by level of abstraction of representations
• Disruption of PFC hierarchy