Underlying Neural Mechanisms of the Triple-Code Model

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Underlying Neural Mechanisms of the Triple-Code
Model

• Tariqa Ackbarali
• Barry University
• Dehaene, S., M. Piazza, P. Pinel, and L. Cohen.
  2003. Three parietal circuits for number
  processing. Cognitive Neuropsychology, 20
  487-506.

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Introduction

• Cognitive and Neuro-anatomical model of number
  processing.
• Schematic Diagram of the architecture of the
  triple-code model (Dehaene Cohen, 1995).

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Proposition of Triple-Code Model
Triple Code Model
Analog Magnitude Code
Visual Arabic Code
Auditory Verbal Code
Direct Asemantic Route
Indirect Semantic Route
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Three Codes

• Analog Magnitude code
• Semantic knowledge of numbers
• Bilateral inferior parietal area
• Visual Arabic code
• Multi-digit operations and parity judgements
• Bilateral Ventral Occipito-Temporal Area
• Auditory Verbal code
• Rote verbal memory
• Left-Hemispheric Perisylvian area

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Code 1 Analog Magnitude Code

• Magnitude Comparison
• Proximity
• Simple quantity manipulations
• Bi-lateral inferior parietal cortices.

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Code 2 Visual Arabic Code

• Multi-digit operations
• Parity Judgements
• Bi-lateral inferior ventral occipito-temporal
  areas

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Code 3 Auditory Verbal Code

• Rote arithmetic facts
• Perisylvian network of dominant hemisphere

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Routes

• Direct Asemantic Route
• Visual Identification
• Visuo-verbal transcoding
• Verbal sequence completion
• Indirect Semantic Route
• Semantically meaningful manipulations
• Transmittal of resulting quantity
• Naming

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Research Question

• This study will investigate the triple-code model
  by examining the relationship between performance
  on standard neuropsychological tests and
  performance on algebra problems.

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Method
Code Brain Areas Mathematical Cognition Mathematical Cognition Parallel Cognitive Function Parallel Cognitive Function
Code Brain Areas Function Code Test Function Neuropsychological Test
Analog Magnitude Bilateral Inferior Parietal Area Magnitude Comparison Approximations Simple quantity manipulations Partial replication of perceptual and symbolic representation of magnitude test (Temple Posner, 1998) Visuospatial Cognition Visually guided hand and eye movements Imagery of movements Grooved Pegboard (Matthews Klove, 1964)
Visual Arabic Bilateral Ventral Occipito-Temporal Area Multi-digit operations Parity judgements Manipulation of numbers in Arabic format Replication of Single-digit calculation test (Dehaene Cohen, 1997) Visual perceptual integration Hooper Visual Organization Test (Hooper, 1958)
Auditory Verbal Left-Hemispheric Perisylvian area Rote arithmetic fact retrieval Manipulation of verbal representations of numbers Arithmetic test from the Wechsler Adult Intelligence Scale (Wechsler, 1981) Sequence Execution Abstract thought Spatial reasoning Speech Sounds Perception Task from the Halstead-Reitan Neuropsychological Battery (Reitan Wolfson, 1993)
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Results