Posted by EarlyWarning on March 30 2011 08:45 PM
#5
DYSCALCULIA
Learning disabilities involve brain processes, not artificial delineations between aptitude and achievement.
Neuropsychological models of academic tasks assume a heterogeneous make-up, with numerous subtypes of each disorder.
Symptoms of Dyscalculia
* problems becoming fluent in a new skill to the point where it becomes automatic, for example reading, writing and driving a car
* taking longer than other students to complete tasks
* organising work and other aspects of their lives
* a poor sense of passage of time, mixing up dates, times and appointments
* poor short-term memory for carrying out instructions or copying from the board and remembering what has just been read and/or said
* retrieving words when speaking and mispronunciations caused by motor problems or difficulties in discriminating sounds
* directional confusions, getting easily lost , having problems using maps or finding their way to a new place
* poor motor control resulting in a range of difficulties including handwriting, inaccurate reading and spelling
* retaining the visual image of words, signs, symbols, formulae, musical notation
* reading text due to visual distortions such as blurring or moving letters
* comprehension, despite appearing to read fluently
* sequencing letters in spelling, or numbers and signs in maths, difficulties using dictionaries, encyclopaedias and directories, remembering phone numbers and dialling them accurately
* sequencing, such as instructions and mathematical procedures, sequencing of numbers or letters and difficulties taking messages
* attention span and concentration
* particular susceptibility to stress, which may be associated with deadlines or examinations
* noticeable inconsistency between what can be achieved on “good” and “bad” days.
4 Common Fallacies Associated with Math
* Math abilities are a by-product of IQ.
* Boys outperform girls in math.
* Left hemisphere dominant for most academic tasks including mathematics.
1. Math is a right hemispheric task.
“Triple-Code Model of mathematics suggest that multiple neural networks are involved in the
processing of stored quantitative knowledge (Dehaene & Cohen, 1997).
* Math is independent of language.
1. Verbal retrieval for archived information is vital to learning over-learned facts such as
multiplication tables and basic addition and subtraction facts.
2. The language of math is critical to comprehending basic word problems (Levine & Reed, 1999).
3. Math is interdependent on language!!
Basic Terminology:
* Math Disability
(1) Poor language and verbal retrieval skills
(2) Working memory skills
(3) Executive functioning skills
(4) Faulty visual-spatial skills
1. Language Skills (ie. Poor language and verbal retrieval skills)
*
o Direct Statements
o Indirect Statements
o Inverted Sequences
o Inverted Syntax
o Too much information
o Semantic ambiguity
o Important “little” words
o Multiple Steps
o Implicit Information
2. Working memory skills
* Phonological Loop - holds and manipulates acoustic information. Housed in left temporal lobes.
• Retrieval of math facts
• Writing dictated numbers
* Visual-Spatial Sketchpad. imagery. Housed along inferior portions of frontal lobes
• Mental math
• Magnitude comparisons
• Geometric Proofs
* Central Executive System - Anterior cingulate
• Transcoding mental operations
• Deciphering word problems
• Determining plausibility of results
• Inhibiting distracting thoughts
• Modulating anxiety
• Regulating emotional distress
• Fueling two “slave systems” for working memory
efficiency.
Central executive system serves to inhibit any negative distractors when problem solving (Hopko, 1998).
3. Executive functioning skills
Executive control mechanisms such as planning, self-monitoring, organizing, and allocating attention resources to effectively execute a goal directed task. Executive functioning dictates “what to do when”, a critical process in solving word problems. Executive functioning allows students to follow an algorithm when problem solving.
* Dorsal-lateral cortex - helps to organize a behavioral response to solve complex problem solving tasks.
Planning Skills
• Poor estimation
• Selection of math process impaired
• Difficulty determining salient information in word
problems
Organization Skills
• Inconsistent lining up math equations
• Frequent erasers
• Difficulty setting up problems
Self-Monitoring
• Limited double-checking of work
• Unaware of plausibility to a response.
Retrieval Fluency
• Accuracy of recall of learned facts is inconsistent
* Orbitofrontal cortex - rich interconnections with limbic regions and helps modulate affective problem solving, judgment. It Mediates empathic, civil, and socially appropriate behavior, with acute personality change being the hallmark feature of orbitofrontal dysfunction (Chow & Cummings, 1999). It has rich interconnections with limbic regions and helps modulate affective problem solving, judgement, and social skill interaction (Blair, Mitchell, & Peschardt, 2004).
Retrieval Fluency
• Slower retrieval of learned facts
* Anterior cingulate cortex - allocates attention resources and modulates motivation. It serves a multitude of functions linking attention capabilities with that of a given cognitive task. According to Carter (1998), this region helps the brain divert its conscious energies toward either internal cognitive events, or external incoming stimuli. In addition, the anterior cingulate cortex also functions to allow us to both feel and interpret emotions.
Selective Attention
• Procedure/algorithm knowledge impaired
• Poor attention to math operational signs
• Place value mis-aligned
4. Faulty visual-spatial skills
______________________________________________
SUBTYPES OF MATH DISORDERS
(1) Verbal Dyscalculia:
consists of students who have difficulty with counting, rapid number identification skills, and deficits retrieving or recalling stored mathematical facts of over-learned information. In essence, the verbal subtype of dyscalculia represents a disorder of the verbal representations of numbers, and the ability link symbolic with nonsymbolic representations of numbers. In fact, these students may have difficulties in reading and spelling as well (von Aster, 2000). Interestingly, Dehaene and Cohen (1997), noted that lesions along the left-hemispheric perisylvian areas, a similar brain region also responsible for processing linguistic endeavors such as reading and written language, often result in an inability to identify or name digits.
(2) Procedural Subtype:
While children with verbal dyscalculia frequently have difficulty learning language arts skills, children with a procedural subtype tend to have learning difficulties solely related to math (von Aster, 2000). In essence, there is a
breakdown in the syntax rules for comprehension of a numeric symbol system; however, there is not necessarily a breakdown in the syntax rules associated with the alphabetic symbol system used for reading. Furthermore, while the verbal subtype tends to hinder the retrieval of over-learned math facts from memory, the procedural subtype is
more related to deficits in the processing and encoding of numeric information. According to Dehaene and Cohen (1997), the procedural coding of numbers is localized to both the left and right inferior occipital-temporal regions. Consequently, the fundamental breakdown in this subtype is more in the execution of arithmetical procedures.
For instance, a student may have difficulty recalling the sequences of steps necessary to perform multi-digit tasks such as division, or there may be a breakdown in procedural operations such as an inability to start at the right-hand column when doing subtraction (van Harskamp & Cipolotti, 2001). Indeed, there is a syntactical system for mathematical procedures which allows for multiple step calculations.
(3) Semantic Subtype:
The third subtype of dyscalculia is referred to as the semantic subtype, and reflects an inability to decipher magnitude representations among numbers (Dehaene & Cohen, 1997). The semantic comprehension of mathematics becomes extremely useful when monitoring the plausibility of a result (Dehaene & Cohen, 1997). Furthermore, the semantic comprehension of numbers also allows for transcoding mathematical operations into more palatable forms of operations. For example, taking the operation 9 X 4 and recoding it as (4 X 10) - 4 requires a basic conceptual framework for interpreting the magnitude of numbers. The horizontal inferior parietal sulcus (HIPS) remain critical because these regions hold semantic knowledge about quantitative information which allow for estimation skills, making quantity judgments, determining strategy formation, checking the plausibility of results.
(4). visual-spatial:
_________________
~ Philip A De Fina, Ph.D, School neuropsychology Training Program, THE NEUROPSYCHOLOGY OF MATHEMATICS ~
Posted by eoffg on March 29 2012 02:37 PM
#13
Early,
Our brain only provides us with 3 types of thinking processes.
Auditory, Visual and Spatial.
Where Dyscalculia is a symptom of Spatial thinking difficulties.
Though Spatial thinking is a complex process, where their can be various difficulties. Just as their are a range of different Auditory and Visual thinking difficulties.
So that not everyone with Spatial thinking difficulties, will have Dyscalculia.
For Spatial thinking, the brain uses a lobe behind each ear, to concieve of space on each side.
Then the information from both sides, is fed into a cortex in between them. Which can then combine this information from both sides, and do a whole range of different things with it.
But a most important way that it uses these two sides?
Is that it uses these 2 sides, to locate a beginning and an end point.
Where it uses the lobe behind your right ear, to locate a beginning point, and the end point behind your left ear.
But the crucial factor about having located these opposite beginning and end points? Is that the space between them can then be divided up, from beginning to end?
Then after we divide this space up? We can then give it names, for each space in between the beginning and end points?
Which we call numbers.
So that when we think of 1+1= 2.
What is actually going on in the brain, is that it adds these spaces together, to form a larger space. Which is called 2.
Where numbers are actually concieved of as a 'quantity'.
Which can actually be thought of without the words and symbols that we use for numbers.
But Spatial thinking needs to be understood as a 'Set of Spatial Thinking Tools'? So that a difficulty can be identified as difficulty with a specific 'Tool', rather than the symptoms?