1. Associations between Reading, Attention and Timing performance in a time-reproduction paradigm.
Emma Birkett
Joel Talcott
Cognitive & Affective Neuroscience Group Life & Health Sciences
Aston University, Birmingham
Motor Timing, Reading & Attention - Associations & Implications for assessing Co-morbidity
stopwatch

2. Overview Introduce Motor Timing in dyslexia (and ADHD)
Describe an experiment exploring Motor Timing tasks
Describe associations found between Motor Timing, literacy and attention.
Implications for studying comorbidity

3. Introduction 1 – TP & Motor Timing
Temporal Processing as Motor Timing
Why Motor Timing?
Millisecond Level
Focus on action & coordination
Potential insights into Comorbidity
There are many symptoms associated with dyslexia, including difficulties with temporal processing.
Typically temporal processing tasks have included gap detection, rapidly or changing sequences of auditory or visual information which have all implicated difficulties in dyslexia with stimuli occurring rapidly in the order of milliseconds.
Here we have focused on a Motor timing task as a suitable measure of temporal processing, as such we have used a finger tapping task where participants tap their finger in time to a beat.
This task focuses on the ability to time coordinated action at the millisecond level. It is at this millisecond level that we get closest to a reflection of neural mechanisms that underlie these tasks, mechanisms which likely occur in the same sort of time windows.
Finally, bearing in mind what we know about the considerable overlap between dyslexia and adhd, this type of TP was of interest, because difficulties with motor timing have been found in both dyslexia and adhd.
As we know, dyslexia is often found to be comorbid with other disorders. Feasibly, some aspects of temporal processing may be associated with dyslexia, and other aspects of temporal processing may be associated with comorbidity.

4. Introduction 2 - Potential Overlap?
Studies using Finger Tapping measures of Motor Timing:
Dyslexia:
Reduced accuracy & increased variability, related to literacy measures (e.g. Wolff1; Thomson et al.2)
Associations also found in control populations
(e.g. Waber et al.3, Delatollas et al.4)
ADHD:
Increased variability (Ben Pazi et al.5, Toplak & Tannock6, Pitcher et al.7)
Implications for explaining co-morbidity?
If we find a difficulty that does overlap between two comorbid disorders it would be potentially very useful in explaining mechanisms contributing to comorbidity.
explain what increased variability is

5. Comorbidity or Task? Comparing the Studies:
Motor Timing in Dyslexia Auditory Timing Tasks
(from an interest in auditory processing / phonology)
Motor Timing in ADHD Visual or Bimodal Tasks
(tasks which capture a child’s attention)
Questions
Effects of task parameters
How performance relates to measures of literacy / attention
When we explore the research a little further we see that studies of motor timing are not completely comparable
explain what Bimodal is.
Questions – if we want to know whether the difficulties seen on this task in dyslexia and adhd are comparable we need to find out a couple of things:
Effects of task parameters - expect greater variability with visual task
- unknown effect on children
Need to understand how the tasks relate to reading and attention.

6. Method 1: Participants & Measures
Adults: 27 adults (13 females) university staff & students
Children: 21 school children (11 females) from typical classrooms
Cognitive / Behavioural Measures
Verbal & Non-verbal reasoning (WASI)
Reading & Spelling (WIAT)
Non-word & Irregular word reading
Self / Teacher Reports of ADHD Symptoms
Stroop Task (adults) or Subtests of Sustained attention & attentional control (TEA-Ch) (children)
We conducted this experiment with adults and children drawn from typical populations, to assess the effects of the tasks within the normal population and examine relations to behavioural or cognitive measures. Since motor timing performance has been related to these measures within unselected samples we expect to find similar associations with this sample.
Measures given

7. Participant Descriptives
Adults
Children
n (males) 27 21
Age
21.3 (4.3) years
115 (9.0) months
Reading SS
108.4 (7.4)
106.9 (10.2)
Spelling SS
108.7 (11.1)
104.9 (12.3)
Verbal Reasoning SS
109.3 (9.3)
119.0 (9.4)
Non-Verbal Reasoning SS
103.4 (13.2)
104.9 (10.5)
Hyperactivity / Impulsivity Symptoms
5.2 (2.7)
2.9 (4.1)
Inattention Symptoms
6.9 (3.3)
4.8(5.4)
Population of average reading spelling & reasoning ability
Means (standard deviations) unless indicated
ADHD measures max score 18
SSs: mean 100, SD 15

8. Method 2: Finger Tapping Task
Stimulus Intervals
Train of 40 stimuli
330 ms
Auditory
50 ms tone Or
Visual
50 ms shape
Measured
IRI & Asynchrony of 30 responses
Response
IRI
Participants completed the finger tapping task which comprised of…
Participants received Auditory trials and visual trials, that were couterbalanced and interspersed with distractor trials to prevent becoming entrained at 3Hz, they had 3 trials in each modality.
Asynchrony
IRI Data decomposed into ‘timekeeper’ variance and ‘implementation’ variance8.

9. Results 1: Effect of Mode on Asynchrony
1-2) We can see that there is greater asynchrony between stimulus and response in the visual task compared to the auditory task. And also that the children show generally greater asynchrony than the children.
3-4) greater variability in the asychrony produced on the visual task compared to the auditory task. So over the course of the 30 responses analysed, the asychrony varied more. The difference in asynchrony variability between adults and children was also significantly greater.
5) Bearing in mind that this visual task has been used in populations of children with ADHD, it is worth noting that it is a more difficult task anyway, and this may be a confound in the studies.
Support for reduced accuracy and greater variability in visual task (e.g. Kolers & Brewster; Kurgansky)

10. Results 2: Effect of Mode on Decomposed Variance
Timekeeper
Stats technique to decompose variance
TK variance (steady)
Imp variance (random with each output)
Results - When this is decomposed into timekeeper vs implementation variance, we find that for both the adults and the children, there is greater timekeeper variance in the visual modality, and reduced motor variance in the visual modality.
This fits with previous explanations of how we complete visual timing tasks:
Visual stimuli provide brain with info that has relatively poor temporal resolution
Due to this paucity of information, the timing system i.e. timekeeper struggles to produce a reliable timed output
So instead, the brain chooses to ignore the timekeeper system and instead implement a kind of stereotypical motor response i.e. a repeated stream of signals that are sent to the motor system to output a response, despite this being an unreliable way of completing the task.
The results found here, reflect this in how the participants completed the visual task: with increased variance in the timekeeper, and decreased implementation variance.
So we have confirmed the effect of the visual task in both adults and children.
Implementation
Confirmation with adults and children: Visual task shows
low implementation variance & high timekeeper variance (Kolers & Brewster9; Kurgansky10)

11. Results 3: Associations for Adults
Auditory Timing Performance
No significant associations
(Less within & between participant variability)
Visual Timing Performance
Mean Asynchrony associated
with Reading (r = -0.65, p<0.01)
with Spelling (r = -0.40, p<0.05)
Asynchrony Variability associated with Reading (r = -0.43, p<0.05)
Just looking at key variables Reading Spelling & Attention.
Here, no associations between auditory task & variables
Visual task performance was associated with reading & spelling in the adults
Supports findings from previous studies where associations have been found between literacy and motor timing, although this time, only on the visual version of the task.
Decomposed timing variance
Timekeeper and Implementation variance were not associated with other variables.
In adults the visual asynchrony measure (incorporating several variance components) predicts literacy skill.

12. Results 3: Associations for Children
Auditory Timing Performance
No significant associations
(Less within & between participant variability)
Asynchrony variability related to Sustained Attention (r = 0.5, p<0.05)
(lower attention score – reduced variability)
Visual Timing Performance
Decomposed timing variance
Visual Timekeeper Variance related to attentional control (r = 0.66 p<0.01)
Visual Implementation Variance related to
Reading (r = -0.53, p<0.05)
Sustained attention (r = -0.48, p<0.05)
Also found auditory performance not related to variables studied.
And contrast to adults, visual performance related to sustained attention (positive correlation)
Decomposed, see that attentional control relates to TK (positive)
And attention and reading related to implementation variance

13. Results 4: Associations for Children
Typically Visual task = higher timekeeper variance
& low implementation variance
Visual task Correlations show:
Children low attentional control low timekeeper variance
Children low sustained attention high implementation variance
Children poor at reading high implementation variance
Children with lower scores on reading and attention tasks perform the timing task in an atypical manner
Atypical performance not necessarily at a cost
(low sustained attention related to reduced variability overall).
Support for motor timing differences related to reading and attention.

14. Conclusions Adults & Children have same response to visual task
Auditory tasks low within participant variability
(group difference studies)
Visual tasks high within participant variability
- will show associations
- less direct access to timing system, source of variability unknown
Bimodal tasks fall in between
- additional competition between sensory streams
Tasks not comparable, challenge for assessing comorbidity.
Reading & Attention relate to timing; further research to assess the source.

15. Ongoing Research Continue to use methods from the timing field.
Assessing how children with dyslexia and ADHD perform on the visual timing task.
Using the reliable auditory task to examine characteristics of timing variance in children with dyslexia, controlling for attention.
Continue to use methods from the timing field to provide insight into temporal processing deficits in developmental disorders and to help ensure we understand the tasks that have been used to explore comorbidity

16. References Wolff, P. H. (2002). Reading & Writing, 15, 179-206.
Thomson et al. (2006). Journal of Research in Reading, 29,
Waber et al. (2000). Developmental Neuropsychology, 17,
Delatollas et al. (2009). Archives of Clinical Neuropsychology, 24,
Ben Pazi et al. (2003). Developmental Medicine & Child Neurology, 45,
Toplak & Tannock (2005). Perceptual & Motor Skills, 100,
Pitcher et al. (2003). Human Movement Science, 21,
Wing & Kristofferson (1973). Perception & Psychophysics, 14, 5-12.
Kolers & Brewster (1985). Journal of Exp Psychology: HPP, 11,
Kurgansky (2008). Human Physiology, 34,
This research is supported by an Open Competition Studentship from the ESRC (ES/G013845/1)
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