1. Perceptual-Motor Deficits in Children with down syndrome: Implications for Intervention
Study by: Naznin Virji-Babul, Kimberly Kerns, Eric Zhou, Asha Kapur and Maggie Shiffar
Summary Presentation by: Justin McCullick

2. Purpose
The purpose of this study was “to examine the visual analysis of point-light displays of human and object motions in a group of young children with Down Syndrome” (Virji-Babul, Kerns, Zhoue, Kapur, & Shiffrar, 2006).
Goals
To determine if children with Down Syndrome can perform basic perceptual discrimination between human motion and object motion
To evaluate the ability of children with Down Syndrome to process more complex emotional stimuli
To determine if children with and without Down Syndrome differ in their abilities to perceptually discriminate between complex motoric stimuli
They designed three experiments to answer the three goals they had for this study. (Virji-Babul et al., 2006).
(Virji-Babul et al., 2006).

3. Experiment 1: Human Motion vs Object Motion
Purpose Statement: to determine if children with and without Down Syndrome can accurately discriminate between point light displays of human and object motion.
Hypothesis: The level of impairment in individuals motor abilities will be related to their ability to accurately discriminate between human motion and object motion.
Methods:
12 children with Down Syndrome; ages 8-15 years old
Adaptive Age was evaluated to determine age equivalent. The researchers then chose typically developing students from that age range. The age range for typically developing students this experiment was students ages 4-8
Shown video files of human and object motion shown as digital files initially, then shown side by side of point light and digital video, finally just the point light. Make sure students understood how to ID point light on motion.
After students were able to demonstrate understanding of task, they were given 8 videos that showed a 4 human point light motion and 4 object point light motion in random sequence and asked to identify “person or not a person”
Results
Point was given for correct answers
Down syndrome score was 6 average; Typically developing students 7.5 average
Independent T-Test was performed; Responses were significantly different
Then one tailed one sample t-test performed used to compare scores to that of chance; indicated they were able to discriminate between the two and not just guessing.
Discussion
Children with Down Syndrome can discriminate between human motion and object motion but less accurately than typically developing peers.
(Virji-Babul et al., 2006).

4. Experiment 2: Emotive Human Movement
Purpose Statement: to determine if children with Down Syndrome can identify the emotional cues available in body movements
Methods:
12 children with Down Syndrome; ages 8-15 years old
Adaptive Age was evaluated to determine age equivalent. The researchers then chose typically developing students from that age range. The age range for typically developing students this experiment was students ages 4-8
It was determined that the individuals with Down Syndrome could identify the correct drawn face that represented one of four emotions: Happy, Sad, Mad or Scared
After students were able to demonstrate their ability to correctly identify emotion. The were given 8 point light displays. With each display they were given a forced choice between two emotions and were asked to identify the correct emotion expressed by the dance.
Results
Point was given for correct answers and answers across participants was averaged
Down syndrome score = 81% correct – Happy, 95% - Sad, 63% - Mad, 90% - Scared; Typically developing students = 100% correct – Happy, 100% - Sad, 91% - Mad, 100% - Scared
One Tailed One sample t-test was performed; Demonstrated students with down syndrome only sad response was not significantly above chance. They were unable to identify when motion demonstrated sadness.
Mixed Design 2x4 ANOVA
Effect demonstrating typically developing children outperformed children with Down Syndrome, but both groups showed similar pattern of performance on identifying emotion.
Discussion
The authors stated that there are two possible interpretations
Children with Down Syndrome may suffer from a selective impairment in the visual perception of the emotional states of other people
Children with Down Syndrome can perform simple discriminations with point-light displays but are unable to perform more complex discriminations with point displays
(Virji-Babul et al., 2006).

5. Experiment 3: Typical vs Atypical Gait
Purpose Statement:
Indicate whether children with Down Syndrome are compromised in their perception of complex point-light displays
Indicate whether motor difficulties associated with Down Syndrome might alter the visual perception of action in individuals with Down Syndrome.
Methods:
Utilized four typically developing students and two students with cerbal palsy and two children with Down syndrome to create various gaits for point light displays.
12 children with Down Syndrome; ages 8-15 years old
Shown video files of regular and irregular gaits as digital files initially, then shown side by side of point light and digital video, finally just the point light. Make sure students understood how to ID point light on motion. The students were given instructions on “regular gait” and “not regular or funny”
After students were able to demonstrate understanding of the different gait patterns, they were given 8 videos that showed a 4 regular gaint point light displays and 4 atypical point light displays in random sequence and asked to identify regular or funny gaits.
Results
Point was given for correct answers
Down syndrome score was 4.8 average; Typically developing students 6.3 average
Independent T-Test was performed; Responses were significantly different
Then one tailed one sample t-test performed used to compare scores to that of chance; indicated that the students with Down Syndrome did not perform significantly higher than chance.
Discussion
Children with Down Syndrome are impaired in the perception of complex visual motion cues, they have difficulty identifying the dynamic cues the discriminate between typical and atypical gaits.
(Virji-Babul et al., 2006).

6. Discussions and Implications for APE
It appears from the combination of experiments that when students with Down Syndrome are asked to complete complex motion analysis, their ability to correctly discriminate between different types of movement decreases.
In APE when we ask students to watch a demonstration of a motor skill and then practice it, they may not know where to focus their attention to correctly perceive the skill and translate it into a correct replication of the movement.
The authors suggest early interventions focus on helping students use eye gaze and focus their attention when interacting with others.
In APE, we could facilitate motor learning by breaking a skill down in a task analysis approach and assist the student by directing their focus to specific parts of the movement initially when learning a new motor skill.
(Virji-Babul et al., 2006).

7. References
Virji-Babul, N., Kerns, K., Zhou, E., Kapur, A., & Shiffrar, M. (2006). Perceptual-motor deficits in children with Down syndrome: implications for intervention. Down Syndrome Research and Practice. 10(2), Retrieved from