1. Motor and attentional development

2. Brain organization for motor behavior
Similar to organization for sensation
Brain sends signals through thalamus, down spinal chord, controlling movements of limbs etc.
Involves long axons, myelination is important

4. Motor development Reflexes
Reflexes usually involve little or no cortical activity
Some reflexes only go as far as synapses in spinal cord
Others go to brainstem, still others to cortex
Reflexes that are present in babies are probably mostly subcortical or spinal cord types
Why might reflexes be beneficial to babies?

6. Motor control
Requires 2 things
Stability
Flexibility

7. Coordination
Basal Ganglia
Cerebellum

10. Reaching
Reaching in adults is both stable (can be repeated easily) and flexible (adults can reach to any location
These abilities develop gradually in infants
First infant develop general reaching abilities
Infants will grab things put into their hands, but will only voluntarily reach beginning at about 4 months.
Flexibility occurs with practice at reaching
How might plasticity relate to these developments?

11. Infants also perseverate – once they are able to reach, they often are unable to stop reaching – Why?
Possibly development of inhibition
Possibly memory or control over actions

12. Other motor behaviors Locomotion Motor Planning
Development is probably related to several factors
Strength
Balance
Control over limbs – myelin
Motor Planning
Involves areas other than primary motor cortex
These areas probably mature much later

14. Attention
Richards has measured attention development in very young babies.
Rothbart and Posner have proposed that there are multiple attention systems in the human brain, and that they develop on different schedules

15. Early attention A general arousal system likely develops early
Four phases of attention
Automatic interrupt
Orienting response
Sustained attention
Termination of attention
Heart rate varies with phase of attention
Decreases during orienting and sustained attention

16. Sustained attention Visual fixation
Lack of response to peripheral stimuli
Decreased heart rate
Sustained attention and changes in sustained attention may relate to cognitive development.

17. Orienting Networks Covert orienting Develops fairly early
Visual areas including frontal eye fields
Interactions with parietal lobes
Visual cortex
Basal Ganglia
Develops fairly early
Novelty – infants prefer to look at something new – may be subcortical
Infants can engage attention with an interesting stimulus early in life, but once they’re fixated, it’s hard to break away.

18. Alerting
Vigilance
Both orienting and alerting probably rely on posterior and “low level” brain systems
Parietal lobes
Thalamus
Frontal eye fields

20. Executive Control
Involves more voluntary attention, most likely is late to develop (around 2 years)
May be related to performance on cognitive tasks (e.g., reversal tasks, hiding tasks)
Has also been implicated in more general development (e.g., social attention).
Individual differences may relate to temperament – more excitable children may have a harder time disengaging, and may be more reactive.

21. Language Development Issues: Phonological Development Vocabulary
Grammar
Pragmatics