ADHD 2

Question 1

Superior colliculus

Answer 1

Linked to distractibility
Controls eye movements
When impaired- don’t react to a distractor
If the SC is damaged in the left hand side of the brain the person is unable to divert their attention away from a stimuli when they are told to do so

Question 2

Hyper-responsiveness of SC

Answer 2

In animal models, rats with ‘ADHD’ fire more neurons in the SC to a light stimulus than normal rats

Question 3

Hot line to the brain’s interrupt system

Answer 3

Inject chemical into superior colliculus and see where it ends up- tells you what part of the brain is controlling it
Sub-thalamic nucleus- interruption of the STN makes you stop what you’re doing
Proves that the SC is communicating with an area that controls distraction

Question 4

Collicular impairments

Answer 4

The colliculus is involved in multi-sensory integration- multisensory neurons show enhanced responses to multisensory stimuli

Simultaniety judgement task- subjects presented with multisensory stimuli (auditory beep and a visual pattern at a range of stimulus onset asynchronies)
Asked to determine if they occurred at same time or different
Measure- proportion of trials that stimuli were reported as simultaneous
Compared people with high and low ADHD traits
People with high ADHD traits were more likely to see them as separate

Question 5

Do ADHD treatments affect the colliculus

Answer 5

ADHD drugs reduce activity of the superior colliculus

Question 6

Dopamine

Answer 6

Colliculus regulates dopamine neuron
SC is the primary source of visual input to dopamine neurons