Lecture 25 Flashcards
Why is voluntary control over the fixation reflex and reflexive eye movements essential for strategic orienting?
Voluntary control over these oculomotor reflexes is crucial for effective strategic orienting.
What is the difference between reflexive and voluntary eye movements in terms of their neural control?
Reflexive eye movements rely on subcortical structures, while voluntary eye movements involve cortical regions like the frontal eye field (FEF).
At birth, which brain regions are believed to be mature, and which is not fully developed?
Subcortical structures are believed to be mature at birth, while the cerebral cortex is not fully developed.
Describe the participants in the Fixation Offset Effect experiment and its results for 1.5-month-old infants.
The participants were 1.5, 3, or 6-month-old infants. The 1.5-month-olds showed significantly slower responses on fixation overlap trials, indicating a stronger fixation reflex in them.
What does the maturation of the cortex in older babies suggest in terms of strategic control over the fixation reflex?
Maturation of the cortex in older babies may enable better strategic control over the fixation reflex, shifting from predominantly exogenous control to increasing endogenous control.
How does the immaturity of cortical pathways in infants manifest in their natural orienting behavior?
Infants at about 1-2 months of age often exhibit prolonged periods of fixation and have difficulty looking away from fixated stimuli.
Why do newborns exhibit a poverty of strategic behaviors, and what contributes to this?
Newborns exhibit a poverty of strategic behaviors because the frontal cortex is immature, and they are largely controlled by external stimuli.
When do the frontal lobes fully develop, and how does this relate to the development of strategic control?
The frontal lobes do not fully develop until around 15 to 20 years of age, and their maturation corresponds to the development of strategic control.
Describe the anti-saccade task and what it requires from participants.
In the anti-saccade task, participants must inhibit a reflexive saccade and instead execute a voluntary saccade in the opposite direction of a stimulus.
What does a high percentage of reflexive eye movements in the anti-saccade task indicate?
A high percentage of reflexive eye movements suggests difficulty in imposing voluntary control over reflexive eye movements.
Describe the results of Experiment 1 involving participants aged 9-20 years in terms of direction errors and reaction times.
Between ages 9 and 15, there was a rapid decrease in the frequency of direction errors and a decrease in reaction times for correct anti-saccades.
What were the findings of Experiment 2 regarding children aged 5-15 years and their performance in anti-saccades?
There was a dramatic improvement in anti-saccade performance between ages 5 and 15. Children aged 5-8 had the most direction errors.
How does healthy aging affect the ability to perform anti-saccades compared to young adults?
Healthy aging can disrupt strategic visual orienting, leading to poorer performance in anti-saccades in older adults.
What determines oculomotor behavior in the brain, and how are subcortical and cortical levels involved?
Oculomotor behavior is determined by cells in various brain areas at both subcortical and cortical levels.
What role do subcortical cells play in oculomotor responses?
Subcortical cells mediate more primitive reflexive oculomotor responses.
