VN - Gaze Patterns - Week 10 Flashcards
What are twof actors that affect how we normally direct our gaze?
Elemental visual features
A conscious intent to find something specific about the visual scene
When looking at a clockface vs a control group, explain how AD patients view the clockface in terms of where they looked, duration, saccade magnitude, and how long they were in regions of interest.
Control group would look mostly at numbers pointed to by the arrows, with some tracking along the arrows
AD patients spent more time looking at the centre of the clockface, a non-informative region
Fixation was longer in duration
Saccades were smaller
Less frequently in regions of interest
Describe how alzheimers disease typically affects an individuals saccades (2).
Being unable to inhibit unwanted saccades
Neglecting to generate saccades where top-down knowledge of a scene would suggest an unusual element
What aspect of the brains physiology is related to the onset of schizophrenia?
Occurs in late teens to early 20s, a decade later for females (20-30)
This is around the time the prefrontal cortex is being finalised
Briefly summarise what happens with schizophrenia (4).
Seeing, hearing, or feeling things that arent real
Having strange beliefs that are not based on facts (delusions - i.e. that a person believes they hear the voice of god or the devil etc)
Thinking in a confused way, or being unable to make order out of the world, shifting from one thought to the next quickly
Having emotions, thought, and moods that do not fit with events
What are the most robust eye movement abnormalities seen in schizophrenia (2)?
Reduced smooth pursuit gain
Poor reflexive saccade suppression on the antisaccade task
What can be said of schizophrenic eye movement abnormalities vs alzheimers disease?
Schizophrenia patients do correct their errors, AD patient sdo not
Are reflexive saccades intact with schizophrenia?
Yes
What region of the brain is required for reflexive saccade inhibition? Is this region affected or unaffected with schizophrenia?
Relies on the DLPFC
-same region found to be affected in schizophrenia
How do normal individuals typically passively view faces and how does this compare in individuals with schizophrenia? How does this compare if they are asked to determine facial expression? How do these viewing patterns compare to other forms of stimuli? Explain what this means.
Normals have a midface triangle in which they view the two eyes, nose and mouth
Schizophrenia patients tend to look mostly in between the two eyes
-this normalises when asked to determine facial expression
This is similar across the board for didfferent forms of stimuli
-they have much less exploration of the images
Describe social phobia and note why individuals avoid certain parts of a face. Is this condition known to affect basic eye movement?
An anxiety disorder characterised by fear of negative evaluation in social situations
Avoidance of eye contact is common
-it is a key area which conveys emotion, including disapproval
This condition is not been shown to affect basic eye movement at all
Describe the scan paths of individuals with social phobia on faces (2).
They go out of their way to avoid fixating on eyes, especially sad faces
They have longer scan paths
Describe how autism patients generally perform on saccade and antisaccade tasks.
Poorly on antisaccades
Otherwise intact saccades
Do autism patients generate a midface triangle when viewing faces?
No
In a study showing toddlers with autism pictures of other toddlers next to geometric shapes, descibe how the toddlers with autism split their time viewing these side-by-side images.
They significantly preferred the geometric shapes over pictures of the other children
-some still spend considerable time looking at the other children rather than geometric shapes
