w4 Flashcards
what is the what stream
temporal/ ventral
what is the where stream
parietal/ dorsal
lesions in the what stream lead to
specific impairments in object recognition
lesions in the where stream lead to
deficits in spatial attention
what is simultanagnosia
unable to focus attention on more than one object at a time
what is Balint’s syndrome
damage to parietal cortex leading to simultanagnosia and problems combining features of a stimulus
what has been found about the parietal cortex and feature binding
during conjunction search, posterior temporal cortex and parietal cortex show increased activation over baseline control conditions
what does TMS to parietal lobe disrupt
conjunction search, but not feature search
what is hemispatial neglect
lack of awareness of stimuli presented to the side of space on the opposite side to the brain damage
what is extinction
Patients detect a single stimulus presented to one visual field, but fail to detect the same stimulus when another stimulus is simultaneously presented to the other field
how much processing happens with objects in hemispatial neglect
a lot of basic perceptual processing happens to things in the neglected field
there is a priming effect with objects in the neglected field- what does this mean
An object presented to the neglected field can change the patient’s behaviour, so the object has been semantically processed
where would a lesion underly neglect
Right inferior parietal lobe
what are neglect and extinction deficits of
deficits of attention not
perception
what is neglect due to impairment of
the stimulus-driven system
what system is intact for neglect patients
endogenous orienting system
when are neglect patients most impaired
when trying to disengage attention from intact side
neglect/extinction has most prevalence after
right brain damage
which type of attention has evidence suggested has disproportionately more problems
exogenous attention
what is ADHD characterised by
hyperactivity, impulsivity, and inattention beginning in childhood
ADHD is 3x more common in
boys
prevalence of ADHD in adulthood
2.5%
symptoms of predominantly inattentive ADHD
Difficulty in finishing a task, following instructions; easily distracted
symptoms of predominantly hyperactive ADHD
Difficulty in sitting still for long periods; fidgeting; speaks or acts at inappropriate times
most common ADHD subtype
Combined inattentive and hyperactive
what iOS the heritability of ADHD
parents/siblings of a child with ADHD 5x more likely to be diagnosed with ADHD
which factors make ADHD more likely
- Pre-natal exposure to alcohol and nicotine
- Premature birth and low birth weight
- Perinatal brain injury
- Environmental toxins e.g. lead, pesticides
there is a 3% reduction in volume of which area in ADHD patients
overall cortical and especially prefrontal
where is there reduced grey matter in ADHD patients
fronto-parietal attention network
where do ADHD patients have reduced cortical connectivity
between hemispheres
and within fronto-parietal attention networks
where do ADHD patients have hyperactivity
prefrontal cortex, especially dACC
molecular differences in ADHD patients
Imbalance in dopamine and noradrenaline circuits
what does reduced volume, activity, and connectivity in brain regions in ADHD patients lead to
the endogenous attention system and executive functions
which drugs are commonly prescribed for ADHD
Methylphenidate (e.g. Ritalin) and Dextroamphetamine (e.g. Attentin)
how do medications work to treat ADHD
by blocking the reuptake of norepinephrine (NOR) and dopamine
(DOP) and facilitating their release, enhancing availability in prefrontal cortex and basal ganglia
