S1
Primary somatosensory cortex (brodmann's area 3,1,2)
Brodmann's area 4
primary motor cortex
brodmann's area 17
primary visual cortex
brodmann's area 41
primary auditory cortex
Anterior Zone of the Parietal lobe
Somatic sensations and perceptions (includes areas 3,1,2)
Posterior zone of the parietal lobe
integrates sensory input. Mainly between somatic and visual for the sake of controlling movement
Where does the visual "dorsal stream" terminate?
in the posterior parietal lobe
What happens if someone's dorsal stream is lesioned?
Problems with:
1. Object recognition
2. Guidance of movement
What would someone have problems with if their posterior parietal area was lesioned?
problems with our cortical/mental map: they would get lost constantly
What are some common problems associated with a parietal lobe lesion
-people can't tell left from right
-difficulty with "mental manipulation" or rotation of objects, difficulty calculating things, problems with language (tap v pat), movement sequence issues
What are some common somatosensory symptoms of a parietal lobe lesion?
-an S1 lesion leads to astereognosis or "afferent paresis" in which you don't have feedback to aid movement
-simultaneous extinction
-"blind touch
List the asomatognosias that people with a parietal lobe lesion have
-anosognosia: denial of illness
-anosodiaphoria: indifference to illness
-autopagnosia: can't localize/name body parts "finger agnosia"
-pain asymbolia: can 'sense' pain, but means nothing
anosognosia
denial of illness
anosodiaphoria
indifference to illness
autopagnosia
when one can't localize or name their body parts. Finger agnosia is common
pain asymbolia
people can sense pain, but it means nothing
What causes Balint syndrome?
a bilateral parietal lobe lesion
What are some symptoms of Balint's syndrome?
-Simultagnosia: people can't fixate on visual stimuli and when they can, they only focus on one thing at a time
-Optic ataxia: difficulty reaching for something using vision for guidance
Which side of the body do people often neglect? What's the cause of this?
People neglect their left side b/c of damage to the right parietal lobe
T/F you can have neglect syndrome from lesioning areas other than the parietal lobe.
True
Why do people with parietal lobe damage have difficulty recognizing objects in unusual viewpoints?
because it would require mental rotation which they have issues with
What side of the parietal lobe is lesioned in Gestermann Syndrome?
What are the symptoms?
-Left side of parietal lobe lesioned
-finger agnosia
-right-left confusion
-agraphia (inability to write: NOT dyslexia)
-acalculia
What causes dyslexia?
small clusters of neurons migrated too far from where they should be (in the ectopic position)
What is apraxia and what are the two kinds associated with parietal damage?
-Apraxia: loss of a skilled movement
1. ideomotor apraxia: inability to copy movements/make gestures (left lesion)
2. Constructional apraxia: can't put together a puzzle, build treehouse, draw picture (left or right lesion)
Would a left or right parietal lobe lesion be more likely to lead to left-right confusion?
Left lesion
Which side of the parietal lobe would be worse to lesion?
right side
What subcortical structures lie below the temporal lobe?
limbic cortex, amygdala, hippocampus/beginning of fornix
What are the 3 main functional areas of the temporal lobe?
1. Auditory: dorsal part of lobe
2. Visual areas
3. Medial areas
What comprises the visual areas in the temporal lobe?
-STS streams and ventral streams: important for perceiving movement
-"inferiotemporal cortex": does STS and ventral stream functions AND integrates vision and audition
What do the medial parts of the temporal lobe do?
memory, olfaction, limbic functions (fusiform gyrus: facial recognition)
What could happen if the Papez circuit is lesioned?
amnesia or korsikov's syndrom
Papez circuit
Neocortex-> Cingulate Cortex->Hippocampus->hypothalamus-> Anterior Nuclei of Thalamus
Why is the hippocampus so commonly studied?
it only has 3 layers: simple wiring
Dentate Gyrus of the Hippocampus
one of only 2 areas in adult brain where new neurons can form
What are the mechanisms involved in LTP, what does it stand for?
Long Term Potentiation (of EPSP amplitude/synaptic strength)
1. Phosphorylation and strengthening of AMPA Channels
2. Increase number of AMPA Channels
3. NT release back across the cleft increases # of synapses
What are the mechanisms involved with LTD and what does it stand for?
Long Term Depression (of EPSP amplitude/synaptic strength)
1. Dephosphorylation and weakening of AMPA channels
2. Internalization or decrease in # of AMPA Channels
3. Trim synapses
Temporal Summation
before one EPSP can fade, another must come in at the same point in space
Spatial Summation
2 EPSP's coming from different points in space come together to create a larger EPSP
Explain LTP
a burst of high frequency stimulation causes temporal and spacial summation, this excitation activates two types of Glutamate receptors: 1. AMPA (excitatory) 2. NMDA (requires more energy to open, so AMPA must be stimulated first). NDMA lets calcium into
T/F LTD could be considered forgetting.
False, LTD and LTP are both forms of learning
What structure is damaged in Korsokov's Syndrome?
Mammilary bodies due to a thymine deficiency
Korsokov's syndrome
A thymine deficiency causes damage to the mammilary bodies which results in severe retrograde amnesia and confabulation (making up wild stories to make up for not being able to remember)
Which thalamic nucleus is damaged in korsokov's syndrome?
DM (dorsomedial nucleus) of the thalamus
Uncinate fit
seizure causing nasty smell and taste, accompanied by disturbances of consciousness (deja-vu, jamais-vu) and fear and anxiety
What are symptoms of a lesion to the left side of the temporal lobe?
speech perception problems "central deafness" when people can hear, but can't process the words
What are symptoms of a lesion to the right side of the temporal lobe?
-inability to understand tone/prosody, lack of rhythm
-affective problems: loss of fear (kluver-bucy) release of sexual behavior
What are some general symptoms of a temporal lobe lesion?
-auditory hallucinations
-learning and memory problems
-difficulty categorizing things
Which lobe has the most Brodmann's areas?
Frontal: 20% of cortical tissue
What are the 3 major functional areas of the frontal lobe?
-Motor Cortex (Area 4): does movement
-Premotor Cortex (Areas 6,8): selects and plans movements
-Prefrontal Cortex: coordinates and controls cognitive executive functions so that movements are performed at the right time and place and in the right order
What structure is reciprocally connected to the prefrontal cortex?
the DM (dorsomedial) nucleus of the thalamus
What symptom does frontal lobe damage share with korsokov's syndrome?
Working memory problems
Where do Olfaction and taste occur in the frontal lobe?
Area 13 does olfaction and taste (also found in insular lobe)
What is the prefrontal cortex vital for?
-temporal memory: delayed response tasks (what they've seen most recently)
-working memory
-"autonoetic awareness": autobiographical sense of self built up over the lifetime
Reference memory
knowledge of aspects of a task that remain consistent between trials
Which side of frontal lobe lesion causes pseudopsychopathology?
Right side
Which side of frontal lobe lesion causes pseudodepression
Left side
What symptoms does a bilateral frontal lobe lesion bring about?
difficulty knowing the time and decoding proverbs (metaphors etc)
What left-right asymmetries exist in the frontal lobe?
Left: language-related movements
Right: nonverbal stuff: facial expressions
Area 6
premotor area: lights up when thinking about a movement
Area 8
if damaged, lose control of voluntary gaze (superior colliculus)
What does a loss of corrallary discharge lead to?
Proprioceptive problems
Convergent thinking
one answer to a question (this is what IQ tests test)
Divergent thinking
multiple solutions to a problem: thinking on your feet/planning. People with frontal lobe damage have issues with this
Perseveration
doing a useless motion over and over again