from the book Flashcards
What are the three main sections of the Frontal lobe and what do they do?
Oribitofrontal/ventromedial region- emotion regulation, reward monitoring, personality. Damage to orbitofrontal area will lead to disinhibition, damage to ventromedial region results in disordered reward processing
Dorsolateral region- broad executive functioning, Damage here leads to dysexecutive syndromes, impairments in working memory, and poor attention control of behavior
Dorsomedial region- important for intentional and behavioral activation. Damage here leads to impairments in initiated behavior including akinetic mutism (alert and awake but cannot move or speak)
What are the three main sections of the Temporal lobes and what do they do?
Temporal polar cortical areas: inter-sensory integration and semantic memory
Ventral temporal areas: object recognition and discrimination; bilateral damage can produce object or face agnosia
Posterior temporal region: middle and superior sulci, contains the primary auditory areas and Wernickes area in the Left. Important for language comprehension, prosodic comprehension in the non-dom hemisphere.
What are the three regions of the Parietal lobe and what do they do?
Superior parietal: sensory motor integration, body schema, spatial processing
Temporoparietal junction: phonological and sound based based processing; language comprehension (left) and music comprehension (right)
Inferior parietal lobule: complex spatial attention, integration of tactile sensation, and self awareness
What are the two main visual pathways in the Occipital lobe:
ventral visual pathway: connecting occipital and temporal lobe, important for object and face recognition, item based memory, and complex visual discrimination (recognizing visual forms, such as faces and objects)
dorsal visual pathway: connecting the occipital and parietal lobes via the superior temporal sulcus, important for spatial vision and visuomotor integration. (visual motor integration- reaching and manipulating objects
neocortex versus limbic brain
The Neo cortex has 6 layers and the limbic brain/cortex 3.
Note: portions of the DLPFC (neocortex) have a lot of layer 4- which contains input from the thalamus.
More dorsally placed lesions produce visual impairments in ________________.
More ventrally placed lesions produce visual impairments in _____________.
Dorsal lesions: spatial perception, attention, visuomotor processing (e.g., hemispatial neglect, impaired visual reaching).
Ventral placed lesions: perceptual disturbances, disorders of recognition of familiar objects and/or faces (agnosia)
Severe disorders of memory (amnestic syndromes) are caused by focal damage to three areas_____________.
medial temporal lobes
medial diencephcephalon
basal forebrain
Tell me about the hippocampus structure and function
in the temporal lobe
consists of the dentate gyrus, sectors of Ammons horn, and the subiculum
The primary internal connections of the hippocampus comprise the trisynaptic circuit (entorhinal cortex- gentate granule cells- CA3 mossy fibers)
most connections are with the parahippocampal region- which includes the rhinal (entorhinal and peririhinal cortex), pre- and parasubicular cortex, and parahippocampal cortex.
There are three main subcortical projections from the hippocampus to structures outside of the temporal lobe memory circuit:
1) CA1, CA3 and the subculum project to the precommissural fornix to the lateral septal nucleus
2) Subicular projections travel in the postcommissural fornix and terminate on the mammillary bodies or anterior nucleus of the thalamus ….aka the Papez Circuit…. aka medial limbic circuit
3) hippocampus projects to the amygdala, nucleus accumbens, other regions of the BF, and ventromedial hypothalamus.
What is the two system theory of amnesia?
Explains how amnesia can be caused by several different lesion profiles.
Amnesia can occur when both the lateral and medial limbic circuit are damaged. AKA the lesions interrupt both the fornix (disrupting the paper circuit) and the ventral amygdalofugal pathways (lateral circuit).
Due to extensive research we can conclude four things about the temporal lobe and amnesia …
1) damage to cortical and subcortical structures within the temporal lobe, whether focal or extensive, can result in amnesia
2) amnesia most likely results from image to both the hippocampally based medial limbic circuit and the amygdala based lateral limbic circuit
3) damage to individual elements of these circuits can all result in amnesia, provided both circuits are damaged
4) the hippocampus appears critical for episodic memory, whereas the amygdala appears more directly involved in emotional aspects of cognition, including emotional memory and assigning emotional significance to memory.
Explain APGAR score
7-10 is reassuring / normal
