Neuro Exam 4

Front 1

Frontal lobe

Back 1

boundaries - central sulcus and lateral sulcus
size > 1/3 of entire cerebral cortex
largest of lobes
major fn areas
- primary motor cortex
- premotor cortex
- frontal eye fields
- prefrontal cortex
- broca's motor speech area

Front 2

premotor cortex location

Back 2

location -
- ant and parelle to primary motor cortex
- extends on to medial surface of frontal love just ant to paracentral lobule (supplementary motor area)
- corresponds t oBA 6

Front 3

premotor cortex inputs and outputs

Back 3

inputs
1. motor thalamus (specifically VA)
2. parietal association areas (reciprocal
3. prefrontal cortex

outputs
1. primary motor cortex
2. also contributes to descending motor pathways (CST)
3. putamen

Front 4

fns of premotor cortex

Back 4

. It is involved in the sensory guidance of movement, and controls the more proximal muscles and trunk muscles of the body. For example, the premotor cortex would help to orient the body before reaching for a glass of water. The supplementary motor area lies medial to the premotor area, also in front of the primary motor cortex. It is involved in the planning of complex movements and in coordinating two-handed movements.

- planning and coordination of complex patterns of motor output
- req greater intensity of stimulation and involves larger groups of mm than primary motor cortex
- frontalaversive field - e-strim may cause rotation of eyes, trunk and head to opposite side
- supplementary motor area has rostral (pre-SMA) and caudal (SMA proper) components

pre -SMA involved in acqusition of new motor sequences
- SMA involved w/execution of autonomic/well-rehearsed motor patterns

Front 5

lesions of premotor cortex

Back 5

-most commonly observed deficit = motor apraxia - impaired ability to carry out purposeful, complex, voluntary mvmts in the absence of paralysis
- also seen following damage to parietal assoc areas - extensively interconnected w/premotor cortex
- ant (premotor) apraxia can be differentiated from post (parietal) apraxia - both do poorly on motor test only post do poorly on perceptual tests
- clumsiness in writting ad drawing
- grasp reflex may return
- alein hand sign - may be present - hand has mind of her own This is more common when damage is relatively selective for the supplementary motor area although some case studies have also been reported following parietal lesions

Front 6

frontal eye fields location

Back 6

ant to premotor cortex
post parts of middle front of gyrus (primary FEF)
dorsal part of inferior frontal gyrus (secondary FEF)
includes parts of BA 6,8, 9

Front 7

frontal eye field input and outputs

Back 7

major inputs
1. post parietal cortex
2. ant cingulate cortex
- imp for attention
Major outputs
1. sup. colliculus
2. brain stem gaze center or in reticular formation
- activate brainstem nuclei of cranial n involved in eye mvmts

Front 8

FEF fn

Back 8

The primary eye fields allow for voluntary direction of gaze
The secondary eye fields contain a “mirror image” of primary fields. Involved in relaxation of antagonistic muscles during voluntary eye deviations.

saccadic eye movements- directed “searching” eye movements; not to be confused with occipital association areas involved in “tracking” eye movements, such as those that occur after locking on to a moving visual stimulus (e.g. watching the ball at a tennis match).


A willful decision to direct visual attention to the left would be initiated in the right FEF. Descending projections to the paramedian pontine reticular formation mediate activation of the left lateral rectus and—via MLF connections with the contralateral oculomotor nucleus—coordinated contraction of the right medial rectus, resulting in deviation of the eyes the left.


Controls voluntary conjugate eye movements.
Electrical stimulation causes deviation of eyes to opposite side.
May also cause other patterns of eye movement
Unilateral stimulation may cause bilateral opening or closing of eyelids.

Front 9

FEF lesions

Back 9

cause deviation of eyes toward side of lesion and impairment of voluntary conjugate eye movement toward opposite side.
Convergence and involuntary tracking/smooth pursuit movement of eyes remain intact (mediated by occipital areas).

Front 10

prefrontal cortex location

Back 10

frontal poleand orbital regions of frontal lobe
-inculdes several broadmans areas
last cortical area to fully mature - myelination of fibers that come in and go out - abt late teens to early/mid twenties

Front 11

input and output of prefrontal cortex

Back 11

major inputs
1. mediodorsal nuc of thalamus
2. amygdala
3. parietal and temporal association areas

major outputs
1. premotor cortex
2. caudate (PFC can influence premotor cortexdirectly or indirectly via basal nuclei)

Front 12

premotor cortex fn

Back 12

- highest order motor association area
- planning, attention, foresight, abstract thought
- working memory
- use of previous experience and emotionalstatus to promote behavioral responses appropriate to current situation
- many of the fns whose subtle individual variations give rise to "personality"

all executive fns

Front 13

working memory

Back 13

ability to hold a fact or concept in mind to bridge the temporal gap between acquisition of that information and executing behavior appropriate to that information.

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Front 14

executive fn

Back 14

a set of cognitive abilities that control and regulate other abilities and behaviors.

Executive functions are necessary for goal-directed behavior.
They include the ability to initiate and stop actions, to monitor and change behavior as needed, and to plan future behavior when faced with novel tasks and situations. Executive functions allow us to anticipate outcomes and adapt to changing situations.
The ability to form concepts and think abstractly are often considered components of executive function.