Forebrain: Telencephalon / Cerebral Hemispheres Flashcards
What lobe?
Emotional regulation, planning, reasoning, goal-oriented behavior,personality, and voluntary movement.
Frontal Lobe
What lobe?
Sensation and spatial relationships
Parietal Lobe
What lobe?
Visual processing
Occipital Lobe
What lobe?
Hearing, memory and learning
Temporal Lobe
Localized function of the cerebral cortex
Primary sensory cortex discriminates among?
Primary sensory cortex discriminates among different intensities and qualities of sensory information.
Localized function of the cerebral cortex
Secondary sensory cortex performs?
- Secondary sensory cortex performs more complex analysis of sensation.
- Secondary sensory areas analyze sensory input from the thalamus and the primary sensory cortex
Localized function of the cerebral cortex
Primary motor cortex provides?
Primary motor cortex provides descending control of motor output.
Localized function of the cerebral cortex
Motor planning areas organize?
Motor planning areas organize movements?
Localized function of the cerebral cortex
Association cortex:
controls?
interprets?
processes?
Association cortex controls behavior, interprets sensation, and processes emotions and memories.
Primary visual cortex distinguishes between?
Primary visual cortex (18-21)
- Distinguishes between light, dark, various shapes, location of objects, and movement of objects.
Pathway from retina to lateral geniculate body of thalamus and then to primary visual cortex.
Primary sensory area
Primary sensory areas receive information directly from?
Primary sensory areas receive information directly from the ventral tier of the lateral group of thalamus.
Primary somatosensory cortex located within?
What does it do?
- Primary somatosensory cortex located within central sulcus and on adjacent postcentral gyrus.
- Location of stimuli and discriminate among various sizes, shapes and textures of objects.
- Tactile and proprioception, DCML; three neuron pathway.
- Identify location of stimuli
- Discriminates among size, shape and texture of objects.
Primary auditory cortex is located in?
What does it do?
- Primary auditory cortex is located in the lateral fissure and on adjacent superior temporal gyrus.
- Conscious awareness of the intensity of sound.
Primary visual cortex is located in?
What does it do?
- Primary visual cortex is located in calcarine sulcus and on the adjacent gyrus.
- Light / dark, various shapes, locations of object and movements of object
Primary auditory cortex’s job?
Primary auditory cortex = conscious awareness of intensity of sound.
- What cortical area?
- What number?
- Lesion results in?
- What cortical area = Primary somatosensory (discriminates shape, texture, or size of objects)
- What number = 3-1-2
- Lesion results in = loss of tactile localization and conscious proprioception.
Primary sensory areas of the cerebral cortex
- What cortical area?
- What number?
- Lesion results in?
- What cortical area = Primary visual (Distinguishes intensity of light, shape, size, and location of objects).
- What number = 17
- Lesion results in = Homonymous hemianopia = Visual field defect that involves vision loss on the same side of the visual field in both eyes
Primary sensory areas of the cerebral cortex
- What cortical area?
- What number?
- Lesion results in?
- What cortical area = Primary Vestibular (Discriminates among head positions and head movements, contributes to perception of vertical).
- What number = 40
- Lesion results in = Change in awareness of head position and movement and perception of vertical.
Primary sensory areas of the cerebral cortex
- What cortical area?
- What number?
- Lesion results in?
- What cortical area = Primary Auditory
- What number = 41
- Lesion results in = Loss of conscious localization of sound.
Primary sensory areas of the cerebral cortex
- What cortical area?
- What number?
- Lesion results in?
- What cortical area = Secondary Somatosensory (Stereognosis and memory of the tactile and spatial envirnment)
- What number = 5,7
- Lesion results in = Astereognosis (Inability to identify objects by touch and manipulation, despite intactdiscriminativesomatosensation).
Secondary sensory areas
Stereognosis = the mental perception of depth or three-dimensionality by the senses, usually in reference to the ability to perceive the form of solid objects by touch.
- What cortical area?
- What number?
- Lesion results in?
- What cortical area = Secondary Visual (Analysis of motion, color; recognition of visual objects; understanding of visual spatial relationships; control of visual fixation)
- What number = 18-21
- Lesion results in =
- Visual agnosia (inability to visually recognize objects, despite having intact vision)
or - Optic ataxia (inability to accurately point to or reach for objects under visual guidance with intact ability when directed by sound or touch despite normal strength).
Secondary sensory areas
- What cortical area?
- What number?
- Lesion results in?
- What cortical area = Secondary Auditory (Classification of sounds)
- What number = 22,42
- Lesion results in = Auditory agnosia (unable to differentiate and recognize sounds).
Secondary sensory areas
- What cortical area?
- What number?
- Lesion results in?
- What cortical area = Primary motor cortex (voluntary controlled movements).
- What number = 4
- Lesion results in = Paresis, loss of fine motor control, spastic dysarthria.
Motor areas of cerebral cortex
- What cortical area?
- What number?
- Lesion results in?
- What cortical area = Premotor Area (Control of trunk and girdle muscles, anticipatory postural adjustments).
- What number = lateral 6
- Lesion results in = Apraxia (loss of ability to execute or carry out skilled movement and gestures, despite having the physical ability and desire to perform them).
Motor areas of cerebral cortex
- What cortical area?
- What number?
- Lesion results in?
- What cortical area = Supplementary motor area (Initation of movement orientation planning, bimanual and sequential movements).
- What number = Superomedial 6
- Lesion results in = Apraxia (loss of ability to execute or carry out skilled movement and gestures, despite having the physical ability and desire to perform them).
- What cortical area?
- What number?
- Lesion results in?
- What cortical area = Broca’s Area (Motor programming of speech, usually left hemisphere)
- What number = 44, part of 45
- Lesion results in = Broca’s aphasia (usually left hemisphere)
- Inferior frontal gyrus (usually right hemisphere) = Planning nonverbal communication (emotional gestures, tone of voice; usually in the right hemisphere).
- Lesion = Difficulty producing nonverbal communication.
Motor areas of cerebral cortex
Apraxia
- Apraxia can be considered “motor agnosia”; the knowledge of how to perform skilled movement is lost
- The person is unable to perform a purposeful movement, despite intact sensation, normal muscle strength and coordination, and an understanding of the task.
- Occurs as a result of damage to the premotor or supplementary motor areas or the inferior parietal lobe.
Motor areas of cerebral cortex
Ideomotor apraxia
vs.
Ideational apraxia
- Ideomotor apraxia: patient is able to carry out habitual tasks automatically and describe how it is done but is unable to perform on command
- Ideational apraxia: it is the inability to perform purposeful motor act, either automatically or on command, unable to describe how the task is performed
Constructional apraxia
- Constructional apraxia: Inability to comprehend the relationship of parts to whole.
- Deficit impairs the ability to draw and to arrange objects correctly in space.
Dysarthria?
- Dysarthria is a speech disorder that is characterized by poor articulation, respiration, and/or phonation”.
- Speech disorder resulting from spasticity or paresis of the muscles used for speaking.
- Difficulty involves the mechanics of producing sound accurately, not grammar or finding words.
- Lesion of primary motor cortex.
Motor perseveration
- Motor perseveration: uncontrollable repetition of a movement.
- Example: continue to lock and unlock the brakes of a wheelchair despite intending to lock it
Motor planning area disorders
Broca’s aphasia
- Broca’s aphasia: difficulty expressing oneself using language.
- Impaired in both speaking and writing
- Occurs with damage to the Broca’s area (left hemisphere)
- Lesion affecting the inferior frontal gyrus on right side interfere with nonverbal communication
Motor planning area disorders
Association areas of cerebral cortex
- What cortical area?
- What number?
- Function?
- What cortical area = Medial dorsal pre-frontal association
- What number = medial 8 and 9; 10
- Function = emotion, motivation, personality
Association areas of cerebral cortex
- What cortical area?
- What number?
- Function?
- What cortical area = ventral prefrontal association
- What number = 11, 44, 45, 47
- Function = Emotion, motivation, personality
- What cortical area?
- What number?
- Function?
- What cortical area = Parietotempotal Association
- What number = 39, 40, parts of 7, 19, 21, 22, 37
- Function = Sensory integration, problem solving, understanding language and spacial relationships.
- What cortical area?
- What number?
- Function?
- What cortical area = Dorsolateral prefrontal association
- What number = lateral 8 and 9; 46
- Function = Goal-oriented behavior, self-awareness
Damage to Dorsolateral prefrontal cortex causes?
- Damage to this area causes inability to set goals, plan, execute a plans, and monitoring the execution of a plan.
- People with prefrontal lesions function poorly in daily life because they lack goal orientation and behavioral flexibility; their behavior misinterpreted as uncooperative.
Ventral and medial dorsal prefrontal association cortex are involved in?
- Involved in impulse control, personality, and reactions to surroundings.
- Medial dorsal prefrontal cortex involved in emotions, motivation (One’s emotions and other’s emotions).
- Lesion: lack of apathy and lack of emotions and insight; lack of understanding others emotions, belief and intentions
Flow of information from primary sensory cortex to motor output.
- Primary sensory cortex = simple sensory discrimination (intensity, quality)
- Secondary sensory cortex = recognition of sensation
-
Association cortex =
(a) goal selection, planning, monitoring
(b) interpretation of sensation
(c) emotions, memory processing - Motor planning area = movement composition, sequencing
- Primary motor cortex = cortical motor input
Parietotemporal association cortex involved in?
Damage to left vs. right?
- Parietotemporal association cortex: Problem-solving and comprehension of communication and of spatial relationships occur here.
- Spatial coordination system of this area is essential for constructing an image of one’s own body and for planning movements.
- Damage to this area in the LEFT hemisphere causes Wernicke’s aphasia.
- Damage to the same area in the RIGHT hemisphere causes deficits in comprehending space and understanding nonverbal communication.
Comprehension of language occurrs in?
Comprehension of language occurs in the Wernicke’s area, subregion of left temporoparietal cortex located at the temporoparietal junction
Flow of information during conversation.
- Primary auditory cortex = Auditory discrimination
- Secondary auditory cortex = Classification of sounds (language vs. other sounds)
- Wernicke’s area = Auditory comprehension, vocabulary
- Subcortical connections = Link between Wernicke’s area and Broca’s areas
- Broca’s area = Instructions for language output
- Oral / Throat region of sensorimotor cortex = Cortical output to speech muscles
Language disorders
Aphasia
vs.
Alexia
vs.
Agraphia:
- Aphasia: Affects spoken language
- Alexia: impairment in reading ability
- Agraphia: impairment in writing ability
- **Broca’s ** (nonfluent / motor / expressive): Is difficulty expressing oneself using language
- Wernicke’s (sensory / receptive / fluent): Language comprehension is impaired
Lesion to #1
Lesion to #1 = Contralateral hemiplegia; loss of fractionation; spastic dysarthria
Lesion to #2
Lesion to #2 = Difficulty with anti-phase hand movements, perseveration.
Lesion to #3
Lesion to #3 = Apraxia, perseveration
Lesion to #4
Lesion to #4 = Broca’s aphasia
Lesion to #5
Lesion to #5 = Lack of emotions and understanding of other people; inactivity; bilateral lesions cause severe apathy with loss of anxiety and self-consciouness.
Lesion to #6
Lesion to #6 = Loss of goal-directed behavior, divergent thinking, and conscientiousness
Lesion to #7
Lesion to #7 = Disinhibited social behavior, poor real-life decisions; impulsiveness, changes in extroversion/interoversion.
Lesion to #8
Lesion to #8 = Impaired declarative memory
Lesion to #9
Lesion to #9 = Contrlateral loss of tactile location and conscious proprioception.
Lesion to #10
Lesion to #10 = Astereognosis; apraxia
Lesion to #11
Lesion to #11 = Impaired sound location
Lesion to #12
Lesion to #12 = Auditory agnosia
Lesion to #13
Lesion to #13 = Spatial neglect; inability to navigate; personal neglect
Lesion to #14
Lesion to #14 = Impaired compassion, cooperation, politeness (bilateral lesions)
Impaired language comprehension (usually left side)
Impaired nonverbal communication; neglect, anosognosia (usually right side lesion).
Lesion to #15
Lesion to #15 = Impaired language comprehension
Lesion to #16
Lesion to #16 = Inability to recognize faces, bodies, words
Lesion to #17
Lesion to #17 = Optic ataxia
Lesion to #18
Lesion to #18 = Homonymous hemianopia
Lesion to #19
Lesion to #19 = visial agnosia
