Cerebrum has frontal region {frontal lobe}| [Barcelo et al., 2000] [Brickner, 1936] [Churchland, 2002] [Colvin et al., 2001] [Damasio and Anderson, 2003] [Dennett, 1969] [Eliasmith, 2000] [Fuster, 2000] [Nakamura and Mishkin, 1980] [Nakamura and Mishkin, 1986].
purposes
Frontal lobe stores systematic semantic concepts and relationships. It analyzes and stores somatosensory, visual, and auditory information. It anticipates motor and cognitive effects. It is about attention, arousal, anxiety, and mood. It affects spatial, recognition, and short-term memory.
purposes: behavior
Frontal lobe establishes action plans and maintains motivations. It controls movement schedule and sequence. It regulates motor, emotional, sexual, and appetitive behaviors. It controls bipedal posture and habituation. It determines energy level and interests. When preparing for motion, frontal-cortex neurons have high-frequency oscillations.
damage
Frontal-lobe damage can impair voluntary movements and delayed responses. Damage can cause hyperactivity, after one day. Damage can eliminate chronic pain responses. Damage can cause no-emotion states. Damage can prevent solving problems that have multiple answers or that require multiple object views. Damage can cause repeated behavior {perseveration, frontal lobe}, as shown by Wisconsin card-sorting test. Damage can cause impaired associational learning. Damage can reduce introspection and daydreaming. Damage can prevent goals. Damage can cause people not to know that they are deficient.
anatomy
Frontal lobe connects to nucleus accumbens, locus coeruleus, hypothalamus, limbic system, precentral cortex, striatum, and posterior parietal, prestriate, and temporal lobes.
attention
Attention affects frontal lobe [Huerta et al., 1986] [Schall, 1997].
Frontal-cortex midline gyrus {anterior cingulate gyrus} {anterior cingulate cortex} (ACC) is for attention, consciousness, voluntary control, and pain. It measures pain unpleasantness. It has Brodmann areas 24, 25, 32, and 33. Multisensory cells resolve conflicts between signals, such as Stroop effect.
Left-frontal-lobe inferior regions {Broca's area} {Broca area}, above lateral sylvian fissure, in front of motor cortex, control speech muscles that make grammatical language [Di Virgilio and Clarke, 1997].
Broca's area and Wernicke's area connect {arcuate fasciculus}.
Broca's area seems to have existed in Homo habilis.
Frontal-lobe midline region {cingulate gyrus}| surrounds corpus callosum.
Frontal-lobe areas {entorhinal area} {entorhinal cortex} can connect to hippocampus, dentate gyrus, sensory frontal lobe, temporal lobe, cingulate neocortex, and olfactory cortex. Entorhinal cortex receives from olfactory bulb. Entorhinal cortex sends sense input to hippocampus.
damage
Entorhinal cortex loss causes inability to consciously remember facts or events, such as new category members or unique examples. Damage does not affect perceptual-motor skills with no conscious internal representations, such as mastering task over several sessions or retrieving previously acquired factual knowledge.
evolution
Entorhinal cortex developed early in evolution.
Frontal-lobe interior orbital surface posterior part {insula, brain}| {insular cortex} includes amygdala and hippocampus. Posterior insula receives from ventral medial posterior thalamus and ventral medial basal thalamus and sends to anterior insula, which sends to anterior cingulate and ventromedial frontal lobes. Insula controls trophotropic behavior through parasympathetic nervous system. Anterior insula responds to pictures of self. Insula receives from taste neurons. Insula helps recognize consonants.
Left lateral frontal lobe {left lateral frontal lobe} stores word meanings, together with Wernicke's area [Churchland, 2002] [Dennett, 1969] [Eliasmith, 2000]. Damage blocks understanding of verb classes but not noun classes.
Damage to fusiform and lingual gyri {lingual gyri} causes no color perception.
Frontal-lobe neuron system {mirror-neuron system} {mirror neuron}, in rostral ventral premotor area F5, allows perception, understanding, and action imitation. Neurons are active when people perform actions and when other people perform same actions. Brain connects voluntary-muscle commands, proprioception, visual perception, and sounds.
theories
Perhaps, action recognition recreates motor-brain-area motor action {direct-matching hypothesis}. Perhaps, perceptual brain areas analyze perceptions by context, body parts used, and motions caused {visual hypothesis} [Ramachandran, 2004] [Rizzolatti et al., 1996].
Frontal-lobe regions {orbitofrontal cortex} {Brodmann area 11} can be above eye orbit bones, be for smell and affective values, and process learned stimulus-reward associations. It develops before prefrontal cortex.
Brain regions near eye {orbito-frontal lobe} can be for planning, priorities, unexpected, and attention.
A frontal-lobe region {premotor frontal lobe}, Broadmann area 6, between medial motor cortex and dorsomedial prefrontal cortex, stops movements, blocks repetition, coordinates muscles, and is for rehearsal before action or imagination.
Frontal-lobe rostral regions {rostral frontal lobe} can connect to thalamus, hypothalamus, and septum. Rostral frontal lobe is for inherited and acquired social behavior. Large rostral frontal-lobe lesions cause little attention to others' feelings and behavior, failure to greet friend or newly introduced stranger appropriately, emotionless conversation, and failure to say good-bye properly.
Prefrontal regions {supplementary motor area} (SMA), between medial motor cortex and dorsomedial prefrontal cortex, can receive from higher sense regions. SMA applies memories, goals, feelings, and will. It sends to premotor regions, which coordinate and integrate signals sent to motor cortex, and to midline, where brain sequences actions to fit plan {motor plan}. It has readiness potential and lateralized readiness potential.
In insula are hippocampus major {horn of Ammon} and hippocampus minor {hippocampus}| [Freund and Buzsáki, 1996] [Parra et al., 1998].
functions
Hippocampus is for long-term and short-term memory. It is necessary to store new memories, but conscious associative fact and event memory also requires other brain regions. Hippocampus is for motivation, reward, rehearsal, and space. It controls ergotropic behavior through sympathetic nervous system. It detects movement direction, head attitude with respect to body, and movement sequence. Neurons can find relations among facts and experiences. Neurons can find fact and experience conjunctions, while neocortex builds learning structures.
damage
Hippocampus damage blocks habituation to repeated stimulation. Hippocampal formation and parahippocampal cortex loss causes inability to consciously remember facts or events, such as new category members or unique examples. Damage does not affect perceptual-motor skills with no conscious internal representations, such as mastering task over several sessions or retrieving previously acquired factual knowledge. Hippocampus damage does not affect perception, consciousness, habits, skills, language, classical conditioning, instrumental conditioning, or motor control.
damage: Alzheimer's
In Alzheimer's disease, basal-forebrain cholinergic-neuron degeneration causes low hippocampal choline acetyltransferase activity.
input
Parahippocampal gyrus and hippocampus have multisensory cells.
output
Hippocampus sends through septum and nucleus accumbens to hypothalamus. It sends to cholinergic neurons at forebrain base, nucleus basalis magnocellularis, medial septal nucleus, and nucleus of diagonal band of Broca. It connects to medial temporal lobe.
process: memory
Brain stores memory only if cerebral neocortex sends information to three different areas close to hippocampus and then into hippocampus itself. Hippocampus then passes message back through medial temporal lobe to originating site in cerebral neocortex.
process: place
Spatial information travels from thalamus to neocortex to hippocampus. Hippocampus has non-topographic cognitive space map, stored in pyramidal place cells. Place-cell fields are stable and form in minutes [Brown et al., 1998]. Place cells increase firing when body is at that location [Ekstrom et al., 2003] [Frank et al., 2000] [Nadel and Eichenbaum, 1999] [O'Keefe and Nadel, 1978] [Rolls, 1999] [Scalaidhe et al., 1997] [Wilson and McNaughton, 1993] [Zhang et al., 1998]. Place cells also recognize textures, objects, and contexts. For example, they fire only when animal sees face (face cell), hairbrush, or hand.
waves
Hippocampus has 4-Hz to 10-Hz theta rhythm during active movement and alert immobility, synchronized between hemispheres in 8-mm region along hippocampus longitudinal axis. Other behaviors have local and bilaterally synchronous 40-Hz rhythm. A 200-Hz wave associates with alert immobility. Awake brain has synchrony, which increases with attention and preparation for motor acts. When neocortex desynchronizes with low-voltage rapid potentials, hippocampus synchronizes with theta waves. When neocortex synchronizes, hippocampus desynchronizes.
Frontal lobe has hippocampus major, hippocampus minor, and subiculum {hippocampal formation}.
Spatial information travels from thalamus to neocortex to hippocampus. Hippocampus has non-topographic cognitive space map, stored in pyramidal place cells. Some hippocampus neurons {place cell, hippocampus} increase firing when body is at that location [Ekstrom et al., 2003] [Frank et al., 2000] [Nadel and Eichenbaum, 1999] [O'Keefe and Nadel, 1978] [Rolls, 1999] [Scalaidhe et al., 1997] [Wilson and McNaughton, 1993] [Zhang et al., 1998]. Place-cell fields are stable and form in minutes [Brown et al., 1998]. Place cells also recognize textures, objects, and contexts. For example, they fire only when animal sees face (face cell), hairbrush, or hand.
Primate hippocampus has some neurons {spatial view cell} that fire only when viewing or recalling a location (with 30 degrees), no matter what head orientation or body location.
4-Zoology-Organ-Nerve-Brain-Cerebrum
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Date Modified: 2022.0225