prefrontal cortex

Examples of prefrontal cortex in the following topics:

• Motor Areas

  • The motor areas of the brain are located in both hemispheres of the cortex.
  • Premotor cortex: Located anterior to the primary motor cortex and responsible for some aspects of motor control.
  • Dorsolateral prefrontal cortex – Important for executive functions, including working memory, cognitive flexibility, and abstract reasoning.
  • Various experiments examining the motor cortex map showed that each point in motor cortex influences a range of muscles and joints, indicating significant overlapping in the map.
  • $$Topography of the human motor cortex, including the premotor cortex, SMA, primary motor cortex, primary somatosensory cortex, and posterior parietal cortex.

• Executive Function and Control

  • Though prefrontal regions of the brain are necessary for executive function, it seems that non-frontal regions come into play as well.
  • Dorsolateral prefrontal cortex: associated with verbal and design fluency, set shifts, planning, response inhibition, working memory, organizational skills, reasoning, problem solving, and abstract thinking.
  • Anterior cingulate cortex: inhibition of inappropriate responses, decision making, and motivated behaviors.
  • Orbitofrontal cortex: impulse control, maintenance of set, monitoring ongoing behavior, socially appropriate behavior, representing the value of rewards of sensory stimuli.
  • The different parts of the prefrontal cortex are vital to executive function.

• Neural Correlates of Memory Storage

  • Recent functional-magnetic-resonance-imaging (fMRI) studies detected working memory signals in the medial temporal lobe and the prefrontal cortex.
  • Activity in different lobes of the cerebral cortex have been linked to the formation of memories.
  • Short-term memory is supported by brief patterns of neural communication that are dependent on regions of the prefrontal cortex, frontal lobe, and parietal lobe.
  • The hippocampus receives input from different parts of the cortex and sends output to various areas of the brain.
  • The processes of consolidating and storing long-term memories have been particularly associated with the prefrontal cortex, cerebrum, frontal lobe, and medial temporal lobe.

• Describing Consciousness

  • Higher brain areas are more widely accepted as necessary for consciousness to occur, especially the prefrontal cortex, which is involved in a range of higher cognitive functions collectively known as executive functions.
  • This image shows the location of the prefrontal cortex, an area of the brain heavily involved in consciousness.

• Limbic System

  • The limbic system makes up the inner border of the cortex and is vital for emotion, motivation, and memory.
  • The term "limbic" comes from the Latin limbus, for "border" or "edge," because the limbic system forms the inner border of the cortex.
  • Amygdala: Involved in signaling the cortex of motivationally-significant stimuli, such as those related to reward and fear, and in social functions, such as mating.
  • The limbic system is also tightly connected to the prefrontal cortex.
  • To cure severe emotional disorders, this connection was sometimes surgically severed, a procedure of psychosurgery called a prefrontal lobotomy.

• Basal Ganglia

  • They are situated at the base of the forebrain and are strongly connected with the cerebral cortex, thalamus, and other brain areas.
  • The "behavior switching" that takes place within the basal ganglia is influenced by signals from many parts of the brain, including the prefrontal cortex, which plays a key role in executive functions.
  • The pallidum receives its most important input from the striatum (either directly or indirectly), and sends inhibitory output to a number of motor-related areas, including the part of the thalamus that projects to the motor-related areas of the cortex.
  • The subthalamic nucleus (STN) receives input mainly from the striatum and cortex, and projects to a portion of the pallidum (interna portion or GPi).

• Neural Underpinnings of Consciousness

  • Several studies have demonstrated that activity in primary sensory areas of the brain is not sufficient to produce consciousness: it is possible for subjects to report a lack of awareness even when areas such as the primary visual cortex show clear electrical responses to a stimulus.
  • Higher brain areas are seen as more promising, especially the prefrontal cortex, which is involved in a range of executive (higher-order) functions.
  • There is substantial evidence that a "top-down" flow of neural activity (i.e., activity propagating from the frontal cortex to sensory areas) is more predictive of consciousness than a "bottom-up" flow of activity.
  • The prefrontal cortex is not the only candidate area, however: studies have shown that visually responsive neurons in parts of the temporal lobe reflect the visual perception in the situation when conflicting visual images are presented to different eyes.

• Cerebral Lobes

  • The cortex is divided into four main lobes: frontal, parietal, occipital, temporal.
  • The frontal lobe contains most of the dopamine-sensitive neurons in the cerebral cortex.
  • A report from the National Institute of Mental Health indicates that a gene variant that reduces dopamine activity in the prefrontal cortex is related to poorer performance in that region during memory tasks; this gene variant is also related to slightly increased risk for schizophrenia.
  • For example, it comprises the somatosensory cortex and the dorsal stream of the visual system.
  • The superior temporal gyrus includes an area where auditory signals from the ear first reach the cerebral cortex and are processed by the primary auditory cortex in the left temporal lobe.

• The Brain

  • As a rule, the smaller the cerebrum, the less convoluted the cortex.
  • The cortex of a rat or mouse is almost completely smooth.
  • The cortex of a dolphin or whale, on the other hand, is more convoluted than the cortex of a human.
  • The left and right hemispheres of the cerebral cortex are nearly symmetrical.
  • When the physical symptoms of emotion appear, the threat they pose returns to the limbic centers via the hypothalamus, then to the prefrontal nuclei, increasing anxiety.

• Association Areas

  • Associative areas of the cortex integrate current states with past states to predict proper responses based on sets of stimuli.
  • The parietal, temporal, and occipital lobes, all located in the posterior part of the cortex, organize sensory information into a coherent perceptual model of our environment centered on our body image.
  • The frontal lobe or prefrontal association complex is involved in planning actions and movement, as well as abstract thought.
  • The association areas are organized as distributed networks, and each network connects areas distributed across widely spaced regions of the cortex.
  • The processes of language expression and reception occur in areas other than just the perisylvian structures such as the prefrontal lobe, basal ganglia, cerebellum, pons, caudate nucleus, and others.