Frontal Lobes: the largest region of the brain, comprising nearly one-third of the “cerebral cortex.” (Blumenfeld, 906) Located at the front of the brain, beneath the ‘frontal bone’ of the skull. (Kolb, 6) Extend back to the “central sulcus.” Separated by an especially deep “sulcus” called the “Sylvian Fissure.” (Blumenfeld, 24)
Concerned with abstract processes like judgment, foresight and planning. (Ramachandran, 116). Play a key role in our ability to think and plan ahead. (Hockenbury, 519) Involved in planning actions and keeping goals in mind long enough to follow through on them. (RamachandranTTB, 20) Concerned with sequencing. (Goldberg, 26) Discovered by “localizationists” to be the seat of the brain’s motor system, which initiates and coordinates the movement of our muscles. (Doidge, 48) The orchestrator of voluntary and skilled movements. Seat of moral reasoning, “self-control,” and some aspects of “language.” (Blakeslee, 10) Involved in processing, understanding and storing action words (verbs). This takes place near the motor cortex, which makes sense since mental representations of (actions) are based mostly on skilled movements. (Goldberg, 26-29) Dysfunction in this area linked with “obsessive-compulsive disorder.” (Hockenbury, 519) If (the left frontal lobe) is damaged, the patient may withdraw from the social world and show a marked reluctance to anything at all. If (the right frontal lobe) is damaged, the patient will seem euphoric even though he really won’t be. Such a patient seems to lose all interest in his own future and shows no moral compunctions of any kind. (RamachandranTTB, 21) Responsible for decisions, for actions, for many functions that are often now called “executive functions.” Deciding what to do, where to go, what to eat, what to say, and probably more importantly what not to do, what not to say, and where not to go. The seat of central control in the brain. (Rose, Episode 1 Anthony Movshon) Editor’s note - functional structures include the “orbitofrontal cortex,” the “motor cortex,” and the “premotor cortex.” Also referred to as "frontal cortex."
Anterior Paracentral Gyrus: lies in the medial surface of the frontal lobe. Between the “central sulcus” and the “paracentral sulcus.” The majority of the “motor homunculus” lies along the precentral gyrus, but the leg dangles along the anterior paracentral gyrus. (Fisch, 282)
Basal Forebrain: ventral surface of the frontal lobe. (Fisch, 442) Includes the ‘septal’ and ‘preoptic’ areas. (Fisch, 363) May play a role in “memory” primarily through its “cholinergic neuron” outputs to the medial “temporal lobes.” (Blumenfeld, 829)
Broca’s Area: located on the side of the frontal lobes and adjacent to the face area of the “motor cortex,” this area specializes in language. (The Brain-Norman Geschwind, 110) Presumed to coordinate the movements of the muscles of the lips and tongue. First discovered when Dr. Broca dissected the brain of a patient who had lost the ability to speak and could utter only one word. Broca found damaged tissue in the left frontal lobe. The place came to be known as Broca’s area. Along with “Wernicke’s Area” it helped sell the concept of “localization” which lasted for 100 years. (Doidge, 16) A language-critical zone located on the left side of the frontal area but not on the right. (Lynch, 153) Also referred to as ‘anterior language area.’
Inferior Frontal Gyrus: a region that normally processes speech. (However,) no sound source is evident while the activation occurs. (John Medina Substack, 19Feb2024) Lies between the “inferior frontal sulcus” and the “inferior” border of the frontal lobe. (Fisch, 278)
Middle Frontal Gyrus: lies between the “superior frontal sulcus” and the “inferior frontal sulcus.” (Fisch, 278)
Orbital Gyri: lay on top of the orbital ridges of the eyes. (Blumenfeld, 25) The orbits of the eyes lie underneath the orbital gyri. (Fisch, 284)
Pars Opercularis: bordered by the “ascending ramus” of the Sylvian fissure. (Fisch, 287)
Pars Orbitalis: bordered by the “anterior horizontal ramus” of the Sylvian fissure. (Fisch, 287)
Pars Triangularis: bordered by the “anterior horizontal ramus” and the “ascending ramus” of the Sylvian fissure. (Fisch, 287)
Precentral Gyrus: the gyrus running in front of the “central sulcus.” (Blumenfeld, 25)
Prefrontal Cortex: lies anterior to the motor, “premotor,” and “limbic” areas. Connections are mainly with the “association cortex.” Important connections with the limbic cortex exist as well, especially with the “anterior cingulate gyrus” and ”orbitofrontal cortex.” (Blumenfeld, 907) Involved in planning, recent memory, abstracting, and categorizing information. (Fields, 5) Plays the central role in forming goals and objectives and then in devising plans of action required to attain these goals. (Goldberg2, 24) Responsible for organizing things in time. Involved in cause and effect considerations. For example, when reading the newspaper, figuring out what the news of an impending recession means to your job. (Goldberg, 26) Left prefrontal (pathways) involve feelings of joy and happiness. (Discover, 2007) The seat of executive function and self-esteem. Regulates “emotion” and its influence on thought and memory. (Kandel4, 57) Imaging studies show that while people are in exhilarating, upbeat states, the prefrontal cortex is the area of the brain that displays the most activity. (Goleman, 270) Functional studies have implicated the ‘dorsolateral’ prefrontal cortex in spatial mnemonic functions. (Friedman, 1)
Superior Frontal Gyrus: lies above the “superior frontal sulcus.” (Fisch, 278) Constitutes the majority of the “medial surface” of the frontal lobe. (Fisch, 282) Also referred to as ‘medial frontal gyrus.’