In addition, the superior longitudinal tract SLT also integrates the neuronal network which extends beyond the frontal lobe, having, for example, involvement in the selection of sensory stimuly related to processing of attention, which occurs through the functioning of the frontoparietal circuitry. In this context, the authors suggest the subdivision of the SLT into three segments, namely the SLT I, SLT II, and SLT III, which connect, respectively, the superior parietal region to the dorsal prefrontal and dorsal premotor cortex; the inferior parietal region to the dorsolateral prefrontal and medial premotor cortex; and the supramarginal gyrus to the premotor ventral cortex [ 20 ].
Other examples connecting the frontal lobe to different cortical regions include the superior fronto-occipital fasciculus SFOF , which corresponds to the long association system of the dorsal visual pathways and appears to have a role in the interaction of the visuospatial function with superior integrative functions. This tract has a hemispheric trajectory located medially, with projections located on the superior edge of the anterior branch of the internal capsule and along the length of the lateral portion of the caudate nucleus, laterally to the posteroinferior elongation of the lateral ventricle horn.
Thus, the SFOF connects the mediodorsal parts of the occipital lobe, angular gyrus located in the inferior parietal lobe , Brodmann area 19, and the precuneus Brodmann area 7 to the dorsal and medial portions of the premotor and prefrontal region Brodmann areas 6 and 8. The inferior fronto-occipital fasciculus IFOF has the primary function of connecting the inferolateral and dorsolateral frontal cortices with the posterior temporal and ventral occipital cortices, via a lateral hemispheric route, along the lateral portion of the lentiform nuclei, claustrum, and the external and extreme capsules.
Studies show that this fasciculus connects the visual Brodmann areas 20 and 21 and auditory Brodmann area 22 associative areas, situated in the temporal lobe, with the prefrontal cortex, playing a role, together with other tracts, in complex visual integration and language and memory processing [ 17 ]. Other important structures include the external capsule and the extreme capsule.
The external capsule is situated between the putamen and the claustrum and has associative pathways coursing through it connecting the ventral and medial prefrontal cortices, ventral premotor cortex, precentral gyrus, rostral superior temporal, inferior temporal, and preoccipital regions. The extreme capsule is situated between the claustrum and caudal insular cortex and between the claustrum and orbitofrontal cortex in its rostral portion, representing the principle connective pathway between the ventrolateral prefrontal cortex and the caudal fronto-orbital cortex with the superior temporal region [ 17 ].
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Some of the connecting pathways cited in this subsection are exposed in Figures 5 — MRI tractography in sagittal view showing anterior cingulate A. C fibers, fornix and uncinate fasciculus U. F fibers. MRI tractography in coronal view showing anterior cingulate A. In addition, with the advancement of knowledge on cognitive science made possible by technology, important examples of network models showing the broad cerebral neuronal connections have been demonstrated recently.
The DMN is basically a network associated with passive task conditions and with self-referring mental activity, whose main structures are the posterior cingulate and adjacent precuneus cortex, medial prefrontal cortex, and inferior parietal lobe [ 21 ]. For didactic purposes and practical applicability, several cases illustrating these clinical situations will be reported in the ensuing subsection.
Subsequently, the lesions were reconstructed using tractography based on the atlas of white matter obtained from the diffusion tension imagings DTIs of healthy adults [ 2 ]. In , Harlow described the case of Phineas Gage, a year-old man who sustained perforation of the left frontal part of his skull by an iron bar after an accident in the workplace.
According to the descriptions, after the event, Gage became unrecognizable to his friends; he became more flippant, used foul language, was more impatient when disagreed with, failed to display empathy and, although no neuropsychological description was made at the time, the clinical manifestations were believed to be linked to deficits in decision-making and emotion processing after sustaining the lesions to the frontal lobe.
In addition, there was partial disconnection of the frontal lobe in relation to the amygdala, thalamus, and striatum. With regard to the fasciculi, the authors cited damage of the inferior longitudinal, superior frontal, and uncinate fasciculi. There were also lesions occurring in the orbitopolar and frontal aslant tracts.
Other partially affected connective pathways were the frontostriatal, frontopontine and anterior thalamic projections [ 2 ]. At the time of hospitalization, Leborgne was divorced and had recently lost his father, which may have explained his long stay at this clinic. On the postmortem analysis of Leborgne, Broca identified damage to the posterior third of the left inferior frontal lobe.
The following connective pathways were affected: arcuate fasciculus, the first third of the superior longitudinal fasciculus, the frontal inferior longitudinal, frontal orbital polar, and the frontal aslant tracts. There was also partial involvement of the frontopontine, frontostriatal, and corticospinal tracts, the second third of the superior longitudinal fasciculus and anterior thalamic radiations [ 2 ]. Henry Molaison H. In , his case was assessed by William Scoville, a neurologist who was studying the effects of temporal lobectomy in reducing the frequency of epileptic seizures.
That same year, H. After surgery, there was an improvement in the frequency of the epileptic seizures but, unexpectedly, the presence of severe anterograde amnesia was evident, along with apparent problems remembering new facts and events as a result of the predominant impairment in recall memory. The results of the analysis showed that besides the medial temporal lobe, there were changes in the orbitofrontal cortex, retrosplenial cortex, and gyrus rectus.
In relation to the connective pathways, the main observation was damage to the right uncinate fasciculus, while other tracts were partially affected, such as the anterior commissure, fornix, and left and right ventral cingulate. In the three cases, analysis based on functional MRI studies showed that the abnormalities were compatible with the damage to most of the fasciculi involved in the computed structural reconstruction [ 2 ].
In , Krause et al. In that sample, there were 15 patients with severe executive dysfunction associated with brain lesions outside the frontal lobe. Some examples taken from this study will be cited below [ 15 ]. This fact suggested a possible disruption of the circuitry involving modulation of the frontal cortical functioning, even without cortical or subcortical white matter lesions [ 15 ]. A year-old female patient, one week after an infection of the upper airways, presented an acute clinical picture characterized by neuropsychiatric manifestations followed by awareness impairment.
Among the initial complementary exams, the brain MRI FLAIR-weighted sequence disclosed bilateral hyperintense lesions in the posterior parietal regions, posterior thalamic regions, hippocampus, internal globus pallidus, caudate nuclei, and occipital optic tract. After improvement using pulsotherapy, the radiologic abnormalities were later considered components of the diagnosis of acute disseminated encephalomyelitis ADEM , since there were no conclusive results on other exams cerebrospinal fluid, Anti Nuclear Factor, serology, brain biopsy. A year-old male patient was admitted after onset of sudden dysarthria, left hemiparesis, ataxia, and fluctuation in level of consciousness.
Brain MRI disclosed bilateral cerebellar and thalamic infarcts affecting the dorsomedial and centromedian nuclei and parts of the right pulvinar, without evidence of damage to the frontal lobes. These symptoms partially improved during the course of the next year, but the patient remained dependent for care and cognitive deficits persisted [ 15 ]. A year-old female patient presented rapidly progressive disorientation, gait and balance difficulties, dysarthria, and transient hemiparesis to the right side. Previously, an active individual engaged in social activities, since the onset she displayed abulia, grasping and grouping, visual grasping, imitation behavior, clonic perseveration, utilization behavior, ideomotor apraxia, and parkinsonism.
Brain MRI T2-weighted sequence revealed hypersignal in the anterior two-thirds of the putamen, besides lesions to the anterior portions of the lateral ventricles. The clinical and radiological pattern suggested involvement of the occipitofrontal fasciculus [ 15 ].
In , Starowicz-Filip published a case of a year-old male patient who presented, besides ataxic manifestations, typical symptoms of frontal lobe damage euphoric mood, inappropriate social behavior, loss of decorum, tendency to encroach on personal space secondary to a stroke affecting the right cerebellar hemisphere confirmed by computerized cranial tomography and brain MRI [ 23 ]. In the discussion of this case report, the authors cited the original paper of Schmahmann and Sherman , reporting a case series of 20 patients with cognitive-behavioral symptoms, as well as motor abnormalities due to cerebellar damage vascular, infectious, and autoimmune nosology.
At the time, this clinical entity was coined cerebellar cognitive-affective syndrome, a term used to this day [ 24 ]. Since , major advances have been made to elucidate the different connections of the cerebellum with supratentorial cortical structures, which are related to nonmotor language, cognition, and emotions. Apraxia of speech, for example, caused by deficits in motor planning of speech and in coordination, occurs as a result of injury, typically, to the region of the motor area of language in the dominant hemisphere.
Characterized by impaired speech articulation, which can also be inconsistent, marked by hesitancy, with phonetic changes in vowel and consonants, dysdiadochocinesia, abnormality in prosody and slow articulation [ 25 ], apraxia of speech is an entity which shares many semiological features with ataxic dysarthria result of lesion in the right superior vermis region and paravermis regions, characterized by slow, monotone, slurred speech which tends to be explosive and with phonation—all classes of consonants—affected more than articulation [ 26 , 27 ]; therefore, these similarities suggest that both conditions occur as a result of disconnection between the anterior motor region of planning of speech and coordination, which suggests a functional interaction between the anterior motor speech area in the dominant hemisphere of language and the contralateral cerebellar hemisphere [ 25 ].
Neuropsychological studies have also shown that patients with cerebellar abnormalities have less capacity for word retrieval phonologic fluency and for producing words according to a semantic rule semantic fluency. Therefore, the cerebellum may be responsible for changes in the dynamic of language, resulting in transcortical aphasia behavior and even mutism due to inhibition of speech and of language production involving circuits connecting with frontal regions.
Those findings warrant further elucidation [ 24 , 28 , 29 ]. Many other changes, in terms of cerebellum involvement and cognitive domain of language, can be found in patients with cerebellar lesions besides those cited above. Thus, the role of the cerebellum regarding another cognitive function should be noted: that of working memory.
Cerebellum damage is believed to cause deficits in attention related to working memory and in executive functions, where functional studies including the use of methylphenidate, a dopamine transporter inhibitor, have shown activation of the left side of the cerebellum with subsequent improvement in working memory performance [ 30 , 31 ].
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It is believed that symptoms of cerebellar cognitive-affective syndrome occur due to extensive disconnection of neuronal circuits involving the cerebellum and prefrontal, superior temporal, posterior parietal, and limbic cortices [ 32 ]. This also explains the visuospatial change found in patients with vermis lesions [ 33 ]. There is also a relationship of the cerebellum with many pathologies that are highly characterized by behavioral changes, such as autism, schizophrenia , and attention deficit hyperactivity disorder ADHD.
The New Executive Brain Frontal Lobes in a Complex World Information
Prefrontal cortex of left cerebral hemisphere. Shown in red. Want to know more about the brain and how we work? Check out our Science of Psychotherapy podcast! Frontal Lobe Brain Anatomy. The frontal lobes are probably of most interest to psychotherapy interventions such as CBT because they are home to the PFC, an area vitally involved in executive functions such as concentration, organization, judgement, reasoning, decision-making, creativity, emotional regulation, social—relational abilities, and abstract thinking—in other words, all the functionality we rely on for healthy relationships with ourselves and others.
We will look at the PFC separately because of its special importance to psychotherapy; however, the frontal lobes in general regulate voluntary movement, the retention of non-task-based memories that are often associated with emotions, dopamine -driven attention, reward motivations, and planning, to name just a few. The PFC is the part of the cerebrum that lies directly behind the eyes and the forehead.
More than any other part of the brain, this area dictates our personality, our goals, and our values. When we have a long-term goal, for example, which we are pursuing with value-congruent action, we maintain a neural representation of that goal so as to not be distracted or influenced by competing goals or alternate values Grawe , If the PFC is damaged, it affects our personalities and the ability to orient our behaviour in line with our values and goals.
The PFC is vital to the sense of self and others necessary for healthy interpersonal relationships and decision making. As in the case of so many discoveries in neuroscience, we often learn what a brain area can do when it becomes damaged in some way.
Phineas Gage was a young, reflective, determined, and goal-oriented man who, despite his youth, had been promoted to foreman on an American railroad construction project. But in an unfortunate accident on September 13, , an explosion drove a tamping rod up through the left side of his face and out the top of his head.
The rod passed through and destroyed much of his left PFC. Amazingly, Gage survived, and was even speaking within minutes of the accident. John Harlow:. The equilibrium or balance, so to speak, between his intellectual faculties and animal propensities, seems to have been destroyed. He is fitful, irreverent, indulging at times in the grossest profanity which was not previously his custom , manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires, at times pertinaciously obstinate, yet capricious and vacillating, devising many plans of future operations, which are no sooner arranged than they are abandoned in turn for others appearing more feasible.
A child in his intellectual capacity and manifestations, he has the animal passions of a strong man. Previous to his injury, although untrained in the schools, he possessed a well-balanced mind, and was looked upon by those who knew him as a shrewd, smart business man, very energetic and persistent in executing all his plans of operation. Harlow, , pp.
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The left and right sides of the PFC have different biases, with the left side oriented more toward approach, positive goals, and emotions, and the right side specialized more in avoidance and negative emotions. Individuals who appear to have a bias toward positive emotions may have a more activated left PFC, whereas right PFC activation is correlated with more negative emotional experiences. In studies of the neural correlates of depression , it has been found that left PFC activity is underactive relative to right PFC activity. It seems that less access to the positive bias of the left PFC may make it more difficult for the depressed individual to engage in positive goal-oriented thought and behaviour.
Studies have found that the depressed individual is generally more sensitive to what may be perceived as punishment and does not respond as well to rewards. Moreover, the relative underactivation of the whole PFC in depressed individuals could account for them having less motivation for planning, problem solving, creativity, and so forth. In depression , not only is there underactivation of the PFC, but its volume has been found to be reduced as well. A depressed person with an underactive PFC of reduced volume is not going to demonstrate the rational problem solving abilities of someone without such deficits—the neural integrity to support such resilience is simply not there.
This is where the active, approach-oriented and positively biased PFC of a therapist can be of great value to the depressed client. We will discuss the supportive right brain-to-right brain activity of therapy further when we address specific psychopathologies. The PFC has been divided into a number of functionally distinct regions, described below. The DLPFC is the topmost part of the PFC and is considered to have overall management of cognitive processes such as planning, cognitive flexibility, and working memory.
This is an area specialising in problem solving and how to direct and maintain attention to a task. When we are focused on what is happening now, our working memory is engaged with the DLPFC and connecting with the hippocampus for the retrieval and consolidation of long-term explicit memories.
A dysfunction in this area may lead to problems with working memory, processing in the hippocampus , and long-term memory, as well as the integration of verbal expression with emotions. Other DLPFC deficits can manifest as a lack of spontaneity and affect flat rather than negative , and attention deficit—due to an inability to maintain sufficient attention to see a task through to completion. In obsessive—compulsive disorder which we will consider separately in a later section the DLPFC plays an important role in strengthening attentional skills to momentarily break the compulsion circuit and give the orbitofrontal cortex a chance to inhibit the runaway activation of the amygdala.
As with many brain regions, there are significant hemispherical differences within the dorsolateral prefrontal cortex , the left DLPFC being associated with approach behaviours and the right with more avoidant behaviours. The ventromedial prefrontal cortex helps us make decisions based on the bigger picture gathered from connections to the amygdala , temporal lobe, ventral segmental area, olfactory system, and the thalamus.
Ventromedial prefrontal cortex vmPFC. This part of the PFC helps us make decisions based on the bigger picture gathered from connections to the amygdala , temporal lobe, ventral segmental area, olfactory system, and the thalamus. It is very well connected, receiving and sending a lot of information that influences many brain regions, including the amygdala. It is also vital for personal and social decision making and the ability to learn from our mistakes.
Our capacity to make judgements and allow our emotions to assist in decision making is mediated by this region of the brain. Activation of the vmPFC is also associated with courage, suppression of negative emotions, compassion, shame, and guilt. Matt Dahlitz has done so much with The Neuropsychotherapist journal and this book takes a next step. It is an excellent resource. It truly is exactly what it says on the cover and provides engaging discussion on the pathology of oft-encountered disorders and their brain basis together with insights into how awareness of the neuroscience underpinning effective therapy can guide a therapist.
Beautifully illustrated and filled with cutting edge understanding of the interface of brain, body, mind, mental illness and psychotherapy, I can highly recommend this book. Simply the fact that mindfulness necessarily activates the PFC, developing better PFC- to limbic control mechanisms and like anything that is practiced it becomes more rstablished. PFC activation becomes an easier default when there is a need to control emotional responses — in other words affect regulation becomes easier — enhanced.
You need a hug? A Dedication. The Frontal Lobes at a Glance. A Closer Look at the Frontal Lobes. Inside the Black Box. References and Notes. DecisionMaking Styles and the Frontal Lobes.