3PFK, korteksin en çok bağlantıya sahip bölgesidir PFK bölgelerinin dış uyaranların işlendiği duyu alanları ile bağlantıları vardır (işlenmiş dış uyaran bilgisi)PFK bölgelerinin emosyonel durumların gözlendiği ve düzenlendiği bölgeler ile bağlantıları vardır (içsel bilgi)PFK bölgelerinin motor işlevlerden sorumlu olan bölgeler ile bağlantıları vardırPFK konumu ve bağlantıları dış uyaranların içsel bilgiler ile entegre edilmesine olanak sağlayacak şekildedir
4Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press The prefrontal cortex has expanded over mammalian and primate evolution. A greatly enlarged prefrontal cortex is a distinctively human and primate feature.According to Brodmann (1909), the prefrontal cortex accounts for 29% of total cortex in humans, 17% in the chimp, 11.5% in the macaque, and 3.5% in the cat.While whales and dolphins have large brains, it is the parietal rather than frontal cortex that has expanded in these mammals.Cognition, Brain and Consciousness: An Introduction to Cognitive NeuroscienceEdited by Bernard J. Baars and Nicole M. Gage2007 Academic Press
5Prefrontal cortex can be divided into lateral (side), medial (midline), ventral (bottom), and dorsal (top) regions. The lateral division divides into dorsal and ventral halves separated by a major horizontal fold, the inferior lateral sulcus
6DorsolateralInput mainly from medial, dorsolateral cortical areas. (somatosensory, visuospatial information)LateralInputs mainly from ventrolateral and ventromedial cortical areas (auditory, visual pattern information)
7The dorsomedial thalamic nucleus is a point of convergence, the ‘summit’ of the integration occurring within the specific thalamic nuclei.
8The Frontal CortexConfers emotional meaning (semantic content) onto objects in the worldEmotional salience (attachment)Seat of the Self and PersonalityLove, Morality, Decency, Responsibility, SpiritualityConscious “choice”
9Prefrontal cortex Effortful Control: Involves explicit processing Delay of gratificationInhibition of dominant responses (overlearned or innate); e.g., turning your head away from a light stimulus (anti-saccade); not peeking at a present for a childPay close attention to detail (= focused attention)Persevere in unpleasant tasks
10ventro-medial Prefrontal Cortex Damasio A, Bechara A: research on patients with vmPFC lesions“Myopia for the future,” cognitive impulsiveness- prefer immediate but disadvantageous rewardsover rewards that are delayed but advantageous in the long run- guided primarily by immediate prospects and insensitive to pos or neg future consequences- deny or are unaware of the problem (analogous to “denial”)vmPFC patients are similar to Substance Abusing pts
11Working memory isThe ability to keep information in your mind for a short period of time (seconds) and be able to use this information in your thinking.
12Working memory is closely linked to the critical role the frontal lobes play in the temporal organization of behavior and controlling the proper sequence in which various mental operations are enacted.Since the selection of information required to solve the problem at hand is made in the frontal lobes, they must ‘know’, at least roughly, where in the brain the information is stored.
14Executive systemAn organism’s ability to guide its behavior by internal representations -- the formulation of plans and then guiding behavior according to those plans2. An organism’s ability not only to guide its behavior by internal representations, but also the capacity of ‘switching gears’ when something unexpected happens
20Frontal Lob Anatomisi Motor Korteks Primer Premotor Suplementer Frontal göz alanıBroca konuşma merkezi
21Motor korteks Primary motor area Premotor area Supplementary B4B6Central sulcusSupplementarymotor area(medially)Frontal eye fieldB 8Lateral sulcus/Sylvian fissureMotor speecharea of BrocaB 44, 45
22Prefrontal KorteksBütün kaynaklardan (duyusal sistemler, limbik sistem, subkortikal yapılar) gelen bilgileri toplar, bütünleştirir, formülleştirir, uygular, denetler, değişiklikler yapar ve yargılar. Sonuçta ortaya çıkarılacak davranışa karar verir
23Prefrontal korteks 2- Medial prefrontal korteks 1- Dorsal prefrontal korteks2- Medial prefrontal korteks3- Ventral orbitofrontal korteksDış dünyayla ilgili algılar, dünya hakkındaki düşünceler, bedenin kendisindeki olaylar bu bölgelerden gelen bilgiler aracılığı ile oluşturulur
24Ventromedial Prefrontal Cortex and Somatic Markers Somatic marker “biasing signals” are regulated by VM premotor cortex; these signals help regulate decision-making in uncertainty
25The somatic marker hypothesis posits that deficits in emotional signalling (somatic states) lead to poor judgment in decision-making, especially in the personal and social realms. Similar to this hypothesis is the concept of emotional intelligence, which has been defined as an array of emotional and social abilities, competencies and skills that enable individuals to cope with daily demands and be more effective in their personal and social life. Patients with lesions to the ventromedial (VM) prefrontal cortex have defective somatic markers and tend to exercise poor judgment in decision-making, which is especially manifested in the disadvantageous choices they typically make in their personal lives and in the ways in which they relate with others. Furthermore, lesions to the amygdala or insular cortices, especially on the right side, also compromise somatic state activation and decision-making. This suggests that the VM, amygdala and insular regions are part of a neural system involved in somatic state activation and decision-making.
26the prefrontal cortex is an ability to deal with cognitive novelty. The dark areas in this composite brain image show regions that control novel actions, but which lose activity when the identical actions becomes automatic with practice.
28Ayna NöronlarClass of neurons in F5 (BA 44) and ventral premotor cortex that discharge both:when animal performs object-directed actionwhen animal observes OD action in othersSubset appear to be “communicative” motor neuronsFunctionsImitationAction understandingPotentially important for understanding social learning and imitation effects
29To do that, you must have the capacity to form an internal representation of the other person’s mental life -- or as it is called in cognitive psychology, to have a theory of mind. Your actions will be chosen under the influence of your theory of the other person’s mind formulated in your own mind.This makes the executive processes required for success in an interactive environment much more complex than those required in a solitary situation.
33Ingvar (1985) coined the phrase ‘memories of the future‘ referring to one of the most important functions of advanced organisms: making plans and then following the plans to guide behavior.Unlike primitive organisms, humans are active, rather than reactive, beings. We are able to form goals, our visions of the future. Then we act according to our goals.In order to guide our behavior in a sustained fashion, these mental images of the future must become the content of our memory: thus the ‘memories of the future’ are formed
35Orbito-frontal cortex : processing site fpr learmed associations between affective stimuli and their reinforcement value (reward/punishment), thus playing a crucial role in subsequent decision making; role is in repeated learning; impulse control and social cognitive skills including theory of mind tasksSevere lesions: oblivious to social and emotional cues, poor decision making capacity, sociopathic tendencies, loss of fear regulation: inhibition of inappropriate thoughts and actions.Anterior cingulate: experience of emotion, helps to focus attention and may be required to properly integrate emotion and cognitionto tune in on one’s own thoughts
36Orbitofrontal cortex inhibits hypothalamus, the area responsible for basic appetitive behaviors such as feeding, fighting, fleeing, and mating.
37The amygdala and orbitofrontal cortex influence autonomic and endocrine function via their connections with the brainstem and hypothalamus. He does not agree that “somatic states” generate emotions (i.e., James-Lange Theory or Damasio’s Somatic Marker Hypothesis) but rather thinks that these states prepare the animal for different types of action including fight, flight, feeding and sex.The amygdala and orbitofrontal cortex can influence the selection of behavioral actions through 1) brain systems that operate implicitly and have been present in primates and some other mammals for millions of years, such as the ventral striatum and other parts of the basal ganglia; and in humans 2) higher cortical systems that can process multiple “If..the” statements to implement a plan to obtain a reward or avoid punishment. Deferring action may be part of the plan.
38Lesions to the ventral frontal lobes can result in difficulties altering behavioral strategies in response to a change in environmental reinforcement contingencies (Rolls, 2000)Damage is associated with changes in social behavior (disinhibition) and problems identifying vocal and facial emotional expression (Rolls, 2000; Phillips, 2003)Studies described later indicate that bilateral orbitofrontal lesions cause more severe problems with social and emotional functions, but that unilateral lesions cause some subtle difficulties. Problems also appear to be more severe in patients with more diffuse damage (e.g., caused by head trauma or stroke versus surgical lesions)Results of studies are inconsistent regarding whether the laterality of the lesion is important in symptom presentation (Honak et al., 2003; Tranel et al., 2002.
39Thayer and Lane (2000) propose that the ACC serves as a point of integration for viseral, attentional and affective information that is critical for self-regulation and adaptability.The ACC seems to be associated with the conscious allocation of attention (I.e. including inhibition of irrelevant informaton).The ventral and rostral regions of the ACC are associated with affective, motivated and autonomic behavior; whereas the dorsal region is associated with response selection as well as pain
40PFK alt alanları Dorsolateral: 9,46 Ventrolateral: 44,45,47 Orbitofrontal: 10,11- Anterior: 8, 10- Medial: 11, 25, 32
431. Motor Döngü SMA, Premotor,Motor Putamen VL Globus Pallidus Dil1. Motor DöngüSMA,Premotor,MotorPutamenVL GlobusPallidusVL, VA, CMThalamusHypo-thalamusSuplementar Motor & Premotor: motor programların planlanması, başlatılması ve depolanması, hareketlerin ince ayarıMotor: hareketin plana göre yönetilmesiKonuşma
452. Okulomotor Döngü Frontal Eye Field Central Caudate DM Globus PallidusSubstantiaNigraVA, MDThalamusİstemli tarayıcı göz hareketleriBağımsız görsel uyaranlar
463. Dorsolateral Prefrontal Döngü DLCaudateDM GlobusPallidusSubstantiaNigraVA, MDThalamusYönetsel işlevler: motor planlama, dikkati yönlendirme, bilişsel setleri değiştirmeDikkat ve işlem belleği aracılığı ile davranışı monitorize etme ve uyumlandırma
47Dorsal prefrontal korteks İşlem belleği ve motor planlama ile ilişkilidir.
48dorsal system (incl. hippocampus, dorsal ACC & dorsolateral PFC) Dorsal ACC: involved in target & motor response selection, error detection & performance monitoring, novelty detection, motivational valence assignment & reward based decision makingif not working properly likely difficulty in becoming motivated or interested in new things & looking forward to rewards
49DLPFC: things held in mind here, working memory, with volition; integrating the outcome of two or more separate cognitive operations in pursuit of a higher behavioural goal” in addition to executive function at an abstract level;Ventromedial PFC: involved in extinction of fear responses
504. Lateral Orbitofrontal Döngü VMCaudateDM GlobusPallidusSubstantiaNigraVA, MDThalamusInfero-lateral prefrontalOrbito-frontalDuygusal yaşam ve kişilik yapısıUyarılma, motivasyon, duygu, çeldirici uyaranların baskılanmasıBilinçlilik, ödül sistemiSosyal biliş
51Frontal lobe syndromes - Orbitofrontal The orbitofrontal syndrome is in many ways the opposite of dorsolateral syndrome: the patients are behaviorally and emotionally disinhibited. Their affect is rarely neutral, constantly oscillating between euphoria and rage, with impulse control ranging from poor to non-existent.Their ability to inhibit the urge for instant gratification is severely impaired: they do what they feel like doing, when they feel like doing it, without any concern for social taboos or legal prohibitions.
52orbitofrontal cortex (OFC): centre for sensory integration, modulation of autonomic reactions & anticipation in learning, prediction & decision-making for emotional and reward-related behavioursreward value & expected reward value, & even subjective pleasantness of food & other reinforcers are represented in OFC
55Prefrontal CortexInvolved with intellect, cognition, recall, and personalityContains working memory needed for judgment, reasoning, persistence, and conscienceDevelopment depends on feedback from social environment
56Attentional functions might may be influenced bu the frontal lobes as well as an ‘attentional loop’ combining frontal, brainstem, and posterior cortex.Breakdown anywhere along this loop may interfere with attention, thus producing a form of attention deficit disorder. Thus, any damage to the prefrontal cortex or its pathways may result in attentional impairment.
57Working memory is closely linked to the critical role the frontal lobes play in the temporal organization of behavior and controlling the proper sequence in which various mental operations are enacted.Since the selection of information required to solve the problem at hand is made in the frontal lobes, they must ‘know’, at least roughly, where in the brain the information is stored.
58Dikkat İşlevi Uyaranın keşfedilmesi (odaklanma) Saptanan uyaranın kodlanması veya işlenmesiİlgili uyarana dikkat devam ederken diğer uyaranların filtre edilmesiUygun olduğunda dikkatin kaydırılmasıİstemsiz kaymaların engellenmesi (distraktibilite)Giren bilgiye bir yanıt oluşturulması
61Yönetsel işlevler Dorsolateral PFK (yönetsel) Caudate v Ventromedial PFK andSingulat(değerlendirici)vCaudatePutamen
62Difficulties with academic performance are due to weaknesses in the core executive processes: Problems with any process will affect learning:Planning & Goal SettingSelf-Monitoring & CheckingOrganizingPrioritizingShifting FlexiblyMemorizingFrom: Meltzer, 2007
63Yönetsel işlevleriBedenden ve dış dünyadan gelen duyuları birleştirmekKendine yönelik konuşmanın içselleştirilmesiMotivasyon ve uyanıklık durumuYeniden yapılandırma
64Yönetsel İşlevleri Gelecekteki eylemin sonuçlarını öngörebilme Uygun motor tepkiyi seçmek, karar vermeYeni sorunlara çözüm üretmeDavranışı planlamak ve düzenlemeDavranışların zaman içindeki ardışıklığını sağlama
65Yönetsel işlevleri Duyguları kontrol etme Yargılama Soyutlama Dürtüleri denetlemeKendilik kavramı, kimlik duygusuRuhsallık (Spirituality)
66The orbitofrontal cortex is not the only part of the frontal lobes linked to socially mature behaviors: the anterior cingulate cortex (ACC) is closely linked to the prefrontal cortex and has been linked to emotion and regulation of distress.
67The ACC appears to be active during situations of social rejection: in a task designed to evoke the sense of social rejection (as felt by a child in a ball game), the frontal part of the cingulate ‘lights up’.
69Motor KorteksPrimer motor korteks hasarları: Karşı taraf motor işlevleri / tonus; kuvvetPremotor korteks hasarları: Karşı taraf proksimal kaslarda orta derecede güçsüzlükSuplementer motor hasarlarda mutizm, akineziFrontal göz alanı destrüktif hasarlarında gözler hasar tarafına, irrite edici hasarlarda göz karşı tarafa deviye olur.Broca konuşma merkezinin hasarlarında motor afazi
71Attentional functions might may be influenced bu the frontal lobes as well as an ‘attentional loop’ combining frontal, brainstem, and posterior cortex.Breakdown anywhere along this loop may interfere with attention, thus producing a form of attention deficit disorder. Thus, any damage to the prefrontal cortex or its pathways may result in attentional impairment.
72orbital pathway Arousal changes: Adynamia or agitation: Likely due to orbital frontal damage, usually extensive.ACA territory lesions and adynamiaLow motivation; decreased initiative: Probable loss of reward/motivation due to decreased striatal inputReduced insight. Concept of “theory of mind” recent data on role of anterior medial frontal gyrus in TOM, may underlie deficits in insight.Control of attention and selection in anterior cingulate damage.Reduced impulse control; deficits in response inhibition in OF lesions
73Dorsal yolEye motor control deficits: Frontal Eye fields direct EM based on spatial information from PLWorking memory impairment: Lesions in DLPFC ; also single unit studies in monkey PFC; delayed component; manipulation component; response selection componentReasoning, problem solving deficits; poor “fluid” reasoningIntegration of informationPerseveration: 46/44 direct stimulation produces perseveration deficitsAppears separate from WM
74Dorsolateral- Spatial delayed response- Spatial delayed alternation task- No deficit in discriminationLateral- Object alternation- Delayed non-match to sampleOrbital- Deficits in olfactory, taste, visual and auditory discrimination- Discrimination reversal learning.
75Lateral Prefrontal Region (8,9,46) Lesions in this region produce impairment in a variety of “executive” skills that cut across domains. Some degree of material-specificity is present, but relatively weak.A) Fluency: impaired verbal fluency (left) or design fluency (right)B) Memory impairments: defective recency judgment, metamemory defects, difficulties in memory monitoringC) Impaired abstract concept formation and hypothesis testingD) Defective planning, motor sequencingE) Defective cognitive judgement and estimation
76Frontal Operculum (44,45,47)A) Left: Broca’s aphasiaB) Right: ‘expressive’ aprosodiaSuperior Mesial (mesial 6, 24)A) Left: akinetic mutismB) Right: akinetic mutismBilateral lesions of mesial SMA (6) and anterior cingulate (24) produce more severe form of akinetic mutism
77Prefrontal alanların lezyonunda Genel zeka, algı, uzun süreli bellek sağlam kalırken, günlük yaşamı sürdürmek için gerekli olan plan yapma ve günlük aktiviteleri düzenleme becerisi bozulur.Hareketi başlatma sorunlarıZihinsel ve davranışsal değişiklikler yapabilme zorluklarıDurdurma sorunlarıKişisel farkındalıkta yetersizlikSomut ve açık tavır
78Dorsolateral prefrontal hasar Dikkatte azalma, çelinebilirlikte artmaİlgi azlığıDuygusal tepkide azalmaYönetsel işlevlerde bozulmaİşlem belleğinde ve anımsamada bozulmaPerseverasyon
79Most common symptoms of dorsolateral syndrome are perseverative behavior, field-dependent behavior, and mental rigidity. These patients often typically have a flat affect: an emotionless voice and facial expression.Perseverative behavior: a patient will have an inability to initiate behaviors. Once behaviors are initiated, the patient is equally unable to terminate or change the behavior.
80Field-dependent behavior highlights the distractibility seen with frontal lobe injury. A patient will drink from an empty cup, put on a jacket belonging to someone else, or scribble with a pencil on the table surface, merely because the cup, jacket, and pencil are there, even though these actions make no sense.
81DorsolateralMental rigidity is a frequent symptom of frontal lobe injury. Mental flexibility is a critical aspect of frontal lobe processing. These patients will show an inability to change their mental state or approach to a problem.The Wisconsin Card Sorting task is frequently used to asses mental rigidity in frontal lobe patients.
82Dorsomedial prefrontal hasarlarda Uyanıklılık ve farkındalıkta azalma,Apati, yavaşlamaMotivasyon azlığıSpontan davranışta azalmaAmaca yönelik davranışta azalma
83Anterior singülat hasarı Akinetic MutizmApatikSpontan konuşma yokluğuAynı heceyi tekrarlamaDuygusal tepki yokluğu
85OrbitofrontalThe orbitofrontal syndrome is in many ways the opposite of dorsolateral syndrome: the patients are behaviorally and emotionally disinhibited. Their affect is rarely neutral, constantly oscillating between euphoria and rage, with impulse control ranging from poor to non-existent.Their ability to inhibit the urge for instant gratification is severely impaired: they do what they feel like doing, when they feel like doing it, without any concern for social taboos or legal prohibitions.
86Involved in social and emotional functioning Damage produces: DisinhibitionHyperactivityEmotional labilityAggressivenessReduced self-awareness