Frontal lobe and cognitive development.
Aging, Neuropsychology, and Cognition The study sought to examine the role of frontal lobe functioning in focal prospective memory (PM) performance and its relation to PM deficit in older adults. PM and working memory (WM) differences. Psychological Bulletin. Vol. sistently been found to reveal age-related performance decline as early aging is that cognitive functions supported by the prefrontal cor- . neuropsychology has indicated that the prefrontal cortex is also. radation in the frontal lobes occurs with aging (Anderson &. Craik, ; West, ), and the are age-related changes in frontal functioning the primary, or sole, cause of .. Applied Cognitive Psychology, 20, Davidson, P., & Glisky.
The basis of 'higher-level' cognitive functions such as inhibition, flexibility of thinking, problem solving, planning, impulse control, concept formation, abstract thinking, and creativity often arise from much simpler, 'lower-level' forms of cognition and behavior.
Thus, the concept of executive function must be broad enough to include anatomical structures that represent a diverse and diffuse portion of the central nervous system.
Psychologists Don Norman and Tim Shallice have outlined five types of situations in which routine activation of behavior would not be sufficient for optimal performance: A prepotent response is a response for which immediate reinforcement positive or negative is available or has been previously associated with that response. For example, on being presented with a potentially rewarding stimulus, such as a tasty piece of chocolate cakea person might have the automatic response to take a bite.
However, where such behavior conflicts with internal plans such as having decided not to eat chocolate cake while on a dietthe executive functions might be engaged to inhibit that response. Although suppression of these prepotent responses is ordinarily considered adaptive, problems for the development of the individual and the culture arise when feelings of right and wrong are overridden by cultural expectations or when creative impulses are overridden by executive inhibitions.
In the s, the British psychologist Donald Broadbent drew a distinction between "automatic" and "controlled" processes a distinction characterized more fully by Shiffrin and Schneider in and introduced the notion of selective attentionto which executive functions are closely allied. Inthe US psychologist Michael Posner used the term "cognitive control" in his book chapter entitled "Attention and cognitive control".
For example, Posner proposed that there is a separate "executive" branch of the attentional system, which is responsible for focusing attention on selected aspects of the environment. Psychologist Alan Baddeley had proposed a similar system as part of his model of working memory  and argued that there must be a component which he named the "central executive" that allows information to be manipulated in short-term memory for example, when doing mental arithmetic.
This is due to the delayed maturation of the prefrontal cortexwhich is not completely myelinated until well into a person's third decade of life.
Development of executive functions tends to occur in spurts, when new skills, strategies, and forms of awareness emerge. These spurts are thought to reflect maturational events in the frontal areas of the brain. Cognitive flexibility, goal setting, and information processing usually develop rapidly during ages 7—9 and mature by age Executive control typically emerges shortly after a transition period at the beginning of adolescence.
Yet, it is during adolescence when the different brain systems become better integrated. At this time, youth implement executive functions, such as inhibitory control, more efficiently and effectively and improve throughout this time period. Adulthood[ edit ] The major change that occurs in the brain in adulthood is the constant myelination of neurons in the prefrontal cortex.
These skills begin to decline in later adulthood. Working memory and spatial span are areas where decline is most readily noted. Cognitive flexibility, however, has a late onset of impairment and does not usually start declining until around age 70 in normally functioning adults. Models[ edit ] Top-down inhibitory control[ edit ] Aside from facilitatory or amplificatory mechanisms of control, many authors have argued for inhibitory mechanisms in the domain of response control,  memory,  selective attention,  theory of mind  emotion regulation,  as well as social emotions such as empathy.
In these new situations, attentional control will be a crucial element to help generate new schema, implement these schema, and then assess their accuracy. Self-regulatory model[ edit ] Russell Barkley proposed a widely known model of executive functioning that is based on self-regulation. Primarily derived from work examining behavioral inhibition, it views executive functions as composed of four main abilities.
A second component is the management of emotional responses in order to achieve goal-directed behaviors. Thirdly, internalization of self-directed speech is used to control and sustain rule-governed behavior and to generate plans for problem-solving.
Frontal lobe - Wikipedia
Lastly, information is analyzed and synthesized into new behavioral responses to meet one's goals. Changing one's behavioral response to meet a new goal or modify an objective is a higher level skill that requires a fusion of executive functions including self-regulation, and accessing prior knowledge and experiences.
According to this model, the executive system of the human brain provides for the cross-temporal organization of behavior towards goals and the future and coordinates actions and strategies for everyday goal-directed tasks. Essentially, this system permits humans to self-regulate their behavior so as to sustain action and problem solving toward goals specifically and the future more generally.
Mind and the Frontal Lobes: Cognition, Behavior, and Brain Imaging
Thus, executive function deficits pose serious problems for a person's ability to engage in self-regulation over time to attain their goals and anticipate and prepare for the future. While this model may broadly appeal to clinicians and researchers to help identify and assess certain executive functioning components, it lacks a distinct theoretical basis and relatively few attempts at validation. We assume that the PFC serves a specific function in cognitive control: They provide bias signals throughout much of the rest of the brain, affecting not only visual processes but also other sensory modalities, as well as systems responsible for response execution, memory retrieval, emotional evaluation, etc.
The aggregate effect of these bias signals is to guide the flow of neural activity along pathways that establish the proper mappings between inputs, internal states, and outputs needed to perform a given task.
Executive functions - Wikipedia
In the case of confabulation, someone gives false information while maintaining the belief that it is the truth. In a small number of patients, uncharacteristic cheerfulness can be noted. This effect is seen mostly in patients with lesions to the right frontal portion of the brain. Similarly, those who experience Capgras syndrome after frontal lobe damage believe that an identical "replacement" has taken the identity of a close friend, relative, or other person and is posing as that person.
This last effect is seen mostly in schizophrenic patients who also have a neurological disorder in the frontal lobe. During agingDNA damage is markedly increased in the promoters of the genes displaying reduced expression in the frontal cortex. In cultured human neurons, these promoters are selectively damaged by oxidative stress. A frontal lobotomy sometimes called frontal leucotomy successfully reduced distress but at the cost of often blunting the subject's emotions, volition and personality.
The indiscriminate use of this psychosurgical procedure, combined with its severe side effects and a mortality rate of 7. The frontal lobotomy has largely died out as a psychiatric treatment. More precise psychosurgical procedures are still used, although rarely. They may include anterior capsulotomy bilateral thermal lesions of the anterior limbs of the internal capsule or the bilateral cingulotomy involving lesions of the anterior cingulate gyri and might be used to treat otherwise untreatable obsessional disorders or clinical depression.
Theories of function[ edit ] Theories of frontal lobe function can be separated into four categories: Stuss suggests a differentiation into two categories according to homogeneity and heterogeneity of function.
However, further research will show if a unified theory of frontal lobe function that fully accounts for the diversity of functions will be available. Other animals[ edit ] Many scientists had thought that the frontal lobe was disproportionately enlarged in humans compared to other primates.