prefrontal and anterior temporal lobes chapter 28

association cortex

cerebral cortex areas not directly involved with sensation or movement

prefrontal cortex divided into 3 areas

named for their anatomic location

-latereal prefrontal association cortex

-medial prefrontal association cortex

-ventral prefrontal association cortex

executive function

refers to a spectrum of abilities including working memory, judgment, planning, sequencing activity, inhibition, task switching, abstract thought, behavioral regulation, decision-making, and initiation

sustained attention

the ability to attend to an activity over time

selective/prioritization attention

the ability to attend to important information and ignore distractions

divided attention

the ability to attend to important information and disregard distractions

shifting/switching attention

the ability to change from one task to another

goal directed behavior (executive function): lateral prefrontal cortex

deciding on a goal

planning how to accomplish the goal

executing a plan

monitoring the execution of the plan

divergent thinking: lateral prefrontal cortex

the ability to conceive of a variety of possibilities

lateral prefrontal cortex lesion (impaired executive function)

-unable to set goals, plan, execute a plan, or monitor the execution of a plan

-have little effect on intelligence as measured by conventional intelligence tests

despite the ability to perform normally on conventional intelligence tests

people with prefrontal lesions function poorly in daily life because they lack goal direction and behavioral flexibility

medial prefrontal association cortex

-Involved in emotions, self-awareness, and motivation

-Identifies emotional stimuli and generates and perceives emotions

-Perceives others' emotions and makes assumptions about what other people believe and their intentions

emotion

is short-term subjective experience

medial prefrontal association cortex lesions

-cause apathy and lack of emotions and insight

-people report not feeling an emotions

-abnormal processing here (with BG and thalamus) impairs understanding of other's emotions, beliefs, and intentions

the emotion loop

-involves multiple brain areas

-links emotion, cognitive, and motor systems

-involved in reward-seeking behavior; concerned with finding pleasure

regulating emotions

-involves multiple brain areas

-loss of normal regulation of emotions causes emotional lability

emotional lability

abnormal, uncontrolled expression of emotions

3 aspects of emotional lability

-abrupt mood shifts

-involuntary, inappropriate emotional expression in the absence of subjective emotion

-emotion is triggered by nonspecific stimuli unrelated to the emotional expression

motivation

a reward seeking and an avoidance seeking pathway

-ventral striatum lesions cause behavioral disturbances

motivation: reward seeking pathway

reward pathway comprises dopamine neurons

dopamine

the motivation neurotransmitter all natural stimuli that reinforce behavior and all drugs of abuse increase dopamine in the ventral striatum

addiction

loss of behavioral control in response to a stimulus combined with the continued use of a substance, regardless of the negative consequences

motivation: avoidance seeking pathway

People can also be motivated to avoid undesired outcomes

ventral prefrontal association area

connects with areas regulating mood and affect

-part of our decision-making process involves imaging consequences and then attending to resultant emotional signals

for people with lesions in the social behavior loop

poor judgement and defective social intelligence cause severe problems in social function, employment, interpersonal relationships, and social status

thoughts and emotions

influence the functions of all organs

3 systems create stress response

-somatic nervous system

-autonomic nervous system

-neuroendocrine system

neurologic/psychiatric signs and symptoms

-delirium

-delusions

-hallucinations

-mania

-depression

-anxiety

-obsessive compulsive though and behaviors

-post traumatic stress disorder (PTSD)

-somatic symptom disorder

-autism spectrum disorders

-bipolar disorder

-schizophrenia

delirium

a transient mental disorder with a relatively rapid onset, a course that typically fluctuates, and is of brief duration (hours to weeks, typically days)

delirium symptoms

-reduced ability to maintain attention to external stimuli and to appropriately shift attention to new external stimuli, and disorganized thinking as manifested by rambling, irrelevant, or incoherent speech

-acute onset

-level of consciousness affected

delusions

are false beliefs, despite evidence to the contrary

hallucinations

sensory perceptions experienced without corresponding sensory stimuli

mania

is excessive excitement, euphoria, delusions, and overactivity

-racing thoughts, a disregard for consequences, and energetic behaviors typify mania

depression

a syndrome of hopelessness and a sense of worthlessness, with aberrant thoughts and behavior

-frequently occurs in dementia, parkinsons disease, multiple sclerosis, epilepsy

depression is linked to

neurotransmitter and neural activity abnormalities rather than to structural abnormalities

-people with depression have reduced levels of serotonin metabolites in their cerebrospinal fluid

anxiety

-the feeling of tension or uneasiness that accompanies anticipating danger

-autonomic system is overactive, skeletal muscles are tense, and the person is excessively alert

panic disorder

an episode of intense fear that begins abruptly and lasts 10-15 minutes

symptoms of panic disorder

-pounding heart

-rapid heart rate

-sweating

- feeling of choking

- difficulty breathing

-nausea

-feeling faint or light headed

-fear of fainting, going crazy, or dying

obsessive-compulsive disorder

characterized by persistent upsetting thoughts and the use of compulsive behavior in response to the obsessive thoughts

post traumatic stress disorder

-can develop in survivors of war, physical and sexual assault, abuse, accidents, disasters, and other serious trauma

people with PTSD

re-experience the original event in flashbacks or nightmares, avoid stimuli linked to the trauma and are hyperaroused

somatic symptom disorder

the disorder is psychologic with the patient subconsciously generating the problem to avoid responsibilities or conflict, or to demand care and emotion support from others

autism spectrum disorders

characteristics of autism spectrum disorder include a range of impaired social skills, restricted interests, and repetitive behaviors

bipolar disorder

-formerly called manic depression

-causes extreme mood swings that include emotional highs and lows

-mood swings alter activity levels, judgement, behavior, thinking and sleep

schizophrenia

-is a group of disorders consisting of disordered thinking, delusions, hallucinations, lack of motivation, apathy, and social withdrawal

-executive function, including planning, goal-orientation, and behavioral inhibition are impaired

-poor working memory interferes with considering possible alternatives

traumatic brain injury

people show poor judgment, decreased goal directed behavior, memory deficits, slow information processing, attentional disorders, and poor divergent thinking