Intelligence, Personality, and Morality PDF

Intelligence, Personality and Morality  Frontal Lobes 1 Intelligence is an umbrella term that encompasses many abilities, including the capacities to reason, to plan, to solve problems, to think abstractly, to comprehend ideas, to use language, and to learn. Personality...

Intelligence, Personality and Morality  Frontal Lobes 1 Intelligence is an umbrella term that encompasses many abilities, including the capacities to reason, to plan, to solve problems, to think abstractly, to comprehend ideas, to use language, and to learn. Personality has to do with individual differences among people in behavior patterns, cognition and emotion. Morality is the differentiation of intentions, decisions, and behaviors between those that are good or right Evidence suggests that intact frontal and those that are bad or wrong. lobes (with participation from other non-frontal areas) are necessary to express intelligence, personality and morality.  Frontal Lobes 2 Silent lobes to the organs of civilization The importance of the frontal lobes for intelligence, personality and morality has only been recently appreciated. Unlike the busy sensory processes that occur in the other lobes, the frontal lobes were not easily linked to any single, or set of, easily defined function(s) and were known as ‘the silent lobes’. “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 … A child in his intellectual capacity and manifestations … His mind was radically changed, so decidedly that his friends and acquaintances said he was ‘no longer Gage’.” [Dr. Harlow, description of Phineas Gage’s recovery in 1848 from the passage of an iron bar through his head (i.e., left frontal lobe)].  Pre-Frontal Lobes 1 The concepts of intelligence, personality and morality are now intimately linked to the function of the frontal lobes. However, the frontal lobes sub-serve other functions (e.g., motor control), and other areas participate in these functions (i.e., the frontal lobes are necessary but not sufficient). Frontal lobe Premotor  The prefrontal lobes express Prefrontal cortex Motor lobe intelligence, personality and morality. cortex  Pre-Frontal Lobes 2 Three possible ways to define pre- frontal cortex: non-motor areas granular frontal cortex (layer 4 is present – thalamic input) projection zone of the dorsal- medial nucleus of the thalamus. The DM nucleus is critical for gating of information to and from prefrontal cortex. This feedback contributes to selective attention, enhanced Dorsal-medial responses for relevant stimuli nucleus and suppressed responses for distractive stimuli.  Phylogeny of the Pre-Frontal Lobes 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. Other animals have larger brains (e.g., whales and dolphins); however, it is the parietal rather than frontal cortex that has expanded in these mammals.  Divisions of the Pre-Frontal Lobes Prefrontal cortex is usually divided into lateral (side) and medial (midline) regions, and dorsal (top) and ventral (bottom) regions. The part of the ventromedial prefrontal cortex that overlies the eyes is sometimes called the orbitofrontal cortex. The exact borders of each region are ill-defined. DMPFC VMPFC DLPFC – dorsolateral prefrontal cortex VLPFC – ventrolateral prefrontal cortex APFC – anterior prefrontal cortex DMPFC – dorsomedial prefrontal cortex VMPFC=OFC – ventromedial prefrontal cortex  Connections of Pre-Frontal Cortex Prefrontal cortices (shown inside the yellow box to the right) are reciprocally interconnected and receive projections from most, if not all of the distinct functional units of the brain. The DLPFC receives inputs from the where pathways out of the sensory cortices; the VLPFC receives inputs from the what pathways.  Intelligence Psychologists have long debated how best to conceptualize (and to measure) intelligence. Questions include: how many types; and how represented in the brain. The oldest theory suggests a single underlying construct, called the general intelligence factor (g). This is sub- divided into: fluid intelligence, which refers to the ability to learn new ways of solving problems/performing activities; and crystallized intelligence, which refers to accumulated knowledge. Other theories argue for many distinct intelligences, including socio-emotional. This idea has been influential in the field of education (i.e., teach to an individual’s strengths).  Neurobiology of Intelligence Modern intelligence assessments (e.g., the Wechsler Adult Intelligence Scale or WAIS-IV) assess several aspects of intelligence (e.g., verbal comprehension; Disability Gifted visuospatial reasoning; working memory). Totals scores are compared to normative, age-matched samples to calculate a standardized IQ score. medial view Neuroimaging studies suggest that IQ is lateral view related to the size of, neural activity within, and communication efficiency within various brain networks. Two major networks involving pre-frontal cortex are the task-positive (blue) and the default mode (purple) networks. Higher IQ corresponds to greater anti-correlation between these two networks (when one is more active the other is less so).  Task Positive Network 1 The Task-Positive Network is thought to be important for problem solving, focusing of external-directed attention, making decisions, and control of action. It supports fluid intelligence. d Dorsolateral prefrontal cortex (DLPFC) forms plans of action (inputs from PPC - dorsal streams and VLPFC-ventral streams; outputs to secondary motor cortex) stores short-term memory (inputs from medial temporal lobe – MTL) directs top-down (endogenous) attention to accomplish its goals Posterior parietal cortex (PPC) Bottom-up (exogenous) attention controller Note that lateral and medial views of the brain (inputs from dorsal streams; novelty) are superimposed here (DLPFC only found on lateral surface). Dorsal anterior cingulate cortex (dACC) activity monitor – flags errors in execution  Task Positive Network 2 Much of the experimental evidence for the function of neural structures in the task- positive network comes from laboratory tests such as the Wisconsin Card Sorting and the Stroop tasks. In the WCST, a number of stimulus cards are presented to the participant. The participant is told to match cards, but not how to match them (e.g., color, number, shape); however, he or she is told whether a particular match is right or wrong. The test is how the subject responds when the rule is changed unexpectedly (test of the DLPFC). In the Stroop task, subjects are asked to vs vs name the ink color that color words are printed in when the ink color and word meaning are the same (for example the word “red” in red ink) or conflict (“red" in yellow ink) (test of the dACC).  Default Mode Network The Default Mode Network plays a central temporo role in social cognition, emotional self- lateral view -parietal junction awareness, and moral decision making. It is very active when the brain is at “rest” or mind is “wandering”. It supports socio- emotional and crystallized intelligence. Dorsomedial prefrontal cortex (DMPFC) “reads” the mental states of others, such amygdala hippocampus as their beliefs, desires, and intentions. Called theory of mind or mentalizing medial view Social cognition DMPFC Ventromedial prefrontal cortex (VMPFC) including amygdala: emotional control with temporal-parietal junction: morality Hippocampus + Posterior Cingulate Cortex posterior cingulate Papez circuit: episodic memory cortex VMPFC  Personality 1 Personality refers to individual differences in characteristic patterns of thinking, feeling and behaving. The term personality trait refers to enduring personal characteristics that are revealed in a particular pattern of behavior in a variety of situations. Personality can be determined through a variety of tests (e.g., Rorschach Inkblot test) or by self- report (answering questions that asks participants to indicate the extent to which sets of statements or adjectives accurately describe their own behavior or mental state). Personality is usually broken into components called the Big Five.  Personality 2 Evidence suggests that four of the Big Five personality traits have distinct biological substrates (brain areas of larger volume; not exclusively in prefrontal cortex). (DLPFC) (VMPFC) Whether cause or effect of experience cannot be determined.  Morality 1 Morality is the differentiation of intentions, decisions, and behaviors Principle of Double Effect between those that are good or right Side effect vs Intentional harm and those that are bad or wrong. In its descriptive sense, morality refers to personal or cultural values, social mores or codes of conduct. It does not connote objective claims of right or wrong, but only refers to that which is considered right or wrong. Morals can differ from person to person, but some are widely held.  Morality 2 The brain areas involved when humans reason about moral issues have been investigated in many studies. Intuitive reactions to situations containing implicit moral issues arise from the (right) temporoparietal junction (TPJ), whereas the explicit making of moral right and wrong judgments coincides with activation in the VMPFC. TPJ mirror neurons, which fire when another person is observed doing a certain action, may play a role not only in action understanding, but also form the basis of empathy (an ability to TPJ recognize and vicariously experience what another individual is undergoing). VMPFC  Frontal Lobe Pathology Frontal lobe syndromes Damage to different parts of the frontal lobes produces clinically distinct syndromes. The most common types are dorsolateral and orbitofrontal. DLPFC syndrome Inability to act or change plans – loss of short-term memory – decreased attention (both top-down and bottom-up)  loss of fluid intelligence Apathetic, indifferent (not conscientious) OFC syndrome Wild emotional swings (euphoria to rage)  loss of emotional intelligence Egocentric, anti-social Abnormalities in moral judgements and behavior (lack of empathy)