(8-31-22)
Anatomy of Behavior: a bedtime story for psychology students
Your brain: approximately 86 billion neurons,
approximately an equal number of non-neuronal cell,
possibly trillions of synapses,
20% of your body’s caloric matabolism,
Front Hum Neurosci. 2009; 3: 31.
Published online 2009 Nov 9. Prepublished online 2009 Aug 5. doi: 10.3389/neuro.09.031.2009
J Comp Neurol. 2016 Dec 15; 524(18): 3865–3895.
Published online 2016 Jun 16. doi: 10.1002/cne.24040
PNAS June 26, 2012 109 (Supplement 1) 10661-10668; first published June 20, 2012; https://doi.org/10.1073/pnas.1201895109
Lets start with some useful generalities:
- Your brain is so mild-boggling complex that even very useful models may, at some level, be deceptive and erroneous
- We understand much more about brain structure than brain function
- Most of the time you think with your whole brain: your brain works in an integrated way
- Your brain is conservative: structures may have been “re-purposed” to deal with new challenges our species faced over historical epochs
- Your brain shows a certain amount of redundancy: really important functions my be replicated in different ares and/or with different degrees of sophistication in different areas
- Your brain is an energy hog relative to the rest of your body: this suggests that neural activity contributed a significant evolutionary benefit but that benefit came at a cost which, among other things, your brain works to keep as low as possible
A very basic (over simplified) and useful understanding
- Luria: three brain areas: brain stem, subcortical, cortical
- Paul MacLean, the “triune brain”; Layer 1 (reptilian), Layer 2 (mammalian), Layer 3 (primate)
- Lisa Feldman Barrett (2020) vehemently rejects the triune brain notion (she doesn’t like Inside Out either), Seven and a Half Lessons About the Brain. NY: Houghlin, Mifflin, Harcourt.
- I. brain stem and mid-brain structures
- ascending (and descending) reticular systems (brain stem)
- arousal/(editing)
- (MacLean) mid-brain structures: basic life functions
- Cerebellum: refinement of motor control and coordination, some procedural learning
- arguably, even in the brain stem we see very basic information processing: orienting reflexes
- eat it (approach), flee from it (escape), ignore it
- ascending (and descending) reticular systems (brain stem)
- II. Limbic system(s) (sub-cortical)
- arousal/attention/(editing)
- biological drives (basic instincts)
- emotional behavior/reinforcement
- temperament and individual differences in personality (?)
- consolidation of verbal learning/memory
- information processing (a possible reflection of Kahneman’s system 1 [fast. automatic, instinctive, emotional, relies on heuristics, very efficient energy utilization])
- indirect regulation of autonomic function and hormone release
- sympathetic nervous system (SNS): response to arousing circumstances: “fight, flight, freeze stress response”; “four F’s–feeding, fight, fleeing, and sex”
- parasympathetic nervous system (PNS): calm, vegetative states
- Some important limbic structures:
- Thalamus: arousal, editing
- Hippocampus: consolidation of verbal (declarative) learning
- Amygdala: evaluates environmental stimuli with respect to threat; fear, anxiety, anger, disgust, pain; arousal
- Hypothalamus: regulates hormone and autonomic nervous systems
- Striatum and nucleus accumbens: reward circuit
- Ventral tegmental area: manufactures dopamine
- III. Cortex
- sensory unit: processing input
- posterior: temporal, parietal, & occipital lobes
- motor unit: executive functions, “pause and plan”
- thought is an action
- frontal area, frontal lobe: frontal cortex, rest of frontal cortex, premotor area, motor cortex
- expressive language (Broca’s area)
- arousal/attention/(editing)
- executive functions
- forming plans: abstract reasoning and problem solving
- executing plans
- verifying results
- Kahneman’s system 2 (slow, effortful, logical, deliberative, high energy utilization)
- “doing the hard thing when it’s the right thing” (Sapolsky, 2017)
- divisions of the frontal cortex
- prefrontal cortex: “the decider” (Sapolsky, 2017),
- dorsolateranl PFC: logical reasoning (wrong but useful, as are many simplistic heuristics), Mr. Spock, cost analysis
- ventromedical PRC: emotional reasoning (ditto above), Dr. McCoy (Deanna Troi in Next Generation)
- another model/view of the PRC:
- Dorsolateral PRC
- Dorsomedial PFC
- Ventrolateral PRC
- Ventromedial PRC
- Orbitofrontal PRC
- premotor area
- motor area (most posterior area, closeest to central sulcus)
- prefrontal cortex: “the decider” (Sapolsky, 2017),
- interesting trivial pursuit: the frontal cortex has a relatively unique type of neuron: von Economo neurons (spindle neurons), first thought to be unique to humans but also found in other primates, whales, dolphins, and elephants (all socially complex species). In humans only found in insula (gustatory and moral disgust) and anterior cingulate (empathy).
- another over simplistic (and possibly useful ) model of prefrontal functioning: Kelly McGonigal (2012) speaks of the prefrontal cortex having three regions:
- upper left prefrontal cortex specialized in “I will” power: “It helps you start and stick to boring, difficult, or stressful tasks” (p. 14)
- upper right prefrontal cortex specialized in “I won’t” power: “holding you back from following every impulse or craving” (p. 14)
- lower and middle of prefrontal cortex keeps track of your goals and desires, “I want”: motivation to take action and resist temptation; “remembers what you really want, even when the rest of your brain is screaming, ‘Eat that! Drink that! Smoke that!, Buy that!'” (p. 14)
- Arciniegas & Beresford (2001) discuss five major frontal-subcortical circuits: (this is the most anatomical correct discussion)
- motor (voluntary motor function)
- frontal eye fields (eye movements)
- dorsolateral prefrontal (executive function)
- lateral orbitofrontal (social intelligence)
- anterior cingulate (motivation and emotional experience)
- Bradshaw (2001) discuss, “a series of five semi-independent, parallel, frontal-subcortical circuits”
- skeletomotor circuit
- oculomotor circuit
- dorsolateral perfrontal circuit
- lateral obitofrontal circuit
- anterior cingulate circuit (important for maintaining drive and motivation)
- your author considers several areas of the cortex:
- Insula: posterior insula: awareness of bodily states, anterior insula: conscious repesentation of subjective states
- self of bodily self, pain, subjective feelings
- intrinsic motivation, empathy, feeling of self
- disgust, visceral and moral
- Prefontal cortex
- right PFC: “no-go” motivations; “behavioral activation system” (BAS)
- left PFC: “go motivations; “behavioral inhibition system” (BIS)
- Orbitofrohntal Cortex: reward-related processing, considering options, inhabiting inappropriate actions, delay of gratification
- Ventromedial Prefrontal Cortex: integrates affective-based information with social cues, social judgment
- Dorsolateral Prefrontal Cortex: decision making on basis of facts, self-control, social competence
- Anterior Cingulate Cortex: monitors conflicts, “top-down” executive control
- Insula: posterior insula: awareness of bodily states, anterior insula: conscious repesentation of subjective states
- class activity: the trolley problem
- The Trolley Problem (Do we sacifice 1 to save 5? Under what circumstances?)
- DLPFC (dorsolateral prefrontal cortex)
- VMPFC (ventromedial prefrontal cortex)
- Amygdala
- Greene: two moral minds (dual processing) (emotion and reasoning)
- emotions (automatic processing): VMPFC
- reasoning (manual processing): DLPFC
- He argues that moral emotons and other automatic processes work to enable cooperation within groups (putting Us above Me). This does no help with cooperation between different groups who differ in values/culture/gods (Us getting along with Them).
- He advocates Utilitarianism as a, “common currancy” for resolving Us versus Them issues (greatest good for the greatest number).
- This can be contrasted to Kant’s categorical imperative (people should never be used as a means to an end);
- or with T.M. Scanlon (1998) What We Owe to Each Other
- A “problem”/”issue”/”concern” with Greene’s solution: Huxley’s Brave New World
- This can be contrasted to Kant’s categorical imperative (people should never be used as a means to an end);
- sensory unit: processing input
- IV. Hormones and neurotransmitters
- hormones have a “lock and key” relationship with receptor cells in body
- hormones can affect the activity of particular proteins, turn certain genes on or off, alter the metabolism of cells, cause cells to grow, atrophy, devide, or die
- hormones usually affect the functions of target cells over the course of hours to day and cells throughout the body
- hormones can have relatively permanent organization affects during early development
- neurotransmitters have a “lock and key” relationship with receptor sites on dendrites or soma of the neuron they affect
- neurotransmitters affect the excitability of the postsynamptic neuron: decreasing (excitatory) or increasing (inhibiting) polarization
- neurotransmitter signaling occurs in milliseconds and only affects the neurons on the other side of synapes
- let us consider two hormones:
- Testosterone
- Testosterone is secreted by the testes as the final step in a Hypothalamic/pituitary/testicular axis (also by the adrenal glands in both males and females).
- Testosterone is commonly suspected as a hormonal cause of aggression
- among other animals, males produce the most aggression
- in every known human culture males produce the most violence (again, definitional issues arise)
- in nearly all specices, males have more ciculating androgens (testosterone and related hormones) than females
- male aggression is most common when testosterone levels are highest (adolescence and mating seasons among seasonal breeders)
- there are high levels of testosterone receptors in the amygdala and in its target sites
- castrate a male and levels of aggression decrease, give the castrated indivdual replacement testosterone and precastration levels of aggression return (Sapolsky, 2017)
- but
- some aggression remains even with complete removal of testosterone
- the more aggressive a male is prior to aggression, the more aggression continues
- aggression leads to increases in testosterone levels in males
- testosterone levels in an individual don’t reliably predict who will be aggressive (normal levels, different things occur with superphysiological dosing in athletes and body builders abusing anabolic steriods: aggression does go up here; but (again) it’s not random who does such dosing: abusers may have been predisposed to violence; and, superphysiological levels generate anxiety and paranoia, and the aggression may be secondary to those effects)
- so, what does Testosterone do?
- decreases empathetic mimicry in humans, makes people less adept at identifying emotions by looking at people’s eyes, and the faces of strangers activate the amygdala more
- increasses confidence and optimism, while decreasing fear and anxiety: “Testosterone makes people cocky, egocentric, and narcissistic” (Spaolsky, 2017, p. 103), boosts impulsivity and risk taking, “making people do the easier thing when it’s the dumb-ass thing to do.” (ibid. p. 103), and feels good (testosterone increases activity in the ventral tegmentrum, source of mesolimbic and mesocorical dopamine projections).
- Testosterone’s effects are hugely context dependent: “rather than causing X, testosterone amplifies the power of something else to cause X.” (ibid, p. 104), “if the amygdala is already responding to some realm of social learning, testosterone ups the volume.” (ibid, p. 105). Testosterone makes a monkey aggressive only towards monkeys lower in the domiance hierarchy of their troop.
- watching your favorite team win increases testosterone levels: this is the psychology of dominance, identification, and self-esteem
- in subjects playing the Ultimatium Game, people given testosterone before hand make more generous offers: the hormone “makes” you do what increases you status in the situation (Eisenegger & Fehr,2010)
- The ultimatum game is an experimental situation used to study economic exchanges. It was first used by Werner Güth, Rolf Schmittberger, and Bernd Schwarze. “One player, the proposer, is endowed with a sum of money. The proposer is tasked with splitting it with another player, the responder. Once the proposer communicates their decision, the responder may accept it or reject it. If the responder accepts, the money is split per the proposal; if the responder rejects, both players receive nothing. Both players know in advance the consequences of the responder accepting or rejecting the offer.”
- in subjects playing the Ultimatium Game, people given testosterone before hand make more generous offers: the hormone “makes” you do what increases you status in the situation (Eisenegger & Fehr,2010)
- Challange hypothesis: Testosterone makes us more willing to do what it takes to attain and maintain status.
- Oxytocin and Vasopressin
- oxytocin and vasopressin are chemically similar hormones, the DNA sequences are similar and occur close to each other on the same chromosome. They resulted from a single ancestral gene that several million years ago accident duplicated in the genome and the DNA sequences drifted apart functionally. This duplication occurred as mammals were emerging and other verebrates have only the ancestral version, vasotocin, structurally between the two mammalian hormones. Up until recently the two homornes were known only for effects outside the CNS: oxytocin stimulated uterine contraction during labor and milk letdown after birth; vasopressin (aka antidiruetic hormone) regulated water retention in the kidneys.
- Then it was discovered that the hypothalmic neurons that made oxytocin and vasopressin also sent projections throughout the brain, including the dopamine-related ventral tegmentum and nucleus accumbens, hippocampus, amygdala, and frontal cortex–all with receptors for the hormones; and, there were synthesized and secreted elsewhere in the brain. They began being referred to as “neuropeptides (small proteins that were neuroactive messengers).
- Oxytocin prepares a female’s body for birth and lactation, facilitates maternal behavior, wanting to nurse their child, and remembering which one is their child. Administering vasopressin enhances paternal behaviors (but only in species where males are paternal).
- In mammalian species that evolved monogamous pair-bonding, oxytocin steengthens the bond. Other studies found that adminisering oxytocin lead to people rating faces as more trustworthy, and being more trusting in economic games, but had no effect when the subjects believed they were playing with a computer; and made people better at detecting happy versus angry, fearful, or neurtral faces; and better at recognizing subliminal projections of words with positive (versus negative) social connotations; and made people more charitable.
- but
- Is it about prosociality or social competence? These neuropeptides also foster social interest and competence. Oxytocin enhances activity in the temporoparietal junction (region involved in Theory of Mind), we are better at “reading” other people: women improve at detecting kinship relatons, while men improve at detecting dominance relations; oxytocin increases accuracy in remembering faces and emotional expressions; people with the “sensitive parenting” oxytocin receptor gene varient are very good at assessming emotions.
- abnormalities in these neuropeptides may increase the rsik of disorder with impaired sociality: autism spectrum disorders..
- The effects of these neuropeptides are context contigent (like testrosterone’s effects).
- One factor: gender, oxytocin enhances different aspects of social competence in males and females
- oxytocin’s calming effect on the amygdala are more consistent in males than females
- Oxytocin enhances charitability, but only in people who are already so
- And culture affects the behavioral effects of oxytocin (support seeking depends on genetic variant of your oxytocin receptor, whether you are stressed, and whether you were raised in an “American” versus “East Asian” culture
- the dark side of neuropeptides
- ok, oxytocin and vasopressin decreases aggression in rodent females, except aggression in defense of one’s pups, which the neuropeptide increases via effects on the central amygdala
- in the human economic game research, oxytosin made subjects more likely to preemptively stab the other play in the back if they were on another team (versis one of your roommates), oxytocin makes you more prosocial to people like you but less prosocial toward the Others who are a threat. On an Implicit Association Test of unconscious bias, oxytocin exaggerated biases again two out-groups in Dutch subjects. de Dreu (2011) put forth the idea that oxytocin evolved to enhance social competence to make us better at identifying who is an Us versus an Other.
- Oxytosin makes us more prosocial to Us and worse to everyone else, the actions of these neuropeptides depend upon context (who you are, your environment, who that person is (drawn from Sapolsky, 2017).
- The world is complicated, human behavior is complicated, hormone effects in humans are complicated. Beware of people offering simple explanations of any of these.
- Testosterone
One more model, metaphor, bedtime story for psychologists (not based on assigned structure); this version below was articulated by Gilbert (2010) but there are other, similar formulations
“There are many different emotional systems within our brain that interact together to regulate our emotional world, and ensure that our basic needs for survival (such as food, reproduction, etc) are met. There are three particularly important emotional regulating systems, which work with each other to help us to manage the ups and downs of life’s challenges by helping us to calm our emotional experiences. Each system is designed to do different things nd also to work with the other systems so they remain in balance with each other.”
(Lee, 2012, pp. 27-28)
- Threat Protection System: anger, anxiety, disgust
- threat-focused, protection and safety seeking, activating/inhibiting
- fight, flight, freeze (submission, dissociation)
- sympathetic/parasympathetic nervous system
- Panksepp’s RAGE primary-process feeling
- Achieving and Activting System: driven, excited, vitality
- incentive/resourced focused, wanting, pursuing, achieving, consuming, activating
- sympathetic perpherial nervous system
- Panksepp’s SEEKING primary-process feeling
- Affilative and Soothing System: content, safe, connected
- non-wanting/affiliative focused, safeness-kindness, soothing
- parasympthetic perpherial nervous system, Vagus nerve; restorative
- Panksepp’s CARE primary-process feeling; Porges’s social engagement system
Where do psychopaths come from?
- A wide range of variables correlate with antisocial behavior: genetic, poor prenatal care, neurological, lack of empathy, early abuse and neglect, modeling, poverty, neighborhood violence, societal anome: no single factor explanations are adequate (any single factor theory produces high rates of false positives and false negatives)
- Frontal lobe dysfuction (or damage: Phenius Gage) is a polular neurological model for psychopathy. Many (possibly most) projections from the prefrontal cortex are inhibitory; problems here could lead to disinhibition–acting out against moral or societal rules.
- Simon Baron-Cohen argues that a lack of empathy is the essence of evil (but recognizes a problems with this: ASD individuals over have limited empathy but no propensity to psychpathy)
- Abigail Marsh offers an interesting prespective: psychopathes lack perception/awareness of fear in others:
- She studied both “world class alturists” and psychopaths
- “one of the best predictors of altruism is responsiveness to fearful facial expressions. Individuals at the very low end of the caring continuum–psychopaths–are notably insensitive to these expressions, probably as a result of dysfunction in the amygdala.” (Marsh, 2017, pp 185-186)
- The Amygdala is sensitive not only to personal threat, but to distress in other (in most of us): oxytocin shifts amygdala activation from fear to caring (Marsh, pp 190-191), empahty, and altruism
- Marsh believes the data supports a view that the facial features of infants (humans and many other species) resemble fearful facial expressions, which elicits caring
- The difference between being fearless and being brave: “Many psychopaths are genuinely fearless, and as a result they have difficulty understanding others’ fear. That altruists are so empathically responsive to others’ fear suggests that, rather than being fearless, they are unusually sensive to fear.” (Marsh, p. 153)
- allomothering, literally “other mothering”: taking care of infants other than one’s one. Allomothering is altruism, really, Species that allomother are prerennially attuned to vulnerability, distress, and need, and tehy are primed to resond with nurturing and care when the spot it, even if the object of their care if unfamiliar or unrelated to them.” (Marsh, p. 184)
- “key stimuli” of babies’ faces: large eyes, high brows, and rounded appearance
- Dr. Marsh believes that fearful expressions evolved because these lead to social facilitation and support within early groups
- And, spearing of fear, consider epigenetic effects of mothering behavior in rats on fearful behavior (see Harding, 2019)
- Good (frequent grooming of infant rats) and Bad (less grooming of offsping) mothering in rats
- Rats raised by good mothers grow up to show less “anxiety” (more explorative behavior, less signs of distress)
- Female rats raised by good mothers grow up to be good mothers, and pass these characteristics on to their offspring in turn.
- And, if we switch the offspring of bad mothers to good mothers: they grow up to be good mothers (the females). Methalization can “turn off” genes associated with fear responses in rats. Frequent early grooming seems to effect this.
- psychotherapy for rats: early grooming–less anxiety. Yeah!
- But, suppose you don’t live in a world of caring experimental psychologist who take good care of you. Suppose you live in a world of hungry predetors and you are small and weak. Maybe in that world less fear gets you eaten and the more “neurotic” rats are more likely to live and reproduce.
- Fear, anxiety, worry isn’t pleasant but it isn’t always a bad thing. Fear (usually) warns us of real dangers and motivates us to avoid or escape from these threats.
- Things are complicated (have I mentioned this before?)
- Good (frequent grooming of infant rats) and Bad (less grooming of offsping) mothering in rats
Summary
brain and behavior, our first kind of answer to, “Why did she do that?”
“several nuclei in the brain stem, hypothalamus, and telencephalon are in charge of producing the behavior to which I referred above, know as drives, motivations, and emotions with which the brain responds to a variety of internal and external conditions with preset program of actions (e.g., secretion of certain molecules, actual movements, and so forth).”
(Damasio, 2018, p. 63)
For Dr. Damasio homeostasis is the fundamental organizing principle of all life (plant, animal; single celled, us)
Behavioral avoidance/withdrawal systems
- A number of theorists and researchers have also suggest a system that responds to punishment and threat
- avoidance system (Cloninger, 1987)
- withdrawal system (Davidson, 1995)
- behavioral inhibition system (Gray 1994b): “BIS”
- The neurotransmitter Serotonin has been suggested by some to be involved in threat sensitivity or anxiety; this is still actively debated (Carver & Miller, 2006)
- Other candidates for some involvement in the inhibition system are the neurotransmitters gamma-aminobutyric acid (GABA) (panic disorder patients tend to have low levels of GABA and treatments that increase GABA reduce anxiety patients with panic attacks)
- and norepinephrine (produced in response to stress)
Jeffrey Gray has developed theoretical models relating brain system to personality dimensions (Gray, 1987, Corr, 2002, Fowles, 2006); he suggests that:
- a system involving the locus coeruleus (LC), limbic system, and the frontal cortex is related to certain basic personality features
- The locus coeruleus is a lower brain structure near the ARAS (ascending reticular activating system), it appears to modulate our response to novel stimuli and stimuli associated with aversive events, it may serve as a warning that dangerous or unknown stimuli are being encountered
- The limbic system is associated with emotional reactivity and valence (strength and direction–negative or positive–of affective responses), encoding and retrieval of lost-term, semantic memory, and linking memories of actions and consequences
- The frontal cortex is associated with higher mental functions such as control of motor behavior, planning and carrying out behavior, abstract and sequential reasoning, and evaluating consequences of actions
- BAS, more associated with positive emotional states, is activated more easily in impulsive, extraverted persons
- learning associated with rewards more than with avoiding punishment
- BIS, more closely associated with negative emotional states, is activated more easily in anxious persons
- learning associated with avoiding punishment than with rewards
- support for this position draws on both physiological and self-report measures