NBB 201 Notes PDF

8/29 Notes 4 Explanations of Behavior(for the polar bear) ○ Proximate(usually the scientific reason/how it happens) Emotional bonding, hormonal regulation, physical touch, nutrition from breast milk ○ Ultimate An adaptive beh...

8/29 Notes 4 Explanations of Behavior(for the polar bear) ○ Proximate(usually the scientific reason/how it happens) Emotional bonding, hormonal regulation, physical touch, nutrition from breast milk ○ Ultimate An adaptive behavior that increases the chances of success If polar bears don’t nurse their cubs, they die and she can’t transfer her genes and be reproductively successful ○ Phylogenetic Has to do with the ancestral behavior of the animal She is a mammal and feeds her young(this is a trait from a common ancestor of a past mammal) ○ Developmental She learns how to nurse her cubs, firstborns don’t survive as likely as later offspring Why do we need brains ○ Brains allow organisms to actively seek out resources important for survival and reproduction and avoid hazards How brains carry out function ○ Sense the environment ○ Integrate sensory information from different modalities ○ Decide on a course of action(or inaction) ○ Formulate a motor plan ○ Enact a motor plan Somatosensory cortex is responsible for sensing the environment ○ Posterior association area and limbic association area integrates sensory info Prefrontal cortex decides on a course of action- it integrates info to decide what we should do Pre motor cortex formulates a motor plan ○ Primary motor cortex enacts the plan(by sending the command down the spinal cord out to the muscles) Amygdala is located beneath the cortex in the limbic system, and decides whether a situation is dangerous(emotion center) ○ All the sensory modalities go into the basal lateral amygdala(collects all the sensory information) ○ Central nucleus of the amygdala Induces fear Activates the sympathetic nervous system(fight or flight) 9/3 Notes-Adaptation and Evolutionary Processes Evolution: A change in the genetic material of a population over time ○ Nature generates gene variation ○ Some individuals allowed to seed next generation ○ The frequency of genes in a population changes over time ○ The population evolves Gene: A unit of inheritance passed from parents to offspring, codes for a functional protein Genotype: The genetic makeup of an individual Phenotype: A set of observable characteristics that result from genes Coloration of peppered moths is an adaptation Speciation occurs with Geographic barriers, selection against hybrids, or due to differences in reproduction or behavior ○ Dark peppered moths ○ Kettlewell noticed that moths in certain areas had different morphs where the frequency of white vs. dark changed over a landscape (rural to urban gradient) --> moths had evolved to change colors based on environment Mechanisms for Evolution ○ Natural Selection Individuals with traits that are better adapted to their environment will be more likely to survive and reproduce(Struggle for existence) There must be variation Variation must be heritable Variation must influence differential survival and reproductive success Directional selection Selection is favoring one phenotype Change in mean value of a trait in the population Stabilizing selection Selection is favoring the intermediate phenotype No change in mean value of a trait in the population Disruptive Selection Selection is favoring extreme phenotype Loss of intermediate phenotype ○ Genetic Drift A change in the gene pool of a population due to chance “Bottleneck Effect”  ○ Drastic reduction in population and the surviving individuals have less variation(disastrous event) Next gen after that will have a much different genetic makeup/set of traits(full 180) “Founder Effect” ○ A few individuals from a population start a new population with a different allele frequency than the original population(separation/migration) Mechanisms for Variation ○ Mutation: A permanent change in the DNA sequence that makes up a gene ○ Recombination: Genetic reshuffling during meiosis produces offspring with a combination of traits that differs from each parent ○ Gene Flow: Transfer of genetic variation form one population to another 9/5 Lecture Notes Macroevolution: Evolution of new species or higher taxonomic groups ○ Change can be small, favored by selection or genetic drift, but it can also be rapid When a population divides into two or more species it is called speciation ○ Biological Species can breed and produce fertile offspring Phylogenetic species: A group of organisms that all share one or more unique feature pointing to a unique common ancestor, which in turn is not shared by members of other species Allopatric speciation ○ Physical barrior isolates population preventing mating and gene flow Sympatric speciation: No physical barrier but mutation, behavior changes, seasonal reproduction etc can result in speciation Intro to Primates Primitive traits: Traits inherited from a distant ancestor Derived traits: Shared traits due to a recent common ancestor that sets that taxa apart from ancestral taxa Distinguishing features of primates ○ Pentadactylism- 5 digits on hands and feet ○ Elongation of the fingers and toes ○ Opposable thumb and big toe ○ Increase reliance on vision and reduction in olfaction Arboreal hypothesis: Forward facing eyes to help jump through trees(depth perception)  Visual predation hypothesis: Catching prey is easier with forward facing eyes Stereoscopic vision: Forward facing eyes that allow for accurate depth perception Color Vision: Mammals are dichromats but most primates are trichromats ○ Nails instead of claws Good for dexterity especially for smaller times * Not all primates have these traits and the exceptions can highlight the selective pressures that shape morphological differences Large Brains: Large brains relative to body size and large neocortex Primate Taxa ○ Strepsirhines Long snouts, Wet noses, Eyes reflect light, nocturnal(most), solitary(most), small bodied, smaller brains, faster life histories Lemurs(found only in Madagascar) ○ Size: The size of a large domestic house cat ○ Diet: Omnioverse ○ Behavior: Highly social, uses scent to defend territory, FEMALE DOMINATED Slow Loris ○ Size: Small bodied, large goggle eyes, no tail ○ Diet: Omnivores ○ Behavior: Solitary, nocturnal, arboreal, slow moving. One of the world's only venomous mammals ○ Haplorhines Short snouts, dry noses, single upper lip, larger body size, larger relative brain size, slower life histories(monkeys and apes), eyes lack a tapetum(used in the eye for low brightness), slower life histories Tarsiers(Found in Philippines and Indonesia) ○ Size: Small bodied, large eyes, dry nose.. Elongated tarsier that helps them with powerful leaping locomotion ○ Diet: Insectivores(only strictly carnivorous primates) ○ Behavior: Nocturnal, solitary, eyes twice as big as their brains, arboreal Ceboidea: “New World” Monkeys ○ Flat noses with lateral facing nostrils  ○ Found in South and Central America. Migrated from Africa to the Americas 36 mya ○ Prehensile Tails(if you see a monkey hanging from their tail they have to be new world) ○ Small to medium bodied Capuchin Monkeys ○ Size: Medium bodied, sexually dimorphic ○ Diet: Omnivores: fruits., leaves, bird eggs, vertebrates ○ Behavior: Highly intelligent, biggest brain to body size of any primate, cooperative, use of tools and have social rituals. Cercopithecoidea: “Old World Monkeys”(Found in Africa and Asia) Medium to large bodied with hooked noses with downward facing nostrils. Mostly terrestrial Lack prehensile tails Large Social Groups, A lot of coloration/variation in this taxa ○ Gelada monkeys Size: large sized, hourglass red skin patch on chest Diet: Gramnivores; only eat grass Behavior: Largest group of any primate, wide range of vocalization including sounds reminiscent of human speech Hominoidea(lesser apes and great apes): No tail(monkeys have one), large bodied, large barrel chest, flexible shoulder joints ○ Gibbons and Siamangs Size: Medium bodied, sexually dichromatic(males and females have different colors), long arms Diet: Frugivores: Fruits, leaves, and insects Behavior: Variety of vocalizations including duets between pairs, “lesser apes”, monogamous primates ○ Orangutans Size: Large Bodied, some males have flanged faces Diet: Frugivores: fruits, leaves, small vertebrae Behavior: Solitary, two male morphs ○ Gorilla Size: Large bodied  Diet: Foliovers: Mostly leaved Behavior: Silverback male leads troop, captive gorillas can use sign language ○ Chimpanzee(Across West Africa) Size: Large bodied Diet: Mostly eat fruit but will hunt for meat Social Life: Multi male/female social groups, females leave social groups, males form strong bonds. Male dominant Behavior: Hunt, highly territorial and conduct border patrol where they kill rival groups, varied tool use, males monopolize and guard females ○ Bonobos(Democratic Republic of the Congo) Size: Smaller and more slender than Chimps Diet: Maily plant material and fruit Social Life: Multi-male, multi female social groups, female philopatric, females from strong bonds, female dominated Much less aggressive than chimps. Use sex to form social bonds and lesson tension. Same sex behavior is common 9/10 Lecture Notes Last time chimps and bonobos shared a common ancestor was 6-8 million years ago Pan troglodytes ○ This is the chimp ○ 400 cc of brain mass vs 1400 for humans Humans didn't evolve from chimpanzees or any other living ape species Hominin ○ Modern humans as well as our immediate ancestors(fossil specimens that are more closely related to mod3rn humans than to modern chimpanzees or bonobos) Inferred primarily from evidence for bipedalism The fossil evidence ○ Organism must become buried in sediment ○ Bone or teeth must mineralize ○ Surrounding sediment must harden The molecular clock ○ Human DNA differs from chimpanzee DNA by only 1.6% Skeletal adaptations for bipedalism  ○ Foramen magnum is in the center for a human instead of the ack for a chimpanzee ○ Human spine is s shaped, ape spine has a slight curve ○ Human pelvis is bowl shaped, ape pelvis is longer and more narrow ○ Human femurs angle inward to the knees; ape femurs angle out a bit ○ Human knee can support more weight Australopithecines came in two forms ○ Gracile(Slender) A. afarensis(East Africa) A africanus(South Africa) ○ Robust(powerful) They were eating very tough fibrous plant food. Big wide jaws/skulls A boisei(East Africa) A robustus(South Africa) “Lucy” ○ Bipedal ○ 3.2 mya ○ 3.5 ft tall ○ 65lbs ○ Australopithecus afarensis She was gracile and the most developed skeletal structures Laetoli ○ 3.6 mya ○ East Africa ○ Bipedal Have a big toe and a little arch in the footprints Bipedalism precede encephalization(enlargement of the brain) Ardipithecus ramidus ○ 4.4 mya ○ 4 ft tall, 112 lbs ○ Bipedal(pelvis) ○ Small, chimp-sized brain(skull) ○ Climbers(grasping big toe)---> surprising ○ Woodland/forest environment Is bipedalism an adaptation ○ Theory 1: Humans use less energy with bipedalism vs chimpanzees 9/12 Lecture Notes General trend in the genus homo- reduced face, jaws and teeth, growing brain Homo habilis ○ 2.4-1.4 mya ○ Slight increase in body size 3ft 4 in- 4ft 5 in 70 lbs ○ 500-700 cc brain volume ○ Stone tool use Oldowan technology Cores and flakes to cut things ○ Scrapes on the bones suggest that they probably scavenged animals for meat ○ Very pronounced brow ridge and large teeth Homo erectus/ergaster ○ ⅛- 0.2 mya ○ 700-1200 cc brain volume ○ Increase in body size(5.5- 6 ft tall) ○ Longer legs relative to arms ○ Small teeth ○ Migrated through Europe and Asia(first to migrate out of Africa) Acheulean technology Crafting sharp stones/tools(including hand axes) Homo Heidelbergensis ○ Went back to Africa, Levnt, and went to Western Eurasia ○ Gave rise to homo sapiens Had a very small brow ridge Craniofacial feminization ○ Smaller brow ridge and shortening of upper facial skeleton, may indicate us becoming less aggressive Neanderthals ○ Europe and western Asia ○ 400,000- 300,000 ya ○ 5’3 - 5’6 tall ○ 120-145 lbs ○ Heavily muscled, 1450 cc brain ○ Short lifespan  ○ Lots of injuries ○ Limited cultural and technological sophistication Differences in the skull between Neanderthals and modern humans(Cro Magnon-that outcompeted Neanderthals) Neanderthals have a long, low, and flat skull Human are high, short, and round(globulized brain) Bone and antler tools Art and musical instruments Innovation *Humans outcompete Neanderthals due to superior cultural transmission(better social learning) of knowledge and innovation. Also through longer lifespans and increased population density Homo sapiens ○ Origins at 200,00- to 100,000 ya ○ Migrated out of Africa around 60,000 ya and (mostly) replaced existing hominins ○ Greater cultural and technological sophistication Music, art Bone and antler tools Art, musical instruments Grave goods The capacity for innovation ○ Extension of lifespan, increased population density Mitochondrial DNA ○ Humanas have one tenth the variation of chimpanzees We use Mitochondrial DNA to map human migration Mitochondrial DNA accumulates mutations 10x faster than in nuclear DNA Inherited only through the mother 9/17+ 9/19 Lecture Notes- Brain Basics Peripheral Nervous System ○ 31 pairs of spinal nerves ○ Parts of the spine are named after their location ○ Cranial Nerves Responsible for movement of head and neck(receive sensory information) Cranial Nerve Nuclei ○ Cluster of nerves(12 pairs)  ○ Autonomic Nervous System Sympathetic Nervous System Fight or flight response Parasympathetic Nervous System Rest, recovery They have opposing effects Central Nervous System ○ Triune Brain Model Reptilian Brain Highly stereotyped, instinctive behaviors Sex, aggression, and food getting ○ Brainstem and basal ganglia Paleomammalian Brain(limbic system-emotions) Characteristic of early mammals Involved in experience and expression of emotions Social attachment Neomammalian Brain(Cerebral Cortex) Characteristic of higher mammals Thinking and reasoning Suppression/regulation of instincts and emotions ○ Neural Tube Creates the brain and spinal chord Divisions of the Brain ○ Spinal Cord Incoming sensory afferents from body Outgoing motor efferents to body ○ Medulla Respiration Blood Pressure ○ Cerebellum Lateral: Fine motor control, and some cognition Vermis: Balance ○ Pons Ventral: Cerebrocerebellar connections Dorsal: Sleep, respiration, etc ○ Midbrain -Tectum(Vision, hearing) Tegmentum DA neurons  Cranial nerve nuclei Diencephalon ○ Thalamus Sensory relay gate Decides “what” we are consciously aware of from sensory information ○ Hypothalamus Appetite Sexual behavior Emotions Endocrine function Cerebral hemispheres ○ Limbic system(memory and emotion processing) ○ Basal ganglia(movement, reward, motivation) ○ Cerebral Cortex(perception, thought, reason, movement) Cerebral Cortex ○ A lot of folds Due to increasing surface area from evolution ○ Sulci and Gyri Lateral Sulcus ○ Neuron cell bodies are concentrated in gray matter(cortex and nuclei). Axons are concentrated in white matter The neuron contains the cell body, dendrites, axon, axon terminals ○ Cortex has cellular architecture aht varies across space Layer 4 Afferent cortical inputs Layer 5 Efferent cortical outputs ○ Korbinian Brodmann 52 areas of the brain Cortical Columns ○ White matter tracts Projection fibers Connect cerebral cortex to brainstem and gray matter nuclei Commissural Fibers Association Fiber Project in the same atmosphere Cortico-Limbic interactions ○ Orbitofrontal Cortex  Neurotransmission ○ Neurons shoot action potentials that are all or nothing Some inputs are excitatory and others are inhibitory ○ Neurotransmitters Glutamate(excitatory) GABA(inhibitory) ○ Neuromodulatory Serotonin, dopamine, norepinephrine 9/24 Notes- Brain Evolution Endocast: ○ When the skull fossilizes Can tell you the shape and size of the brain. Can be made naturally with minerals forming Can be made with a CT scan(virtual endocast) or naturally Lines of evidence with respect to brain evolution ○ Direct: Paleoneurology Direct evidence of brain evolution through study of fossilized brain casts ○ Indirect: Comparative neuroanatomy of living species A much more abundant source of evidence for brain evolution ○ Indirect: Archeological record(hominins) Studying hominin remains ○ Comparative approach Human brain is absent in all other primate brains, then infer that this trait evolved in the lineage after humans diverged from chimps about 6 million years ago Relative Brain Size ○ Ratio between body weight and brain size Usually body weight increases faster than brain size for mammals ○ Brain gets larger in postnatal life Allometry- Study of how one part of an organism grows in relation to the whole organism or to another part ○ Describes rules of growth ○ Reveals evidence for adaptation by natural selection(departures from allometry) ○ Y=bx^a logY= alog(x) + log(b) ○ Brain allometry in fossil vertebrates ○ When a is less than 1 Allometry is negative  That means ratio between the organ and body gets smaller as body gets bigger ○ When a is greater than 1 Allometry is positive That means that the ratio between the organ and body get larger as the body gets larger ○ When a is equal to 1 We call that isometry Encephalization Quotient ○ A proposed measure of intelligence ○ A measure of brain size relative to body size ○ Actual brain size divided by the expected brain size for an average living mammal of the same body size ○ Expected brain weight E=0.12*Body weight^/2/3 ○ Average mammalian EQ= 1 ○ Average anthropoid EQ= 2 Frugivores have larger residuals than folivores ○ Frugivores have greater spatial and temporal variability in their food supply which demands greater memory capacity ○ Frugivores have smaller guts and can afford larger brains Explanation: Maybe Frugivores eat bigger brains because it is more challenging to forage for fruit instead of leaves ○ Primates with relatively large brains have relatively small guts and vice versa ○ Large brains are needed for a long lifespan Memory for emergency food sources during periodic crisis involving food shortages ○ Relative neocortex size is correlated with group size among anthropoid primates 9/26 Lecture Notes- Evolution of the Brain II Comparative Genomics More neuroblasts= more neurons Rhinal sulcus- defines border between paleocortex and neocortex Evolution of the primate brain ○ Expansion of neocortex ○ Reduction of olfactory bulb and olfactory cortex  ○ Appearance of Sylvian Fissure ○ Expansion of visual cortex ○ These trends are more pronounced in anthropoid primates than prosimians Cultural Intelligence ○ Our brainfs are large enough to transport culture from one generation to another 10/8 Lecture Notes- Evolution of Social Behavior Lorenz: Imprinting(Ducks) Frisch: Bee Waggling Socioecology ○ The study of how social and ecological variables come together to produce a social system ○ Why do animals form groups? Protection, Mating, etc Helps mitigate predation pressure ○ Sociality is favored when it: Predation pressure is high Group defense is beneficial ○ Group Size is constrained when High resource competition Disease Social system ○ Refers to the size, composition, and social cohesion of groups ○ Different types Solitary, Pair Bonded, Group Living: Multi male/one female, one male/multi female, multi male/multi female ○ Complex groups Multi level societies→ Geladas are in this system Fission Fusion societies→Capuchins are in this system Groups merge(fusion) or split(fission) as they move through the environment making a group composition a dynamic property Size and composition of subgroups vary Types of competition ○ Between Group forms groups, within group competition organizes it Building a model(Females)  ○ Female primates go where the resources are Pregnancy and lactation are energetically costly Limiting resource for female reproduce success is food intake ○ Resources can be dispersed or clumped Dispersed resources aren’t head to head(Scramble Competition) Clumped resources are head to head(Contest Competition). Additionally, a lot of the item is in one place ○ Think of Easter Eggs vs Pinata ○ These things all affect female relationships When between group competition is high: ○ Larger group will outcompete smaller groups ○ Cooperate to defend territory When within group competition is high ○ Despotic: Strict linear hierarchies ○ Nepostistic: Matrilineal lines of dominance When within group competition is low ○ Tolerant: Less strict hierarchies, more tolerance of subordinates ○ Egalitarian: Prosocial behaviors are directed towards kin and non-kin Building a model(Males) ○ Females are a limiting resources for male primates Folivore paradox ○ Many primates that eat leaves(folivores), live in small groups ○ They eat a dispersed resource(leaves)- should increase group size ○ They presumably still have lots of predators- should increase group size Gelada Paradox ○ Geladas eat a dispersed non-monpolizable resources-grass ○ Expect: Egalitarian, tolerant, with little aggression within and between groups ○ Actual: Nepotistic, despotic social system with strict dominance hierarchies, and lots of aggression Problems with the model ○ Breaks from this model could highlight that resource competition is not what it appears ○ Other factors that the model does not account for→ social factors, infanticide risk, parental care, disease ○ Differences in cognitive abilities→ Alter social relationships and foraging efficiency ○ Simplifies male and female roles→ Males help in resource defense and females are more than just a resource for males and females care about more than just food for babies. 10/10 Reproductive and Sexual Behavior Natural Selection ○ Variability ○ Differential Survival ○ Heritable Struggle for Existence Sexual Selection ○ Variability ○ Differential Reproduction ○ Heritable Struggle for Mates ○ Traits can evolve if they increase reproductive success even at the cost of survival Male competition(intra-sexual selection) Goal: Gain access to Direct competition for access to mates Physical fights and displays Selection for armaments(weapons) Male-Male competition Mate Choice(intersexual selection) Goal: attract mates Courtship displays and ornamentations Selection for extravagant traits Female mate choice Anisogamy ○ Sexual reproduction wherein males and females produce gametes of different sizes Bateman’s Principle ○ Males benefit from promiscuity and females do not ○ Reproductive success is directly correlated to the number of females a man is exposed to For women it is relatively the same Argues females should be selective Parental Investment Theory ○ “Typical” species: females tend to invest more in offspring than males, gestation, and lactation, and provide most post-parturition care ○ Females should be choosy  ○ Since there are less fertile females than reproductive males, males need to compete Victorian Era ○ Industrial Revolution altering social and economic fabric of society ○ British Empire→ Imperialism + white supremacy ○ Citizen of the Empire- What makes an ideal British citizen? True Womanhood→ Piety, purity, submission, and domesticity ○ Misconceptions Females are passive agents: males are the heroes that are strong, acquiring and possessing females for reproductive gain Animals only have sex to reproduce Same sex behavior, pleasure, bonding, etc are all reasons against this idea Songbirds leave eggs and mate next door, Hyaene female dominated society Sexual Selection: Revise or Reject? ○ Sexual selection was not made in a vacuum? We need to consider our biases Anchor bias: We tend to rely too heavily on the first piece of information we receive on a topic Confirmation Bias: We tend to find what we are looking for ○ Shapes scientific questions being asked Ockham’s razor: Central tenet of science to trust the evidence and choose the most simple explanation ○ The ornithologist John Marzluf and Russel Balda studied blue jays These Jays rarely had conflict and when they did Male Reproductive Strategies ○ Direct competition Fighting Sexually selected signals: Short hand cues of a male's condition or fighting ability Strong selection for traits that can help males win fights with other males ○ Indirect competition Alternative male mating tactics/sperm competition Sperm Competition: Post copulatory strategy where only the best sperm fertilizes the egg Sexual Coercion: Forced or sneaky copulation with females  Infanticide: Killing of non-related dependent offspring to accelerate cycling in females ○ Invest in parental care Males invest in care and protection of offspring Why did it evolve? ○ Maternal Relief Hypothesis: Due to high costs of offspring rearing, paternal care can enhance offspring success, accelerate mother’s return to fertility or both Wehen males carry infants for long periods of time Reduces female energy expenditure Decreases interbirth intervals ○ Infanticide avoidance hypothesis: Males are needed to protect infants from other males Males form a long-term bond with a female while she has a dependent infant to protect the infant from infanticide If he leaves her to find other matings, his offspring will be killed by another male ○ Future Mating hypothesis Complex, Multi-level groups have the greatest amount of male-male competition ○ Male-Male competition leads to greater sexual dimorphism 10/17 Female Sexual Selection Trivers ○ The single most important difference between the sexes is the difference in their investment in offspring The general rule is females do all the investing; males do none of it Females only get a few chances at offspring(blue cycling period) Selection will favor females who are able to detect good things for the and their offspring ○ Female choice Choose the best mate Mate that give you a direct benefit ○ When men can share the meat with het ○ When men can care for infants Mate that gives you an indirect benefit ○ Good genes: Females select males seen to have a genetic advantage that increases the quality of the offspring  ○ Sexy sons: Females prefer an arbitrary trait that provides no link to genes or health but her sons wil lhave it and her daughter will have that preference for it Sexually selected signals ○ Signals that increase reproductive success Males condition or genetic quality Female choice- Traits that signal something about quality of a mate ○ The evolution of exaggerated traits and colors are often a sign of female choice Primates are extremely colorful Proximate mechanism->Testosterone, blood circulation, oxygenation, pigmentation Ultimate explanation→ Sexual selection ○ Mandrills have brightly colored faces Coloration is linked to testosterone and rank Females spend more time in proximity with brighter males ○ Rhesus macaques have faces that differ in redness Males have increased red in their cars during mating season Male redness is not linked to dominance Dark red males receive more sexual solicitations from females The evolution of exaggerated traits and colors are often a assign of female choice ○ Proximate mechanism→ Testerone, blood circulation, oxygenation, pigmentation ○ Ultimate Mechanism: Sexual selection Cryptic female choice ○ Post copulatory mechanism→ choosing sperm ○ Physical or chemical mechanisms to control a male’s success of fertilizing an egg Sexual conflict- strategies of one sex imposes fitness costs on the other Battle of the sexes ○ Male strategies Sexual Coercion(chimps+baboons) Cycling females receive more aggression from males and more injuries than non-cycling females ○ This is bad because they aren’t able to choose the mate they actually want. A lot of mate-guarding as well Female counter strategy(bonobos) ○ Form social bonds, coalitions, concealed or deceptive ovulation Engage in Female-Female sex Deceptive swellings in bonobo females  ○ Sexually available nearly ¾ of the year which makes it harder for males to mate gourd Infanticide(Gelada) Common male strategy ○ Long periods of lactation, low probability of being the father and high probability of siring future offspring, short tenure as alpha/high mating skew Female counterstrategies Confused fraternity(can’t be sure who the father is —> No maury show), friendships, deceptive ovulation(PREVENTION) Bruce Effect: Failed preganancy in mice when she is exposed to a different male within 24hrs ○ Vandenbergh Effect- The acceleration of maturantion in the presence of a novel male ○ Humans vs Primates Human have sex for pleasure a lot more, delay and control reproduction, monogamy/marriage, love 10/22 Cooperation and Social Relationships What is cooperation? ○ Author and Recipient can have a cost and benefit relationship Benefit Benefit-Mutualism Benefit only for recipient- Selfish Cost only for the author(for the better good)-Altruism Cost for both-Spite ○ Altrium Paradox Group selection: Being altruistic for the benefit of the group Darwin proposed that these behaviors evolved because they enhance the survival of the whole group(Vervet Monkey Calls) ○ Hypothesis: When the total benefit of all group members exceeds the cost of one individual giving the call Fitness of the altruist decreases while fitness of the non altruist increases. Pays to cheat Selection occurs at the level of the individual not the level of the group Kin Selection: Being altruistic to kin is beneficial to you because it increases inclusive fitness  Hypothesis: Selection can favor altruistic acts with genetically related relatives when the cost of performing the action is less than the benefits discounted by how closely related the individuals are ○ If you can help your kin, you are helping yourself(by passing on your genetic code) Direct Fitness: IMpact that an individual has on the survival and reproduction of relatives Inclusive fitness= Direct Fitness + Indirect Fitness ○ Hamilton’s Rule: A trait will be favored by natural selection if the benefits of ding the behavior, multiplied by relatedness are greater than the costs doing it rB>C ○ Relatedness x benefit > cost to self Coefficient of relatedness(r): The probability that two individuals share the same allele Nepotism is acting preference towards kin but can be regardless of costs or benefit to self ○ Kin recognition: Primates recognize their relationships with others. Matrilineal kin Playback experiment to test if females vocally recognized the distress calls of their own infants Found that females respond stronger(looking and moving towards the speaker) when the call of her juvenile was played ○ Other females looked at the mother when the juvenile called Associating the call with a specific juvenile and that specific juvenile with his/her mother Reciprocal Altruism: Is helping another in expectation that the favor will be repaid in the future Are reciprocal and equitable Prisoner’s Dilemma: Two prisoners are brought in and questioned separately for a crime. Only they know what happened ○ To occur the following must be true Repeated interactions Keep track of helpers and cheaters Reward altruists and punish cheaters `10/24 Evolution of Cooperation Altruism Paradox ○ Hard to track these relationships. “Currency” isn’t always the same ○ Long term social bonds between primates results in equitable time spent grooming but short term does not. Need long term studies Do animals punish cheaters? ○ Chimps are good at confronting cheaters when directly interacting with them = Cognition ○ The mental act of acquiring, processing, and understanding information Comparative cognition ○ The study of mental abilities of closely related species Primate Brain ○ Primates have large and complex brains compared to other animals Does Brain Size Matter Adaptive: Large brains can process and storm more information Costly: 2% of your body weight but requires 20% of your energy to maintain ○ Expensive tissue not used is lost ○ What selected for large brains Social Intelligence Hypothesis: Large brains and advanced cognitive abilities in primates evolved as a response to the challenges associated with living in large and complex social groups Social demands leads to an increase in brain size ○ As group size increases 2 major predictions Positive relationships between social complexity and brain size Positive relationship between social complexity and socio-cognitive abilities ○ Kin Recognition primates recognize their relationships with others. Matrillineal kin Playback experiment to test if females vocally recognized the distress calls of their own infants Found that females respond stronger when the call of her juvenile was plated Limitations: Measuring social complexity is difficult  ○ Some species are solitary and have large brains ○ Nota all cognition is social ○ Model doesn’t work with carnivores ○ Scrub Jays(monogamous, pair bonded) vs Pinyon Jays(large group) Excelled in different cognitive tasks Scrubs were good at memorizing pais but struggled to apply that knowledge to new pairs Pinyons applied rules to new relationships Ecological Complexity Hypothesis: Selective forces in their physical forces environment, such as the necessity to locate and extract food, are responsible for larger brains and advanced cognitive traits Ecological complexity: Can be measured by home range size, types of food consumed, evidence of extractive foraging ○ Limitations: Uses relative brain size not neocortex size, and group size is not the best measure of social complexity ○ Large brains evolved due to the necessity of spatial information storage and survival ○ Main evidence: Frugivores have larger relative brain sizes than folivores Limitations Difficult to disentangle social and ecological environment Highly social species are smart but not extractive foragers, done use tools The case of the New Caledonian Crow ○ Also great physical cognition problem solvers in general ○ They are exceptional users despite being solitary but The most complex tool use in wild birds occurs among parrots, some of the most socially complex bird groups and the NEw Caledonian crows are members of the corvid family, a largely social bird family Cultural Intelligence Hypothesis: Social learning, behavioral innovation and tool use may have played an important role in primate brain evolution. Humans may have evolved a specialized social skill set Physical Tasks: Understanding space, quantities, and causality  Social Task: Social Learning, com munication, and theory of mind ○ Humans significantly outperform apes in social learning and theory of mind Other tasks are relatively similar These hypotheses are not mutually exclusive. They are ALL CORRECT Cognition can evolve in a mosaic pattern, with different evolutionary processes shaping different cognitive traits Goffin’s Cockatoo sequential tool use ○ Goffin’s cockatoos show high levels of problems oblong and intelligence Intelligence is the ability to ○ Acquire new knowledge form interactions with the physical or social environment ○ Use this knowledge to organize effective behavior in both familiar and novel contexts ○ To engage with and solve novel problems Specialized intelligence(domain-specific) ○ Cognition produced 10/29 Cultural and Social Learning Cultures are systems of linguistically encoded conceptual phenomena that are learned through teaching and imitation, socially transmitted within populations, and characteristic of groups of peoples ○ Cultures are those group-typical behavior patterns shared by members of a community that rely on socially learned and transmitted information Innovation: Initial inception of a behavior Diffusion: Behavior must spread to others Social Transmission: Behavior must be socially transmitted and learned with or from others ○ Material Culture: Tools and technology Helps solve ecological problems Positive relationship between time spent with association and time spent with others Positive relationship between geography and cultural differences Pull through method(Gombe) Direct mouthing method(Tai) Positive relationship between time spent in association with others and the number of food related cultural variants How is behaviors transmitted ○ Social transmission  ○ Behavior must be socially transmitted and learned from others Social facilitation: Activity of one animal indirectly increases the chance that other animals will learn that behavior on their own Trial and Error: I learn from you Observational Learning: “naive” animals learn how to perform an action by watching and imitating the behavior or experience of a skilled animal Social Culture: Social rituals and traditions Over imitation Imitate unnecessary steps and irrelevant actions ○ Happens with kids a lot Allows for relatively reliable transfer of information Ratchet Effect Observational learning through immigration and teaching allows for rapid cumulative cultural change ○ Invention→ Imitation→ Quick spread Each time the behavior is imitated the ratchet goes up on tooth but the magnitude of the effect is exponentially bigger(Cumulative Culture) 10/31 Lecture Notes - Theory of Mind Theory of mind is the ability to attribute mental states(beliefs, intents, desires, emotions, knowledge) to oneself, and to others ○ And, the ability to understand that others have beliefs, desires, intentions, and perspectives that are different from one’s own It is a “theory” because no one has direct access to the mind of another Zero Order intentionality ○ Not knowing anything Warning coloration on a moth A vervet monkey uttering a startle response to seeing a python First Order intentionality ○ I know something A vervet monkey uttering an alarm call because she believes a python is nearby A vervet monkey sees a python and utters the alarm call for a python Second order intentionality ○ I know that you know(or don’t know) something ○ This is what is called “Theory of Mind”  Theory of Mind ○ Appears to be innate ability in humans, but it requires social experiences and cognitive development to fully develop(by age 5-6) Spontaneous and reflexive- we can rarely “turn it off” We even attribute mental states ot animals and inanimate actors Problems with determining theory of mind in animals ○ Theory of Mind: Subjects could indeed have an understanding Captive studies can help decode what animals know and what others know ○ Understanding of Goals and Intentions 6 mo infants look more when experimenter reaches for a new toy and not the one he showed interest in, suggesting an understanding of intent 18 mo kids recognize adult movies and goals and are strongly motivated to help, even when they derive no benefit ○ Chimpanzees Were given a choice to beg for food from two experimenters, one that could see and one that could nt Have a non-rudimentary theory of mind while dogs do ○ This is because dogs co-evolved with humans Chimps are more competitive Chimps helped others by giving them the “right” tool when the helper could assess the partners situation Understanding Perception and Knowledge ○ Goal: To steal food from an informed or uninformed dominant ○ Experiment 1: Dominant was informed or uninformed about the foods location ○ Experiment 2: Dominant A was informed of food location and either allowed to compete or Dominant A was switched to Dominant B Subordinate was more likely to obtain food in the switch condition where a subordinate completed against Dominant B Capuchins preferentially watch more experienced nutcrackers, suggesting that they know which individuals are better tool users Sally-Anne Test ○ Children under 4-5 co nsistently fail the Sally Anne test. They cannot discern that others have false belief ○ Children greater than 5 are able to correctly answer ○ Children with Down’s syndrome answer correctly 86% of the time Theory of Mind- Who has it ○ Human children Yes- although incomplete before 5 yo ○ Adults Yes most adults do, although some non- neurodiverse show defects 11/7 Notes Exploration vs Exploitation ○ The more the person uses the resources the more they run out. Eventually they will go elsewhere to start exploring This is in the desire to find a spot with more resources Value ○ Outcome value: Refers to the value of a reinforcer upon consumption(liking) ○ Decision Value: Refers to the net value of a specific decision option that is under consideration(wanting) Rats will work to self-stimulate along the mesolimbic dopamine pathway, suggesting that such stimulation is positively reinforcing or rewarding Mesolimbic dopamine pathway consistent of dopamine neurons in the ventral tegmental areas(VTA-midbrain) Neurons in the VTA release dopamine from the axon terminal to the Nucleus Accumbens Factors that determine the value of prey species Time required to find it Time required to harvest it Payoff if it is found Risk Basal Ganglia ○ Striatum Dorsal Striatum Caudate and putamen Ventral Striatum, Nucleus accumbens PET Scans ○ Inject radioactive water I.V ○ Accumulates in brain areas where blood flow is greatest ○ Emitted positrons collide with and are annihilated by electrons ○ Two photons are emitted in opposite directions ○ Photons are detected by PET scanner and localized in brain ○ Low temporal resolutions One minute to produce an image== Collect one image- every 10 min Chocolate study for valuation system ○ They found that the more chocolate they ate the less they wanted it In the brain as the chocolate was ate more VTA, NA, and mOFC activation decreased  MRI ○ FMRI Oxy and Deoxy-Hemoglobin Increases in neural activity are followed by increases in oxygenated blood flow Oxy and Deoxy hemoglobin have different magnetic properties that can be detected by the scanner Food valuation and body weight study They found that high calorie food light up the VTA, NA, and mPFC ○ Human, monkey, and rat brains have similar value systems for food Neuroeconomics ○ The study of how the brain assigns value to various decision options VTA Neurons encode expected value in monkeys ○ THe firing rate of VTA neurons increases as the expected value of the cue increases Expected Value in Humans using fMRI ○ Increased activation in VTA, NA, and mOFC as expected value of cue increases Norepinephrine ○ Locus coeruleus: This is what releases it in the brainstem LC Neurons ○ Phasic activity(focused and engaged) of LC neurons is hypothesized to be associated with exploitation(Low tonic) ○ High tonic(distractible) activity of LC neurons is hypothesized to be associated with exploration If you can stimulate that locus coeruleus you can make them more likely to leave the patch and explore(high tonic state) ○ They found that with rats as they made the award less for the rats the rat started looking elsewhere Found other “patches” with better rewards. Encourages exploration 11/12 Lecture Notes Avoiding Predation: Threats There are still animal predation ot this day ○ Physiological Response to emergencies Two arms of the physiological stress response Sympathetic Nervous System ○ Fight or flight(fast)  HPA is an endocrine response(slow), Driven by norepinephrine which is secreted from sympathetic nerve endings in hypothalamus Epinephrine secreted from nerve endings in the adrenal medulla Biosynthesis from tyrosine ○ Monoamines Catecholamines and Indoleamines Serotonin is made from indoleamines ○ HPA Stress response In times of stress specific cells in the hypothalamus secrete a hormone called corticotropin releasing hormone(CRH) CRH stimulates the pituitary gland to secrete adrenocorticotropic hormone(ACTH) ACTH stimulates the cortex of the adrenal glands to secrete cortisol Cortisol effects: Mobilization of energy, immune suppression, negative feedback to hypothalamus Cortisol feeds back to the hypothalamus and decreases CRH which means less ACTH and cortisol production Parasympathetic ○ Digestion, slow responses, recovery Functional components of the mammalian stress response ○ Mobilization of glucose and fatty acids Glucose is stored as glycogen in liver and muscle cells Fatty acids are stored as triglycerides in fat cells Hormones/neurotransmitters that release glucose and fatty acids Epinephrine, norepinephrine, glucocorticoids ○ They mobilize energy and fatty acids ○ Increased oxygen uptake ○ Dilation of pupils ○ Memory and cognition sharpened Memory enhancement for emotionally arousing stimuli An inverted u-shaped curve ○ Increased inflammatory response/Inhibition of antiviral response Prepares body for injury In terms of predation this helps with protecting you from an infection in the case that you are wounded  ○ Stressed induced analgesia Vets don’t feel the bullet until way later Endogenous opioids released from anterior pituitary gland ○ Inhibition of digestion Sympathetic activation and parasympathetic deactivation Blood flow to stomach and gut decreased ○ Inhibition of reproduction Reduced testosterone(males) and estrogen(females) levels Deleterious consequences of chronic stress ○ Diabetes Chronic mobilization of glucose and fatty acids Chronic blockade of storage ○ Ulcer ○ Irritable bowel syndrome Sympathetic nervous system stimulates muscular movement in large intestines ○ Reproductive disorders ○ Inflammation related disorders ○ Infectious disease and cancer metasis ○ Depression and anxiety Anxiety disorders involve hyperactivation in the amygdala Information from all of the sensory systems feeds into the lateral nucleus of the amygdala ○ The central nucleus of the amygdala orchestrates physiological and emotional responses to threatening stimuli Lesioning the CeA ○ Monkeys: Lesioning the central nucleus of the amygdala resulted in monkeys not taking time to get the peanut despite a snake being there(they were quick with it) Shows how the central nucleus is involved in the fear response ○ Humans: Those with the bilateral lesions couldn’t rate the untrustworthy faces correctly SERT Polymorphism and amygdala function(codes for serotonin transporter) ○ There is a long allele and a short allele of the gene Short allele + Trauma = Anxiety(BAD) Cognitive Behavioral Therapy for Generalized Anxiety Disorder ○ Assessed neural response to fearful and angry relative to happy faces before and after 10 sessions of CBT ○ CBT normalized amygdala hyperactivity in GAD Pharmacological Treatments  ○ Benzodiazepines(Lorazepam) Lowers the amygdala response to fearful faces High addictive potential ○ SSRIs(Escitalopram) Also decreases the amygdala response to fearful faces Nonapeptides ○ Oxytocin/Vasopressin OT is released into the peripheral circulation via the posterior pituitary gland OT is also released into the brain, where it can affect behavior Oxytocin synthesis ○ Made in the hypothalamus in the periventricular and super oculant nucleus ○ In rats, OT decreases the firing frequency of neurons in the central nucleus of the amygdala ○ PVN OT mediates mating-induced anxiolysis in male rats Oxytocin acting in the amygdala decreases their anxiety Oxytocin and Amygdala function ○ Inot attenuates the amygdala response to threatening scenes and faces OT normalizes amygdala hyperactivity in social anxiety disorder ○ Summary Activation of the sympathetic nervous system and HPA axis promotes adaptive responses to physical emergencies such as the threat of predation Chronic activation of the SNS and HPA axis can cause health problems Lesions studies in rats and monkeys implicate the amygdala in threat detection Studies of patients with amygdala lesions and fMRI studies also implicate the amygdala in threat detection in humans The amygdala is composed of several nuclei with different functions including botha sensory input zone and an output zone that orchestrates the behavioral and physiological responses to threats 11/14 Notes Faces ○ Facial Identity Faces are a special class of visual stimuli Newborn infants usually track the face stimulus more than the others  ○ Some newborn human infants will imitate their caregivers facial expressions Mona Lisa Illusion: Failure to perceive a severe distortion of a face when presented in upside-down configuration(normal subjects) ○ Relates to the inversion effect We suck at recognizing faces that are flipped upside down Prosopagnosia: A neurological condition characterized by the inability to recognize the faces of familiar people, including one’s own face, while other aspects of brain are fine ○ Damage to the ventral occipitotemporal cortex Viewing pictures of human faces activates the FFA FFA is part of the fusiform gyrus Fusiform gyrus/lateral occipital temporal gyrus is where prosopagnosia patients have damage ○ Where do we process emotion for faces Occurs in the superior temporal sulcus and superior temporal gyrus STS responds to any type of motion When you ask participants to focus on gaze they activate the STS When you ask participants to focus on identity they activate FFA ○ Inferior Occipital Gyrus- Initial Processing of Face ○ Superior Temporal Sulcus- Facial Expressions ○ FFA- Face Identity Macaque face cells ○ Those potentials are fired in a monkey Face expression cells(STS) Face identity cells(ITS) Key difference humans vs monkeys Macaques activate ITS for face identity while humans activate the FFA ○ Evolution of language shifted face processing area of human brain in comparison to monkeys ○ Facial Attractiveness Better looking people are more likely to get paid more, be treated well, and have better opportunities moFC and nucleus accumbens have activity with attractive faces 11/19 Lecture Notes Competition ○ Among mammals males typically have greater variance in reproductive success than females Testerone ○ Steroid Hormones Steroid hormones bind to receptors inside the nucleus where they affect gene expression ○ Testerone prepares males to succeed in mating; anatomically, physiologically, and behaviorally Motivates the pursuit and defense of both mates and social status ○ Female reproductive development Gonads develop into ovaries Mullerian ducts develop Uterus Fallopian Tube Cervix Wolffian ducts regress Prenatal ovarian hormones are not involved in this process ○ Male reproductive development At 6 weeks TDF gene on Y chromosome causes gonads to develop into testes Testes produce testosterone starting at about 8 weeks, peaking at 14 weeks Levels then decline markedly SDN POA in Rats ○ The sexually dimorphic nucleus of the preoptic area of the hypothalamus(SDN-POA) is five times larger in male vs. female rats Organizational effects of T Early testosterone affects the size of this brain structure Does testosterone facilitate aggression? ○ Female mice show male levels of aggression if Exposed to testosterone on first day of life(organizational effects) Organizational effects are effects are effects that happen early in development that change brain anatomy  Given testosterone as adults(activational effects) Activational Effects: Happens later on in life, occurs because it activates a circuit organized earlier in life. Organizational effects of Testosterone on Monkey aggression ○ Male monkeys show more rough and tumble play as juveniles ○ Exposing female fetuses to testosterone in utero increases rate of rough and tumble play ○ Blocking androgen receptors in male fetuses in utero decreases rough and tumble play Activational Effects of Testosterone on aggression in monkeys ○ During the mating season rhesus macaques show Increased testes size Increased plasma testosterone concentrations Increased muscle mass Increased rates of aggression Relationship between T and aggression is bidirectional ○ Physiological injections of T exaggerate existing patterns of aggression ○ Aggression can affect T Winning vs losing Activational Effects of Testosterone on Human Aggression ○ Some studies fail to find associations between T levels and aggression in humans Cells that bind testosterone in monkeys are concentrated in Midbrain(PAG) Hypothalamus Amygdala Affective Rage Circuit in the Domestic Cat ○ Electrical stimulation of midbrain(PAG), medial hypothalamus, or amygdala produce affective aggressive response Growling Hissing Piloerection Back arch Paw Strike Stria terminalis links amygdala and hypothalamus ○ T increases firing frequency if its already firing Testerone and the Amygdala Response to threatening faces ○ Men with higher testosterone levels tend to have a higher amygdala response to threatening faces  Testerone facilitates rejection of unfair ultimatum game offers by suppressing medial OFC activations Testosterone inhibits mOFC which then disinhibits the amygdala Serotonin ○ Serotonin and Aggression in Free Ranging Rhesus Macaques Low CSF 5-HIAA is associated with Severe unprovoked aggression Deficits in impulse control Serotonin, Testosterone and Aggression in Free-Ranging Rhesus Macaques ○ High T/ low 5-HIAA associated with highest rates of aggression T provides competitive drive Serotonin regulates the threshold for aggression Mena with Damage to OFC are more likely than men with damage in other brain regions to have outbursts of rage at family members, friends, and colleagues ○ Serotonin agonists increase glucose metabolism in OFC ○ This increase is blunted in patients with aggressive impulsive personality disorder MAOA ○ Neurotransmission Monoamine oxidase enzyme breaks down monoamines in the synapse Large Dutch kindred with MAOA mutation with persistent and extreme reactive aggression in some males(murder, rape, assault) ○ This is an X linked problem Male MAOA knockout mice are hyper aggressive Men with L allele of MAOA are at risk for committing violence, particularly if they were abused as children ○ This is a gene/environment relationship OT and Maternal Aggression ○ OT acts in Central Nucleus of Amygdala to facilitate maternal aggression 11/21 Sexual and Mating Behavior Notes Lordosis posture ○ High end elevated ○ Tail deflected to one side to facilitate intromission by male Female lordosis  ○ Male forpaws on flank ○ Estradiol in VMH triggers descending motor pathway, leading to contraction of lower back muscles Male copulation ○ Female pheromones and male testerone act in MEA to stimulate male arousal ○ Testosterone acts in mPOA to trigger descending motor pathways involved in copulation SDNA POA in rats ○ The secually dimorphic nucleus of the preoptic area of the hypothalamus(SDN-POA) is five times larger in male vs female rats ○ Responsible for male typical sexual behavior Lesioning disrupts copulatory behavior Electrical stimulation elicits mounting and thrusting ○ Larger male SDN-POA dependent on early exposure to testosterone Do steroid hormones play a role in human sexuality? ○ Women Bilateral oophorectomy decreases circulating levels of ovarian steroids and sexual desire Estrogen-only therapies that produce periovulatory levels of circulating estradiol increase sexual desire in postmenopausal women ○ Men Testosterone increases sexual desire in men Heterosexual males have larger INA3 than heterosexual females or homosexual males ○ Replicated larger INAH-3 in heterosexual males vs heterosexual females ○ Did no replicate for heterosexual and homosexual males Erotic films more strongly activate the hypothalamus in hetero-sexual males vs hetero-sexual females Nucleus accumbens activity predicts not only weight gain but also sexual desire ○ NA works for all types of value 11/26 Rat Maternal Behavior Parental care is uncommon in invertebrates, fish, reptiles and amphibians ○ But is ubiquitous in birds and mammals Components of Rat Maternal behavior ○ Nursing  ○ Licking and Grooming ○ Nest building ○ Pup Retrieval Males and nulliparous female rates avoid or even attack pups Postpartum female rats are promiscuous maternal immediately postpartum ○ Dramatic changes after pregnancy Oxytocin Synthesis ○ Found in the hypothalamus of both men and women. Found specifically in the PVN and SON Maternal Behavior in Rats ○ Virgin female rates avoid or even attack pups ○ Intracerebroventricular(ICV) oxytocin elicits maternal behavior in virgin female rats Essentially if you give a rat that has not gone through pregnancy(mali porous) estrogen followed by oxytocin she will become promiscuously maternal. Will engage in motherly behaviors Rat Maternal Behavior ○ Males and nulliparous females will exhibit parental behavior 7 days of pup exposure Nulliparous females and males are aversive/avoidant to the pups scent Lesioning the olfactory bulbs or the medial amygdala accelerates the onset of parental behavior in males and nulliparous females housed with pups ○ Exhibit parental behaviors in 3 days instead of 7 Mesolimbic DA system and approach ○ Dopamine is released into the nucleus accumbens during maternal behavior ○ Lesions of VTA and NA disrupt maternal behavior ○ The mesolimbic DA system is more active in rat mothers that lick and groom their offspring more frequently Medial Preoptic Area(MPOA) ○ The MPOA has multiple parts Sexual Behavior in men(bigger than for women) which we already talked about There is also an area involved in parenting as well MPOA lesions disrupts maternal behavior ○ MPOA activates approach system and inhibits avoidance system For it to do that it needs the stimulus of the pups and exposure to estradiol/oxytocin ○ Oxytocin Receptors and Maternal Behavior  High licking and grooming rat dams have more OT receptors in MPOA Female prairie voles with more OT receptors in NA are more likely to exhibit spontaneous alloparental care in the absence of pregnancy Cuteness/Baby Scheme is an adaptation that makes adults want to take care of you ○ We saw more activation in the NA of the participants, making them want to take care of prairie voles. Clearly the mesolimbic dopamine is interacted with in humans as well The fathers with the strongest VTA response to looking at a photo of their child, were also the ones who were the most involved with their toddler child Oxytocin attenuates the amygdala response to infant cries in adult human females ○ Cry becomes less anxiety provoking. It inhibits that avoidance system in adult females Fathers have higher plasma OT ○ Giving the fathers intranasal oxytocin results in them engaging with their infant more via touch, vocally, etc Infant looks at their father more as a result, as they notice their fathers are more engaging than usual Infants are also releasing more oxytocin on their own as a result. This is a positive feedback loop ○ Increasing oxytocin in father→ More toddler engagement with toddler→ Increase in oxytocin/stares in the toddler Giving father’s intranasal oxytocin in creases the caudate nucleus response to pictures of the toddler child(Nigrostriatal pathway as opposed to the mesolimbic system) The Brain Reaction to viewing faces of opposite and same sex romantic partners ○ Similar pattern of activation and deactivation across both gender and sexual orientation It appears that who you romantically involved doesn’t affect activation. VTA is still active Prairie Voles ○ Life-long pair bonds following mating ○ Paternal care ○ Mate guarding Montane Voles ○ Promiscuous ○ No pair bonding ○ No paternal care ○ No mate guarding  Oxytocin and Vasopressin are the key to why prairie voles have pair bonding while montane voles do Prairie voles have more OT receptors in the NA compared to montane voles Prairie voles have more vasopressin receptors in the ventral pallidum Female prairie voles ○ Mating releases dopamine from midbrain(VTA) into NA and PFC ○ Mating releases OT from PVN of hypothalamus to NA Male Prairie Voles ○ Mating releases dopamine form midbrain(VTA) into the ventral pallidum ○ Mating releases vasopressin into the ventral pallidum *KEY DIFFERENCE Male prairie need to release both vasopressin and dopamine to have pair bonding(just dopamine for females) Intranasal oxytocin for females increased NA response to viewing pictures of their male partner. Did not do this for males though ○ It appears that the partner is more “valuable” Males were asked to walk towards an attractive girl ○ Those in relationships and took intranasal oxytocin kept more distance between him and the girl Oxytocin is maintaining the man’s pair bond. HE KNOWS WHERE HOME IS 12/3 Cooperation The Great Apes eat fruits, plants, insects Importance of food sharing in hunter gatherers ○ 1000 cal/person/day to maintain body weight What is the optimal strategy in an iterated PD? ○ Axelrod’s tournament2 Tit for Tat Nice(always start by cooperating) Retaliatory(if the other person does not cooperate you are going to stop cooperating) Forgiving Tit for Tat Weaknesses  Susceptible to mutual recriminations ○ Locked into mutual defection Doesn’t exploit undiscriminating altruists Psychological adaptation to support reciprocal altruism Trust Overcoming greed ○ Subjects with a greater tendency to persist with CC show stronger activation in the ventral striatum ○ More investors transfer the amount of money following treatment with Intranasal Oxytocin Oxytocin promotes trust Mesolimbic dopamine system is activated when we have mutual cooperation ○ Mutual cooperation leads to the strongest activation with the mOFC and ventral striatum There's a sense of fulfillment when you both cooperate Intranasal oxytocin increases the ventral striatum response to mutual cooperation Oxytocin is able to enhance the social reward of cooperating Discriminating against non-reciprocators ○ What brain regions respond to unreciprocated cooperation in the Prisoners Dilemna Game? Bilateral activation in the anterior insula for Uncreciporcated-reciprocated cooperation(CD-CC) Activation is due to the poor social interaction and not the monetary reward ○ The anterior insular(a somatosensory cortex) is activated by a variety of different negative social interactions Social exclusion Unfair offers in the ultimatum game Seeing a loved one go Responsible for the bad feeling we have when our cooperation is not reciprocated Summary ○ In contrast to other animal species, reciprocal altruism with non relatives is a common feature of human social life  ○ The iterated prisoner’s dilemma game is a model for relationships based on reciprocal altruism ○ Tit for tat is an effective PD strategy because it is “nice”, retaliatory and driving ○ Reciprocal altruism is dependent on the capacity to trust, reciprocate(restrain greed) and discriminate against non reciprocators ○ Trust may be facilitated by OT mediated suppression of amygdala activity ○ Reciprocation of trust may be facilitated by activation of brain rewards systems in response to mutual cooperation and by OFC frontal pole regions that value the long term benefits of cooperative relationships ○ The anterior insula may be involved in the bad feeling we have when our cooperation is not reciprocated and may motivate discrimination against non-cooperators 12/5 Lecture Notes- Language What’s special about language ○ Voluntary/volitional ○ Symbolic(semanticity or meaning) ○ Syntax: Organization of communication above the level of the single symbol What is language for ○ Language as a substitute for grooming Social bonding Efficient for large groups ○ Mapping physical and social environments Gossip ○ Coordinating actions when cooperating ○ Teaching and learning from others Some animals, such as parrots, dogs and non-human primates have limited symbolic abilities ○ Non-human vocabularies do not exceed 1,000 words ○ College graduates have a vocabulary of about 40k words Only humans combine thousands of arbitrary symbols according to a defined set of rules to create phrases with a nearly infinite variety of meanings The Classic Model ○ Damage to Wernicke’s area in the left hemisphere leads to deficits in speech comprehension  ○ Damage to Broca’s area in the left hemisphere leads to deficits in speech production ○ Damage to the arcuate fasciculus outside of Wernicke’s and Broca’s area leads to deficits in word repetition but intact speech comprehension and production abilities Brodman’s areas ○ Wernicke’s area= BA 22 In the superior temporal gyrus ○ Broca’s Area= BA 44, 45 Pars opercularis(BA 44) Pars Triangularis(BA 45) In the left inferior frontal gyrus ○ Semantic Areas= BA 21, 37, 39 Processing meaning of Words In the ventral lateral part of temporal lobe Macaque monkeys have areas with a similar architecture to humans ○ Only the left temporal gyrus is responsible for language production in the macaques Three neuroanatomical specializations for human language ○ Wider cortical columns in Broca’s and Wernike’s areas in humans(as opposed to monkeys) Means more integration from other brain regions ○ Leftwards asymmetries in Broca’s and Werinicke’s areas Human Wernicke’s area has leftwardly asymmetric minicolumns(not the case in chimps and other monkeys) Broca’s area volume is larger in the left hemisphere for humans ○ Expanded Articulate Fasciculus Pathway Pathway is leftwardly asymmetric(makes sense because language is usually in the left hemisphere) The pathway in chimps/monkeys is much shorter than in humans ○ Our’s is much more expanded which is likely why we have language and they do not. ○ It is theorized that as the language cortex expanded it pushed the visual cortex and the FFA(fusiform face area) in a posterior and ventral direction ○ Lesion studies for the Arcuate Fasciculus show that it is key for Word repetition Naming Complex Syntax Speech Fluency  Word and Sentence Comprehension FOXP2 Gene ○ Autosomal dominant mutation ○ Orofacial movement disorder manifest most strikingly during speech ○ Unlike other primate species, human evolution involved two amino acid changes to the FOXP2 protein Likely why we are seeing language in humans Neanderthals Neanderthals had the same version of the FOXP2 protein as humans have ○ Suggests that they likely had language as well 12/10 Lecture Notes- Theory of Mind/Empathy As humans we are really good at social learning because of Theory of Mind Mirror Neurons ○ Cells that discharge both when an individual makes a manual or orofacial gesture when the individual observes another individual making the same gesture Found in PF, Inferior Frontal Gyrus, BA 44(Broca’s area for monkeys) homolog , and BA 6(ventral part of prefrontal cortex) of monkeys ○ Mirror neurons in macaques ○ Superior Temporal Sulcus visually codes the actions of others ○ Mirror neuron map the actions onto the motor repertoire of the observer F5 codes the goal of the action ○ Form a natural link between the sender and the receive of a gesture that allows the receiver to stimulate the brain state of sender Simulation Theory ○ We understand other by imagining our own behaviors, feelings, or thoughts in a similar situation ○ Allow receiver to grasp the intentions of the sender Ballet and Capoeira video Expertise on a certain area can better run a simulation of that action better in your brain Ballet dancers react more to ballet videos and capoeira with capoeira  Empathy ○ Anterior Insula(under the sylvian fissure) Visceral somatosensory cortex Senses changes to our internal organs(talked about it in the prisoner’s dilemma game- bad feeling) Empathy for pain involves the affective but not sensory components of pain ○ Females subjects scanned in 4 conditions Painful electric shock Non-painful shock Painful electric shocks to male partner Non-painful electric shocks ○ Post scan empathy questionnaires Study showed anterior insula activation when both the women was shocked and when her spouse was shocked Showed that she is sort of “feeling his pain” as well. Hence empathy ○ More empathetic people have more anterior insula activation Bonobos have higher gray matter density in the right anterior insula explaining why they are likely more empathetic/less aggressive than chimps Theory of Mind System(Cognitive Empathy) ○ TOM stimuli in Neuroimaging studies Stories with fictitious stories Comic strips Shapes moving interactively with implied inventions(coaxing, tricking) vs shapes moving at random or in a goal-directed fashion(chasing, fighting) Real Social interaction that people are personally embed in ○ Brain areas activated in TOM neuroimaging studies Dorsomedial Prefrontal Cortex Posterior superior temporal sulcus/Temporal Parietal Junction Posterior cingulate/precuneus x Summary ○ Social learning is the foundation for human cumulative culture, and mental metnal perspective-taking facilitates social learning ○ Three different neural systems are involved in mental perspective taking  The mirror neuron system is involved in understanding others actions, including facial expressions The anterior insula is involved in feeling what others are feeling DMPFC, TPJ and Post. Cingulate/Precuneus are involved in understanding other’s knowledge and beliefs