IB SL psychology biological

what is the localization of function

 idea that every behavior is associated with a specific region of the brain

what is the cortex of the brain

• Covers the outside of the brain (largest part)

what is the cortex of the brain associated with

• higher-order functions such as abstract thought or voluntary action

what are teh four lobes the cortex is split into

frontal lobes, partietal lobe, occipital lobe, temporal lobe

frontal lobes

• reasoning, planning, thinking and decision making, voluntary action, complex emotions, etc.

parietal lobe

• movement, orientation, perception, recognition

occipital lobe

• visual processing

temporal lobe

• processing sound, memory, and speech

is the temporal lobe the only area of the brain that deals with memory

no! dont localize stuff

what is the limbic system made up of

emotions, thalamus, hypothalamus amygdala, hippocampus

what is the thalamus

-limbic system,  mostly sensory, nerves from almost all sensory organs go here

what is the hypothalamus

-limbic system, emotion, thirst, and hunger

what is the amygdala

limbic system, memory, emotion, and fear

what is the hippocampus

limbic system, learning, memory (transferring short-term memory), spatial orientation

what studies support the localization of the brain

neuroplasticity

 ability of the brain to change throughout the course of life

how does your brain chain

• Making/breaking synaptic connections between neurons

• Can be caused by genetic (normal brain development) and environmental factors (learning or injury)

what is a Synapse

•  formed where the axon of a neuron (the part that transmits signals) approaches the dendrite or soma of another neuron (the parts that receive signals)

what are two neurons connected by

synpase

when are neurotransmitters released into the synaptic gap (synapse) from the axon terminal

when the action potential teaches the axon

what are Neurotransmitters

• chemical messengers

what does excitary neurotransmitters do

• allow neural impulses to cross the synapse

what do inhibitory neurotransmitters do

• stop the neural impulse, preventing it from crossing the synapse

what happens when When excitatory and inhibitory neurotransmitters are out of balance

• there can be behavioral malfunctions (such as mental disorders)

what are agonists

• chemicals that enhance the actions of neurotransmitters

example of agonist

cocaine - blocks the dopamine transporters from carrying the dopamine out of the synaptic cleft.

antagonists

• chemicals that counteract a neurotransmitter and prevent a signal from being passed further

example of antagonists

selective serotonin reuptake inhibitors (SSRIs)

what do dendrites do

Dendrites are extensions of neuron cells that receive signals from other neurons, facilitating communication within the nervous system.

what are neural networks

Neural networks are interconnected groups of neurons that work together to process and transmit information, forming the basis of learning and memory within the brain.

Fisher, Aron, and Brown(2005) set up and reasoning

studied the effect of dopamine on romantic love. There were 10 men and 7 women who were “intensely in love” (not with eachither) and had been for an average of 7 months. They were all placedin an fMRI scanner and went through 4 stages of experimentation. Viewed picture of the person they were in love with for 30 seconds. 40 second filler activity (count backwards from a certain number). Viewed picture of emotionally neural acquaintance for 30 seconds. 20 seconds of counting backwards from a certain number. Repeat 6 times

Dopamine

excitatory neurotransmitter that is involved in our desire to get things done/motivation, in controlling the brain’s reward and pleasure centers, and in regulating emotional responses

results of Fisher, aaron, and Brown (2005)

Results showed specific pattern of brain activation when looking at loved ones

• Activation in dopamine-rich neural systems (specifically the ventral tegmental area and caudate nucleus)

• dopamine activity is a role in love

Computerized axial tomography (CAT scan)

computer linked to an x-ray machine to make a series of detailed pictures of areas inside the body

Electroencephalogram (EEG)

a functional imaging tool that seek to monitor brain activity. Data is shown through brain waves that are gathered from elctrodes on head.

Positron emissio tomography (PET)

measures metabolic activity of cells of body tissue, uses a scanning device to detect photon semitted by a radionucludid in the organ being examined

Magnetic Resonance Imaging (MRI)

noninvasive medical test that produces detailed images of almost every internal structure in body

functional magnetic Resonance Imaging(FMRI)

a type of MRI that can show which areas of your brain are most active

BOLD measure

tracks blood flow in different parts of the brain

Brain Stem

• main function is to regulate the basic vital processes such as breathing or heartbeat  

studies that support strict localization

Paul Broca (1861), Wernicke’s area(1874), Penfield

paul broca(1861)

• “Tan” (Louis Leborgne) lost the ability to speak

  • led to Broca’s aphasia(lost of articulated speech)

• When he died, Broca autopsied his brain and discovered a lesion in a region that is now known as Broca’s area and is associated with speech

wernicke’s area (1874)

• discovered Wernicke’s aphasia

  • Can talk fine, but can’t comprehend speech

Penfield

• Map of sensory and motor cortex (cortical homunculus)

• Stimulated certain parts of the brains of his patients and observe the effects on behavior

Relative localization

• localization for some functions under certain conditions, but localization is limited

synaptic plasticity (smallest scale)

• the ability of the neuron to form new synaptic connections and break up the old ones  

cortical remapping (largest scale)

•  the phenomenon when brain area X assumes the functions of brain area Y (example: due to injury) 

study for remapping of the sensory cortex

merzenich et al (1984)

merzenich et al (1984) Why and results

• Researchers studied the cortical representation of the hand in eight adult owl monkeys 

• Results: 

  • 5 distinct areas in the brain → each responsible for 1 finger, and adjacent fingers were represented in adjacent areas in the cortex 

Draganski et al (2004) why and set up

-neuroplasticity

• Two groups of participants: jugglers and non-jugglers (even though none of them could juggle)

  • Preliminary brain scan taken of all participants

• “Juggler” group members took juggling classes for three months

  • Brain scan taken after three months

• Three months in which jugglers were told to not practice at all

  • Another brain scan taken after these three months

• Non-jugglers lived their normal life besides having their brains scanned at the same intervals

Draganski et al (2004) results

• Baseline brain scans were the same. After second scan, juggler group had significantly more grey matter in the cortex (specifically the midtemporal area) of both hemispheres, which is known to be associated with coordination of movement. After the third scan, grey matter of jugglers was still larger than the baseline scan

  • Juggling participants who trained better had more changes in grey matter than jugglers who weren’t as good

what did Draganski et al (2004) learn ab the brain

• Brain grows as you learn things, but without practice, they shrink again

Draganski et al (2006) set up

• 38 med students and 12 controls that matched in age and sex

• Baseline brain scan taken three months before med school exam, scan taken a day or two after exam, and third scan taken three months after

Draganski et al (2006)

• No difference in grey matter at baseline but two changes overtime

  • Med students had increased grey matter in the parietal cortex of both hemispheres after the second scan and this growth didn’t decrease after the third. The information they learned stuck with them

  • Increase of grey matter in posterior hippocampus that continued to grow after taking the exam 

what did draganski et al (2006) support the role of

• Supported the role of these two areas in the formation of new memories

Maguire et al (2000) set up

• Participants were 16 healthy right-handed males who were licensed taxi drivers in London

  • To get the license, they had to undergo intense training and pass a series of difficult examines

  • Years of experience ranged from 1.5 to 42

  • Brain scanned via MRI

• 50 control participants with similar characteristics (healthy right-handed males within a certain age range) also had their brains scanned

maguire et al (2000)

• Increased brain matter volume in posterior hippocampus in taxi drivers

  • Controls had more grey matter in anterior hippocampus

  • No difference in overall volume of hippocampus, it was just distributed differently (“shift” of brain matter)

what was the differences between taxi drivers in maguire et al (200) due to

a result of nerouplasticity- Correlation between hippocampal volume and the amount of time spent as a taxi driver was examined

• Significant positive correlation between experience as taxi driver and hippocampal volume

what is a hormone

• Another kind of chemical messenger that’s released into the bloodstream (can cover more areas than neurotransmitters)

what doo hormones do

• Regulate long-term, ongoing processes such as growth, metabolism, reproduction, etc.

Can some chemicals be both neurotransmitters and hormones

yes- the nervous system and endocrine system can interact with eachother

what are hormones released by

released by endocrine glands

what are all the endocrine glands

• Adrenal glands

• Hypothalamus

• Pineal gland

• Pituitary gland

• Thyroid

• Parathyroid

• Thymus

• Pancreas

• Testes

• Ovaries

what are target cells

cells that have receptors for the particular hormone

what biologically can hormones affect

target cells

what do hormones activate or surpress

certain genes- hormones don’t affect our behavior directly

what happens when a hormone binds to a receptor

, it launches a sequence of changes, some of which are genomic:

gene activation or gene suppression

hormones do not influence behaviour directly, instead change the probability that a certain behaviour will occur in response to a certain environmental stimulus 

what are hormones produced in the body

• adrenaline, noradrenaline, cortisol, oxytocin, insulin, testerone, oestrogen, oxytocin

where is oxytocin produced and where is it released

• the hypothalamus and released into the blood by the pituitary gland 

what is oxytocin and its role

plays a role in sexual reproduction, childbirth, and social bonding → referred to as “the love hormone”, “the bonding hormone”, “the cuddle chemical”

studies for oxytocin

romero et al (2014), kosfeld et al (2005) Scheele et al (2005), De Dreu et al (20012)

Romero et al(2014) set up

• Dogs received either oxytocin or placebo via nasal spray and then placed in a room with their owner and another dog for an hour

  • Owner was told to move around every ten minutes but not actively interact with the dog

Romero et al (2014) results

• Dogs sprayed with oxytocin showed a higher affiliation towards their owner

  • Operationalized as sniffing licking, gentle touching, playful bouts, and body contact

  • Also spent significantly more time in close proximity to the owner

what did other dogs do to the test dog in Romero et al (2014)

• Other dog in the room approached test dog more if the test dog had oxytocin

what happened the more the dog interacted with uts owner- Romero et al (2014)

• The more the dog interacted with its owner and the other dog, the more oxytocin it produced

• Oxytocin promotes social interaction and social interaction triggers the release of more oxytocin

The Role of Oxytocin in Interpersonal Trust

• Kosfeld et al(2005)

• concluded that oxytocin specifically affects trust in impersonal interactions 

The Role of Oxytocin in Fidelity

• Scheele et al(2005)

• by selectively influencing men in a relationship to keep greater distance from attractive women they do not know, oxytocin may promote fidelity 

The Role of Oxytocin in Inter-Group Conflict 

• De Dreu et al (2012)

• negative effects of oxytocin 

• concluded that oxytocin-induced non-cooperation is motivated by the desire to protect vulnerable group members (not as much desire to protect oneself) → reinforces the role of oxytocin in creating bonds with the members of the ingroup, but also shows how oxytocin has a reverse, negative side (defensive and non-cooperation with others) 

Scheele et al(2005)- oxytocin in infidelity set up

• Participants were 86 straight men, some single, some in a relationship

• All got either oxytocin or a placebo via nasal spray

• Two tasks

  • “Stop-distance paradigm”

    • Subjects stood on a marked line on one side of a room and an attractive female stood on the other side

    • Participant had to walk closer to her until he was at a distance where he felt slightly uncomfortable (too close)

  • “Approach/avoidance task”

    • Participants viewed a series of pictures on a screen 50 cm away. Pictures were flashed for 2 seconds each

    • Pictures were either positive social (attractive women), positive nonsocial (beautfiul landscape), negative social (mutilations), and negative nonsocial (dirt)

    • If they liked the picture, they were told to pull on the joystick in front of them that zoomed the image in and if they didn’t like it, they were told to push the joystick away which zoomed it out

results of Scheele et al (2005)

• First task

  • Men with oxytocin who were in a relationship kept a greater distance than any other group

• Second task

  • Men with oxytocin who were in a relationship had a slower reaction time to the pictures of attractive women

    • More reluctant to pull the joystick

  • Oxytocin selectively inhibits approach to certain stimuli (attractive women) in men who are in a relationship but not in single men

• Oxytocin promotes fidelity

The Role of Oxytocin in Human Ethnocentrism

De Dreu et al(2011)-oxytocin creates inter-group bias by increasing ingroup favouritism

what are pheromones

Chemical communication among species

where do most mammals process pheromones

• in the vomeronasal organ which connect to a special region in the brain called the accessory olfactory bulb

  • Humans don’t have either of these systems

Criticism of human pheromone research

• Population validity: most experiments are self-selected samples, not much diversity

• Participant bias: to determin eif participants qualify for experiment, some details about the aim of the experiment need to be revealed

• Ecological validity: studies use concentration of pheromone that is much higher than what’s naturally produced

• Internal validity: difficult to control participants’ oderlessness

• Experimenter bias: gender, looks, behavior of experimenter could affect results and are difficult to control

• Construct validity: even if chemicals have an effect on participants, it doens’t mean they’re pheromones

• Ethics: some experiments can be gross and/or personal

pheromone studies

Lundstrom and Olsson(2005), Hare et al (2017), Cutler, Friedman and McCoy(1998), McCoy abd Pitino(2002)

Lundstrom and Olsson (2005) set up and results

• Studied women’s moods after being exposed to either androstadienone or a control substance and then being in the presence of a male or female experimenter

• Androstadienone increased women’s mood in the presence of a male experimenter but had no effect when the experimenter was female

Androstadienone

• derivative of testosterone and chemical  component of sweat

Hare et al (2017) set up and results

• Men exposed to potential pheromones were asked to assign genders to facial morphs and rate their attractiveness

• Chemicals had no affect, suggesting that they’re not pheromones

Cutler, Friedmann, and McCoy(1998) set up and results

• 38 men tracked their sexual behaviors for two weeks, then tracked them again for 6 weeks while using aftershave lotion with a pheromone in it or a control lotion

• Men with pheromone saw a significant increase in amount of sexual behavior with women, but not by themselves

genotype

set of traits encoded in DNA

phenotype

• physical manifestation of traits (appearance or behavior)

nature vs nurture

• Is human behavior determined primarily by biological actors (genetics) or environmental factors (education/friends)?

Genetic heritability

• the quantitative measure of the relative contribution of genetic factors into a trait or behavior

falconer model

• Phenotypes are influenced by genetics, shared environment, and individual environment

falconer model example

• 1 = A + C + E

  • 1 is 100% of observed variation in the phenotype (nothing else influence the phenotype except these three variables)

  • A = genetic inheritance

  • C = shared environment

  • E = individual environment

niche-picking

• phenomenon when genetic predisposition causes individuals to select environments that start to affect their behavior

methods of research in genetics

• Twin studies

• Family studies

• Adoption studies

• Molecular genetics

twins-study-Bouchard and McGue (1981)

• Compared the IQ correlation between MZ (identical) twins reared together, MZ twins reared apart, DZ (fraternal) twins reared together, siblings reared together, parents/offspring reared together, siblings reared apart, parent/offspring reared apart, and adoptive parent/offspring

Bouchard and McGue (1981) results

• Using Falconer’s formula, they calculated that intelligence is 54% genetically inherited