PSY100 Midterm #1 UofT

Empiricism

The view that knowledge comes from observed/sensory experience

Empirical evidence

Refers to the data that has been collected (or the knowledge that has been gained) by scientific observation

What is the role of theories?

Scientific theories typically explain the relationship between two or more variables.

What must scientific theories be?

Testable, falsifiable, parsimonious

What is the intergroup contact theory by Pettigrew?

That under certain circumstances, positive intergroup contact can reduce prejudice toward the outgroup

What is the social comparison theory by Festinger?

When more objective measures are unavailable, people will evaluate their own abilities/qualities by comparing themselves to similar ones

What is an Operational definition

Definition of theoretical constructs that are stated in terms of concrete, observable procedures

What is a construct?

Internal attributes or characteristics that cannot be directly observed but are useful for describing and explaining behaviour such as intelligence and anxiety

What are the different types of research?

Descriptive research - involves observations and case studies, and may result in claims regarding the frequency of some behavior.

Correlational research - May lead to claims regarding the association between two variables and looking at the relationships between two things

Experimental research - May lead to claims regarding the causal relationship between two variables and finding out what causes what

What is a confound?

Anything that may unintentionally vary along with the independent variable, they limit our ability to make causal claims. For example if the independent variable is amount of caffeine and the dependent variable is how well students perform on test, a confound could be amount of time preparing for test, or amount of classes attended that would affect the results.

What is Random assignment?

Each participant has an equal chance of being assigned to each experimental condition. It ensures groups are equivalent on average.

What is a random sample?

Each member of the population you are interested in has an equal chance of being chosen to participate

What is a population?

The group that you want to be able to generalize your findings to

What is a sample?

The group of individuals from this population who are actually a part of your study

Discuss Quasi-Experiments

Look a lot like "real" experiments, but they have no random assignments to conditions and the risk of potential confounds limits the claims that a researcher can make. However they can be very useful for studying variables where manipulation isn't possible or ethical.

Discuss correlational studies

They tell us about relationships between variables. For example " There is a relationship between academic success and self esteem" or " There is a relationship between outdoor temperatures and ice cream sales". These are positive examples meaning both variables change in the same direction. However remember that Correlation is not causation. There could be a third variable problem or a directionality problem.

What are the different types of data collection methods?

Observational technique, Self report method, Response performance.

What are the different types of observation?

Naturalistic observation: Passive, observers do not change or alter anything intentionally.

Participant observation: Active observation. The researcher is actively involved in the situation.

Laboratory observation: Systematic observations are made within a laboratory setting rather than in the real world.

Discuss Self-Report bias

People will respond in a socially desirable way, what they think others would want to hear instead of how they actually feel. People will also rate their abilities to do something if asked, better than average.

Discuss response performance.

Things are tested like reaction time, response accuracy and stimulus judgements. These things are used to quantify perceptual or cognitive processes in response to a specific stimulus.

For example how long does it take you to name the colour of a word?

What is the stoop effect?

Words that spell out a different colour than the colour of the font are presented and you are asked to name the colour of the font. However your responses are delayed because we automatically read the words and this causes a mismatch of information in our brains.

How do we know that we have good data?

Good date must be:
- Accurate
- Valid
- Reliable

Discuss the accuracy of data and the two different types of error that can occur.

Accuracy refers to the extent to which an experimental measure is free from error.

Random error: Statistical fluctuations in either direction from the precision limitations of whichever measurement device you are using. They usually come from the experimenters inability to take the same measurement in the exact same way every time.

Systematic error: Any biasing effect, in the environment, methods of observation or instruments are used, which introduces error into an experiment and always affects the results of an experiment in the same direction.

Discuss the validity of data as well as the 3 types of validity.

Validity refers to the extent to which the collected data addresses the hypothesis in the way intended (Are we measuring what we mean to measure?)

Construct validity: The degree in which the independent and dependent variables in a study truly represent the abstract and constructs in which the researcher is interested.

Internal validity: The extent to which your findings provide evidence of causality. Laboratory experiments tend to be high in internal validity because they eliminate confounds.

External validity: The extent to which your findings accurately describe what happens in the real world.

What is a Double blind study?

An experiment in which neither the participant nor the researcher know who is receiving the treatment. Very effective in eliminating bias.

Discuss the Jim Twins

Identical twins that were separated at birth and raised completely different and ended up being the exact same for even the uncanniest of things.

Discuss Twin + Adoption studies

They help researchers study the impact of genetic versus environmental influences. Looking at monozygotic and dizygotic twins but in specific the difference between monozygotic twins raised apart and separately.

What is Epigenetics?

Changes in gene expression due to non-genetic factors, like the environment. Epi = outer.

Discuss the experiment of role of genotype in the cycle of violence in maltreated children.

Nature predictor variable: Type of MAO-A Gene, in lower or higher levels

Nurture Predictor variable: Maltreatment during childhood or not

Outcome variable: Whether or not they are convicted of violent crime by the age of 26

Result: Low-MAO gene + maltreatment results in increased probability of being a violent criminal.

What is Heredity?

The genetic transmission of characteristics from parents to offspring.

What is the heritability coefficient?

The degree of variation in a phenotypic trait as a result of genetic diversity in the population.

What is the estimated heritability of intelligence?

Between 40 and 80%

What are the different components of the nervous system?

CNS = Central Nervous System: Brain and Spinal cord

PNS = Peripheral Nervous System: Comprised of the Somatic and the Autonomic nervous system.

Autonomic nervous system is further broken down into the sympathetic and parasympathetic nervous systems.

What is a neuron?

It is the basic unit of the nervous system which operates through electrical impulses and communicates with other neurons through chemical signals.

What are the different types of Neurons?

Sensory (Afferent)
Motor (Efferent)
Inter Neurons

SAME (Sensory, Afferent, Motor, Efferent)

What is an action potential?

The neural impulse that passes along the axon and subsequently causes the release of chemicals from the terminal buttons.

Discuss Excitatory and Inhibitory signals

Excitatory signals increase the likelihood that the neuron will fire

Inhibitory signals decrease the likelihood that the neuron will fire.

They do this by affecting the polarization of the cell

The neurons fire if the excitatory input reaches a certain threshold.

What is the all or none principle?

A neuron fires with the same potency each time, there is no fire that is stronger or not. it either fires or it doesn't. However how frequently they fire can vary.

Discuss saltatory conduction

If an axon is myelinated action potentials are a lot faster. There is 20-300 layers of insulation over the ranvier, so each time the action potentials are regenerated at each node to overcome the next level of insulation and this speeds up the process but if it is unmyelinated than the action potential is slower and it goes through like a regular electrical circuit.

Discuss the resting state of a neuron

Neurons are polarized at rest and the resting membrane potential is about 70mV. The inside of the cell is more negative than the outside. There is more Na outside and more potassium inside.

Discuss depolarization

If the neuron reaches its excitatory threshold, it will fully depolarize causing it to fire. The Sodium channels open and the charge across the membrane reverses (becomes more positive inside of the cell because of the influx Na+)

Discuss repolarization

At the peak of the action potential, Sodium channels will close and potassium channels will open, allowing potassium to leave the cell. This outflowing potassium leads to a temporary overpolarization, in which the cell cannot fire. This is called the refractory period.

Discuss neurotransmitters.

They are chemical substances that carry signals from one neuron to another and are stored in vesicles inside of the terminal buttons. Action potentials cause the vesicles to fuse to the presynaptic membrane and release their contents into the synaptic cleft, where they are received by postsynaptic receptors on the postsynaptic membrane. Ligand-gated channels with receptors for neurotransmitters control what is let into the postsynaptic neuron. Dendrites receive them and terminals transmit.

Discuss the common neurotransmitters and their functions.

Glutamate - Primary excitatory transmitter

GABA - Primary inhibitory transmitter

Serotonin - Mood, impulsiveness, hunger, sleep

Dopamine - Reward and motivation, voluntary movement

Acetylcholine - Motor control at the junctions between nerves and muscles, learning, memory, sleep

Epinephrine - energy

Norepinephrine - arousal, alertness

What do high levels of dopamine, low levels of serotonin and a breakdown of production in Acetylcholine cause?

High levels of dopamine = Schizophrenia

Breakdown of Acetylcholine = Alzheimers

Low levels of serotonin = Depression

What do agonists do and what are some examples of them?

Agonists enhance neurotransmitters actions by:

Increasing the release of neurotransmitters

Blocking the re-uptake of neurotransmitters

Mimicking a neurotransmitter and activating a postsynaptic receptor

Cocaine and meth are some examples.

What do antagonists do and what are some examples of them?

Antagonists inhibit neurotransmitters actions by:

Blocking the release of neurotransmitters

Destroying neurotransmitters in the synapse

Mimicking a neurotransmitter and blocking neurotransmitter binding.

Beta blockers and Botox (botulinum toxin) are some examples.

What are the following responsible for:

Cerebral cortex:
Limbic system:
Basal ganglia and Cerebellum:
Brain stem:

Cerebral cortex = complex mental activity

Limbic system = Emotion and basic drives

Basal ganglia and cerebellum = movement

Brain stem = survival

Discuss the brainstem

- Controls life sustaining functions of the autonomic nervous system, including breathing, digestion, heart rate, etc. It is made up of the Midbrain, the pons and the medulla.

Reticular formation controls your alertness and sleep.

Discuss the Cerebellum

Essental for coordinated movement and balance

Discuss the hypothalamus

A region of the brain lying right below the thalamus, it is tiny but powerful and is the brains master regulatory structure. It connects the nervous system to the endocrine system and is vital to:

Hunger
Thirst
Body Temperature
Fatigue
Anger
Love
Metabolism

Discuss the Thalamus

The Thalamus is the gateway to the brain, and the gatekeeper of higher cognitive functioning. It is often known as a relay station, it handles all incoming sensory information except for smell. Tatiana and Krista Hogan are conjoined twins who share a bridge between the thalamus.

Discuss the Hippocampus

It is very important for the storage of new memories.

A hippo on campus? Ill never forget seeing that!

Discuss the Amygdala

It is essential to our ability to associate things with emotional responses and is located in front of the hippocampus. Intensifies memory's function during times of emotional arousal.

Discuss the cingulate gyrus

Regulating emotions and pain and is meant for predicting and avoiding negative consequences

Discuss the basal ganglia

It is a system of subcortical nucluei:

Caudate nucleus
Putamen
Globus pallidus
Nucleus accumbens

Also important in producing and planning movement.

The context sends a message to the basal ganglia which sends a message to the motor centres of the brainstem. Also projects back to the cortex's motor planning area through the thalamus.

What is the cerebral cortex

The outer layer of the brain, each central hemisphere has four lobes and the corpus callosum which is a massive bridge of axons connects the hemispheres and allows information to flow between them.

What are the lobes of the cerebral cortex and their functions?

Occipital lobes - vision and the primary visual cortex.

Temporal lobes - Hearing and the primary auditory cortex.

Parietal lobes - Touch and the primary somatosensory cortex.

Frontal lobes - Planning and movement and the primary motor cortex along with the prefrontal cortex.

Discuss the prefrontal cortex

It is approximately 30% of the human brain. It is very important for attention, working memory, decision making, social behaviour, personality. In many ways your prefrontal cortex is what makes you who you are.

Discuss the cortical sensory and the homunculi

Connected parts of the body tend to be represented beside each other. More sensitive regions tend to have more cortical area devoted to them like the lips and fingers.

Discuss the plasticity of the brain.

The brain is "plastic" and is able to be changed, reorganize as a result of experience, drugs or injury. Rats raised in an enriched environment had full and complete neurons while rats raised in impoverished environments had small and incomplete neurons.

Discuss the Peripheral nervous system

Transmits info to the CNS, responds to messages form the CNS to perform certain behaviours or make bodily adjustments and is divided into the SNS (somatic nervous system) and the ANS (autonomic nervous system)

Discuss the Somatic nervous system

Concerned with the external environment and controls functions that are under conscious and voluntary control. It consists primarily of motor neurons responsible for sending signals form the brain to the muscles. CNS to the SNS to the muscles (efferent pathway) . It also contains sensory neurons which send signals to the brain. Muscles to the SNS to the CNS (afferent pathway)

Discuss the Autonomic nervous system,

Concerned with the internal environment. Glands and internal organs will send a message to the CNS through the somatosensory neurons. or the CNS will send a message to the glands and internal organs through motor neurons and the signals from the CNS to the glands are split up into sympathetic division and parasympathetic division.

Discuss the sympathetic division of the ANS

It prepares the body for action (fight or flight). Pupils dilate, lungs relax, heartbeat strengthens, stomach and intestine activity is inhibited and blood vessels contract. If this system is activated chronically or too often it will cause high blood pressure, heart and kidney failure.

Discuss the parasympathetic division of the ANS

Returns the body to its normal state (rest and digest or feed and breed). Opposing functions of sympathetic. If this system is activated chronically or too often it can cause low blood pressure, depression and withdrawal.

Discuss the Endocrine System

It works with the nervous system to regulate psychological activity. The nervous system uses electrochemical signals, the endocrine system uses hormones. Hormones are chemical substances that are released into the bloodstream by endocrine glands until they reach the targeted tissues. The communication is slower because it is through the bloodstream but effects are longer lasting and more widespread.

Discuss coordinate systems in biopsych.

The hypothalamus connects the systems and the pituitary gland is the master gland. Neural activation causes the hypothalamus to secrete a releasing factor (corticotrophin-releasing factor) which causes the pituitary gland to release a hormone specific to that factor (adrenocorticotrophic hormone) the hormone than travels through the bloodstream to target sites throughout the body (adrenal cortex and releases cortisol)

Discuss the HPA Axis

Hypothalamus, Pituitary gland, adrenal cortex. Stress (psychological or physical) causes the hypothalamus to secrete CRF which activates the pituitary glands to release ACTH to the adrenal cortex which releases cortisol.

What is the difference between perception and sensation?

Sensation: Involves the detection of external stimuli (light, pressure, odours) responses to those stimuli, and the transmission of these responses to the brain.

Perception: Involves the processing, organization, and interpretation of sensory signals int he brain, which results in an internal representation of the stimuli and our conscious experience of it.

What is transduction?

Process by which sensory receptors pass impulses to connecting neurons when they receive stimulation. Most of this information aside from smell goes to the thalamus before being directed to a particular part of the cortex, where the information is then interpreted as sight, smell, taste, etc.

What is an Absolute threshold and a difference threshold

Absolute threshold is the minimum intensity of stimulation required before you experience a sensation.

Difference threshold is the just noticeable difference between two stimuli , the minimum amount of change required for someone to detect a difference (Webers law)

Discuss the sensation of taste

The stimuli for taste are chemical substances from food that dissolve in saliva. Taste receptors , found in taste buds, send signals to the brain, which then produces the experience of taste. Every taste experience is composed of a mix of five basic qualities: Sweet, Salty, Sour, Bitter and umami (savoury)

Discuss the sensation of smell

The stimuli for smell are chemical substances from outside the body that dissolve in fluid on mucous membranes in the nose. The olfactory epithelium (or mucosa) is a thin layer of tissue embedded with smell receptors, which transmit information to the olfactory bulb, which is the brain centre for smell.

Discuss the olfaction test

Thousands of receptors, poorly understood. We are good at discrimination and good/bad judgements, but not at naming specific odours from scent alone.

What is the orbitofrontal cortex (OFC)?

Receives info from smell, taste and visual systems and is involved in flavour perception.

Discuss the sensation of touch.

Temperature, pressure, pain. There are mechanoreceptors that respond to mechanical distortion or pressure. The most sensitive mechanoreceptors are found in the cochlea which is responsible for sound transduction.

What are Nociceptors?

Pain receptors, activated by damaging or possibly damaging stimuli like being pierced or burned. There are the A delta fibres which are myelinated for sharp immediate pain meant for protection. As well as lightly or non-myelinated C fibres which give a dull steady pain meant for recuperation.

What is gate control theory of pain

For pain to be experienced, pain receptors must be activated, AND, the neural gate in the spinal cord must allow the signals through the brain. If the gate is open pain is experienced, if it is closed pain is reduced or prevented.

What is accommodation of vision

Muscles change the shape of the lens, flattening it to focus on distant objects, and thickening it to focus on closer objects

discuss the transduction of vision

Photoreceptors convert the energy from light particles (photons) into a chemical reaction that produces an electrical signal

What is the difference between Rods and Cones

Rods are retinal cells that respond to low levels of light, and result in black and white perception, about 120 million in each retina, located along the edges.

Cones are retinal cells that respond to higher levels of light, and result in colour perception. About 6 million in each retina, located in the fovea.

How is vision transmitted.

Rods/cones send message to Bipolar, Amacrine and horizontal cells which relay to the ganglion cells and the optic nerve which continues onto the thalamus and then goes to the primary visual cortex, than either the where or what stream.

Discuss what versus where for vision.

Visual areas beyond the primary visual cortex form two parallel processing streams.

Dorsal (where): Specialized for spatial perception, determining where an object is and its spatial relation to other objects.

Venral (what): Specialized for perception and recognition of objects, such as determining colour and shape.

What are the three types of cones and their wavelengths and colours perceived.

S cone = short waves and blue light

M cone = medium waves and green light

L = long waves and red light

What is trichromatic theory

the perception of colour is determined by the ratio of activity among these three types of receptors.

What is opponent process theory

Would you ever see a colour that you would describe as being reddish green or bluish yellow? There are three opposing pairs, if one colour is stimulated the other is inhibited.

Red/Green
Yellow/Blue
White/Black

What are the Gestalt Principles of perceptual organization

Principles that help to explain ho we perceive objects in our environment, how we organize elements into groups in order to perceive a unified whole.

Figure-ground relationship:

Whatever is not the figure (focus of visual field) is automatically assigned as the background

Proximity

The closer two figures are, the more likely we are to group them together and see them as being part of the same object

Similarity

We tend to group figured according to how closely they resemble each other

Good continuation

We tend to interpret intersecting lines as continuous rather than changing direction radically

Closure

We tend to complete figures that have gaps

Illusory contours

We tend to perceive contours, even when they don't exist

What is the difference of bottom up processing and top down processing

Bottom up: information sent from lower level to higher level processing areas.

Top down: Information from higher level can influence lower levels in processing hierarchy, expectation inform perceptions.

Binocular disparity

important cue of depth perception caused by the distance between the eyes, which provides each eye with a slightly different image. The brain uses the disparity between these two images to compute distances.

Monocular depth cues

occlusion, relative size, familiar size, linear perspective, texture gradient, position relative to horizon.

Motion cues

motion parallax, objects farther away seem to move more slowly than objects that are closer.

What is contralateral organization?

Right side of brain controls left side of body and vice versa.

What happens if the corpus callosum is severed?

Two half brains, each with its own perceptions, thoughts and consciousness.