Midterm 1 Flashcards
Why do we need psychological Science ?
- Our natural thinking style can fail:
- hindsight bias
- overconfidence error
- Mistakenly precising order in random events - Using science makes us objective and accurate
The Five Characteristics of Good Research
- Use of objective measures
- Generalizability of results
- Reducing sources of bias
- Reporting the findings
- Replication
Objective measures (4 points) :
- The measure is consistent across instruments and observers
- Use of operational definitions helps with objectivity
- The measure must be valid
- The measure must be reliable (test-retest reliability, Alternate-forms reliability, inter-rate reliability)
Generalizability of results (3 points)
- How likely are the results to be found in situations, people, or events
- Ultimately, researchers attempt to make conclusions about a population based on data collected from a sample
- In order to make conclusions about a population based on a sample, you need sample = population (Random Sampling or Convenience Sampling)
Random Sampling
Making sure that every individual in the population has an equal chance of being included in your sample
Convenience Sampling
using samples of individuals who are most readily available
Reducing Sources of Bias:
-Researcher biases
Can control using a Double-blind procedure (neither the researcher nor the participants know what group they’re in
Researcher Biases
When the researcher's own expectations or theoretical slant can influence the study -Three ways researcher bias can occur: Intentional -Wish fulfillment Accidental and inadvertent
Reducing Sources of Bias
1, Participant Biases
- Hawthorn effect
- Demand characteristics
Hawthorne Effect
When participants show a change in behavior due to the fact they are being observed
Demand Characteristics
-Inadvertent cues detected by the participant about how they’re expected to behave in the study (social Desirability, Placebo Effect)
Social Desirability
When participant responses are based more on social acceptability than honesty
Placebo Effect
When participants show change in behavior due to their expectation that their behavior should change
How to Reduce sources of bias?
- Assure participants that their responses are anonymous and confidential
- Assure participants that you’re not looking at individual responses but only group averages
- Use a blind procedure
Reporting the Findings
- written publication in a research journal and/or presentation at a conference
- Peer Review = allows your work to be reviewed, criticized, and scrutinized by other experts in the field
Replication
The process of repeating a study and finding a similar outcome each time
Five Characteristics of Poor Research
- Untestable hypothesis
- Anecdotal evidence
- Data selection bias
- Appeal to authority
- Appeals to (so-called) common-sense or novelty
Research Methods
a set of methods that allows a researcher to test a hypothesis, or a specific prediction about behaviour
Experimental Research (3 bullets)
- the researcher manipulates a variable
- there are different groups of participants and each group is exposed to something different
- allows causal conclusions
Correlational research (4 points)
- How are the variables related to each other
- Researcher just measures two (or more variables) and uses statistics to see if they’re related
- nothing is manipulated
- calculated statistic is called the correlation coefficient and is symbolized by r
Descriptive Research
- allows researchers to describe the characteristics of the phenomenon of interest in the study
- use three methods of data collection to gather this information (case studies, naturalistic observations and surveys and questionnaires)
The case Study
-An in depth investigation of a single participant using a bunch of different data collection techniques
The advantages to a case study
can be a source of support for theories about the cause of behaviour
Disadvantages to a case study
results may not generalize to the rest of the population
Naturalistic Observation
observing and recording the participant’s natural behavior, without influencing the participant
Advantages and Disadvantages to Naturalistic observation
Advantage: behavior is studied under natural conditions
Disadvantages: Difficult to not influence behaviour; requires a lot of patients
Survey and Questionnaire
Participants are asked a series of questions about certain aspects of their behaviour
Advantages and Disadvantages about surveys
Advantages: good to study behaviours that cannot be directly observed; can collect a lot of data in a short amount of time
Disadvantages: careful of wording effects; results depend on what the participant themselves say
Correlation Coefficient
The value ‘r’ tells you how much the two variables you measured are related
Correlation is not causation (explain)
a relationship between two variables doesn’t mean one variable caused the other, because it is equally plausible of many different options. either one causes the other or some type of third party
Advantages and disadvantages of Correlational research
Advantage: useful for studying topics that can’t be studied using experimental methods
Disadvantages: doesn’t allow for causal conclusions
Independent Variable
the variable that is manipulated
dependent variable
variable that is measured
Experimental Group
the group that receives the manipulation
Control Group
The group that does not receive the manipulation
Cause-effect conclusions (explain)
-if the onlu difference between the two groups are the independent variable, then any difference found between groups must be caused by the independent variable
Random Assignment
when each person in your study has an equal chance of going into either of your groups
Between-subjects Design (experimental variations)
when each participant serves in only one group and is tested once
Within-subjects Design (experimental variations)
when each participant is tested in each experimental condition
Quasi -Experiments (experimental variations)
-when the group comparisons in an experiment are based on predetermined characteristics instead of random assignment
(eg comparison between men and women)
-useful to point out differences among preexisting groups, but not causal conclusions
Experiment Research
Advantages and Disadvantages
Advantages: Cause-effect conclusions
Disadvantages: artificial and too simple
-may have ethical and/or practical issues
Glial cells:
found throughout the nervous system
-provide structural support, nourishment, and insulation to the neurons
Neurons
- Directly involved in communication
- Receive, integrate, and transmit information to and from other neurons
Resting Potential:
- If an axon is not sending or receiving any signals, then it is negatively charged at about -70 mV
- Two reasons for negative charge when neuron is in this balanced, resting state (Concentration gradient and Electrostatic gradient)
Concentration Gradient
The tendency for molecules, which are always in motion, to distribute themselves evenly in their environment
-will move from high concentration to low, and low to high
Electrostatic Gradient
ions (molecules with a positive or negative charge will attract or repel each other depending on their electric charge (opposites attract)
Resting Potential (what’s happening)
-Organic ions (a-) (stuck inside cell)
-Potassium ions (K+):
-flows relatively freely across membrane
-concentration gradient wants to push k+ outside cell
-Electrostatic gradient wants to keep K+ inside cell
Sodium ions (Na+);
-Concentration and electrostatic gradients both want to push Na+ inside cell
Why does Na+ stay concentrated outside the cell???
- Difficult to move across membrane
- Sodium-potassium pump (continuously pushes three Na+ ions outside the cell in exchange for two k+ ions
what do you think would happen if Na+ ions were suddenly given an open pathway to get inside the cell?
- Na+would rush into the cell
- this is basically what causes an action potential: (sudden and brief increase in the permeability of the cells membrane)
- Done with help from the voltage-gated sodium channel (detects the charge separation across the membrane and opens up channels for Na+ to cross the membrane
Action Potential
- First, the membrane must be depolarized, or made less negative, by 10 or 20mV
- If cell depolarization reaches a certain level, called threshold, than Na+ channels open
- Neuron’s electric charge swings dramatically to the positive side, reaching a charge of + 40mV
- Voltage-gated sodium channels close until cell returns to resting state
Action potential continued
- k+ channels also open, but with a bit of a lag
- concentration and electrostatic gradients work hard to force k+ ions outside the cell
- shifts permeability advantage back to K+
- causes cells to be hyper-polarized
All-or-none Principle
-Once a neurons’s electric charge reaches threshold an action potential is triggered, that action potential will always occur with the same strength
How can our brain represent information that isn’t all-or-none, but continuous
-can vary rate of firing and number of neurons firing
Neurotransmitters
- 100-150 different neurotransmitters (more substances suspected)
- Each has a different effect
- ->specific ecxitatory or inhibitory
- ->several linked to specific psychological phenomenon
From Electrical to chemical to electrical (neural Communication)
- Action potential reaches axon terminals
- ->each axon terminal contains many synaptic vesicles, or small, balloon-like object that contains molecules of a neurotransmitter
- Causes some of the synaptic vesicles to open
- ->Neurotransmitters are released into the synaptic cleft
- some neurotransmitters reach the postsynaptic neuron and bind with postsynaptic receptors
- -> Causes specificion channels to open, allowing a specific type of ion to pass in or out of the cell
Excitatory postsynaptic potential (EPSP);
-if a positive ion channel opens that allow positive ions to flow into the cell, the cell will depolarized and it will be easier to reach the threshold of an action potential
Inhabitory postsynaptic potential (IPSP);
- if negative ion channel opens and a negative ions are forced into the cell, the cell will hyperpolarize and it will be harder to reach the threshold of an action potential
- Can also occur if potassium channels open and K+ is forced outside the cell (leaves the cell more negative)
Reuptake
occurs when the axon terminals quickly remove the neurotransmitters from the synaptic cleft
one neuron can receive many EPSPs and IPSPs at the same time
- not an all-or-none process like the action potential
- summed effect of EPSPs and IPSPs determine the neuron’s polarization
Exicitation and inhibition of neurons doesn’t predict behaviour as you might think because ….
- Can inhibit inhibitory neurons
- ->Behaviour would increase - Excite inhibitory neurons
- Behaviour would decrease - The cell body has to make sense of all these inputs
- some are quick, some are long-lasting, some excitatory, some inhibitory, some big, some small, some arrive early or late and some may cancel each other out at the dendrites
What are the two main divisions of the nervous system ?
- The central nervous System(CNS)
- -> (brain and spinal cord)
- -> makes decisions for the body
- Peripheral Nervous system
- ->connects CNS with muscles, glands and sensory receptors
- ->sends and receives information to and from the rest of the body
Peripheral nervous system (PNS) breaks into what two components?
- Autonomic nervous System
- ->Regulates activity of the organs, glands and other physiological processes
- Somatic Nervous system
- ->Transmits sensory information and controls movement of the skeletal muscles
The Autonomic Nervous system breaks into 2 components
The Sympathetic Division
–>Prepares the body to react and expend energy in times of stress
–>arouses (fight-or flight)
The Parasympathetic division
–>Maintains body functions; conserves resources
–>calms(rest and digest)
The role of the brain in the central nervous System
- Interprets and stores information and communicates with muscles, glands, and organs
- number of structures controlling behaviour
- ->both voluntary and involuntary
- Two hemispheres (left and right)
- ->number of structures within and beneath
The role of the spinal cord in the central nervous system
- pathways connecting the brain and the peripheral nervous system
- most nerves enter/leave through spinal cord
- spinal reflexes do not involve the brain
The three Sub regions of the Hindbrain (brain stem) (broad)
- Medulla
- Pons
- Cerebellum
Medulla
-Automatic survival functions
breathing, blood circulations, reflexes,
Pons
- sleep and wakefulness
- Coordinates automatic and unconscious movements (swallowing, posture, facial expressions, eye movements)
Cerebellum
- Balance, coordination and time of movements
- Attention and emotion
Two sub-regions of the midbrain
- Superior Colliculus
-orienting visual attention - Inferior colliculus:
orienting auditory attention
Forebrain
-everything above the midbrain, including the cerebral ventricles
–> Spaces in the brain filled with cerebrospinal fluid that provides nutrition and cushioning for many parts of the brain
Composed of the:
–>Basal Ganglia
–>Limbic System
–>Cerebral Cortex
Basal Ganglia
-function in both voluntary movement and responses to rewarding stimuli
(money chocolate, rewards)
Limbic System: (broad)
- An integrated network involved in emotion and memory
- made up of four structures:
- Amygdala
- Hippocampus
- Hypothalamus
- Thalamus
Amygdala
- helps process emotions,especially fear and aggression
- Mediates memory formation for emotional events
Hippocampus
- Processes continuous, episodic memories
- Important in the formation of new memories
Hypothalamus
-Lies below (‘hypo’) the thalamus
-Regulates body temperature
-ensures adequate food and water intake (homeostasis)
-involved in sex drive
-directs the endocrine
system via messages sent to the pituitary gland
Thalamus
- The sensory switchboard
- All sensory messages (except smell) are routed through the thalamus on the way to the cortex
- also sends message from the cortex to the medulla and cerebellum
Cerebrum
- Largest part of the brain
- Responsible for higher level mental activities (learning, thinking, remembering)
- Two halves, called cerebral hemispheres, connected through the corpus callosum
- 3mm outer layer called the cerebral cortex
Cerebral Cortex
- Made up mostly of cell bodies, which are grey in colour so cerebral cortex is often called the grey matter
- Greatly folded and convoluted
- Deeper grooves are used to define the boundaries of the four lobes found in each hemisphere
Occipital Lobe
- Processes visual information
- contains the primary visual cortex, after which visual information is routed along two different pathways:
- ->Object recognition via temporal lobe
- ->where objects are via parietal lobe
Parietal Lobe
- Processes body sensations
- Contains the somatosensory cortex
temporal lobe
- processes auditory information
- contains the primary auditory cortex
- contains Wernicke’s area
- ->Important in speech comprehension
Frontal Lobe
- Speech and skeletal motor functions
- contains the primary motor cortex
- contains Broca’s area
- contains the prefrontal cortex
- ->important in executive functions like planning, decision making, and controlling attention
Cerebral cortex
- primary motor cortex
- ->controls movement on opposite side of the body of over 600 voluntary muscles
- ->Laid out in a pattern represented by a motor homunculus
- ->Amount of cortical space devoted to each motor area is proportional to the sensitivity of the motor function - Somatosensory Cortex:
- -> receives sensory information from opposite side of body
- ->Laid out in a pattern represented by a sensory homunculus
- ->amount of cortical space devoted to each sensory input is proportional to the sensitivity of the sensory function
- Topographically organized
Hemispheric Lateralization
-Refers to the fact that each hemisphereis performs somewhat of a different function
Left Hemisphere
-Language, mathematical, logical abilities, inner voice
Right Hemisphere
-Spatial relations, non-longustic sounds (music), facial processing
organization of the brain
-right visual field is processed in the left
left visual field processed in the right
-normally hemispheres share information, but this can be prevented in split-brain patients (patients with severed corpus callosum)