Psychology Research Methods, Neuroscience, and Sensation & Perception

Facilitated Communication

Means for autistic children to communicate via a third person

Operationalization

Turning an abstract question into a measurable, observable procedure

Internal Validity

How sure can you be your manipulation is what led to the difference you are observing

External Validity

How applicable are these findings in the real world

Naturalistic Observation

Watching behaviour in real-world setting

Pros of Naturalistic Observation

Generalizable, applicable, detailed info

Cons of Naturalistic Observation

Lack of control, time + resource consuming, bias

Case Studies

In-depth examination of one person or small number of people over extended period of time

Pros of Case Studies

Only possible method for creating record of existence, detailed descriptions

Cons of Case Studies

Not generalizable, researcher bias

Self-Report/Survey Methods

Distributing a survey or questionnaire, asking people about their own behaviours, perceptions, etc.

Response Bias

People will respond inaccurately and untruthfully when asked about sensitive topics

Reliability

How consistent is the measure?

Test-Retest Reliability

Are the scores consistent when tested now and re-tested in a while?

Inter-Rater Reliability

How consistent is the measure across different raters?

Cohen's Kappa

Tells the extent of agreement between raters

Validity

Is a measure measuring what it claims?

Correlational/Non-Experimental Studies

Research designed to look at the extent to which variables are associated

Correlation Coefficient

Range from -1.0 to +1.0

Experimental Studies

Must be used to establish causation

Independent Variable (IV)

Manipulated by researcher, causes change to other variable

Dependent Variable (DV)

Variable that is measured to observe the effect of the manipulation

Experimental Design

High internal validity is the certainty that IV caused change in DV

Stanford Marshmallow Experiment

Delay of gratification test

Experimental Bias

Changes in participants' behaviours caused by expectations of researcher

Demand Characteristics

Participant infers hypothesis in study and adjusts behaviour accordingly

Informed Consent

Must tell participants about what is involved

Protection from Harm and Discomfort

Cannot be subjected to more than minimal risks

Tuskegee Syphilis Study

Conducted before ethical guidelines existed, recruited black participants for studying syphilis

Neurons

Brain communicators, specialized in communication with each other

Myelin Sheath

Fatty insulation surrounding axon

Action Potential

Brief electrical charge that travels down neuron

Resting Potential

When neuron is not firing, it is polarized

Neuron Depolarization

When stimulated, neuron depolarizes (gates open, Na+ rushes in: positive ions that were outside rush in and neuron goes suddenly from neg to pos, which is how signal travels from dendrites to axon)

All-or-none law

Either going to fire or not (certain amount of stim required to fire)

Frequency

How often it is receiving stim

Repolarization

Potassium (K+) ions flow out, repolarizing axon (return to its neg charged state)

Return to resting potential

Going to stay neg until next stim

Refractory period

Brief period where neuron can't fire again no matter how much stimulation

Electrochemical communication

Neurons don't touch each other: communicate with other neurons by neurotransmitters

Neurotransmitters

Chemical messengers that help neurons communicate with each other (since they don't touch)

Excitatory messages

Messages that make it more likely a neuron will fire

Inhibitory messages

Messages that make it less likely that a neuron will fire

Release of neurotransmitters

Action potential triggers NT release from vesicles into synaptic cleft (from presynaptic sender)

Reuptake of neurotransmitters

Excess NTs are removed by drifting away, being broken down, or reabsorbed

Agonists

Mimic or enhance the effect of NT (helper)

Antagonists

Block or impede the normal activity of NT (blocker)

Glutamate & GABA

Most plentiful transmitters in system; work tgt to control processes (stop & go)

Acetylcholine

Involved in arousal, selective attention, memory, sleep, moving muscles

Dopamine

Involved in pleasure and reward; helps in attention and voluntary movement

Serotonin

NT made from tryptophan; helps in mood regulation, no depressions

Brain divisions

Hindbrain: controls basic functions; Midbrain: controls movement; Forebrain: manages complex cognition

Cerebral cortex

Outer-layer grey matter has folds - divided into 4 major lobes

Frontal lobe

Planning, decision-making; includes Broca's area for language production

Parietal lobe

Sensation (somatosensory); communicates info to motor cortex

Temporal lobe

Auditory; includes Wernicke's area for language comprehension

Occipital lobe

Specializing for vision processing and higher-order visual functions

Lateralization

Cognitive function that relies more on one side of the brain

Neural plasticity

Brain is adaptable, can change; includes myelination and pruning

Limbic system

Emotional center: role in smell, motivation, memory

Concussion

Brain smashes into skull from the inside (traumatic brain injury that affects brain function)

Phrenology

Skull shape thought to reflect brain size and cognitive function (not true)

Brain damage studies

Understanding how the brain works by seeing how it doesn't

Computerized Tomography (CT) Scan

X-ray passing through head to create image of scan.

CT Scan

Shows structure, not function.

Positron Emission Tomography (PET) Scan

Shows brain activity.

PET Scan

Injection of mildly radioactive substance and monitor changes in blood flow to different brain areas.

Magnetic Resonance Imaging (MRI)

Magnetic fields used to produce picture of tissue.

Functional MRI (fMRI)

Shows changes in metabolic activity over time.

Electroencephalography (EEG)

Recording of electrical activity of brain via electrodes on scalp.

Magnetoencephalography (MEG)

Measures tiny magnetic fields generated by the brain.

Deep Brain Stimulation (DBS)

Modify brain function through implanted electrodes.

Transcranial Magnetic Stimulation (TMS)

Applies strong and quickly changing magnetic fields to the surface of the skull.

Prosopagnosia

Face blindness; issue in perception, not sensation.

Sensation

Detection of physical energy by sense organs.

Perception

Brain's interpretation of raw sensory data.

Transduction

Convert energy from one form into another.

Bottom-Up Processing

Building perception off simple input.

Top-Down Processing

Memory and cognitive processes help interpret incoming sensory info.

Sensory Adaptation

Sensory receptor cells become less responsive because stimulus is not changing.

Absolute Threshold

Minimum intensity of a stimulus that a person can detect half the time.

Subliminal Perception

Perception of stimuli that are presented below absolute threshold.

Just Noticeable Difference (JND)

How much difference must exist between two stimuli before you detect a difference.

Weber's Law

JND between two stimuli depends on intensity of first stimulus.

Selective Attention

Focusing on a specific aspect of sensory input while ignoring other stimuli.

Inattentional Blindness

Failure to detect unexpected stimulus in plain sight if attention focused elsewhere.

Change Blindness

Failure to detect changes in environment.

Eye Structure: Cornea

Clear outer layer, helps to bend and focus light.

Eye Structure: Pupil

Black hole, controls light.

Eye Structure: Iris

Colored muscle ring that controls pupil size.

Rods

Detect black, white, grey; sensitive to movement.

Cones

Sharp focus, color perception, detail.

Trichromatic Theory

Retina contains red, green, blue receptors.

Opponent Process Theory

We perceive colors in terms of three pairs of opponent colors.

Perceptual Constancy

Recognition that object is unchanging, even though sensory input changes.

Monocular Depth Cues

Cues that rely on one eye.

Binocular Depth Cues

Cues that require two eyes.

Conductive Deafness

Malfunctioning of the ear due to failure of eardrum or ossicles.

Nerve Deafness

Damage to auditory nerve.

McGurk Effect

Brain builds coherent experience from multiple sources that results in illusion.