Flashcards
PSY247 Lecture 1 Principles & Methods
Cards in this deck (56)
- 1PsychophysicsThe relationship between physical stimuli and their subjective or psychological correlates
- 2TransductionConverting physical stimuli to nerve impulses
- 3Chemical sensesGustation
Olfaction - 4Body SensesSomatosensation
Equilibrioception - 5SomatosensationTaction/Haptics
Proprioception - 6How much of the cortex is involved in visual processing?50% of the cortex
- 7Failure in recognition due to failure in perceptionApperceptive agnosia
- 8Failure in recognition despite successful perceptionAssociative agnosia
- 9Hierarchical ProcessingNeural impulses travel "up" the system to the cortex
- 10Top down processingPrior knowledge influences what is perceived
- 11Bottom-up or Top-down processing?Forward, backward and lateral connections in the visual pathway demonstrate information can flow in all directions
- 12SelectivityCells respond most to stimuli with certain properties
- 13TuningA cell is "tuned" to the dimension of a stimulus that generates the strongest response
- 14OrganisationWithin sensory brain regions there's often an orderly progression of stimulus preferences
- 15Cortical magnificationLarger amounts of cortex are devoted to processing more important stimulus values
- 16Doctrine of specific nerve energies=> Each sense projects onto a specific cortical area
=> The nature of sensation depends on which sensory fibres are stimulated
(Müller, 1838) - 17NoiseNeural firing is stochastic (random)
-Noise interferes with measurement of responses to stimuli - 18Spontaneous ActivityCells fire a little even with no stimulus
- 19DetectabilityHow easy a stimulus is to detect.
More intense stimuli are easier to detect - 20Detection ThresholdThe minimum intensity required for detection
- 21Absolute ThresholdThe minimum intensity required for detection
- 22SensitivityOpposite of threshold (1/threshold)
- 23Method of Adjustment (MoA) DetectionAdjust a stimulus until subject can just see it
=>Not reliable, people cheat - 24Method of Constant Stimuli (MoCS) Yes-No Paradigm-Vary stimulus intensity
-Subjects respond if they can detect it
-Plot the psychometric function
(curved due to noise)
=>Threshold is the point where detectability is 50% - 25Method of Constant Stimuli (MoCS) 2AFC ParadigmSubjects respond if stimuli was detected in one of two fields
=Threshold at 75, as there is 50% chance of correct guesses - 26Measuring Magnitude: Estimation Technique"Modulus" stimuli presented, acts as a reference for sensory magnitude
-Following stimuli rated by subject compared to modulus which is rated "10" - 27Compressive non-linear functionsIf intensity is increased 2x, sensory magnitude increases <2x
(Except for electric shock) - 28DiscriminationPerceiving the difference between two stimuli
- 29Discrimination thresholdThe minimum difference between two stimuli for discrimination
=>Just noticable difference - 30PrecisionDegree to which repeated measurements show the same result
=>Relates to discrimination threshold - 31AccuracyDegree to which measurements match the true value of a stimulus
=Relates to Bias - 32BiasSomething external to stimulus which changes the way it is perceived
=>Sometimes called the "point of subjective equality" (PSE) - 33Method of adjustment (MOA) MatchingMeasuring discrimination
-Adjust a probe stimulus until it matches the test stimulus
-Slightly different settings each time (noise) - 34Method of adjustment (MOA) Matching => AccuracyRepresented by the mean of several settings
-Good result if mean probe settings are close to true test setting
-Poor results are said to be biased - 35Method of Adjustment (MoA) Matching -PrecisionRepresented by the 'spread' of probe settings
(eg. standard deviation)
-Low spread = good discrimination ability - 36Adaptation (4 consequences)Prolonged stimulation decreases rate of firing
=> Increases detection threshold for similar stimuli
=>Reduces perceived intensity
=>Rate at which magnitude rises with stimulus intensity is increased
=>Perceived properties of similar stimuli can appear biased - 37Anatomical Research MethodsExamining dead brains
- 38Anatomical research methods: staining dead brains (3 features)=> Reveals axons/connections
=> Reveals cell body density & size
=> Reveals activity (cytochrome oxidase) - 39Recording techniques: Single cell recordingElectrode attached to single brain cell
-Invasive
-Anaesthetised or awake (microstimulation)
-High spatial and temporal resolution
-limited information (only one cell) - 40Recording techniques: Optical imagingFilming a working brain with a colour sensitive camera
-Blood flow increases to active areas
=> Active areas become more red
-Invasive
-Only a small area visible
-Slow response to stimulus - 41Visually evoked potentialPresenting a visual stimulus and measuring the brain's response
- 42Magnetoencephalography (MEG)Superconducting quantum interference device (SQUID)
-Non Invasive
-Measures magnetic fields in the brain
-High temporal resolution
-Moderate spatial resolution - 43Electroencephalography (EEG)Electrodes on the scalp detect changes to electric fields in the brain
-Non invasive
-High interference from skull
-Low spatial resolution
-High temporal resolution - 44Positron Emission Tomography (PET)Injecting radioactive dye and tracking it through the brain
-More radioactive blood goes to active areas so is detectable
-Non invasive
-Moderate spatial resolution
-Low temporal resolution - 45Functional Magnetic Resonance imaging (fMRI)Use powerful magnet to detect differences between oxygenated & deoxygenated blood in brain
-Moderate spatial resolution
-Low temporal resolution
-Non-Invasive - 46Anatomical Research Methods: LesionsDestroying (ablating) parts of the brain with neurotoxins (for specific pathways)
or surgery (for specific areas)
and studying what happens
-Invasive - 47Anatomical Research Methods: Human Brain Lesions (Neuropsychology)Studying living humans with damaged brains.
-Damage is usually diffuse
-Damage to fibres can affect areas far from lesion
-Brains recover from damage (plasticity)
-Correct tests are neccessary - 48Transcranial Magnetic Stimulation (TMS) (3 properties)Temporary magnetic field "knocks out" cells over a broad area of the brain
-Temporary
-Temporally precise
-Spatially imprecise - 49AxonAlso known as Nerve Fibre
-Long slender projection of a nerve cell (or neuron)
-Conducts nerve impulses away from the cell body
-In some sensory neurons, electrical impulses travel UP the axon to the cell body - 50Action PotentialA nerve impulse
-Electrical membrane potential rapidly rises and falls back to resting potential
-ion channels on the axon open, allowing sodium ions to gush inside, causing a rise in the electrochemical gradient
-The polarity of the plasma membrane then reverses, closing the ion channels
-Sodium ions actively transported out
-Potassium channels open and potassium ions are released (Repolarisation) - 51Grey MatterNeuronal cell bodies,
with relatively few myelinated axons - 52White matterMostly glial cells and myelinated axons that
transmit signals from one region of the cerebrum to another and further on - 53NeurotransmittersEndogenous chemicals that transmit signals across a synapse from one neuron (nerve cell) to another "target" neuron
- 54Psychometric FunctionDescribes the relationship between a parameter of a physical stimulus and the subjective responses of the subject
(eg. visual acuity) - 55SuprathresholdStimulus of sufficient intensity to generate a response
- 56ThalamusSymmetrical structure between the cerebral cortex and midbrain
-Relays sensory and motor signals to the cortex
-Regulates consciousness/sleep/alertness
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- Flashcards on PSY247 Lecture 1 Principles & Methods, created by mark k on 18/04/2015.
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