1. Research Methods Flashcards
(29 cards)
What does single-cell recording measure?
Action potentials (“spikes”) via micro-electrodes
Spikes per second to quantify neuronal firing
What is a neuron’s receptive field?
The restricted region of the visual field where a neuron responds selectively to specific stimuli
What was the key finding of Hubel & Wiesel’s 1968 study?
Neurons in primary visual cortex show orientation selectivity.
Study Reference:
Authors & Year: Hubel & Wiesel (1968)
Method: Single-cell recordings in cats and monkeys
Key Finding: First evidence that simple cells respond maximally to bars of a particular orientation
What does EEG measure?
Ensemble neural activity recorded from the scalp, offering high temporal but limited spatial resolution.
What are Visually Evoked Potentials (VEPs)?
Time-locked EEG responses elicited by visual stimuli, useful for testing populations unable to give verbal reports (e.g., infants).
What is the N170 component described by Rossion & Jacques (2008)?
A large negative EEG potential ~170 ms after stimulus onset
Larger in amplitude for faces than other objects
Study Reference:
Authors & Year: Rossion & Jacques (2008)
Method: EEG recording of VEPs to faces vs. objects
Key Finding: Evidence for early face-selective processing
What information does structural MRI provide?
Static high-resolution images differentiating grey matter (cell bodies) and white matter (axons) by measuring hydrogen atom signals.
Tags: MRI, Neuroimaging
What underlies functional MRI (fMRI)?
The haemodynamic response—changes in blood flow and oxygenation following neural activity.
Tags: fMRI, Haemodynamics
What does the BOLD signal represent?
Blood-oxygenation-level-dependent changes relative to baseline, giving precise spatial but coarse temporal information.
Tags: fMRI, BOLD
What did Kanwisher, McDermott & Chun (1997) demonstrate?
Existence of the Fusiform Face Area (FFA) by showing greater BOLD response to faces than to objects.
- Tags: fMRI, Face Area
Study Reference:
Authors & Year: Kanwisher, McDermott & Chun (1997)
Method: fMRI contrasts of faces vs. objects
Key Finding: Modular face-selective region in fusiform gyrus
How do lesion studies inform brain function?
By examining behavioral deficits following targeted (animal) or natural (human) brain lesions, inferring functional specialization—though precise localization can be challenging.
Tags: Neuropsychology, Lesion Studies
What is psychophysics?
The study of quantitative relationships between physical stimulus properties and psychological responses, using controlled experimental methods.
Tags: Psychophysics, Fechner 1860
What is a matching task in psychophysics?
Participants adjust a test stimulus until it perceptually matches a reference, measuring appearance (e.g., colour, size).
Tags: Psychophysics, Appearance
What are metamers?
Physically distinct stimuli that are perceptually identical (e.g., different light mixtures producing the same colour match).
Tags: Psychophysics, Metamer
What does the Ebbinghaus illusion illustrate?
Apparent size distortion: central circles of identical size appear different depending on surrounding circle context.
Tags: Psychophysics, Illusions
How do absolute and difference thresholds differ?
Absolute threshold: Minimum intensity for detection of a single stimulus
Difference threshold: Smallest detectable difference between two stimuli
Tags: Psychophysics, Thresholds
What is a perceptual threshold?
The lowest stimulus intensity that can be reliably detected, used to quantify sensory sensitivity.
Tags: Psychophysics, Thresholds
What did Hecht, Haig & Chase (1937) reveal about dark adaptation?
Detection thresholds decrease in two phases in the dark, indicating rods and cones adapt at different rates.
Tags: Psychophysics, Dark Adaptation
Study Reference:
Authors & Year: Hecht, Haig & Chase (1937)
Method: Measurement of detection thresholds after varying dark exposure durations
Key Finding: Two-stage threshold drop consistent with differential photoreceptor adaptation
What is the method of limits?
Gradually increasing or decreasing stimulus intensity until the participant’s response changes; threshold is the intensity at that change point.
Tags: Psychophysics, Method of Limits
What errors can bias the method of limits?
Habituation: Participant maintains same response too long
Anticipation: Participant predicts change and responds early
Tags: Psychophysics, Method of Limits
How does the method of constant stimuli work?
Stimulus intensities are presented in random order with repeats; responses are tallied and a psychometric function is fitted to determine threshold.
Tags: Psychophysics, Method of Constant Stimuli
What is a psychometric function?
A cumulative Gaussian (or similar) curve fitted to response data, whose midpoint (e.g., 50% point) indicates the threshold.
Tags: Psychophysics, Psychometric Function
Why use forced-choice measures instead of yes/no tasks?
They minimize subjective criterion bias by requiring participants to choose between alternatives on each trial.
Tags: Psychophysics, Forced Choice
In a 2-alternative forced-choice (2AFC) design, what performance level defines threshold?
The midpoint between chance (50%) and perfect performance—typically 75% correct.
Tags: Psychophysics, 2AFC
