Cognitive Psychology Methods and Psychophysics

These flashcards cover key concepts related to cognitive psychology methods and psychophysics, focusing on sensory perception, thresholds, and the relationship between physical stimuli and psychological experiences.

What are the methods used in cognitive psychology?

The methods include controlled self-reporting, mental chronometry, neuropsychology, psychophysiology, and imaging.

What does functional imaging measure?

Functional imaging methods measure regional brain activity.

What substance is used in PET scans?

A radioactive substance such as water or glucose is injected.

What does fMRI measure?

fMRI measures BOLD activity which reflects magnetic differences due to blood oxygenation.

What is the subtractive method in imaging?

It is used to compare differential brain activity during two different tasks.

What does psychophysics explore?

The relationship between physical stimuli and the sensations they evoke.

What is Fechner's contribution to psychophysics?

He sought a psychophysical law connecting physical measurement to sensory experience.

What is an absolute threshold?

The minimum intensity at which a stimulus can be detected 50% of the time.

What method is used to determine the absolute threshold?

The method of constant stimuli is used.

What is the difference threshold?

The smallest change in stimulus intensity that can be detected.

What is JND?

Just Noticeable Difference, the minimum perceived difference between two stimuli.

What is Weber's Law?

The principle that the ratio of the increment threshold to the background intensity is a constant.

How does Fechner's Law describe perception?

It states that doubling the physical intensity does not double the sensation experienced.

What is Stevens' power law?

It describes how perceived magnitude relates to stimulus intensity through a power function.

What factors are included in signal detection theory?

Sensitivity, response bias, and payoff.

What do response biases refer to in signal detection theory?

The tendency to respond a certain way regardless of the stimulus presence.

What is the outcome when both high and low tones are presented?

Sensation can vary, indicating the absolute threshold is not the same for each frequency.

What does a ROC curve in signal detection theory represent?

It illustrates the trade-off between hit rates and false alarm rates.

What is the impact of decision-making under uncertainty in psychophysics?

It applies to processes that involve uncertainty, such as memory recognition or sensory decision-making.

What is the significance of the formula d' in signal detection theory?

It quantifies the ability to discriminate between signals and noise.

How can we assess an observer's sensitivity in signal detection?

By calculating d' based on hit rates and false alarm rates.

What is the threshold of hearing expressed in terms of dB?

It varies with frequency and can be different at different decibel levels.

What role does stimulus comparison play in psychophysics?

It helps determine the strength of stimuli and differentiate them.

What is the relationship between strength of stimuli and perceived difference?

The perceived difference can change depending on the existing stimulus intensity.

What can affect the absolute threshold across different senses?

Different modalities (senses) have varied thresholds for perception.

In signal detection theory, what defines a 'hit'?

A hit is correctly identifying that a signal is present.

What does the presence of noise imply in signal detection theory?

It indicates that external stimuli may interfere with the detection of a signal.

What is the psychological interpretation of Weber's fraction for different stimuli?

It indicates the relative change needed for sensitivity across various sensory modalities.

What factor influences the minimal addition or reduction of a stimulus?

The difference threshold or JND dictates this minimal perceptible change.