Spatial Vision

These flashcards cover key concepts related to spatial vision, including definitions, functions, and experimental findings.

What is spatial frequency?

Spatial frequency refers to the number of cycles of a grating pattern per degree of visual angle.

What does a higher spatial frequency indicate?

Higher spatial frequency indicates more cycles or stripes within a given visual angle, resulting in narrower stripes.

What is the formula for contrast (C)?

C = (Lmax - Lmin) / (Lmax + Lmin)

What are the three characteristics of spatial luminance gratings?

Spatial frequency, contrast, and orientation.

What does Fourier analysis allow us to do?

Fourier analysis allows us to break down any wave pattern into a series of sine waves with different frequencies and amplitudes.

What is the importance of the Contrast Sensitivity Function (CSF)?

The CSF measures the ability of the visual system to detect contrasts at different spatial frequencies.

What determines the relationship between optical and neural transfer functions?

The contrast sensitivity function (CSF) depends on the optical transfer function and the neural transfer function.

How does the CSF change with age?

The CSF of infants improves during the first year of life and then changes again later in life.

Which animal species are compared in terms of CSF in the lecture?

Squirrel, monkey, human, macaque, cat, dog, owl, falcon, quail, and rat.

What is the role of the modulation transfer function (MTF)?

The MTF measures the ratio of image to object intensities against spatial frequency to evaluate optical systems like camera lenses.

What experimental method did Campbell & Kulikowski use?

They used masking/adapting gratings combined with variously oriented test gratings to analyze visibility.

What occurs as the angle between the test and masking gratings decreases?

The effect of masking increases, requiring more contrast for the test grating to be seen.

In the context of the CSF, what do selective adaptation effects suggest?

They suggest that different neural channels are specialized for detecting different spatial frequencies.

What is the relationship between spatial frequency and visibility?

Higher spatial frequencies are typically associated with lower contrast detection thresholds.

Why do infants have a different CSF compared to adults?

Infants' visual systems are still developing, thus resulting in different thresholds of contrast sensitivity.