Sensation and Perception

is the science of defining quantitative relationships between physical and psychological events

Psychophysics

Which approach to studying sensation and perceptionwould be concerned with determining the dimmest light you could perceive or the loudest sound you could hear without pain?

Threshold measurements

In order to measure a subject's detection threshold for a spot of light

we present a dot on the screen and ask the subject to report whether they can see it or not. The luminance intensity of the dot was randomly chosen in each trial

Suppose we can just tell the difference between 50 and 52 candles burning in an otherwise unilluminated room. According to Weber's law

we should then be able to just distinguish 200 candles from

This figure illustrates the Steven’s power law

which describes the relationship between stimulus intensity (x-axis) and perceived intensity (y-axis). Which of the following statement is correct?

This graph illustrates _

which suggests that perceived intensity is the logarithm of the physical stimulus intensity

In an experiment where we ask a participant to detect whether the light is on or off. What are the four possible outcomes of a trial in signal detection theory

(i) hit

Under the context of the Signal Detection Theory

which of the following sets of noise (N) and signal + noise (S+N) distributions (the blue curves)

the correct answer graph

D

Airport security is very tight. If a traveler even jokes about a bomb

they are detained and questioned to ensure that no real terrorist threat succeeds. In terms of signal detection theory

Which of the following neuroimaging methods has the best spatial resolution?

Functional magnetic resonance imaging (fMRI)

By Receiver operating characteristic (ROC) curves

we can visualize the outcomes of a detection/discrimination task based on signal detection theory. Observers with different d’ (sensitivity) will fall on different curves. Please put the three d prime values in a correct order

When we use the method of constant stimuli to measure someone’s detection (or discrimination) threshold

we get data like the figure below. ‘In theory’

Which of the following statements about neural activity is correct?

Tuning curve of a sensory neuron reflects the stimulus feature preferred by the neuron

When the light passes into the water form the air and bend

it is being

If we think of our eyes as cameras

which component is like the aperture of the camera controlling the amount of lights entering the eyes

Which part of our eyes is where light energy is turned into electrical neural signals (transduction)

Retina

Which of the following photoreceptors has greater sensitivity at low light levels?

Rods

When adapting to increasing illumination?

More photoreceptors will have their photo pigments bleached

This figure illustrates the condition of myopia

where the image of an object is incorrectly formed in front of the retina. How can myopia be corrected?

Which of the following descriptions about prebyopia is incorrect?

It mainly caused by the deficiency cones

Which of the following is a specialized retinal cell responsible for wiring lateral inhibition?

Horizontal cells

Which of the following is a correct order of info processing in the vertical pathway of retina?

cones/rods- bipolar cells- ganglion cells

Below is the receptive field of an ON-center Off-surround retinal ganglion cell. If the orange-shaded circle represents a spot of bright light (under an otherwise completely dark background)

in which of the following case

Which of the following descriptions about the receptive field structure of retinal ganglion cells is incorrect?

They have preferred orientations

While cones at the fovea make one-to-one connection with the synapsed bipolar cells

multiple rods typically connect to a single bipolar cell. This neural convergence of rods leads to sensitivity and visual acuity.

This figure illustrates the distributions of two types of photoreceptors on the retina. Which of the following is the correct way to label A

B and C.

Humans’ contrast sensitivity function (CSF) normally exhibit an inverted U-shape. Which of the following descriptions about CSF is WRONG?

The falloff of both the right and left side of CSF can be explained by cone spacing

The spatial frequency of a stimulus is measured in

Cycle per degree

Before reaching at V1 (primary visual cortex)

visual info from the retina is sent to a relay station in the thalamus. The relay station is

Simple cells in V1 are selective for the of sine-wave gratings

all of the choices

Which of the following effect (or method) is considered as psychophysicists’ electrode

allowing them to infer the neural ‘channels’ underlying visual perception without directly measuring neural activity?

After adapting to a grating oriented at 45 degree

while all the other factors staying the same (e.g.

Starting from retina

different types of visual information are processed in different pathways. In LGN

V1’s complex cells do NOT show selectivity for which of the following dimension?

phase of a sine-wave grating

Topographical mapping is the

orderly mapping of the world (spatial locations) in the LGN and visual cortex

Cortical magnification means that visual cortex uses more neurons to represent the information about than

foveal vision; peripheral vision

A visual stimulus to the left of the fixation point (i.e.

the left visual field) is projected to the __ half of each retina

The LGN in the right hemisphere (the right side of the brain) does NOT contain information from

Right visual field

In an fMRI experiment

we found that four visual stimuli (A

This hybrid image is created by superimposing two images

each of them is the headshot of a famous person. Interestingly

RATES ARE DONE WITH A DECIMAL NOT PERCENTAGE

O.7 NOT 70%

Evidence indicates that structures in _ cortex are especially important in end-stage object recognition processes

Inferotemporal

The term “grandmother cell” refers to a neuron that

responds best to one specific object (e.g.

A _ process is one that carries out a computation (e.g.

object recognition) one neural step after another

Which of the following is a loosely defined stage of visual processing that comes after basic features have been extracted from the image

and before object recognition and scene understanding?

Gestalt psychologists emphasize that

The perceptual whole is greater than the sum of its parts

Deep neural network (DNN) has exhibited abilities in object recognition that matches or even outperforms humans. However

DNN is not always perfect. Sometimes DNN is susceptible to adversarial attack

After primary visual cortex (V1)

in general

You probably organized both figure I and figure II above into one jagged line and one curved line. Which Gestalt grouping principle guided this decision?

Good continuation

These two stimuli above (Left: Necker Cube; Right: Rubin's face) are typical examples of

which highlights that our perception is inherently uncertain.

The fact that some agnosia patients have no problem recognizing faces

and some prosopagnosia can recognize non-face objects normally has been considered as an evidence that there is __ between object recognition and face recognition.

Which of the following has been considered as an evidence that face image undergoes holistic processing in the visual pathway?

Face inversion effect—difficulty in recognizing upside-down face images

We discussed several common methods used in fMRI research to identify brain regions involved in processing different visual object categories. Which of the following methods trains computational algorithms (e.g.

machine learning or AI) to classify or "predict" the visual images viewed by subjects based on their brain activity during image viewing?

This figure is the wavelength tuning curves for three types of cone in human eyes. From the left to the right label the three cones

S cone

The principle of univariance refers to the fact that infinite combinations of and can lead to the same response from a single type of photoreceptor. Therefore

we need more than one type of photoreceptor to perceive colors.

According to the _ theory

the color of any light is defined in our visual system by the relationships among three numbers of a set.

An individual missing M cone will not be able to distinguish

Red and green

Mixtures of different wavelengths that look identical are called

Metamers

An ____ is a visual image seen after the stimulus has been removed

Afterimage

Which of the following statements is correct?

Two light sources with different spectral power distributions can appear to have the same color as long as they generate the same cone responses.

These two spots of lights have very different spectral power distribution. However

they appear to be in the same color to human eyes. Why is this the case?

When adding colors

blue and yellow create white through color mixing; cyan and yellow create green through color mixing.

_ is the ability of the human visual system to perceive an object's color as relatively stable even when the condition of illumination changes.

Color constancy

Once the lights hit on the retina

our color perception is at least shaped by two neurophysiological processes (I) and followed by (II). Color matching experiment provides evidence for (I)

There exist cone-opponent cells in LGN. The figure above represents a cone-opponent cell (more specifically this is a "single-opponent" cell) that receives excitatory inputs from L cones (in the center) and inhibitory inputs from M cones (in the surround). Which of the following descriptions is correct?

The spike rate of this cell decrease when there are green lights hitting the surround of its receptive field

Which of the following is not one of the means by which the visual system maintains color constancy?

Implementing hue cancellation

Which of the following is the function of visual motion perception?

All the choices

The fact that motion aftereffect (MAE) shows interocular transfer indicates that

Binocular neurons are involved in MAE

The impression of smooth motion that comes from the rapid alternation of objects appearing in nearby locations in rapid succession is

Apparent motion

This diagram illustrates a classic Reichardt detector for motion. Here 1 and 2 represent receptive field of two neurons. “D” and “X” represent what type of computations respectively?

D; delay X: multiplication

The detector in the previous question can be activated by a white dot moving in which direction?

Leftward

If you want the motion detector circuit above to respond to even faster object motions

which changes should you make to the circuit?

This is an example of _

which is the changing angular position of points in an image that one experiences as they move through the world.

Following the previous question

the center of this image is called the “focus of expansion” (FOE)

Motion capture in movies

in which points of light on each joint of the body allow computers to register the motion of actors

Based on fMRI studies

several brain regions are specialized for motion processing. Area is known to process various types of motion signals equally while _ is known to be particularly active when there is biological motion in the stimuli or when the motion conveys interactions between agents/people.

In motion perception

what is the “aperture problem”?

refers to the reduction of visual sensitivity that occurs when we make saccadic eye movements

eliminating the smear from retinal image motion during eye movements.

When you use your finger to push your eyeball while you try to fixating at a black dot on a paper

that black dot appears to move even though it is stationary. The fact that you perceive motion of the dot in this case is because

Motion signals in the retinal images could be either due to the motion of the object or due to the eye movements (while the objects remain stationary). To distinguish the two

theories suggest that the visual system must compares the image displacement(movement) signals with the corollary discharge (efference copy) sent form the motor cortex. In the figure below: