Sensation & Perception Studyguide

Which is not considered one of the five undisputed senses but is, in fact, a human sensory ability?

• Proprioception

The smallest amount of a stimulus necessary to allow an observer to detect its presence is known as the:

• Absolute threshold

Paul is sitting in the movie theater and the lights go down as the show is about to start. For a few moments he has difficulty seeing because which part of his eyes need plenty of light to do their job?

• Cones 

In what structure does information from the right side of both eyes get sent to the left hemisphere?

• Optic Chiasm 

An observer is asked to adjust the level of pressure on the skin until the person can just barely feel the lightest pressure on their skin. Then the observer starts again from a different starting level of pressure. Which technique does this best represent?

• Method of Adjustment 

A condition that develops from an irregular shape of the cornea or the lens, which makes it impossible for the lens to accommodate a fully focused image, is known as:

• Astigmatism

The registering of a physical stimulus on our sensory receptors is referred to as:

• Sensation

Ken is interested in the smallest differences in the wavelength of light that humans can detect. He should therefore design an experiment that will look at:

• Difference Thresholds 

The Purkinje shift refers to the observation that:

• Short wavelengths tend to be relatively brighter than long wavelengths in scotopic vision compared to photopic vision.

Smooth pursuit eye movements allow the eyes to:

• Track moving Objects 

Scotopic vision is associated with which receptor system?

• The rod system

In signal detection theory, if the cost of a miss is very high and the risk of a false alarm is very low, the criterion will be:

• Set very low to maximize hits.

Perception refers to:

The area of the retina that is highest in acuity and the densest in cones is the:

• Fovea 

A column within V1 that is made up of neurons that receive input from only the left eye or only the right eye is called:

• Ocular dominance column.

The fact that a tree that is farther away in-depth looks smaller than a tree that is closer to you is due to ______.

• Perspective Projection (Going for perspective, going for depth.)

A food company wants to develop a psychological measure to evaluate people's perception of sweetness. What should they do?

• Ask participants to rate a number of levels of sweetness on a numerical scale.

Transduction is the process of:

• Converting physical energy into a neural signal.

Rachel enjoys stargazing. When using a flashlight to look at her star chart on a dark but clear night, she should:

• Use a flashlight with red light because red light least interferes with scotopic vision.

If we double the amount of capsaicin in our hot sauce, according to response expansion, we can expect participants to report:

• More than double the amount of perceived piquancy.

Area V1 is located in the:

• Occipital Lobe

The photoreceptors at the periphery of the retina, which are very light sensitive and specialized for night vision, are called:

• Rods 

The doctrine of specific nerve energies argues that:

• Activating visual neurons can only cause a visual experience.

A psychophysical method in which a participant is required to report when or where a stimulus occurs instead of whether it was perceived is known as the:

• Forced-choice method.

Visible light is usually measured by its:

• Wavelength 

What part of your brain is responsible for detecting where an object is in your visual field?

• The Dorsal Stream 

As you are reading this sentence, your eyes keep moving across the page to direct detailed visual information to what part of your retina?

• Fovea 

According the size-arrival effect, smaller objects are perceived as:

• Farther from the viewer

Which of the following best describes how physical properties of light relate to visual perception?

• Wavelength determines color, while intensity determines brightness.

Dr. Wan is doing a psychophysical experiment to determine the smallest concentration of coffee that we can detect by olfaction. In the experiment, he presents some coffee concentrations that are clearly detectable, others that cannot be detected, and some that are just detectable. These presentations are randomized. Dr. Wan can be said to be using the method of:

• Constant stimuli

What is the name of the structure located at the top of the brainstem, just beneath the thalamus, whose main function in mammals (including humans) is the control of rapid eye movements? 

• Superior colliculus

The process of adjusting the lens of the eye so that both near and far objects can be seen clearly is known as:

• Accommodation 

According to Weber's Law, in which of the following scenarios would you be most likely to notice a change in weight (all else being equal)?

• 2 pounds added to a 20-pound weight

Which of the following accurately differentiates sensation and perception?

• Sensation involves stimulation while perception involves interpretation.

In the eye, messages go from the photoreceptors to the brain via the ______.

• Optic nerve

Which is a true statement about the organization of the LGN?

• It shows retinotopic organization.

Which of the following best describes the fovea?

• It processes fine detail of the location you are looking directly at.

The point of subjective equality is:

• The point at which subject estimates correspond to objective measures.

Despite the fact that there is a "blind spot" of sensory information coming into the eye, we do not perceive a gap in our visual field. Why is this so?

• We fill in the gaps with our expectations. (top- down processing.)

The ultimate goal of perception is to:

• Determine what caused a specific sensory measurement in order to make a behavioral decision.

The process whereby the visual system's sensitivity is reduced so that it can operate in higher light levels is known as:

• Light adaptation

Karl is a participant in a psychophysical experiment on visual detection. He is shown a mix of near-threshold stimuli with stimulus-absent catch trials. When Karl indicates that he saw a light in a stimulus-absent catch trial, he makes what kind of mistake?

• False alarm

Retinal ganglion cells that increase their firing rate (excitation) when light is presented in the middle of the receptive field and decrease (inhibit) their firing rate when light is presented in the outside or surround of the receptive field are known as:

• On-center receptive fields

The smallest difference between two stimuli that can be detected is known as the:

• Difference threshold

Which of the following types of sensory receptors is specialized to respond to light?

• Photoreceptors 

Between 1/3 and 1/2 of the cortex is involved in visual processing. The large number of neural processes that are devoted to vision suggests that ______.

• The process of going from the sensory input to the perceptual output is complex.

John is watching his cat Fluffy watch birds out of the window. He notices that Fluffy's eyes contract when the sun comes out and dilate when the clouds cover the sun. What eye structure undergoes this contraction or expansion depending on lighting conditions?

• Pupil 

Which of the following statements correctly describes the relationship between threshold and sensitivity?

• A lower threshold means higher sensitivity because the stimulus can be detected at weaker intensities.

Imagine you are a zoologist studying an animal that only hunts during the night. What might you predict about this animal's retina?

• This animal would have a large number of rods.

A radiologist is reviewing mammogram images for signs of cancer. According to Signal Detection Theory, which scenario best illustrates high sensitivity.

• The radiologist correctly identifies nearly all cancerous tumors while making very few misses.

Sensitivity_ Tells us how hard or easy the task is, very few misses because the task is easy. 

High Sensitivity- We are very good at the task 

Low Sensitivity - Not very good at the task.