Behavioral Midterm 2

Front 1

________ is the theoretical basis for the subjective part of optometric evaluation. It is the relationship between what is physically presented in reality and what is perceived by the individual.

Back 1

Psychophysics

Front 2

_________ requires that the patient must not only be aware of the presence of the stimulus, but also able to identify what the stimulus is.

Back 2

Recognition

Front 3

_________ is the minimum stimulus intensity necessary to elicit awareness of its presence.

Back 3

Detection

Front 4

_________ is the relationship between the internal or psychological scale and the external or physical scale.

Back 4

Scaling

Front 5

The _________ is the minimum physical stimulus needed to evoke a sensation.

Back 5

absolute threshold

Front 6

Something that is ________goes undetected.

Back 6

subliminal

Front 7

The difference threshold is the _________of the necessary change for a detection of difference and the JND is the ________of the subject in noticing this change.

Back 7

quantification, experience

Front 8

________ asserts that in order to double the sensation evoked by a stimulus, the magnitude of the stimulus must be squared.

Back 8

Fechner’s Law

Front 9

__________ asserts that if there is an increase in the intensity of the background, the increment must increase by a constant percentage of the background value in order to remain just noticeably different.

Back 9

Weber’s Law

Front 10

____________ asserts that the magnitude of sensation is equal to the intensity of the stimulus raised to the power of a constant.

Back 10

Steven’ Power Law

Front 11

In the method of ________, the subject is instructed to adjust the stimulus until it matches the preset standard. The end result should be the perception of sameness.

Back 11

adjustment

Front 12

The method of _________ involves the random presentation of a pre-determined set of stimuli, all falling within the interval of uncertainty.

Back 12

constant stimuli

Front 13

In the method of ________, the stimuli are presented in are either in increasing order or decreasing order, and the final response elicited from the subject should be that something is different.

Back 13

limits

Front 14

Saccadic suppression

Back 14

phenomenon in visual perception where the mind selectively blocks visual processing during eye movements in such a way that neither the motion of the eye (and subsequent motion blur of the image) nor the gap in visual perception is noticeable to the viewer

Front 15

Saccade

Back 15

quick, simultaneous movements of both eyes in the same direction. Initiated by the frontal lobe of the brain (Brodmann area 8), saccades serve as a mechanism for fixation, rapid eye movement and the fast phase of optokinetic nystagmus.

Front 16

Fixation

Back 16

the maintaining of the visual gaze on a location

Front 17

Micronystagmus

Back 17

essential to vision

A stabilized retinal image fades away so this prevents photo receptor adaptation

Front 18

Nystagmus

Back 18

neurological condition eye move continuously, cannot fixate, overtly obvious

Front 19

Versions

Back 19

eye movement involving both eyes moving synchronously and symmetrically in the same direction

Front 20

accommodative esotropia

Back 20

uncompensated hyperope with a high AC/A ratio may develop accommodative esotropia (crossed eyes when viewing near targets) due to the excessive demands on accommodation to overcome BOTH the hyperopic refractive condition and the accommodative demand of the near target.

Front 21

Cycloplegic refraction

Back 21

Cycloplegic refraction is often necessary to reveal the full amount of hyperopia, especially in children.

Cycloplegic drugs create an inability of the ciliary muscle to contract, thereby temporarily eliminating accommodation. Because the hyperopic eye must accommodate continuously to see clearly, the ciliary muscle may develop a "spasm" of accommodation and not relax fully when compensating lenses are put in place during examination. Cycloplegic eye drops are used to insure a full relaxation of accommodation in these cases.

Front 22

accommodative spasm is present, cycloplegia will reveal...

Back 22

reduced myopia in myopes

increased hyperopia in hyperopes.

Front 23

Anisometropia

Back 23

The condition in which the optical powers of the two eyes differ by greater than ~ 0.50 D

impossible to create clear retinal images in both eyes simultaneously (accommodation is binocularly linked).