1 Introduction Flashcards
Action
Motor activities such as moving the head or eyes and locomotives through the environment. Action is one of the major outcomes of the perceptual process.
Absolute threshold
Minimum stimulus energy necessary for an observer to detect a stimulus.
Attended stimulus
Stimulus that a person is attending to at a given point in time.
Bottom-up processing (data-based processing)
Processing in which a person constructs a perception by analyzing the information falling on the receptors.
Classical psychophysical methods
Message of limits, adjustment, and constant stimuli, described by Fechner, that are used for measuring thresholds.
Cognitive influences on perception
How the knowledge, memories, and expectations that a person brings to the situation influence his or her perception.
Difference threshold
Minimal detectable difference between two stimuli.
Environmental stimulus
All of the things in our environment that we can potentially perceive at a given point in time.
Knowledge
Any information that the perceiver brings to a situation. See top-down processing.
Magnitude estimation
Cycle physical method in which the subjects assigns numbers to a stimulus that are proportional to the subjective magnitude of the stimulus.
Method of adjustment
Psychophysical method in which the experimenter or the observer adjusts the stimulus intensity in a continuous manner until the observer to text the stimulus.
Method of constant stimuli
Psychophysical method in which a number of stimuli with different intensities are presented repeatedly in a random order.
Message of limits
Psychophysical method for measuring threshold in which the experimenter presents stimuli in alternating ascending and descending order.
Neural processing
Operations that transform electrical signals within a network of neurons or that transform the response of individual neurons.
Perception
Conscious sensory experience
Perceptual process
Sequence of steps leading from the environment to perception of the stimulus, recognition of the stimulus, and action with regard to the stimulus.
Phenomenological method
Method of determining the relationship between stimuli and perception which the observer describes what he or she perceives.
Physiological approach to perception
Analyzing perception by determining how a person’s perception is related to physiological processes that are occurring within the person. This approach focuses on determining the relationship between stimuli physiological responding and between physiological responding perception.
Power function
Mathematical function of the form P = KS to the n power, were P is perceived as magnitude, K is a constant, S is the stimulus intensity, and n is an exponent.
Psychophysical approach to perception
Analyzing perception by determining how he person’s perception is related to stimuli in the environment. This approach focuses on determining the relationship between stimuli in the environment and perceptual processing.
Psychophysics
Traditionally, the term psychophysics refers to quantitative methods for measuring the relationship between properties of the stimulus and the subject’s experience.
Rat-man demonstration
Demonstration in which presentation of “red light” or “manlike” picture influences an observer’s perception of a second picture, which can be interpreted either as a rat or a man. This demonstration illustrates an effective top-down processing of perception.
Reaction time
The time between presentation of the stimulus and observer’s or listener’s response to dismiss. Reaction time is often using experiments as a measure of speed of processing.
Recognition
Ability to place an object in a category that gives it meaning – for example, recognizing a particular red object as a tomato.
Response compression
The result when doubling the physical intensity of stimulus less than doubles the subject of magnitude of the stimulus.
Response criterion
In a signal detection experiment, the subjective magnitude of a stimulus above which the participant will indicate that the stimulus is present.
Response expansion
The result was doubling the physical intensity of a stimulus more than doubles the subjective magnitude of the stimulus.
Signal detection theory
A series stating that the detection of a stimulus depends on both on the participant’s sensitivity to the stimulus and the participant’s response criteria.
Stevens’ power law
Law concerning the relationship between the physical intensity of the stimulus and the perception of the subject of magnitude of the stimulus The law states that P = KS-n.
Top-down processing (knowledge-based processing)
Processing that starts with the analysis of high-level information, such as a knowledge a person brings to a situation. Also call knowledge-based processing. Distinguish from bottom up, or data-based processing, which is based on incoming data.
Transduction
In the senses, the transformation of environmental energy into electrical energy. For example, the retinal receptors transduce light energy into electrical energy.
Visual form agnosia
The inability to recognize objects.
Visual search
Procedure in which a person’s task is to find a particular element in a display that contains a number of elements.
Weber fraction
Ratio of the difference threshold to the value of the standard stimulus and Weber’s law.
Weber’s law
Law stating that the ratio the difference threshold (DL) to the value of the stimulus (S) is constant. According to this relationship, doubling the value of a stimulus will cause doubling of the difference threshold. The ratio DL/ass is called the Weber fraction.
