Chapter 1—Introduction to Perception Flashcards
Action
Motor activities such as moving the head or eyes and locomoting through the environment. Action is one of the major outcomes of the perceptual process.
Absolute threshold
The minimum stimulus energy necessary for an observer to detect a stimulus.
Bottom-up processing
Processing that is based on the information on the receptors. Also called data-based processing.
Classical psychophysical model
The methods 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 a situation influences his or her perception.
Difference threshold
The minimal detectable difference between two stimuli
Environmental stimulus
The stimulus “out there,” in the external environment.
Frontal lobe
Receiving signals from all the senses, the frontal lobe play an important role in perceptions that involve the coordination of information received through two or more senses. It also serves functions such as language, thought, memory, and motor functioning.
Knowledge
Any information that the perceiver brings to a situation.
Magnitude estimation
A psychophysical method in which the subject assigns numbers to a stimulus that are proportional to the subjective magnitude of the stimulus.
Method of adjustment
A psychophysical method in which the experimenter or observer adjusts the stimulus intensity in a continous manner until the observer detects the stimulus.
Method of constant stimuli
A psychophysical method in which a number of stimuli with different intensities are presented repeatedly in a random order.
Method of limits
A psychophysical method for measuring threshold in which the experimenter presents sequences of stimuli in ascending and descending order.
Neural processing
Operations that transform electrical signals within a network of neurones or that transform the response of individual neurones.
Oblique effect
Enhanced sensitivity to vertically and horizontally oriented visual stimuli compared to obliquely oriented (slanted) stimuli. The effect has been demonstrated by measuring both perception and neural responding.
Occipital lobe
A lobe at the back of the cortex that is the site of the cortical receiving area for vision.
Optical system
The parts of the eye through which the physical energy of light passes and whose job is to focus the image for perception.
The parts of the optical system include the cornea, which is at the front of the eye, and the lens directly behind it.
Parietal lobe
A lobe at the top of the cortex that is the site of the cortical receiving area for touch and is the termination point of the dorsal (where or how) stream for visual processing.
Perceived magnitude
A perceptual measure of stimuli, such as light or sound, that indicates the magnitude of experience.
Perception
Conscious sensory experience
Perceptual process
A sequence of steps leading from the environment to perception of a stimulus, recognition of the stimulus, and action with regard to the stimulus.
Namely: 1. Environmental stimulus; 2. Transformation of energy; 3. Receptor processes; 4. Neural processing; 5. Perception; 6. Recognition; 7. Action
Phenomenological method
Method of determining the relationship between stimuli and perception in which the observer describes what he or she perceives.
Physiological approach to perception
Analysing perception by determining how a person’s perception is related to physiological processes that are occurring within the person. This approach focuses on determining between stimuli and physiological responding and between physiological responding and perception.
Power function
A mathematical function of the form P=KSⁿ, where P is perceived magnitude, K is a constant, S is the stimulus intensity, and ⁿ is an exponent.
Primary receiving areas
Areas of the cerebral cortex that first receives most of the signals initiated by a sense’s receptors. For example, the occipital cortex is the site of the primary receiving area for vision, and the temporal lobe is the site of the primary receiving area for hearing.
Principle of representation
A principle of perception that states that everything a person perceives is based not on direct contact with stimuli but on representations of stimuli on the receptors and in the person’s nervous system.
Principle of transformation
A principle of perception that states that stimuli and responses created by stimuli are transformed, or changed, between the environmental stimulus and perception.
Psychophysical approach to perception
Analysing perception by determining how a person’s perception is related to stimuli in the environment. This approach focuses on determining the relationship between stimuli in the environment and perceptual responding.
Psychophysics
Traditionally, the term psychophysics refers to quantitative methods for measuring the relationship between properties of the stimulus and the subject’s experience. In the book, all methods that are used to determine the relationship between stimuli and perception will be broadly referred to as psychophysical methods.
Rat-man demonstration
The demonstration in which the presentation of a “ratlike” or “manlike” picture influences an observer’s perception of a second picture, which can be interpreted either as a rat or as a man. This demonstration illustrates an effect of top-down processing on perception.
Reaction time
The time between presentation of a stimulus and an observer’s or listener’s response to the stimulus. Reaction time is often used in experiments as a measure of speed of processing.
Recognition
The ability to place an object in a category that gives it meaning—for example, recognising a particular red object as a tomato.
Response compression
The result when doubling the physical intensity of a stimulus less than doubles the subjective 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.
Retina
A 0.4-mm thick network of nerve cells that covers the back of the eye and that contains the receptors for vision.
Response expansion
The result when doubling the physical intensity of a stimulus more than doubles the subjective magnitude of the stimulus.
Sensory receptors
Cells specialised to respond to environmental energy, with each sensory system’s receptors specialised to respond to a specific type of energy.
Signal detection theory
A theory stating that the detection of a stimulus depends both on the participant’s sensitivity to the stimulus and on the participant’s response criterion
Steven’s power law
A law concerning the relationship between the physical intensity of a stimulus and the perception of the subjective magnitude of the stimulus. The law states that P=KSⁿ, where P is perceived magnitude, K is a constant, S is the stimulus intensity, and ⁿ is an exponent.
Temporal lobe
A lobe on the side of the cortex that is the site of the cortical receiving area for hearing and the termination point for the ventral, or what, stream for visual processing. A number of areas in the temporal lobe, such as the fusiform face area and the extrastriate body area, serve functions related to perceiving and recognising objects.
Top-down processing
Processing that starts with the analysis of high-level information, such as the knowledge a person brings to a situation. Also called knowledge-based processing. Distinguished 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 recognise objects.
Visual pigment
A light-sensitive molecule contained in the rod and outer cone segments. The reaction of this molecule to light results in the generation of an electrical response in the receptors.
Visual search
A procedure in which a person’s task is to find a particular element in a display that contains a number of elements.
Weber fraction
The ratio of the difference threshold to the standard stimulus in Weber’s law.
Weber’s law
A law stating that the ratio of 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 a doubling of the difference threshold. The ratio DL/S is called the Weber fraction.
