chapter 4: sensory, attentional and perceptual processes Flashcards
What are the three processes needed for the knowledge of the world?
Sensation, attenion, and perception. They are highly interrelated.
Define stimulus.
A stimulus is any object or event that bring out a response. Some stimulis found in the environment are:
- Seen
- Heard
- Smelled
- Tasted
- Felt
What are sense organs?
These sense organs are known as sensory receptors or information gathering systems.
Name the two deep senses.
- Kinesthetics - sense of position and movement of the body
- Vestibular systems - ability to maintain balance and posture.
Define sensation.
It’s the initial experience of a stimulus or an object registered by a particular sense organ.
Name the functional limitations of sense organs.
For being noticed by a sensory receptor, a stimulus has to be of a certain magnitude or optimal intensity.
What is it called when the minimum value of a stimulus required to activate a given sensory system?
Absolute threshold or absolute limen (AL)
for example: if you add a granule of sugar to a water, you wont taste the sweetness. Although if you add more and more you’ll reach a point to taste the sweetness. The minimum amount of sugar granules needed to make the water sweet will be the AL of sweetness.
What is difference threshold or difference limen (DL)
The smallest difference in the value of two stimuli that is necessary to notice them as diffferent.
for example: If we want to add more sugar granules to the same water to experience a different form of sweetness than the previous, we add more to achieve that will be called DL of sweetness.
Define attention.
The process through which certain stimuli are selected from a group of others.
The process of directing or focusing our senses towards someone or something.
Describe the 3 properties of attention.
- ALERTNESS refers to the activeness or readiness of an individual to deal with the stimuli that appear infront of him/her
- CONCENTRATION refers to dfocusing awareness on certain stimuli while excluding others for the moment.
- SEARCH, an observer searches for some specified subset among a given set of stimuli.
Define focal point of attention and fringe of attention.
FOCAL POINT OF ATTENTION - where our focus is centered on a particular object or event
FRINGE OF ATTENTION - when we have vague ideas about the stimulus and are awa from the center of awareness.
Describe Sustained attention. (1)
Defined as the ability to maintain attention on an object or event for longer durations. (also known as “vigilance”)
What are the factors affecting Sustained Attention. (1)
Sensory modality: performance is found to be superior when the stimuli is more auditory than visual.
Clarity of stimuli: intense and long-lasting stimuli facilitate sustained attention, leading to better performance.
Temporal uncertainty: Stimuli can be attented better if they’re kept at regular intervals to keep good track.
Spatial uncertainty: Stimuli that appears in a fixed place are readiluy attended.
Describe Selective Attention (2)
Selective attention is defined as directing our senses to relevant stimuli while ignoring irrelevant stimuli in the environment.
What are the factors affecting Selective Attention (2)
External factors: related to the features of the stimuli such as size, intensity, motion of stimuli. Stimuli which are novel and moderately complex (easy for focus).
Internal factors:
- Motivational factors which relate to our biological and social needs. (eg, when ur hungry, we’d notice a faint smell of food.)
- Cognitive factors include attitude factors like interest, attitude and preparatory set, readily attended by individuals.
What are the Theories of Selective Attention?
- FILTER THEORY
- Developed by Broadbent in 1956.
- According to this theory, many stimuli simultaneously enter our receptors creating a kind of “bottleneck” situation.
- They enter selective filter which allows only one stimulus to pass through for higher processing, other stimulis are screened out.
- Thus, we only become aware of that one stimulus through selective filter. - FILTER ATTENUATION THEORY
- Developed by Triesman in 1962
- This theory proposes that the stimuli not getting access to the selective filter at a moment of time are not entirely blocked.
- The filter weakens their strength. - MULTIMODE THEORY
- Developed by Johnston and Heinz in 1978
- This theory believes that attention is a flexible system that allows selection of stimulus over others at three stages.
- Stage one, the sensory representation (visual images) are constructed.
- Stage two, the semanatic representation (names of objects) are constructed.
- Stage three, the sensory and semanatic representation enter consciousness
Define Divided attention.
WHen focus is directed towards multiple tasks, also known as multi-tasking without people realising.
Define Perceptual process.
Perception is defined as the process by which we interpret the stimuli and give proper meaning to them.
What is Processing Approaches in Perception
BOTTOM UP PROCESSING: It’s the process that begins at entry level (stimulus) with what our senses can detect.
TOP DOWN PROCESSING: It’s the process of the brain sending down stored information to the sensory systems from our available knowledge, experiences and thoughts.
Name the Factors affecting Perception.
- Motivation: The needs and desires of a perceiver strongly incluence their perception. People want to fulfill their needs and desires through various means.
- Expectations: The expectations about what we may perceive in a situation also has a strong impact on our perception.
- Cognitive styles - Refers to a consistent way of dealing with our environment. Affects the way we perceive our environment.
- Cultural Background and Experiences: Different experiences and learning opportunities available to people in different cultural settings also influence their perception.
What is Perception of shape or form.
- The process of organizing visual fields into meaningful wholes is defined as form or shape perception.
- As per Gestalts psychologists, we perceive different diffewrent stimuli not as discrete but as an organised whole that has definite form.
What is figure-ground segregation?
It’s a primitive organisation:
- figure is organised, backGROUND is unorganised.
- figure has definite form, backGROUND has indefinite form.
Name the Principles/Laws of Perceptual Organization.
- LAW OF PRAGNANZ: Also known as law of simplicity. When you’re presented with complex objects, your brain will make it simpler understable.
- PRINCIPLE OF PROXIMITY: Objects that are close together in space or time are perceived together.
- PRINCIPLE OF SIMILARITY: objects that are similar to each other in a set are often perceived as a group.
- PRINCIPLE OF CONTINUITY: we perceive patterns as belonging together if they appear to form a continous pattern.
- PRINCIPLE OF SMALLNESS: smaller areas tend to be seen as figures against a larger background.
- PRINCIPLE OF SYMMETRY: symmetrical areas tend to be seen as figures against an asymmetrical backgrounds.
- PRINCIPLE OF SURROUNDNESS: areas surrounded by others tend to be perceived as figures.
- PRINCIPLE OF CLOSURE: we tend to fill gaps in stimulation and perceive objects as a whole rather than separare parts.
What is perception of space, depth and distance.
The process of viewing the world in three dimensional (3D) in terms of distance or depth perception
Define Binocular cues and Monocular cues.
BINOCULAR CUES: when we use both our eyes
MONOCULAR CUES: when we use only one eye to perceive depth
Talk about Monocular cues.
- Relative size - we perceive objects farther away as close, and objects closer as bigger.
- Overlapping - occurs when an object is covered by another object, viewing the behind object farther away and the object infront closer.
- Linear Perspective - distant objects appear to be closer together than nearer objects.
- Aerial Perspective - microscopic particles of dust that makes distant objects look hazy or blurry.
- Light and shade - light hitting areas becoming highlighted, whereas some parts become darker.
- Relative height - larger objects perceived as being closer and smaller objects farther.
- Texture gradient - visual field having more density of elements seen further away.
- Motion Parallax - objects at different distances move at different relative speeds.
