Perception Flashcards
What are phonemes?
The minimal unit of speech that can result in a difference in the spoken message
What is the phoneme-restoration-effect?
It is hearing phonemes even though they aren’t spoken. AKA. the brain expecting a phoneme and inserting according to context.
What is the place of articulation?
It is where the vocal tract is constricted to form a consonant phoneme. AKA. the place where we pronounce consonants.
What is the primal sketch in Marr’s model?
It is the point in visual processing where the features have been extracted from the stimuli.
What is prosopagnosia?
The inability to recognize faces as result of brain damage.
What is the receptive field?
For example, each ganglion cell has a part of the retina where it receives information -> that area is the ganglion cell’s receptive field.
What and where is the retina?
It is in the back of the eye, and is the inner most layer of cells made up of photoreceptive cells with light sensitive molecules. These molecules change their structure when hit by light, which initiates a photoreceptive process converting light to neural signals.
What is the primary visual cortex?
It is located in the occipital lobe and is the first cortical area to receive visual input. Here is e.g. the hyper columns and the information is about to get organized.
What is perception?
Perception is the process of interpreting and understanding sensory information from the environment
What is bottom-up processing?
Perception that starts with raw sensory input and builds up to complex representations
What is top-down processing?
Perception influenced by prior knowledge, expectations, and context
What is the role of pattern recognition in perception?
Pattern recognition involves identifying a stimulus and categorizing it by matching it with stored representations - template matching models.
There is also feature analysis.
What are Bar and Edge detectors?
These detectors are specialized neurons that respond to specific visual features such as lines, edges, or angles.
Bar and edge detectors only respond to stimulation in small areas of the VF and bars/edges in a small range of orientations and widths.
Respond to patterns in specific visual locations. If the bar has a different width, angle or placement then the detectors won’t pick it up and fire. This means we know the orientation of it based on if it fires or not/ which detectors fire.
What are the Gestalt Principles of Organization?
The principles are: proximity, similarity, closure and good form and good continuation). They help us organise visual scenes into objects.
What is visual agnosia?
Visual agnosia is a neurological disorder where a person can see objects but cannot recognize or interpret them
What is the word superiority effect?
The word superiority effect is the phenomenon where people recognize letters more easily when they are part of a word than when seen in isolation
How does the recognition-by-components theory explain object recognition?
It is the based on Feature Analysis. Recognition-by-components theory proposes that stimuli is recognized by identifying basic 3D shapes called geons,
What is change blindness?
Change blindness is the failure to notice changes in a visual scene due to limitations in attention
How does the brain process visual information in the ventral and dorsal streams?
The ventral stream processes “what” information related to object identification, while the dorsal stream processes “where” information related to spatial location and movement
What are the two main types of perceptual processing?
Bottom-up processing and top-down processing
What is the Template Matching theory of perception?
Template Matching theory suggests that the brain compares incoming sensory information with stored templates to identify objects
What are the limitations of Template Matching theory?
The theory does not account for variability in object appearance, such as differences in size, orientation, or partial occlusion
What is the Feature Analysis theory?
Recognizes objects by breaking them down into basic features. This model is more flexible and explains how we can recognize objects even when they vary in appearance, and it reduces the number of templates
What is the law of similarity in Gestalt psychology?
The law of similarity states that objects that are similar are perceived as part of the same group.
What is the law of proximity in Gestalt psychology?
The law of proximity states that objects that are close together are perceived as a group
What role do expectations play in perception?
Expectations, based on past experiences and context, can influence perception by priming the brain to interpret sensory information in a particular way
What are the two main types of photoreceptor cells in the retina?
Rods and cones
What is the fusiform gyrus responsible for?
Facial recognition
What is a hypercolumn?
A hypercolumn is a functional unit in the primary visual cortex that processes information from a small region of the visual field
What is the role of cones in vision?
Cones are responsible for color vision and function best in bright light
What function do rods serve in vision?
Rods are responsible for vision in low light conditions and do not detect color
What Bar Detectors?
Receptors in the visual cortex. They were discovered in cats. These detectors are neurons that fire off signals very specifically based on a bar of light in a very specific area. They work similarly to on-off receptors in ganglion cells.
What does the 2½ sketch imply?
The step in Marrs theory of visual perception that stems from feature extraction and depth perception. The following step is a 3D model!
What does the 3D-model imply?
The step in Marrs model that follows from feature and depth extraction as well as gestalt principles that allow us to separate features and simple objects in our perception.
What is apperceptive agnosia?
Agnosia (the inability to recognize objects) that stems from damage in the early perceptual processes. Before we create a 3D model of the world. This form of agnosia is also called “object agnosia”.
What is associative agnosia?
Agnosia that stems from damage in the later perceptual processes - when we contextualize objects semantically. This results in an inability to recognize and put objects in context and name complex objects.
What theory is categorical perception?
The theory that we perceive stimuli in categories and not delicate inbetween-values.
