IWA #3 - Psychology Flashcards
What is a feature detector ?
A pattern detecting system.
After V1 what are the two primary streams of visual processing?
Ventral Stream (temporal lobes) - vision for perception
Dorsal Stream (parietal lobes) - vision for action
What is the Ventral Stream?
The ventral stream allows us to interpret WHAT exactly it is we are seeing.
What are some examples of visual illusions which reveal the function of the Ventral Stream?
Size Constancy, Afterimages, Troxler Fading, Motion Induced Blindness, Apparent Motion, Motion in Depth, Shadow Cues.
Explain Size Constancy.
If two things have the same retinal image, then the thing that is perceived to be further, will be perceived as bigger.
What do afterimages tell us about perception?
Afterimages reveal the suppression principle at work (look at the sun - everything is blue after), certain visual cells fatigued.
What does Troxler fading tell us about perception?
That we are designed to detect change, and when things stop changing, we stop perceiving them.
other examples: MIB, apparent motion
Lilac Chaser combines which two effects?
Afterimage and Apparent Motion.
Explain how we perceive an objects spatial height in relation to shadow cues.
If we perceive a shadow significantly below A, then A must be floating. Because of shadow cues this works with or without movement.
Q: What is “feature detection” in visual processing, and what exemplifies this concept?
Feature detection refers to how the brain identifies specific patterns or features in visual stimuli, such as shapes, colors, or directions of motion.
Example: Simple Cells in V1: These cells respond to basic features like edges or lines at particular orientations, forming the basis of more complex visual processing.
What is “size constancy,” and what exemplifies it?
Size constancy is the ability to perceive objects as having a consistent size despite changes in their distance from us (and the change in their retinal size).
Terror Subterra Illusion: When two objects cast the same retinal image but one is perceived as further away, the brain compensates by perceiving the further object as larger.
What are the effects of Prosopagnosia, what do these effects indicate?
Individuals with this condition can recognize objects but fail to recognize faces, indicating that face recognition is a specialized process within the ventral stream.
What is the dorsal stream’s role in vision-for-action, and what is an example of its functioning?
The dorsal stream processes spatial information and motion, aiding in actions like reaching and grasping.
Grasping Movements in Patient DF: A patient with damage to the ventral stream (object recognition) could still accurately perform grasping actions (dorsal stream function), showing the separate roles of the two visual streams.
What is perihand space?
Perihand space is the region near the hands where objects are processed with a focus on action-related features like size and orientation.
How does perihand space influence visual processing?
Objects within perihand space are processed with more detail, as they are within reach and could be interacted with, highlighting how the brain prioritizes action-oriented information near the hands. (Ventral-Dorsal interdependence)
What is multimodal perception?
Multimodal perception is the integration of information from multiple senses, where one sense can influence the perception of another.
What is the McGurk Effect?
When conflicting auditory and visual information is presented, the brain combines these inputs to create a new, often illusory, perception (e.g., hearing one syllable while seeing the mouth form another).
Ventral-Dorsal Interdependence
These two visual pathways are interdependent.
If the world is not perceived as is what is ________?
the cognitive process
we ask what the cognitive process is behind perception, instead of asking what the figments are that fill in the gaps.
Is difference blindness a failure in perception?
Perception is not just the feature detectors ect. It also involves memory, recoding, and comparisons. Any one of these can ‘fail’ or cause difference blindness.
Explain perception according to the Predictive Coding model.
According to the theory of predictive coding, we form predictions about reality, we test those predictions, and then receive confirmation of those predictions (that they were either correct or incorrect) which then inform future predictions. This cycle of prediction, test, confirmation, is in its entirety, perception.
Social information collected
physical appearance, social status, face, gaze
