Lecture 1 Flashcards
perceiving objects (13 cards)
What is perception in cognitive psychology
Perception is the process by which the brain interprets sensory information to create an understanding of the environment.
Why is visual object recognition considered complex?
Because it involves constructing meaning from ambiguous, incomplete, and variable sensory input using context, prior knowledge, and inference.
What does it mean that visual perception is a construction?
It means that the brain creates meaning from raw sensory input—it doesn’t passively record reality like a camera.
What are invariant responses in object recognition?
Neural responses that remain consistent despite changes in the visual appearance of an object (e.g., size, position, viewpoint)
Which brain area shows invariant responses to objects?
The inferior temporal (IT) cortex, where neurons respond to object identity regardless of transformations.
What are the four key properties of object recognition?
- Invariance – recognition despite changes in appearance
- Specificity – selective neural response to specific objects
- Rapidity – fast categorization (e.g., within 120ms)
- Range & generality – recognizing many objects and categories
What is visual agnosia?
A condition where a person cannot visually recognize objects despite normal vision and intact memory.
What brain region is typically damaged in object agnosia (like in Patient S)?
The lateral occipital cortex (LOC), specialized for object recognition.
What is figure-ground segmentation?
A process where the brain distinguishes objects (figures) from their background (ground) using visual cues.
What principles does the brain use for figure-ground segmentation?
Surroundedness – enclosed areas are figures
Size – smaller areas are likely to be figures
Symmetry/convexity – symmetrical/convex regions are favored as figures
Contrast – sharp edges signal boundaries
Familiarity – known shapes are more easily seen as figures
What is an example of disrupted figure-ground segmentation in nature?
Camouflage, where an animal blends into the background to avoid detection by hiding figure-ground cues.
What brain regions specialize in recognizing different types of objects?
LOC: general object recognition
FFA (Fusiform Face Area): face recognition
PPA (Parahippocampal Place Area): place/scene recognition
EBA (Extrastriate Body Area): body form recognition
How does object recognition proceed in stages?
Receive light on the retina
Extract features (edges, motion, color, etc.)
Group features into forms/objects
Identify/recognize objects using memory and context
