Lecture 1- Perceiving Objects Flashcards
(30 cards)
Define Perception
the study of the processes involved in perceiving and interpretating the signals from our senses
What is the importance of Object recognition?
- Interact with the environment
- Navigate
What is Visual Perception?
- The brain creates meaning
- The brain constructs the best and consistent interpretation
What is Visual recognition?
- Transformation of visual signals into a coherent, meaningful interpretation
- it is a construction based on previous experience, inferences, assumptions, and individual experiences
State the properties of Object recognition?
1) Invariance or Tolerance
2) Specificity
3) Rapidity
4) Range and Generality
Explain Invariance or Tolerance as a property of Object recognition
- Able to recognise objects in countless situation, despite variation
Explain Specificity as an property of object recognition
distinguish between very similar objects
Explain Rapidity a a property of Object recognition
- Recognition is extremely fast
- Does not require attention
Explain Range and Generality as a property of object recognition
- Range: we recognise a large range of objects
- Generality: we recognises classes (categories) of objects
What did Desimone et al (1984) do to study recognition?
- Recording of single neurons in the inferior temporal (IT) cortex of Macaques
What did Desimone et al (1984) find?
- Neurons in inferior temporal respond to complex objects such as hands in different positions, but weakly for a hand with no defining fingers
How do IT neurons respond to changes in size, position, context, or viewpoint of a stimulus?
- Responses of inferior temporal neurons a largely invariant to transformations of the stimuli
- Preserves identity information
What is Visual Agnosia?
- Selective inability to identify objects visually
- Patients have no other deficits
What does agnosic mean?
experience a failure of knowledge or recognition
What are the examples if agnosia?
- visual
- Somatosensory/ Tactile
- Auditory
What is Somatosensory/ Tactile agnosia?
inability to recognise objects by touch
what is Auditory agnosia?
inability to recognise music, or speech non-speech, despite normal hearing
What are the causes of Visual agnosia?
- Lesions in the lateral occipital cortex
How does the brain create objects?
1) Figure- ground principles
2) Isolating objects
What are the Figure-ground principles?
- Law of simplcity
- Surroundedness
- Size
Explain Law of simplicity?
- obstruction
- Relatability (connections with smooth convex or concave curve, not an s curve)
Explain Suroundedness
if one region is surrounded by another, it is likely that’s its a figure
Explain Size
The smaller region is likely to be a figure
Explain Isolating objects in terms of creating objects
- Use different properties such as motion, colour, and texture
- combining features into forms e.g., grouping principles
