Introduction to Perception Flashcards
What is sensation?
Information from outside world into body and brain.
Passive process.
What is perception?
Selecting, organising and interpreting the information brought to the brain by the senses.
Active process.
It is subjective.
Physical stimuli are reduced to electrical + chemical events.
Sensation occurs before perception.
Explain the results from the visual cliff experiment (Gibson & Walk) and the importance of experience (Campos).
When infants are able to crawl - they can perceive depth.
Campus showed that 11 days vs 41 days of crawling experience has an impact. Half cross vs less than 1/4 crossed.
Intermodal perception - visual + auditory (parents gave + or - cues).
Why should we study perception?
To understand the world around us.
To design our environment effectively.
To understand features of clinical disorders.
Curiosity.
What are the three main things that can alter our perception?
Experience (e.g. visual illusions). Brain damage (e.g. prosopagnosia). Atypical development (e.g. sensory deprivation - Genie).
Explain how perception is context specific.
Environment influences us cognitively, emotionally physically…
Ebbinghaus effect.
Arcimbaldo (fruit bowl painting) - we are susceptible to faces.
The Thatcher effect - we have a very strong inversion effect. Hard to recognise inverted faces.
Explain how perception is multimodal.
McGurk effect - auditory + visual illusion.
Explain how perception is selective.
Monkey/umbrella illusion.
Kanizsa’s illusory square - visual system is not passive. We automatically extend line segments into parts of the drawing where they are missing.
Reflects the properties of the way the visual system is wired.
What are the two main ways in which information can flow regarding perception?
Bottom-up - implicit + innate processes. Generic across species. Shaped by evolution.
Top-down - knowledge, thoughts + expectations influence perception. Specific to the individual. Shaped by experience.
Explain how the hollow mask illusion occurs.
If participants are engaging with the image (moving) they won’t perceive the illusion compared to participants sitting still.
Explain how illusions with ambiguous information occur.
Perceiving one feature prevents you from perceiving the other.
Visual system groups + separates characteristics in complex images to recognise objects within it.
In perception, we make choices.
What is the constructivist approach to perception (Gregory, 1970)?
Top-down processing - construction of our world from past experiences alongside real-time visual information.
Lots information reaches eye - much is lost by the time it reaches the brain.
Sensory information received from environment - combined with previously stored information (experience).
We actively construct our perception of reality.
Formation of incorrect hypotheses = errors of perception.
What is the Gestalt theory of perception?
Bottom up processing - visual stimuli influence perception - work their way up to higher-order cognitive processes.
Percepts determined by interaction of simple rules describing organisation.
Simplest interpretation is best.
Whole is more than the sum of its parts.
5 laws in Gestalt theory.
What are the 5 laws in Gestalt theory?
Law of proximity - elements close to each other - perceived as one group.
Law of similarity - objects that look alike - organised together.
Law of closure - in perception, there is the tendency to complete unfinished objects.
Law of continuity - objects will be grouped as a whole if they are co-linear or follow a direction.
Law of Pragnanz/simplicity - figures seen as simple elements instead of complicated shapes. Against Gregory’s theory!!!
Name some strengths and weaknesses of Gestalt research.
Strengths - rules are fairly robust in real world.
Weaknesses - Lab-based + only 2D images - low ecological validity.
