Cognitive- Held & Hein Flashcards
Sensation
the process of bringing information from the outside world into the body and to the brain.
Process of sensing our environment through touch, taste, sight, sound, and smell. Requires sensory receptors.
This information is sent to our brains in raw form where perception comes into play.
Perception
the process of selecting, organizing, and interpreting the information brought to the brain by the senses.
Nature
humans are born with all their perceptual functions ready to be used
Bottom up theories of processing: also known as “small chunk” processing, suggests that we perceive our environment by starting with the smaller, more fine details then building upward until we have a solid representation of it in our minds
Nurture
perceptual abilities have to be learned and adapted to
Top down theories of processing: also known as “large chunk” processing, states that we form perceptions of our environment by starting with the larger concepts and then working our way down to the finer details of that concept
5 Study methods
by studying human babies/neonates & cataract patients & animals & different cultures & studying adaptation
Aim
To test whether self produced movements are necessary for visually guided behavior.
Method & Design
Laboratory Experiment
Independent Groups (or independent measures) design. Where each participant is in just one condition of the independent variable Each kitten performed in only one condition of the independent variable
Independent Variable
IV1 – kitten pairs ‘X’ and kitten pairs ‘Y’
IV2 – active kitten and passive kitten
Dependent Variable
Perception
Apparatus
‘Exposure’ apparatus consisting of a striped environment and a carousel. One ‘active’ kitten can walk about freely(or round and round) and through the harness movement is transmitted to the other ‘passive’ kitten, which is placed in a ‘gondola’ preventing movement by its own legs.
A comfortable cage with no light, where each pair of kittens spent non-experimental time with their mother and litter mates.
Controls
All participants in each group were exposed to the same environment for the same amount of time and performed exactly the same tests
All participants had the same ‘living conditions’ and spent time with their mother and litter mates.
Kittens experience
speed of travel direction of travel distance travelled height from the floor contact with the floor the view of the apparatus
Procedure
None of them received light before the experiment, as they were all reared in darkness from birth.
The point of this experiment is that both kittens were made to learn to see the world receiving the same visual stimulation. The difference was that the one moved actively, the other was moved passively.
The pairs spent 3 hours per day in the apparatus for 6 weeks.
When not in the apparatus, all kittens were housed in darkness with their mother and littermates
Each pair was attached to a ‘roundabout’ which was propelled by the movements of kitten A.
A could move up, down, toward or away from the center, and rotated clockwise or counterclockwise.
Kitten B was also attached to the roundabout but was carried in a basket so it could not control its own movements. It moved exactly the way kitten A moved.
Tests of the capacity to make visual-spatial discriminations
Visually-Guided paw placement
Avoidance of Visual Cliff
Blink to an approaching object
Tests of visual receptors and their responses
Visual pursuit of a moving object
Pupillary Reflex to light
Tactual Placing Response
Visually-Guided Paw Placement
the kitten was held above a table and slowly moved towards it. A kitten with normal visual experience extends its paws ready to make contact with the surface.
Avoidance of Visual Cliff
this equipment is like a bridge between two tables with an ‘invisible’ glass surface between them (so the animal can’t fall). One side of the bridge covers a shallow drop and the other side a deep drop. A kitten with normal visual experience walking across from one side to the other will walk onto the shallow surface but avoid the deep drop.
Blink to an Approaching Object
the experimenter brought his hand quickly towards the kitten’s face (stopping just in front of it). A kitten with normal visual experience blinks in response.
Visual Pursuit of a moving object
the kitten was shown the experimenter’s hand moving slowly in front of it. The movement of the kitten’s eyes was recorded. A kitten with normal visual experience follows the movement with its eyes.
Pupillary Reflex to Light
a flashlight beam was moved across the eye and the change in pupil size was noted. The pupil of a kitten with normal visual experience shrinks in response.
Tactual Placing Response
the kitten was held as in the paw placement test but its front paws were put against the vertical surface of the table. A kitten with normal visual experience responds by moving its paws to the horizontal surface.
Findings
The findings fit the idea that self-produced movement and concurrent visual feedback are essential for the development of visually-guided behavior.
Following the 48 hours of freedom in a lighted room the passive kittens were retested.
They displayed normal visually-guided paw-placement and performed all descents to the shallow side of the visual cliff.
However, they were never normal
Explanation
Self-actuated movement is necessary in order to develop the normal visual perception with depth.
Our movement in the world gives the dimension of depth to mere visual sensations.
Movement is the key to understanding the vision.
Overall the evidence is that some parts of perception are learned and some innate, and although it tends to be the more complex ones that are learned, there is still no total certainty as to which are innate and which rely on experience.
Strengths
The amount of control
This shows that the kittens’ visual deficits were due to the fact that its movements were not self-actuated
Weaknesses
May have merely distorted inborn abilities rather than proved that the abilities were learned (Construct validity?)
Can this generalize to all mammals? Even people?
Ethics of working with animals
Subjects
Ten pairs of kittens were used; each pair from a different litter
In each pair there was one ‘active’ (A) and one ‘passive’ (P).
Population= Higher mammals
(humans are higher mammals)
