Held+and+Hein+-+Period+1

toc = Kitten Carousel = Held and Hein (1963)


 * Sensation is the process of bringing information from the outside world into the body and to the brain.
 * We can sense our environment through touch, taste, sight, sound, and smell, this requires sensory receptors.
 * This information is sent to our brains in raw form where perception comes into play.
 * Perception can be defined as the process of selecting, organizing, and interpreting the information brought to the brain by these senses.
 * We are concerned with the development of perception.


 * The debate between nature and nurture is the basis of most research into the development of perception
 * There are five ways in which psychologists have attempted to study this debate:
 * By studying human babies, or neonates
 * By studying cataract patients
 * By studying animals
 * By studying different cultures
 * By studying adaptation

Aim
> The aim of the study was to test whether self produced movements related to changes in stimulation are essential for the development of certain perceptions.

Participant Group
> Ten pairs of kittens were used, and each pair came from a different litter. In each pair, there was one active, and one passive. Kittens are higher mammals, to which humans also belong. >

Research Method
> The method is a Laboratory experiment with a yoked control design, meaning that the rate of responding is compared to that by a control subject.

Procedure
> Each pair of kittens was attached to a 'roundabout' which was propelled by the movements of kitten A. Kitten 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. The apparatus was housed in a cylinder with black, white and metal colored vertical strips on the walls inside. The center of the roundabout, which was also striped, prevented the kittens from seeing each other.

> None of the kittens 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 one moved actively, while the other moved passively. The pairs spent three hours per day in the apparatus for six weeks. When not in the apparatus, all kittens were housed in darkness with their mother and littermates.

There were tests of the capacity for the kittens to make visual-spacial discriminations.


 * 1) Visually guided paw placement: the kitten was held by the experimenter with its head and forelegs free and was carried down to the edge of the table. A kitten with normal visual experience extends its paws ready to make contact with the surface.
 * 2) Avoidance of a visual cliff: the kitten is placed on the central 'bridge' from which it can stay still or walk onto either the 'shallow' or 'deep' side. A kitten with normal visual experience experience avoids the 'deep' side.
 * 3) Blonk to an approaching object: the kitten was held still on a standing position and 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.
 * 4) Visual pursuit of a moving object: the kitten was show 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 it's eyes.
 * 5) 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.
 * 6) 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 response by moving its paws to the horizontal surface.



Findings

 * All of the active kittens developed a normal visually guided paw placement response when they had spent 63 hours (21 sessions) or less in the apparatus. No passive kitten had acquired a visually guided paw placement.
 * All of the active kittens had normal blink responses
 * All of then active kittens had normal responses to the visual cliff, but the passive kittens were crossing to the shallow or deep side at random.
 * 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 cliff.
 * However, they were never //normal.//

Explanations

 * 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 vision.
 * Overall the evidence is that some parts of perception are learned and some innate, and although it tends to be more complex ones that are learned, there is still no total certainty as to which are innate and which rely on experience.

Strengths

 * Control
 * Experience of the kittens was matched
 * Speed of travel
 * Direction of travel
 * Distance traveled
 * Height from the floor
 * Contact with the floor
 * View of the apparatus
 * This shows that the differences were due to the kittens visual deficits, and in turn, 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.