Held+and+Hein+-+Period+2

Aim: To test whether self produced movements related to changes in stimulation are essential for the development of certain perceptions

Participant group: The participant group in this study were two newly born kittens out of a litter. The way kittens were treated was that the two selected kittens spent half of the day in daylight (moving in the carousel) and the second half were spent in darkness with their mother. The rest of the kittens spent every day in darkness with their mother.

Research method: This experiment took place in a laboratory.

Special Equipment: The only special equipment truly required from this study is the carousel used to test the kittens.

Procedure: The two kittens that were taken from the litter were labeled as either Kitten A or Kitten B. When Kitten A was placed in the carousel it was attached to a vest that allowed it to move freely around the carousel in any direction it wanted. However, when Kitten B was placed in the carousel it was placed in a basket and was not allowed to move (by itself) around it. Instead as Kitten A moves it pulls Kitten B around by its own force. These kittens went through this same process every day for three hours, for six weeks. As the kittens were moving/moved around the carousel the researchers put a wall in between them so that in no way could either kitten look at the other.

How was data collected: After the six week period ended the researchers took both kittens and tested them to test their natural reflexes. The tests were: •Visually guided paw placement •Avoidance of visual cliff •Blink to an approaching object •Visual pursuit of a moving objec •Pupillary reflex to light •Tactual placing response



What type of data was collected: -All of the kittens had normal blink responses -All of the kittens had normal responses to the visual cliff but the passive kittens crossed to the shallow side at random -All of the active kittens had normal visually guided paw placement but none of the passive kittens did

Results:

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 the active kittens had normal blink responses

All the 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.

After spending 48 hours in a lighted room with full freedom, the passive kittens were retested and displayed normal visually-guided paw-placement and performed all descents to the shallow side of the visual cliff. However, they were never normal.

Conclusions:

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

Some parts of perception are learned and some are innate. The more complex parts of perception appear to be the ones that are learned but there is no 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 travelled • Height from the floor • Contact with the floor • The view of the apparatus This shows that the differences were due to the kittens visual deficits that were due to the fact that its movements were not self-actuated.

Weaknesses:

May have merely disrorted 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

Eco Validity:

The ecological validity is hurt by the use of a laboratory. Also, it is studied on animals (kittens) whereas humans are different.

Ethics:

They are studying animals and harmed some of the kittens. They stated that the kittens were never normal.