Physiology Psychology - Sperry (1968)

1. The left hemisphere is the 'logical' side. It processes numbers, sequences, language (both to apprehend and to speak) and uses logic to reason events out.
2. The right hemisphere is the 'creative' side which processes whole imagery, patterns, spatial awareness and music.
3. The Corpus Collosum is a bundle of nerves which connects both hemispheres together, allowing information processed from one side of the brain to relay into the other side.

1. Only two of these were described in detail.
   1. The first - A male who had had been suffering from seizures for more than 10 years, an average of two major attacks per week before beggining to suffer reccuring seizure which were at a high death risk. Since having the surgery, the participant has had no seizures and had significantly reduced his medivation and reported an overall improvement in health.
   2. The second - A female in her thirties who reported that she was also seizure free since the operation which was four years prior. The EEG scan she had was reported to have a normal pattern.
   3. Based on the sucess of the first two patients, the surgery was extended to the other nine also used in this study.

Annotations:

• The participants had had the surgery before the study, Sperry took no part in it - The independant variable had not been manipulated.

1. Laboratory Experiment

Annotations:

• Possibility of different interpretations/obervations are lessoned.

1. Quantitatve

   Annotations:

   • The majority of this study is quantitatve data. -Sperry records whether something can be identified or not which allows him to make later conclusions about how the two hemospheres differ in their functions.
2. Qualitative

   Annotations:

   • The qualitative data that Sperry recorded were the experiences of the 'split-brain' patients which add significantly to the attempt to understand why/how thier experiences occured.

1. If the same image was presented in the original visual field the participants were able to recognise the image as one they had seen before.

1. Left hand + Object = Inability to speak - but ability to find the object again in the grab bag.
2. Right hand side could also:
   1. Select similar items, E.g. Clock - Watches.
   2. Can perform simple arithmetic operations.

      Annotations:

      • Arithmetic operation - A mathematic operation involving numbers.
   3. Can understand both written and spoken word, but cannot be understood.
   4. Can identify objection but cannot be verbally speak them.
   5. Can understand instructions
   6. Show emotion

Annotations:

• RVF - Right visual field LVF - Left Visual field

1. They could respond non-verbally by pointing with their left hand to the matching picture of selecting an object presented among a collection of other pictures and objects.
2. This only works with right-handed oarticipants.

Annotations:

• Over the extranuous variables.

Annotations:

• No ethical issues were breached during this study.

Annotations:

• Of the small amount of people who have had the operation.

Annotations:

• Allowed the researchers to investigate the variables in strict laboratory conditions. (The functioning of the two brain hemispheres have never been studied in such depth before)

Annotations:

• Can be replicated with new split-brain patients.

Annotations:

• The small sample of 11 means it cannot be generalised to the whole public - seeing as spilt-brain patients are not a common thing - it is not suprising.

Annotations:

• The fact it was a quasi-experiment meant that the experimenter had no control over the independant varibles.

Annotations:

• The procedure Sperry uses, seperating the two visual fields is something unlikely to occur in real life and if it did - The split brain patients have methods which allow them to cope with such events.
• However, ecologically valid research is studying real problems, which is something Sperry does - Looking at the naturally occurring variable of the results of the split-brain surgery is studying the real life problem. Attempting to understand the effects of the proceedure and if the operation should be any cause for concern for the individuals undergoing it.

Annotations:

• May not be able to compare 'split brain' (severe epilectic brain) to a normal brain.

1. The left is responsible for language and the right side of the body.
2. The right side is responsible for spatial awareness and the left side of the body.