HEMISPHERIC LATERALISATION

Question 1

what is the definition of hemispheric lateralisation?

Answer 1

the idea that the two halves of the brain are functionally distinct, with specific processes dominated by one side

Question 2

what part of the brain acts as a connector?

Answer 2

corpus callosum

Question 3

what is contralateral wiring?

Answer 3

The left hemisphere (LH) controls the right side of the body/visual field, and the right hemisphere (RH) controls the left.

Question 4

what does the left hemisphere specialise in?

Answer 4

Dominant for language (Broca’s and Wernicke’s areas) and logical tasks

‘the analyser’

Question 5

what does the right hemisphere specialise in?

Answer 5

Dominant for spatial tasks, facial recognition, and musicality

‘the synthesiser’

Question 6

what was the sample for Sperry’s split brain research?

Answer 6

11 “split-brain” patients who had their corpus callosum severed (commissurotomy) to treat severe epilepsy

Question 7

what did sperry find in Right Visual Field (LH)?

Answer 7

Patients could easily name the object

Question 8

what did sperry find in the Left Visual Field (RH)?

Answer 8

Patients reported seeing nothing (because the RH lacks language centres)

Question 9

what did sherry find about recognition in touch?

Answer 9

While they couldn’t name the LVF object, their left hand (RH) could find it in a bag of objects

Question 10

what did sherry find in the drawing tasks?

Answer 10

The left hand (RH) was significantly better at drawing 3D spatial images than the right hand, even in right-handed patients

Question 11

what was sperrys procedure?

Answer 11

Used a tachistoscope to flash images to one visual field at a time for 0.1 seconds (too fast for eye movement to share info)

Question 12

what is a strength for hemispheric lateralisation?

Answer 12

Methodological Rigour ~ High level of control (0.1-second exposure) ensured internal validity by isolating each hemisphere

Theoretical Contribution ~ Transformed our understanding of brain architecture, proving that while the brain works as a whole, it contains specialized “hubs” for specific tasks

Question 13

what is a weakness of hemispheric lateralisation?

Answer 13

Generalisation Issues ~ The sample was small (N=11) and unique. Epilepsy and anti-seizure medication may have altered their brain function compared to the “neurotypical” population.

Overstatement of Differences: Modern neuroscience suggests the “left-brain/right-brain” divide is a pop-psychology oversimplification. In healthy brains, the hemispheres communicate constantly, and plasticity allows for functional overlap

Artificiality ~ In everyday life, we use both eyes and move our heads, meaning both hemispheres receive information simultaneously. The isolated findings in the lab may not reflect real-world processing.