Brain Structure, Lateralisation and Neuron Function

The machinery underneath 🧠

This topic is where psychology gets physical. Instead of asking what people do, it asks **which part of the brain does it, and what happens when that part is damaged**. Three things to get straight: where the jobs happen, how the two halves of the brain divide the work, and how a signal actually crosses from one nerve cell to the next. The topic also asks you to notice how psychologists' methods for studying the brain have changed over time.

Four lobes and a cerebellum 🗂️

Learn the job AND the position, because the next screen shows an unlabelled brain facing left:

Find the occipital lobe 🎯

An interactive activity.

Match each region to what it does

What would you expect? 👁️

A patient has damage to the occipital lobe. Which effect would you most expect?

• Difficulty processing what they see
• Poor balance and clumsy movement
• Marked changes in personality and planning
• Difficulty understanding speech

Two halves, different jobs ↔️

The brain is in two hemispheres, and some functions are **lateralised**, meaning they are handled mainly by one side. In most people language is handled largely on the left, and some spatial tasks largely on the right. The two halves are joined by the **corpus callosum**, a thick band of fibres that passes information between them. **Now the part to get right.** "I am a right-brained creative person" is a **myth**. Lateralisation describes specific functions being handled asymmetrically. It does not mean people have a dominant half that determines their personality, and writing that in an answer will cost you.

Which are correct? ✅

Select the TWO correct statements about lateralisation.

• In most people, language is handled largely by the left hemisphere
• The corpus callosum carries information between the two hemispheres
• Creative people use the right hemisphere and logical people the left
• Each hemisphere works entirely independently of the other

The sex-difference explanation ⚖️

The specification asks you to weigh an explanation that says lateralisation differs between the sexes. It is examined on strengths AND weaknesses, so learn both sides, and note the weaknesses are the harder half to remember.

The strongest objection 🤔

Which is the strongest criticism of explaining differences in behaviour by differences in brain lateralisation between the sexes?

• The variation within each group is usually much larger than the average difference between them, so the average tells you little about any individual
• Brain scanners are new technology, so their results cannot be trusted at all
• No psychologist has ever found any difference between the sexes
• It is an uncomfortable thing to research

How a signal travels ⚡

Zooming right in. The brain and spinal cord together are the **central nervous system**, and they are built from billions of nerve cells:

The journey of a message 🔀

An interactive activity.

Match each kind of damage to its effect

The summary 📝

Vision is processed in the _____ lobe, at the back, while planning and personality belong to the _____ lobe. The band of fibres joining the two hemispheres is the _____. Between two neurons is a gap called the _____, crossed by chemicals called _____. Being unable to recognise familiar faces is called _____.

Explain the case ✍️

An interactive activity.