When did you last imagine? Very recently is the likely answer. Indeed, .ĚýPerhaps counterintuitively, though, our imagination isn’t a single thing. Rather, the latest research suggests it exists in at least four forms.

1. Reproductive imagination

Conjure up the image of an apple in your mind’s eye. Is it green or red? Does its skin shine? Does it have a stalk? Can you get a sense of its weight as you gently twirl it? Does it have a scent? If these questions make sense to you, you have created a “sensory image” of an apple. This kind of imagination is known as reproductive. You know an apple’s properties, so you can reproduce apple-like sensations in the absence of the real thing. (Those who are born blind don’t have the visual element of this sort of imagination, but can, of course, imagine movement, a sense of space, smells, sounds and so on).

When you do so, research suggests, the brain regions that activate strongly when you look at an apple activate weakly, giving your imagery its visual feel. We know this because brain imaging has shown directly that visual cortices fire up when we visualise things. Plus, forming an image can have similar physiological effects to looking at the real thing. For example, if you imagine looking into the sun, your pupils will constrict.

2. Creative imagination

Once we can create images of things in their absence, there is plenty of scope for tinkering with them. When we do this, we nudge our reproductive imagination into the productive, also called the creative, kind. We harness this style of imagination in both humdrum contexts (“how will my friend feel if I touch on that difficult subject?”) and innovative ones, such as when a playwright creates a startling denouement or a physicist posits a new fundamental particle.

Imagery seems to be a frequent ingredient in the process of creation – but not an essential one. If someone with aphantasia, who lacks a visual mind’s eye, is asked to imagine an apple behind their eyelids, nothing appears. Yet such individuals can also be creative, producing things that are new and useful, from the latest tech to pieces of music.

3. Perceptive imagination

The two kinds of imagination mentioned previously are arguably the offspring of a more fundamental form, which allows us to experience the world around us. We don’t usually consider our day-to-day perception of everything we see –Ěý the books on our bedside table, our toothbrushes in the bathroom, the sky as we step out of our front door – as “imaginative”, but the latest research indicates there are strong reasons for deeming it so.

Our waking experience depends on our hard-won knowledge of the sensory world – from painstakingly learning to hear, see, smell and experience touch – in collaboration with our brain’s ceaseless activity.

Take colour, for instance. We experience leaves as being green, but “green-ness” isn’t an objective property of a leaf, the way that, say, its mass is. Instead, the way the leaf reflects the light that hits our eyes when we look at it produces what we collectively call “green”. As such, the stance taken by leading neuroscientists, including Anil Seth at the University of Sussex, UK, is that our experience is a controlled hallucination. “We perceive the world not as it is, but as it is useful to us,” Seth writes in his seminal book Being You: A new science of consciousness. This, too, is a type of imagination in action.

4. Cultural imagination

We now come to concealed, or cultural, imagination. We are deeply cultural creatures, shaped by our heritage during our individual lives and adapted to culture by our evolutionary history. Our cultural heritage, from the style of clothes we wear to the tools we use to prepare food and the sort of homes we live in, is the cumulative creative product of human imagination, but its imaginative origins are often invisible to us.

A rich guide to the science of imagination also digs into art

Neurologist Adam Zeman's excellent exploration of the power and complexity of our imaginations literally needs more space to house all its riches

As you might intuit, cultural imagination is often culturally specific. A British person’s cultural imagination is likely to be different from a Japanese person’s. Deep-seated beliefs, like faith in a particular deity or that a specific way of running society is optimal, are the products of imagination.

So, too, are deeply damaging ideas, such as that one race is superior to others. Such cultural beliefs are sometimes mistaken for objective facts.

The science of imagination can surely contribute something here to social good. As cultural creatures, we should respect traditions – they make us who we are – while acknowledging that they are human creations, sometimes wonderful, but still fallible and malleable, with the capacity to result in both extraordinary good and tremendous harm.