THE ROUGH GUIDE TO PSYCHOLOGYperceive the world via a series of discrete snapshots, we nonetheless enjoy
a smooth, borderless visual experience because our brains are constantly
anticipating what’s beyond the borders of each glimpse and glance.
Amnesia
For a memory to graduate from short-term storage into episodic memory
appears to depend on a brain structure called the hippocampus (see p.39).
When this structure is damaged, either through injury or illness, the
result is amnesia. An amnesic will usually be able to tell you about their
life story prior to their illness or accident, and their short-term memory
will also appear intact, but if you were to ask them routine questions, such
as what they’d had for breakfast, or what they’d done yesterday, or who’d
they’d met, they would probably have no idea whatsoever. In other words,
their identity and most of their life story remains intact, but beyond this
it’s as if they are locked perpetually in the present. Amnesia is fairly rare,
with stroke, closed-head injuries, and asphyxiation all possible causes of
the kind of brain injury that can lead to memory loss. A condition called
Korsakoff ’s syndrome, which is induced by poor diet linked with alco-
holism, can also lead to amnesic-like symptoms.
Sometimes an amnesic patient may struggle to recall autobio-
graphical memories from the period preceding the onset of their
Boundary extension: this photo may seem identical to the one on the previous page
but in fact it’s an expanded version.