Articles

I want to talk to you this month about an educational project that’s been running for some years here in New Zealand. The Project on Learning spent three years (1998-2000) studying, in excruciating detail, the classroom experiences of 9-11 year olds. The study used miniature videocameras, individually worn microphones, as well as trained observers, to record every detail of the experiences of individual students during the course of particular science, maths, or social studies units.

A new book, Moonwalking with Einstein: The Art and Science of Remembering Everything, has been creating some buzz recently.

I’ve always been interested in the body’s clocks — and one of the most interesting things is that it is clocks, in the plural. It appears the main clock is located in a part of the brain structure called the hypothalamus (a very important structure in the brain, although not one of much importance to learning and memory). The part of the hypothalamus that regulates time is called the suprachiasmatic nuclei. These cells contain genes that switch on, off, and on again over a 24-hour period, and send electrical pulses and hormones through the body. This is the body’s master clock.

Most cognitive processes decline with age

It does appear that most component processes of cognition decline with advanced age if the difficulty level is sufficiently high. For example, the following processes have all shown age effects:

This is the last part in my series on understanding scientific text. In this part, as promised, I am going to talk about the difficulties novices have with scientific texts; what they or their teachers can do about it; and the problems with introductory textbooks.

Brain autopsies have revealed that a significant number of people die with Alzheimer’s disease evident in their brain, although in life their cognition wasn’t obviously impaired. From this, the idea of a “cognitive reserve” has arisen — the idea that brains with a higher level of neuroplasticity can continue to work apparently normally in the presence of (sometimes quite extensive) brain damage.

The mediotemporal lobe (MTL) is a concept rather than a defined brain structure. It includes the hippocampus, the amygdala, and the entorhinal and perirhinal cortices - all structures within the medial area of the temporal lobe.The temporal lobe is in general primarily concerned with sensory experience - specifically, with hearing, and with the integration of information from multiple senses. Part of the temporal lobe also plays a role in memory processing. It is situated below the frontal and parietal lobes, and above the hindbrain.

There is a very common form of forgetfulness that is not really a failure of memory. When we get in our car to drive to place A and find ourselves instead on the road to the more familiar place B, this is not a failure of memory. When we clear the table and find ourselves putting the margarine in the dishwasher or the dirty plate in the fridge, this is not a failure of memory. When we go into a room intending to do one thing and do something else instead, this is not, really, a failure of memory.

Impaired vision is common in old age and even more so in Alzheimer’s disease, and this results not only from damage in the association areas of the brain but also from problems in lower-level areas. A major factor in whether visual impairment impacts everyday function is contrast sensitivity.

What do we mean by word-finding problems?

Here are some examples:

• increasing use of circumlocutions rather than specific terms (e.g., "I wonder where the thing that goes here is")
• use of empty phrases, indefinite terms, and pronouns without antecedents (i.e., referring to something or someone as "it" or "him / her" without first identifying them by name)
• increased frequency of pauses

These problems are all characteristic of Alzheimer's, but also, to a much lesser extent, of normal aging.