A simple new cognitive assessment tool with only 16 items appears potentially useful for identifying problems in thinking, learning and memory among older adults. The Sweet 16 scale is scored from zero to 16 (with 16 representing the best score) and includes questions that address orientation (identification of person, place, time and situation), registration, digit spans (tests of verbal memory) and recall. The test requires no props (not even pencil and paper) and is easy to administer with a minimum of training. It only takes an average of 2 minutes to complete.

A score of 14 or less correctly identified 80% of those with cognitive impairment (as identified by the Informant Questionnaire on Cognitive Decline in the Elderly) and correctly identified 70% of those who did not have cognitive impairment. In comparison, the standard MMSE correctly identified 64% of those with cognitive impairment and 86% of those who were not impaired. In other words, the Sweet 16 missed diagnosing 20% of those who were (according to this other questionnaire) impaired and incorrectly diagnosed as impaired 30% of those who were not impaired, while the MMSE missed 36% of those who were impaired but only incorrectly diagnosed as impaired 14% of those not impaired.

Thus, the Sweet 16 seems to be a great ‘first cut’, since its bias is towards over-diagnosing impairment. It should also be remembered that the IQCDE is not the gold standard for cognitive impairment; its role here is to provide a basis for comparison between the new test and the more complex MMSE. In comparison with a clinician’s diagnosis, Sweet 16 scores of 14 or less occurred in 99% of patients diagnosed by a clinician to have cognitive impairment and 28% of those without such a diagnosis.

The great benefit of the new test is of course its speed and simplicity, and it seems to offer great promise as an initial screening tool. Another benefit is that it supposedly is unaffected by the patient’s education, unlike the MMSE. The tool is open access.

The Sweet 16 was developed using information from 774 patients who completed the MMSE, and then validated using a different group of 709 older adults.

A study involving young (average age 22) and older adults (average age 77) showed participants pictures of overlapping faces and places (houses and buildings) and asked them to identify the gender of the person. While the young adults showed activity in the brain region for processing faces (fusiform face area) but not in the brain region for processing places (parahippocampal place area), both regions were active in the older adults. Additionally, on a surprise memory test 10 minutes later, older adults who showed greater activation in the place area were more likely to recognize what face was originally paired with what house.

These findings confirm earlier research showing that older adults become less capable of ignoring irrelevant information, and shows that this distracting information doesn’t merely interfere with what you’re trying to attend to, but is encoded in memory along with that information.

In a study involving 15 young adults, a very small electrical current delivered to the scalp above the right anterior temporal lobe significantly improved their memory for the names of famous people (by 11%). Memory for famous landmarks was not affected. The findings support the idea that the anterior temporal lobes are critically involved in the retrieval of people's names.

A follow-up study is currently investigating whether transcranial direct current stimulation (tDCS) will likewise improve name memory in older adults — indeed, because their level of recall is likely to be lower, it is hoped that the procedure will have a greater effect. If so, the next question is whether repeating tDCS may lead to longer lasting improvement. The procedure may offer hope for rehabilitation for stroke or other neurological damage.

This idea receives support from another recent study, in which 15 students spent six days learning a series of unfamiliar symbols that corresponded to the numbers zero to nine, and also had daily sessions of (tDCS). Five students were given 20 minutes of stimulation above the right parietal lobe; five had 20 minutes of stimulation above the left parietal lobe, and five experienced only 30 seconds of stimulation — too short to induce any permanent changes.

The students were tested on the new number system at the end of each day. After four days, those who had experienced current to the right parietal lobe performed as well as they would be expected to do with normal numbers. However, those who had experienced the stimulation to the left parietal lobe performed significantly worse. The control students performed at a level between the two other groups.

Most excitingly, when the students were tested six months later, they performed at the same level, indicating the stimulation had a durable effect. However, it should be noted that the effects were small and highly variable, and were limited to the new number system. While it may be that one day this sort of approach will be of benefit to those with dyscalculia, more research is needed.

Following on from earlier research suggesting that simply talking helps keep your mind sharp at all ages, a new study involving 192 undergraduates indicates that the type of talking makes a difference. Engaging in brief (10 minute) conversations in which participants were simply instructed to get to know another person resulted in boosts to their executive function (the processes involved in working memory, planning, decision-making, and so on). However when participants engaged in conversations that had a competitive edge, their performance showed no improvement. The improvement was limited to executive function; neither processing speed nor general knowledge was affected.

Further experiments indicated that competitive discussion could boost executive function — if the conversations were structured to allow for interpersonal engagement. The crucial factor seems to be the process of getting into another person’s mind and trying to see things from their point of view (something most of us do naturally in conversation).

The findings also provide support for the social brain hypothesis — that we evolved our larger brains to help us deal with large social groups. They also support earlier speculations by the researcher, that parents and teachers could help children improve their intellectual skills by encouraging them to develop their social skills.

Beginning in 1971, healthy older adults in Gothenburg, Sweden, have been participating in a longitudinal study of their cognitive health. The first H70 study started in 1971 with 381 residents of Gothenburg who were 70 years old; a new one began in 2000 with 551 residents and is still ongoing. For the first cohort (born in 1901-02), low scores on non-memory tests turned out to be a good predictor of dementia; however, these tests were not predictive for the generation born in 1930. Those from the later cohort also performed better in the intelligence tests at age 70 than their predecessors had.

It’s suggested that the higher intelligence is down to the later cohort’s better pre and postnatal care, better nutrition, higher quality education, and better treatment of high blood pressure and cholesterol. And possibly the cognitive demands of modern life.

Nevertheless, the researchers reported that the incidence of dementia at age 75 was little different (5% in the first cohort and 4.4% in the later). However, since a substantially greater proportion of the first cohort were dead by that age (15.7% compared to 4.4% of the 2nd cohort), it seems quite probable that there really was a higher incidence of dementia in the earlier cohort.

The fact that low scores on non-memory cognitive tests were predictive in the first cohort of both dementia and death by age 75 supports this argument.

The fact that low scores on non-memory cognitive tests were not predictive of dementia or death in the later cohort is in keeping with the evidence that higher levels of education help delay dementia. We will need to wait for later findings from this study to see whether that is what is happening.

The findings are not inconsistent with those from a very large U.S. national study that found older adults (70+) are now less likely to be cognitively impaired (see below). It was suggested then also that better healthcare and more education were factors behind this decline in the rate of cognitive impairment.

Previous study:

A new nationally representative study involving 11,000 people shows a downward trend in the rate of cognitive impairment among people aged 70 and older, from 12.2% to 8.7% between 1993 and 2002. It’s speculated that factors behind this decline may be that today’s older people are much likelier to have had more formal education, higher economic status, and better care for risk factors such as high blood pressure, high cholesterol and smoking that can jeopardize their brains. In fact the data suggest that about 40% of the decrease in cognitive impairment over the decade was likely due to the increase in education levels and personal wealth between the two groups of seniors studied at the two time points. The trend is consistent with a dramatic decline in chronic disability among older Americans over the past two decades.