School of Sport, Exercise and Health Sciences

Research

Applied Cognitive Research Group

Dr Sarabjit Mastana talks about his research

Dr Sarabjit Mastana, senior lecturer, human genetics

Our aims

Our aims are to investigate cognitive performance:

in relation to screening and classification to enable early detection and to aid access to optimal services, treatments and other provisions
in the assessment of protective/risk related lifestyles, states, environments, interventions and treatments

What is cognitive function, and how do we measure it?

Executive Function and Inhibition

These frontal lobe functions are related to the organisation of behaviour in time (sequencing) and inhibition of automatic overlearned functions. Examples of tests to measure these functions include the Rapid Visual Information Processing task (RVIP, Herbert 2001) and the Stroop Colour Word test (Stroop, 1935). The RVIP test requires participants to identify consecutive sequences of 3 odd or even numbers, which appear consecutively on the screen for 600 ms. The test is sensitive to effects of fatigue and aging, and was shown in several studies to be performed better after caffeine consumption.

The Stroop Test (Stroop, 1935) requires inhibition of an overlearned response, which is to read and not to name the different color of the ink of a color word. As a control the speed of reading color words is used (click on reading comprehension) which is an overlearned function and thus easier. The Stroop test is sensitive to effects of physical fatigue and aging and was shown to be performed better after caffeine, physical endurance performance and also during high estrogen levels.

Motor control

With ageing, people become slower and more so on more complex tests, particularly those that require additional manipulations of information on working memory. The Sternberg memory paradigm (Sternberg, 1969) gives relatively simple motor response times (when recognizing a digit among letters known as the intercept) and complex motor response times (when needing to memorize and recognize strings of letters among letters presented on the screen). Hypoxia was shown to increase response times on these types of tests but so did hyperventilating and just wearing a mask, albeit both to a lesser extent.

Speech production

Broca's area in the fontal lobe is associated with speech production. The Verbal Fluency test (also called COWAT) requires participants to name as many items within a certain category (letters, animals or items of clothing) as you can within one min. It is sensitive to the effects of aging and in some studies was shown to be performed better after estrogenic compounds.

Visuospatial ability

Parietal lobe functions include the mental 2 and 3-D manipulation of objects in space, such as is required when reading maps or building with blocks. Probably the best-known example of a mental rotation test are the rotated block designs originally used by Shepherd & Metzler (1971). Men are traditionally thought to better at mental rotation. However, while we found that men have faster baseline response speeds, they are not actually additionally faster with more complex angles of rotation, than women. Thus, even though men may respond faster to stimuli at all angles of rotation, this speed difference does not indicate that either gender is better or worse at mental rotation, since there is no interaction with rotation angle.

Visuospatial ability

Parietal lobe functions include the mental 2 and 3-D manipulation of objects in space, such as is required when reading maps or building with blocks. Probably the best-known example of a mental rotation test are the rotated block designs originally used by Shepherd & Metzler (1971). Men are traditionally thought to better at mental rotation. However, while we found that men have faster baseline response speeds, they are not actually additionally faster with more complex angles of rotation, than women. Thus, even though men may respond faster to stimuli at all angles of rotation, this speed difference does not indicate that either gender is better or worse at mental rotation, since there is no interaction with rotation angle.

Auditory and visual perception

With age, many people tend to hear and see less well, which can impact on higher cognitive functions (also see Lindenberger & Baltes, 1994, articles by Salthouse, 1991. 1993 etc). With age, it also becomes more difficult to focus on information only from one source when there is distracting information from another modality (e.g. having to look at words and learn them while ignoring words spoken to you at the same time).

The visual sensitivity tests shows effectiveness and speed of responses of visual search and detection of stimuli with an increasing probability in a field of distractors. This test has shown to be very sensitive to ageing and the early signs of dementia (Bandelow, 2006). With high levels of estrogens or estrogenic compounds this test showed worse performance, possibly due to enlargement of the attentional field to the detriment of its effectiveness (see also Robinson & Kimura, 1980). This may be related to alterations in cholinergic function.

Memory

Memory is one of the first functions to show a decline in dementia. One way to test this is by giving people lists of words which they need to recall. In Oxford we found that verbal memory tests are very good at discriminating between different types of dementia. A good overview of other cognitive tests and what they do can be found on www.brainsource.com.

Classification and screening systems

  • Learning Disability
    • IQ based systems (talent spotting, schools etc)
    • Paralympics screening for of learning disabled athletes
  • Dementia
    • differential diagnostics
      • computer diagnostic system (currently tested cross culturally and by nurses in multiple settings)
      • cognitive tests systems (P&P and computer based)
    • modifiable risk and protective factors
      • nutrition/supplements: caffeine, phytoestrogens, folate
      • hormones: sex steroids, thyroid hormones
      • mental and physical activity
      • blood pressure (LE) and other CVD risk factors (e.g. diabetes, smoking, homocysteine, LDL cholesterol)
      • dental status and periodontitus
      • gold standard treatments (cholinesterase inhibitors)
  • Age-related morbidity and cognition
    • Cancer and cognition (DW and FM)
    • Thyroid disorders, stress and cognition (EH FM)

People in the Unit

Professor Eef Hogervorst (Group Leader)
Dr Stephan Bandelow
Dr Fehmidah Munir
Dr Debbie Wallis

Research students

Angela Clifford