Looking at attention

ADHD is associated with poor attention control, the markers of which include reduced inhibition and cognitive flexibility. These refer to the capacity to ignore irrelevant or distracting objects, and the ability to disengage attention from one object and focusing on another, respectively. Laboratory tasks designed to measure these cognitive processes typically involve showing an object on a computer screen, along with other distracting objects that are designed to capture participants’ attention.

In our lab, participants’ attention can be observed using an eye-tracker, which allows us to determine the location on the computer screen that is being focused on at any given moment. This is especially useful in infant research as it is unobtrusive and does not require any overt responses from the participant, like pressing buttons or answering questions. During an eye-tracking session, infants are sat either on their parent’s lap or in a highchair, while viewing moving images on a computer screen.

The eye-tracking system, attached below the monitor, records infants’ eye movements while they view the images on the screen.

The eye-tracking system is made up of projectors that shines infrared light (invisible to humans) and cameras that records the reflection of the light on the eyes. This reflection pattern changes slightly as the eyes rotate and move around while looking at different areas of the screen. The eye-tracker is able to use this to calculate the location of focus throughout the session.

A recording of gaze locations being tracked while a participant is looking at a scene

This allows us to collect information such as the pattern of gazes, the amount of time spent looking at specific objects, and even changes in pupil size, which are then used as measures of inhibition and cognitive flexibility.

How do we measure sleep?

Since our upcoming project is studying the role of sleep in attention development, one of the most important pieces of new equipment in the lab are our sleep actigraphs. These nifty gadgets record movement and when worn through the night, are able to measure the amount and quality of sleep.

The actigraphs that participants will wear

We recently recruited an honorary research assistant to help demonstrate how easy it is to collect the sleep data with the actigraphs and what information can be gleaned from it.

Research Assistant Charlotte inspecting the actigraph before giving it her seal of approval

Using the actigraph is extremely simple. Just put it on the ankle of our infant participants, like you would a watch, and the actigraph will start recording automatically. There are no lights, beeps or buzzes to interfere with regular day-to-day activity and the only input we require is for the grown-ups to note down what time the infants went to bed and got up the next morning.

When the actigraph is brought back to the lab, the data will be downloaded from it and we will be able to chart the sleep patterns, and calculate the quality of sleep.

Charts showing amount of movement during sleep (top), sleep/awake periods (middle), and periods of active sleep phase during the sleep cycle (bottom)

Some of the measures that can be extracted and compared to other participants

One of the aims of the study is to investigate the influence of infant sleep behaviour on attention development in young children and the data collected using the actigraphs is a key component in this. The study hopes to help us better understand attentional disorders such as ADHD and potentially lead to the development of early interventions in the future.