In an article recently published in the journal Psychological Science, Dr Janette Chow and Professor Kim Plunkett (Tutorial Fellow in Experimental Psychology at St Hugh’s), along with colleagues from the University of Oxford and the University of Murica, have shown that 24-month-old toddlers can refocus their attention to a new item by selectively inhibiting their attention to the old item.
Attention switching is a crucial ability required in everyday life: we constantly switch attention between one task and another – from looking at the computer to answering the phone. A typical day for a toddler also involves switching attention — from an old toy to a new toy or from learning what certain objects are called to animal names. Performing these functions requires toddlers to disengage their attention from a no longer relevant item and switch attention to a more relevant one. This begs the question: what mechanisms are involved in the flexible reassignment of mental resources during attention switching?
In Dr Chow’s study carried out at the Oxford Babylab, 24-month-old toddlers were shown sets of three objects on a TV screen. The sets contained a prime object (e.g. X1 or X2), an intervening object (e.g. Y) and a target object (e.g. Z). The prime object was either related or unrelated to the target (e.g., chair-car-table or hat-car-table respectively). By attending to the three objects sequentially, toddlers were effectively switching attention from one object to the other. Their eye-movements, which is indicative of their on-going cognitive processing of audio and visual stimuli, were being tracked by an automated infra-red eye-tracking device.
The study found that toddler’s attention to the target object (in this case a table) was significantly reduced if they previously saw a prime object that belongs to the same semantic category (e.g. a chair, which is also a piece of furniture), but not when they previously saw an unrelated one (e.g. a hat). When a shift of attention occurred from the prime object to the intervening one (i.e. from the chair to the car), the prime object was inhibited. The fact that response to the semantically related target object (i.e. the table) was impaired suggests a spread of inhibition from the mental representation of the prime object (i.e. the chair) to the mental representation of the target one (i.e. the table), either via their shared semantic features or direct links between them in the mental lexicon.
This process is commonly termed ‘backward inhibition’. The findings – backward semantic inhibition in toddlers – is vital in better understanding the development of flexible attention-switching and, more generally, how language drives visual attention. Follow-up work focuses on comparing the timeline of the emergence of backward semantic inhibition in different age groups and different language users.
You can read the full article published in the journal here [Subscription to Psychological Science required].
