Sign-tracking and goal-tracking in humans: Utilising eye-tracking in clinical and non-clinical populations

BACKGROUND

In Pavlovian conditioning, learned behaviour varies according to the perceived value of environmental cues. For goal-trackers (GT), the cue merely predicts a reward, whilst for sign-trackers (ST), the cue holds incentive value. The sign-tracking/goal-tracking model is well-validated in animals, but translational work is lacking. Despite the model's relevance to several conditions, including attention deficit hyperactivity disorder (ADHD), we are unaware of any studies that have examined the model in clinical populations.

METHODS

The current study used an eye-tracking Pavlovian conditioning paradigm to identify ST and GT in non-clinical (N = 54) and ADHD (N = 57) participants. Eye movements were recorded whilst performing the task. Dwell time was measured for two areas of interest: sign (i.e., cue) and goal (i.e., reward), and an eye-gaze index (EGI) was computed based on the dwell time sign-to-goal ratio. Higher EGI values indicate sign-tracking behaviour. ST and GT were determined using median and tertiary split approaches in both samples.

RESULTS

Despite greater propensity for sign-tracking in those with ADHD, there was no significant difference between groups. The oculomotor conditioned response was reward-specific (CS+) and present, at least partly, from the start of the task indicating dispositional and learned components. There were no differences in externalising behaviours between ST and GT for either sample.

CONCLUSIONS

Sign-tracking is associated with CS+ trials only. There may be both dispositional and learned components to sign-tracking, potentially more common in those with ADHD. This holds translational potential for understanding individual differences in reward-learning.

The impact of parental offending on offspring aggression in early childhood: a population-based record linkage study

PURPOSE

To examine the impact of parental criminal offending, both paternal and maternal, on offspring aggression at age 5 years, while also considering key risk factors, including parental mental illness, child's sex, and socioeconomic disadvantage.

METHODS

The sample comprised 69,116 children, with linked parental information, from the New South Wales Child Development Study, a population-based multi-agency, multi-generational record linkage study that combines information from a teacher-reported cross-sectional survey of early childhood development at age 5 years (the 2009 Australian Early Development Census; AEDC) with data obtained via administrative records from multiple sources (e.g., health, crime, education, and welfare). Hierarchical logistic regression analyses were conducted to determine the effects of maternal and paternal criminal court appearances (frequency and type of offending), and mental health service contacts, on offspring aggression measured in the AEDC.

RESULTS

Having a parent with a history of offending was significantly associated with high levels of offspring aggression in early childhood. The strength of association was greatest when parents were involved in frequent (≥6 offences: adjusted odds ratio [aOR] range = 1.55-1.73) and violent (aOR range = 1.49-1.63) offending. Both maternal and paternal offending remained significant predictors of offspring aggression after accounting for parental mental illness, and associations were similar in magnitude for maternal and paternal offending histories.

CONCLUSIONS

Parental history of severe criminal offending increased the risk of high levels of aggression in offspring during early childhood, highlighting the need for intervention with families during this key developmental period.