Neural reinstatement tracks object-based attentional selection in working memory

Working memory (WM) is the ability to hold information in mind in the short-term and use it flexibly for behaviour. Not all items are represented equally in WM. Attention can be allocated to select and privilege relevant WM content. It is unclear whether attention selects individual features or whole objects in WM. Here, we used behavioural measures, eye-tracking and electroencephalography (EEG) to test the hypothesis that attentional selection spreads between an object's features in WM. Twenty-six participants (male and female) completed a WM task that asked them to recall the angle of one of two oriented, coloured bars after a delay while EEG and eye-tracking data was collected. During the delay, an orthogonal 'incidental task' cued the colour of one item for a match/mismatch judgement. On congruent trials (50%), the cued item was probed during memory recall; on incongruent trials (50%), the other memory item was probed. As predicted, selecting the colour of an object in WM brought other features of the cued object into an attended state as revealed by EEG decoding, oscillatory alpha-power, gaze bias and improved subsequent orientation recall performance. Together, the results build a case for object-based attentional selection in WM. Analyses of neural processing at recall revealed that the selected object was automatically compared with the probe, whether it was the target for recall or not, providing a potential mechanism for non-predictive cueing benefits in WM.

Common coding of expected value and value uncertainty memories in the prefrontal cortex and basal ganglia output

Recent evidence implicates both basal ganglia and ventrolateral prefrontal cortex (vlPFC) in encoding value memories. However, comparative roles of cortical and basal nodes in value memory are not well understood. Here, single-unit recordings in vlPFC and substantia nigra reticulata (SNr), within macaque monkeys, revealed a larger value signal in SNr that was nevertheless correlated with and had a comparable onset to the vlPFC value signal. The value signal was maintained for many objects (>90) many weeks after reward learning and was resistant to extinction in both regions and to repetition suppression in vlPFC. Both regions showed comparable granularity in encoding expected value and value uncertainty, which was paralleled by enhanced gaze bias during free viewing. The value signal dynamics in SNr could be predicted by combining responses of vlPFC neurons according to their value preferences consistent with a scheme in which cortical neurons reached SNr via direct and indirect pathways.

Adolescents are delayed at inferring complex social intentions in others, but not basic (false) beliefs: An eye-movement investigation

Most developmental research on Theory of Mind (ToM)—our ability to infer the beliefs, intentions, and desires of others—has focused on the preschool years. This is unsurprising as it was previously thought that ToM skills are developed between the ages of 2 and 7 years. Over the last couple of decades however, studies have provided evidence for significant structural and functional changes in the brain areas involved in ToM (the “social brain”) not only during childhood but also during adolescence. Importantly, some of these findings suggest that the use of ToM shows a prolonged development through middle childhood and adolescence. Although evidence from previous studies suggests a protracted development of ToM, the factors that constrain performance during middle childhood and adolescence are only just beginning to be explored. In this article, we report two visual-world eye-tracking studies that focus on the timecourse of predictive inferences. We establish that when the complexity of ToM inferences are at a level which is comparable with standard change-of-location false-belief tasks, then adolescents and adults generate predictions for other agents’ behaviour in the same timecourse. However, when inferences are socially more complex, requiring inferences about higher order mental states, adolescents generate predictive gaze bias at a marked delay relative to adults. Importantly, our results demonstrate that these developmental differences go beyond differences in executive functions (inhibitory control or working memory) and point to distinct expectations between groups and greater uncertainty when predicting actions based on conflicting desires.