Primary Supervisor: Dr Carmel Mevorach, School of Psychology
Secondary supervisor: Dr Dietmar Heinke
PhD project title: Brain mechanisms underlying atypical attention in the broader Autism and Schizophrenia phenotypes
University of Registration: University of Birmingham
The perceptual saliency of distracting non-target information presents a major challenge for attention selection processes, which are required to bias selection away from distracting, non-target items. Consequently, when atypicality in these processes is present it can have an overarching effect on human behaviour. Independent lines of evidence in autism and schizophrenia spectrum disorder (ASD and SSD, respectively) and the broader spectrum of their traits in neurotypical participants suggest that these conditions are associated with attentional atypicalities (sometimes from as early as the first year of life). In considering the difference between ASD and SSD, which may be more specific to the psychosis/positive symptom domain, it has been proposed that these conditions are at the opposite extremes of the same cognitive continuum, exerting diametric effects on cognition and behaviour, putatively due to reciprocal alterations of genetic risk factors.
Our previous research (e.g., Abu-akel et al., 2018) provided support for this notion, specifically in the context of attention control. Importantly, the direction of the diametrical effects we observed changed as a function of the task, so that if expression of autism was favourable in a specific task, expression of Psychosis proneness was detrimental (and vice versa). One important possibility underlying these effects is that the trait expression is linked to different modes of attention control; namely proactive and reactive suppression. Proactive control involves Static maintenance of the attentional set in preparation of stimulus presentation. In contrast, reactive control involves a dynamic ‘late correction’ mechanisms that kicks in only after events occur. It is therefore possible that expression of autism is associated with a greater drive towards proactive control, while expression of psychosis is associated with a greater drive towards reactive control. These tendencies not only fit with the pattern of behaviour we documented previously in the attention tasks but may also be associated with symptoms in the syndromes. Over-relying on proactive control likely contributes to stereotypical and repetitive behaviour and difficulties in switching and adapting, which is often associated with ASD. In contrast, inability to utilise proactive control may relate to excessive switching and increased bottom-up capture often associated with schizophrenia. This possible modulation of proactive and reactive control may be linked to previously observed neuronal signatures of ASD and Schizophrenia, respectively. For instance, studies have identified the DMN (and the Precuneus specifically) as a network which is hyper-activated in schizophrenia (does not show task-deactivation) but hypo-activated and under-connected in ASD (show reduced within network connectivity during resting state). Similarly, the TPJ (which is strongly associated with attention shifting and reactive control) has also been argued to show more volatile activation in schizophrenia, compared to ASD.
The proposed research will apply converging operations including, brain stimulation and fMRI, individual differences, computational modelling, as well as their combination in the same study (Mevorach et al., 2010) to provide a functional brain mechanistic framework for understanding attention atypicalitites in ASD and SSD. This work may also pave the way for future intervention targets in the syndromes both from a behaviour and neuroscience perspectives.
- Abu-Akel, A., Apperly, I., Sapniol, M.M., Geng, J.J., & Mevorach, C. (2018). Diametric effects of autism tendencies and psychosis proneness on attention control irrespective of task demands. Scientific Reports, 8, Article Number 8478
- Mevorach, C., Hodsoll, J., Allen H. A., Shalev, L., Humphreys, G. W. (2010). Ignoring the Elephant in the Room: A Neural Circuit to Down-regulate Salience. Journal of Neuroscience, 30, 6072-6079
BBSRC Strategic Research Priority: Understanding the Rules of Life: Neuroscience and behaviour
Techniques that will be undertaken during the project:
- Functional and structural MRI;
- Brain Stimulation (TMS and tDCS);
- Artificial intelligence;
- Computational modelling;
- Bayesian modelling;
- Individual differences.
Contact: Dr Carmel Mevorach, University of Birmingham