Mapping out prefrontal control during feature-based attention

• Applicant: Dr. Philipp Schwedhelm
• Subject Area: Cognitive, Systems and Behavioural Neurobiology ; Human Cognitive and Systems Neuroscience
• Term: from 2017 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 342125483

Human and non-human primates can direct their attention selectively and consciously towards specific sensory inputs. This leads to a more robust and faster processing of those stimuli that have particular behavioral relevance at any given time. For example, when driving a car we can covertly monitor the back mirror to observe what happens behind us, even if our gaze is directed towards the traffic ahead of us. But not only such a spatial form of attention is possible, also a global form, directed in parallel to specific image features of the entire visual field exist.On a neuronal level the effects of attention (spatial or feature-based) are well measureable. Single cells in visual cortex of non-human primates raise their activity when coding for stimuli that are currently behaviorally relevant for the organism. Also in humans, such effects are evident by means of neuro-imaging techniques. As a result, the sensory inputs, to which we direct our attention, are more likely (and faster) to gain access to awareness, because their processing gets prioritized along the visual hierarchy. On the other hand, it is largely unknown where and how the brain generates this attentional signal. Recent studies point at an involvement of the prefrontal cortex in the generation of such attentional signal. For example, the frontal eye fields (FEF) seem to play a crucial role in directing spatial attention. However, in the case of non-spatial, feature-based attention, the precise outline of the respective cortical network is not known.Therefore, the focus of this research proposal is the question, which parts of the prefrontal cortex are responsible for the generation of a non-spatial, feature-based attentional control signal. Approaching this question requires experimental work both on the circuit and network (macro) level. For this purpose, multiple different methods will be combined: first, an already collected dataset of concurrent single-cell recordings from visual and prefrontal cortex of two non-human primates (macaca mulatta) will be analyzed. Secondly, two further experiments with human subjects will bridge the gap to the macro level by mapping out prefrontal control during voluntarily deployed feature-based attention. For the human work, we plan to combine two non-invasive imaging techniques (MEG and fMRI), which in their combination give a high-spatial and high-temporal resolution, while at the same time allow for observing activity patterns of the entire prefrontal cortex. This will allow identifying cortical modules involved in the control of feature-based attention. Understanding the neural circuitries generating non-spatial forms of attentional control signals will also pave the way for further clinical development of the treatment of mental disorders like ADHD, schizophrenia or autism.

• DFG Programme: Research Fellowships
• International Connection: Italy
• Host: Dr. Daniel Baldauf