A Functional and Structural Investigation of the Human Fronto-Basal Volitional Saccade Network

Almost all cortical areas are connected to the subcortical basal ganglia (BG) through parallel recurrent inhibitory and excitatory loops, exerting volitional control over automatic behavior. As this model is largely based on non-human primate research, we used high resolution functional MRI and diffusion tensor imaging (DTI) to investigate the functional and structural organization of the human (pre)frontal cortico-basal network controlling eye movements. Participants performed saccades in darkness, pro- and antisaccades and observed stimuli during fixation. We observed several bilateral functional subdivisions along the precentral sulcus around the human frontal eye fields (FEF): a medial and lateral zone activating for saccades in darkness, a more fronto-medial zone preferentially active for ipsilateral antisaccades, and a large anterior strip along the precentral sulcus activating for visual stimulus presentation during fixation. The supplementary eye fields (SEF) were identified along the medial wall containing all aforementioned functions. In the striatum, the BG area receiving almost all cortical input, all saccade related activation was observed in the putamen, previously considered a skeletomotor striatal subdivision. Activation elicited by the cue instructing pro or antisaccade trials was clearest in the medial FEF and right putamen. DTI fiber tracking revealed that the subdivisions of the human FEF complex are mainly connected to the putamen, in agreement with the fMRI findings. The present findings demonstrate that the human FEF has functional subdivisions somewhat comparable to non-human primates. However, the connections to and activation in the human striatum preferentially involve the putamen, not the caudate nucleus as is reported for monkeys. This could imply that fronto-striatal projections for the oculomotor system are fundamentally different between humans and monkeys. Alternatively, there could be a bias in published reports of monkey studies favoring the caudate nucleus over the putamen in the search for oculomotor functions

A different kind of weapon focus: simulated training with ballistic weapons reduces change blindness

Attentional allocation is flexibly altered by action-related priorities. Given that tools – and specifically weapons – can affect attentional allocation, we asked whether training with a weapon or holding a weapon during search would affect change detection. In three experiments, participants searched for changes to agents, shootable objects, or environments in the popular flicker paradigm. Participants trained with a simulated weapon or watched a video from the same training perspective and then searched for changes while holding a weapon or a control object. Results show an effect of training, highlighting the importance of sensorimotor experience for the action-relevant allocation of attention, and a possible interaction between training and the object held during search. Simulated training with ballistic weapons reduces change blindness. This result has implications for the interaction between tool use and attentional allocation

Intergenerational Aspects of Immune and Endocrine Function in Perinatal Depression

Perinatal depression mediates a profound impact on maternal and offspring health. Alterations in endocrine and immune function in depressed mothers have been linked to altered stress responses in offspring and less optimal neurodevelopmental outcomes. This chapter reviews the important changes in immune function that have been documented in depressed mothers and seeks to link changes in immune regulatory and endocrine processes to ultimate outcome in offspring. We identify key interactions between the immune system, the Hypothalamic-Pituitary-Adrenal axis and the oxytocin system that are relevant to understanding the dysregulated immune responses in depressed mothers. Additionally, we review how the above changes have been linked to an increased risk of aberrant development of offspring of depressed mothers, as well as the future manifestation of mental illness. Molecular mechanisms relevant to these processes are highlighted. Our work reinforces the potential importance of biomarkers that could be linked to both immune dysfunction and negative developmental outcomes in offspring in perinatal depression. Through improved screening and intervention protocols that incorporate the above approach, significant progress could be made in reducing the large morbidity associated with perinatal depression.</p