Biology subjects

McKenna, F.

Publications and source records attributed to McKenna, F..

2 recordsLinked to original sources

bioRxiv2026

Cognitive Control in Pediatric Cancer Survivors: A task-fMRI study

BackgroundChemotherapy-related cognitive impairment is a well-documented concern among cancer survivors, yet the neural mechanisms underlying deficits in cognitive control remain poorly understood. This study examined group differences in brain activation during a flanker task using functional MRI (fMRI) between chemotherapy-exposed participants and healthy controls. MethodsParticipants (21 survivors (24.9 years old; 71.4 % female; 15 years from diagnosis) and 21 healthy controls (26.7 years old; 61.9 % female) completed a flanker task during fMRI, with congruent and incongruent conditions. Reaction time, accuracy, and Flanker scores were collected. Whole-brain group comparisons were performed for congruent, incongruent, and incongruent > congruent contrasts. Associations between the incongruent > congruent contrast and cognitive performance were examined. ResultsCompared to controls, the Chemo group had longer reaction times in both congruent and incongruent conditions (p < .001) and lower NIH Flanker scores (p = .01), with no differences in accuracy. They showed reduced activation in the bilateral inferior frontal gyri, supplementary motor area, and bilateral caudate, but greater activation in the right inferior temporal and cerebellar regions. The incongruent > congruent contrast correlated with increased activation in the orbitofrontal cortex, inferior temporal gyri, and fusiform gyrus with cognitive performance. ConclusionsChemotherapy-exposed participants showed cognitive control deficits and altered neural activation during a flanker task, indicating disrupted recruitment of frontoparietal and subcortical regions key for conflict processing. These findings improve understanding of neural causes of chemotherapy-related cognitive impairment and may help identify at-risk survivors and guide personalized rehabilitation.

neuroscience↗

bioRxiv2024

Association between loneliness and hippocampal responses to dynamic social stimuli in psychotic disorders

BackgroundThe incidence of loneliness has increased over the past several decades worldwide and is particularly common among people with serious mental illnesses. However, this public health problem has been difficult to address, in part because the neurocognitive mechanisms underlying loneliness are poorly understood. MethodsTo investigate these mechanisms, a functional magnetic resonance imaging (fMRI) study was conducted which accounted for known cognitive biases associated with loneliness. Participants with (n = 40) and without (n = 60) psychotic disorders (PD) viewed images of faces that appeared to approach or withdraw from the participants, while fMRI data were collected. Following the scanning, participants rated the trustworthiness of the faces, and these ratings were included as weights in the fMRI analyses. Neural responses to approaching versus withdrawing faces were measured, and whole brain regression analyses, with loneliness as the regressor, were performed. ResultsIn the PD and full samples, a higher level of loneliness was significantly associated with greater responses of the hippocampus and areas of the basal ganglia to withdrawing (versus approaching) face stimuli. Moreover, the effects in the hippocampus, but not the basal ganglia, remained significant after controlling for potential confounds such as social activity levels, depression and social anhedonia. Lastly, in a subset of the sample (n = 66), greater hippocampal responses to withdrawing faces predicted greater loneliness one year later. ConclusionsHeightened responses of the hippocampus to withdrawing faces may represent a candidate objective marker of loneliness that could be modified by interventions targeting loneliness.

neuroscience↗