Laetitia Mwilambwe-Tshilobo

Laetitia Mwilambwe-Tshilobo
McGill University | McGill · Montreal Neurological Institute

PhD candidate

About

33
Publications
3,315
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374
Citations
Introduction
I am a Neuroscience PhD candidate at McGill University, working with Dr. Nathan Spreng in the Laboratory of Brain and Cognition. My research explores the neural basis of loneliness. I'm particularly interested in how loneliness impacts brain function, and in better understanding the links between loneliness and neurocognitive aging. I investigate these research questions using a combination of functional MRI, network neuroscience, and behavioral approaches.

Publications

Publications (33)
Article
Social isolation in the pre-stroke environment leads to poorer outcomes after an ischemic injury in both animal and human studies. However, the impact of social isolation following stroke, which may be more clinically relevant as a target for therapeutic intervention, has yet to be examined. In this study, we investigated both the sub-acute (2 week...
Article
An essential task of the auditory system is to discriminate between different communication signals, such as vocalizations. In everyday acoustic environments, the auditory system needs to be capable of performing the discrimination under different acoustic distortions of vocalizations. To achieve this, the auditory system is thought to build a repr...
Article
Full-text available
The ability to discriminate tones of different frequencies is fundamentally important for everyday hearing. While neurons in the primary auditory cortex (AC) respond differentially to tones of different frequencies, whether and how AC regulates auditory behaviors that rely on frequency discrimination remains poorly understood. Here, we find that th...
Article
Natural sounds exhibit statistical variation in their spectrotemporal structure. This variation is central to identification of unique environmental sounds and to vocal communication. Using limited resources, the auditory system must create a faithful representation of sounds across the full range of variation in temporal statistics. Imaging studie...
Article
Full-text available
Social relationships imbue life with meaning, whereas loneliness diminishes one's sense of meaning in life. Yet the extent of interdependence between these psychological constructs remains poorly understood. We took a multivariate network approach to examine resting-state fMRI functional connectivity's association with loneliness and meaning in a l...
Preprint
Full-text available
Previous research in the field of personality neuroscience has identified associations of conscientiousness and related constructs like impulsivity and self-control with structural and functional properties of particular regions in the prefrontal cortex (PFC) and insula. Network-based conceptions of brain function suggest that these regions probabl...
Article
Full-text available
Central to understanding human behavior is a comprehensive mapping of brain-behavior relations within the context of lifespan development. Reproducible discoveries depend upon well-powered samples of reliable data. We provide to the scientific community two, 10-minute, multi-echo functional MRI (ME-fMRI) runs, and structural MRI (T1-MPRAGE), from 1...
Article
The intrinsic functional organization of the brain changes into older adulthood. Age differences are observed at multiple spatial scales, from global reductions in modularity and segregation of distributed brain systems, to network-specific patterns of dedifferentiation. Whether dedifferentiation reflects an inevitable, global shift in brain functi...
Article
White matter hyperintensities (WMH) are among the most prominent structural changes observed in older adulthood. These changes coincide with functional changes to the intrinsic network organization of the aging brain. Yet little is known about how WMH are associated with changes to the whole-brain functional connectome in normal aging. We used a le...
Article
Positions of power involving moral decision-making are often held by older adults (OAs). However, little is known about age differences in moral decision-making and the intrinsic organization of the aging brain. In this study, younger adults (YAs; n = 117, Mage = 22.11) and OAs (n = 82, Mage = 67.54) made decisions in hypothetical moral dilemmas an...
Article
Neuronal variability patterns promote the formation and organization of neural circuits. Macroscale similarities in regional variability patterns may therefore be linked to the strength and topography of inter-regional functional connections. To assess this relationship, we used multi-echo resting-state fMRI and investigated macroscale connectivity...
Preprint
Full-text available
The intrinsic network architecture of the brain is continuously shaped by biological and behavioral factors from younger to older adulthood. Differences in functional networks can reveal how a lifetime of learning and lived experience can alter large-scale neurophysiological dynamics, offering a powerful lens into brain and cognitive aging. Quantif...
Article
Full-text available
Social exclusion refers to the experience of being disregarded or rejected by others and has wide-ranging negative consequences for well-being and cognition. Cyberball, a game where a ball is virtually tossed between players, then leads to the exclusion of the research participant, is a common method used to examine the experience of social exclusi...
Article
Full-text available
Humans survive and thrive through social exchange. Yet, social dependency also comes at a cost. Perceived social isolation, or loneliness, affects physical and mental health, cognitive performance, overall life expectancy, and increases vulnerability to Alzheimer's disease-related dementias. Despite severe consequences on behavior and health, the n...
Data
Excel file containing data for the key figures in the article. (XLSX)
Data
The effect of photostimulation on auditory responses as a function of distance from optocannula and depth. We measured the effect of light activation on multiunit activity during noise bursts. We recorded neuronal activity in the AC of head-fixed awake mice at 0, 0.4, 0.8 and 1.2 mm from the optocannula and at 6 depths between 0 and 1.25 mm from br...
Data
Neither activation (top) nor suppression (bottom) of PVs affected basic PPI parameters. (A) Startle response magnitude in the absence of prepulse signal (no frequency shift between background and prepulse tones) on light-On (color bars) and light-Off trials (gray bars) averaged across mice from PV-ChR2 and PV-Arch groups. ns: Difference not signifi...
Data
Photostimulation does not affect frequency discrimination acuity in mice expressing control viral constructs. (A) Behavioral frequency discrimination acuity as measure by Th is not affected by photostimulation with blue light in mice expressing control viral constructs (n = 6). Left. PPI as a function of frequency shift in light-On (blue) and light...
Data
Light intensity–dependent effect of PVs photostimulation on neuronal activity in PV-ChR2 mice. (A) Light intensity. Left: 0.2 mW/mm2 (n = 330 neurons); middle: 0.5 mW/mm2 (n = 322 neurons); right: 10 mW/mm2 (n = 202 neurons). Each circle represents a single unit. Spontaneous firing rate (FRbase) was suppressed as result of photoactivation of PVs in...
Data
Design of behavioral test for frequency discrimination acuity. The test relied on measurement of inhibition of auditory startle response by PPI. (A) Time course of acoustic stimulation during a single PPI trial. Three stimuli were presented in succession: 1) background tone at frequency (f1) identical to CS+ used in fear conditioning; 2) prepulse t...
Data
PPI elicited by tones of different frequencies in the absence of background tone. Neither activation (A) nor inhibition (B) of PV interneurons affected PPI induced by tones of different frequency without background tone. These results indicate that photostimulation did not change subjective loudness of tones in frequencies used in frequency discrim...
Data
Analysis of light-evoked responses of putative PV interneurons. (A) Peristimulus time histograms (PSTH) of sample putative PV neurons activated (blue, PV-ChR2 mouse) or inhibited (green, PV-Arch) by 250-ms-long pulse of light (outlined by gray rectangle). Inset shows a raster plot of a putative PV interneuron activated by blue light with a short la...
Data
Effect of direct photoactivation of excitatory neurons in CamKIIα-ChR2 mice on neuronal auditory responses. (A) Photoactivation of CamKIIα neurons leads to a significant increase in FRbase of putative excitatory neurons. Top: index of change in the FRbase across neuronal population. Bottom: FRbase in light-On trials versus light-Off trials. ***: on...
Data
Light intensity–dependent effect of PVs photostimulation on sparseness of tuning in PV-ChR2 mice. (A) Light intensity. Left: 0.2 mW/mm2 (n = 215 neurons); middle: 0.5 mW/mm2 (n = 240 neurons); right: 10 mW/mm2 (n = 175 neurons). Each circle represents a single auditory unit suppressed by light. Sparseness of tuning increased due to photoactivation...
Data
Diagram of the DAFC protocol. (A) A discriminative fear conditioning session consisted of 10 presentations of a 15 kHz tone (CS+) coterminated with a mild foot-shock (unconditioned stimulus, US). In addition, 10 unpaired tones (11.25 kHz, CS) were presented along with CS+ with 2 min interstimulus interval (ISI). Randomized inter-trial interval (ITI...
Data
Subjective tone loudness used for frequency discrimination is similar across all used frequencies. Perception of tone loudness was estimated as PPI elicited by prepulse tone without background tone. Each bar represents mean ± SEM across mice in PV-ChR2 group (A, n = 20, repeated-measures ANOVA, p = 0.066) and PV-Arch group (B, n = 16, p = 0.52). (T...
Data
Overlap between photoactivation of PVs with the US presentation during fear conditioning altered conditioned response (freezing) during test but did not affect how specific associative learning was as measured by LS. (A) In US+light group, blue (left) or green (right) light stimulation was 11 s long and overlapped with the presentation of electric...
Data
Coupled excitatory–inhibitory neuronal model requires a saturating synaptic transfer function for inhibitory population to replicate experimental findings. (A) Three additional models that were used to model the excitatory-inhibitory coupled networks. Left: the synaptic transfer function was modeled as linear for both excitatory and inhibitory popu...
Data
Undergoing DAFC does not alter the effect of PV activation on neuronal responses. (A) Diagram of experimental procedure for naïve animals (top) and animals that underwent DAFC prior to recording. Change in spontaneous and tone-evoked firing rate (B) and change in sparseness of neuronal tuning due to photoactivation of PVs (C) were similar for mice...
Data
Matlab code for model presented in Fig 6 and S14 Fig. (ZIP)
Article
Full-text available
Tinnitus is an auditory disorder, which affects millions of Americans, including active duty service members and veterans. It is manifested by a phantom sound that is commonly restricted to a specific frequency range. Because tinnitus is associated with hearing deficits, understanding how tinnitus affects hearing perception is important for guiding...

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