Contact Information
Michael Rosario: michaelrosario340@gmail.com
Brain Plasticity and Neuroimaging Lab: 
brainex@bu.edu
Future Work
Materials & Methods
•
Compare cognitive and brain changes after a 12-week 
exercise intervention to baseline in cohort of healthy, 
sedentary older adults.
•
Compare healthy young adults and healthy older adults 
undergoing the same 12-week exercise training program.
This work was supported by student research award 
from the Boston University Summer Training as 
Research Scholars Program NIH R25HL118693-04, a 
NIH grant R00AG036845 (Karin Schon), and UVI 
RISE NIH 5R25GM06132. We would like to thank the 
staff of the BUSM Center for Biomedical Imaging, the 
General Clinical Research Unit at the BUSM Clinical 
and Translational Science Institute, and the Fitness 
and Recreation Center at Boston University Charles 
River Campus.
Background & Hypotheses
Michael Rosario12, Aletha Baumann2, Dara Hamilton2, Karin Schon1
1Brain Plasticity and Neuroimaging Lab, Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA
2 Department of Psychology, University of the Virgin Islands, Albert A. Sheen Campus, St. Croix
Effect of Aerobic Exercise on Spatial Navigation and Brain Structure as Modulated by Sex and Intracranial Volume
References
•
Burgess, N., Maguire, E. A., & O’Keefe, J. (2002). Neuron, 35, 625–641.
•
Dickerson, B. C. et al. (2009). Neurobiology of Aging, 30, 432–440. 
•
Erickson, K. I., et al.(2011). Proc Natl Acad Sci, 108, 3017–3022.
•
Hegarty, M., & Waller, D. (2004). Intelligence, 32, 175-191.
•
Moser, E. I., Kropff, E., & Moser, M.B. (2008). Annual Review of 
Neuroscience, 31, 69–89. 
•
Praag, H. van; Kempermann, G.; Gage, F. H. (1999). Nature 
Neuroscience, 2, 266–70.
•
Stranahan, A. M., Khalil, D., & Gould, E. (2007). Hippocampus, 17, 1017-
1022. 
•
Vingerhoets, G., Lannoo, E., & Bauwens, S. (1996). Archives of Clinical 
Neuropsychology, 11, 1-9.
•
Whiteman, A. S., Young, D. E., Budson, A. E., Stern, C. E., & Schon, K. 
(2016). Neuroimage, 1, 1-10. 
Acknowledgements
•
Structures in the medial temporal lobe (MTL) memory system 
show experience-dependent neuroplasticity. Within the MTL, this 
plasticity has been observed in the hippocampus (HC) in both 
humans and animal models.
•
A rodent model study found that voluntary wheel running induces 
neuroplasticity in the entorhinal cortex (EC) and HC.
•
The work of Erikson et al. details the relationship between 
cardiovascular fitness and structures of the MTL, particularly the 
HC, in a cohort of older adults who were assigned to either a 
stretching group or an aerobic fitness group. 
•
A previous volumetric analysis in our lab showed that right EC 
volume, but not HC volume, was positively correlated with 
cardiovascular fitness (VO2 max) in healthy young adults.
•
HC and EC are critical for spatial  learning and memory and spatial 
navigation.
Hypotheses
•
Research Question 1: Aerobic training exercise will have an 
effect on medial temporal lobe structures. 
•
Research Question 2: Medial temporal lobe structures recruited in 
tasks of spatial navigation will be related to tasks of spatial 
navigation. 
Left Entorhinal 
Cortex 
Right 
Hippocampus
Design
•
RQ 1: Experimental Study - MANOVA
•
Independent variables:
• Exercise group and time
•
Dependent variables:
• Morphometric measures – Entorhinal Cortex
•
Covariates:
• Sex and intracranial volume
•
RQ 2: Correlational Study – Multiple Regression
•
Predictor variables:
• Left and right EC thickness
•
Outcome variables:
• Performance on tasks of spatial cognition
•
Covariates:
• Sex and intracranial volume
Participants
•
Cross-sectional healthy adult cohort (N = 29, Mage = 
25.4, SDage = 3.3)
•
76% female; 62% assigned to Resistance Training 
Group
Summary & Conclusion

Although we had significant findings, they were not as 
predicted. We failed to reject the null hypothesis that 
aerobic exercise would produce greater growth in EC 
thickness than resistance training group.

The interaction of group by sex on entorhinal cortical 
thickness was unexpected and deserves further 
research. 

For the second research question the null hypothesis 
was rejected for the Road Map Test only. Almost 1/3 of 
the variance in the post-intervention Road Map Test was 
predicted by prior performance as well as morphometric 
bilateral measures of the entorhinal cortex. 

Growth thickness did not predict post-intervention 
Perspective Taking Spatial Orientation scores. 
RQ2: The multiple regression model was significant with a medium 
strength(F(3, 19) = 4.08, p = .023, R2 = .291). The only significant single 
predictor was Pre-Intervention Road Map Test Score.
Predicted Post-Road Map Test Score = 11.305 + .488(Pre-Road Map Test 
Score) + 20.247(Left EC Thickness Growth) + 14.122(Right EC Thickness 
Growth)
RQ1: Males had a small but significantly greater thickness growth for both 
left and right entorhinal cortical thickness  (F(1,28) = 4.532, p = .016 , η2 = 
.159; F(1,28) = 6.718, p = .044, η2 = .219). There were also significant 
interactions between sex and group. Both sexes had the same growth during 
resistance training but males showed a greater increase in cortical thickness 
growth after aerobic training, but females on average declined. 
Results
Limitations
•
Poor generalizability due to small sample.
•
Majority of the participants were female.
•
Although the participants claimed to be sedentary some 
had high pre-intervention fitness levels. 
Instruments
•
3T Phillips Achieva MRI Scanner at BUMC
•
Freesurfer analysis of high-resolution T1-weighted 
images
•
Road Map Test and Perspective Taking/Spatial 
Orientation Task
Procedure
•
Participants were recruited from the greater Boston area 
and underwent:
•
Assessment of VO2 max as measure of cardiovascular 
thickness
•
Whole-brain T1-weighted structural scan
(Voxel size: 1 mm3)
•
Tests of spatial cognition following neuroimaging
•
Randomly assigned to:
• Aerobic Training Group: walking 
• Resistance Training Group:  strength training
MRI Analysis
Freesurfer (5.3.0) MRI analytic software was used to 
calculate cortical thickness and cortical and subcortical 
volume.
Entorhinal 
Cortex
Dentate 
Gyrus
Cornu
Ammonis 3
Hippocampus
Cornu
Ammonis 1
Post 
RMT
Pre 
RMT
Left EC 
Thickness 
Growth
Pre RMT
.546** 
Left EC Thickness Growth
.333
.152
Right EC Thickness Growth
.395*
.403*
.175
Table 1: Correlation coefficient (* p < 0.05, ** p < .01)
A sex by group 
interaction for right 
entorhinal cortical 
thickness was found 
(F(1,28) = 4.908, p = 
0.36, η2 = .170)
A sex by group 
interaction for left 
entorhinal cortical 
thickness was found 
(F(1,28) = 15.903, p = 
.001, η2 = .399)
Generally, aerobic exercise has been shown to have many 
cognitive benefits in regards to brain structure and brain 
function. Structures in the medial temporal lobe including the 
entorhinal cortex and hippocampus are known to be 
implicated in tasks of spatial learning and memory. Using 
secondary data recently obtained from Boston University, this 
research project seeks to identify an effect of aerobic 
exercise on morphological measures of medial temporal 
lobes, specifically the entorhinal cortex and hippocampus 
and their relationship with spatial navigation. Young healthy 
sedentary adults were assigned to either resistance training 
group or an aerobic training group for a 12-week period.  
Intracranial volume and sex were used as covariates. The 
effect of aerobic exercise versus resistance training will be 
analyzed using a MANCOVA, with exercise group as the 
independent variable, intracranial volume and sex as 
covariates and four dependent variables: left and right 
entorhinal cortex and hippocampus.  Two multiple regression 
equations will be used to determine if structural measures 
can predict spatial navigation with intracranial volume and 
sex as covariates.  This research points to the 
neuroprotective effects of aerobic exercise even in younger 
adults.
Abstract