Sofia SakellaridiPeka ChristovaVassilios ChristopoulosAlice VialardJohn PeponisApostolos Georgopoulos

Sakellaridi et al. publish 'small city maps' study

The article "Cognitive mechanisms underlying instructed choice exploration of small city maps" by Sofia Sakellaridi, Peka Christova, Vassilios N. Christopoulos, Alice Vialard, John Peponis and Apostolos P. Georgopoulos appears in the March 20th issue of Frontiers in Neuroscience: Decision Neuroscience.

Figure 1

FIGURE 7. Superimposed eye positions (black dots) on each map of all 12 subjects, and the corresponding isolines illustrating the probability density of the eye positions. Isoline colors describe different levels (0–1) of the contour intervals, with red corresponding to high probability density values, and blue corresponding to low density values.




We investigated the cognitive mechanisms underlying the exploration and decision-making in realistic and novel environments. Twelve human subjects were shown small circular U.S. city maps with two locations highlighted on the circumference, as possible choices for a post office (“targets”). At the beginning of a trial, subjects fixated a spot at the center of the map and ultimately chose one of the two locations. A space syntax analysis of the map paths (from the center to each target) revealed that the chosen location was associated with the less convoluted path, as if subjects navigated mentally the paths in an “ant's way,” i.e., by staying within street boundaries, and ultimately choosing the target that could be reached from the center in the shortest way, and the fewest turns and intersections. The subjects' strategy for map exploration and decision making was investigated by monitoring eye position during the task. This revealed a restricted exploration of the map delimited by the location of the two alternative options and the center of the map. Specifically, subjects explored the areas around the two target options by repeatedly looking at them before deciding which one to choose, presumably implementing an evaluation and decision-making process. The ultimate selection of a specific target was significantly associated with the time spent exploring the area around that target. Finally, an analysis of the sequence of eye fixations revealed that subjects tended to look systematically toward the target ultimately chosen even from the beginning of the trial. This finding indicates an early cognitive selection bias for the ensuing decision process.


Leida Voulgaropoulos

Leida Voulgaropoulos is from Minneapolis and is a senior studying Biology, Society, and Environment at the University of Minnesota. She will be continuing her education in the Twin Cities next year as a medical student at the U of M Medical School. Under the mentorship of Dr. Apostolos Georgopoulos and Dr. Lisa James, Leida is working on a project examining the association of cardiovascular disease risk factors, apolipoprotein E, and PTSD.



Carly PetersonLisa JamesSamantha AndersBrian Engdahl

BSC team release PTSD study findings

Brain Sciences Center researchers Carly K. Peterson, Lisa M. James, Samantha L. Anders, Brian E. Engdahl, and Apostolos P. Georgopoulos have a new publication in the Journal of Neuropsychiatry & Clinical Neurosciences entitled, "The Number of Cysteine Residues per Mole in Apolipoprotein E Is Associated With the Severity of PTSD Re-Experiencing Symptoms

Apolipoprotien E (ApoE) is involved in critical neural functions and is associated with various neuropsychiatric disorders. ApoE exists in three isoforms that differ in the number of cysteine residues per mole (CysR/mole). This study evaluated associations between this informative ordinal biochemical scale (CysR/mole) and symptom severity in veterans with posttraumatic stress disorder (PTSD) or subthreshold PTSD. Results demonstrated a significant negative relationship between the CysR/mole and severity of PTSD re-experiencing symptoms, adjusted for trauma. The findings suggest a genetic influence on PTSD symptomatology and dovetail with recent advances regarding the molecular mechanisms underlying the differential effects of ApoE in the brain.


Updated March 30, 2015