Stress during navigation in space restricts the work of the hippocampus, which is responsible for retrieving memories, and sections of the parietal cortex involved in cognitive control and thus the ability to pass effectively is lost. It found American scientists, who asked the participants of my experiment is to find in the virtual space, the desired object or photograph celebrities (e.g. George Clooney), and beat them current, to trigger the stress reaction — increased cortisol levels. Article published in the journal Current Biology.
Planning any action largely relies on the work of episodic memory, which stores information about what, where, when and how happened. Imagine, for example, that the buyer in the supermarket you need to purchase a specific set of products: for example, milk, cheese, lemon, and ginger root. This whole process will require fetching information about the path to the store, and then about the products you need to buy and where in the supermarket to find. How accurately and quickly you can retrieve memories of episodic memory, ensures the efficiency of the process: the purchase of products will certainly take a little less time if the person will quickly find the way to the store on time and remember that the ginger root and lemon is likely to lie adjacent shelves.
In addition to episodic memory another important mechanism — in fact, the ability to plan, which largely (but not entirely) relies on cognitive control. Both of these mechanisms, on the one hand, strongly depend on each other, and with another — are quite vulnerable to exposure of humans to external factors: for example, caused by stress.
To check exactly how stress affects the ability to plan and episodic memory in navigation in space decided scientists led by Anthony Wagner (Anthony Wagner) from Stanford University. In their experiment involved 38 people in two days they investigated 12 virtual cities. Participants ‘ task was to locate in a virtual environment, any object or image with the face of celebrities (e.g. George Clooney).
After successful training, the participants had to repeat the task during fMRI. Before each task they were shown a plan of the city that had to move, and the plan was highlighted as a classic route — one in which they have walked, and short — most effective. Each participant had a choice: either use the same route, or plan a different, more effective.
Of the 38 participants from 20 the leg was fixed electrodes: with random intervals while navigating through the virtual town, participants zapped. The other participants identified in the control group — their current beat. Physiological indicator experienced by the participants stress the concentration of cortisol in saliva were measured before the experiment, three times in the process and after completion.
All virtual city was small enough in order to be able to use the short, re-planned by participants of the control group chose the shortest path, only 47 percent of cases. The participants, who were electrocuted and the shortest path was chosen in 31 percent of cases. They also spent 20 percent more time to find the correct object or picture, though, and remembered the path exactly the same as the control group. Cortisol levels in the saliva of participants who were electrocuted significantly (p < 0.01) increased after the start of the experiment compared to the control group (they have cortisol, by the way, only to fall).
Analysis of fMRI data showed that participants in the control group during task performance the activity of the hippocampus (a key structure for the storage and retrieval of memories) and parts of the parietal lobes involved in cognitive control, higher than the group that got zapped.