Cognitive Function Test Scores Doubled

The COGfx Study demonstrated that improved indoor environmental quality doubled cognitive function test scores in the 24 study participants. Of note, participants' cognitive performance scores averaged 101 percent higher in green buildings with enhanced ventilation compared to those in conventional buildings.

The largest improvements in cognitive function occurred with crisis response, information usage and strategy.

  • Crisis response scores were 97 percent higher in the green environment and 131 percent higher in the enhanced green environment than in the conventional building environment.
  • Information usage scores in the green and enhanced green environments were 172 and 299 percent higher than in the conventional environment, respectively.
  • For strategy, green and enhanced green scores were 183 and 288 percent higher than conventional.

Better Thinking by the Numbers

Cognitive Results By Indoor Environment

Green Buildings

61% higher

Green Buildings

101% higher

Conventional Buildings

Score Breakdown

Cognitive function Green Cognitive
Score Percent Change
as Compared with Conventional
Enhanced Green
Cognitive Score
Percent Change
as Compared with Conventional
Information Usage 172% 299%
Strategy 183% 288%
Crisis Response 97% 131%
Focused Activity Level 51% 48%
Breadth of Approach 21% 47%
Applied Activity Level 4%* 36%
Basic Activity Level 14% 36%
Task Orientation 3%* 15%
Information Seeking 9%* 11%

The Terminology

Information Usage

Use both provided information and information that has been gathered toward attaining overall goals.


Leverage well-integrated solutions with the help of optimal use of information and planning.

Crisis Response

Plan, stay prepared and strategize under emergency conditions.

Focused Activity Level

Pay attention to situations at hand.

Breadth of Approach

Consider multiple dimensions when making decisions and use a variety of options and opportunities to attain goals.

Applied Activity Level

Gear decision-making toward overall goals.

Basic Activity Level

Make decisions at all times.

Task Orientation

Make specific decisions that are geared toward completion of tasks at hand.

Information Seeking

Gather information as required from different available sources.

This study suggests that indoor environments can have a profound impact on the decision-making performance of workers, which is a primary indicator of worker productivity. These results are provocative for three reasons. First, they suggest that the levels of carbon dioxide and volatile organic compounds that we commonly encounter in conventional office buildings are associated with decreases in worker performance compared to when those same workers are in green building environments. Second, when we enhance ventilation and optimize indoor environmental conditions, we see improvements in the cognitive function of workers. And third, these results fill important knowledge gaps in existing research about the relationship between green buildings and occupant health.”
Dr. Joseph Allen
Assistant Professor of Exposure Assessment Science at the Harvard T.H. Chan School of Public Health, Director of the Healthy Buildings Program at the Center for Health and the Global Environment at Harvard Chan School, Principal Investigator for the study

Optimized Environment For Productivity


Indoor Environmental Quality Conditions

Carbon dioxide levels at 950 parts per million

Ventilation rates at 20 cubic feet per minute of outdoor air per person

Indoor total volatile
organic compounds

between 500-700 micrograms/cubic meter

Enhanced Green

Indoor Environmental Quality Conditions

Carbon dioxide levels at 600 parts per million

Ventilation rates at 40 cubic feet per minute of outdoor air per person

Indoor total volatile
organic compounds

less than 50 micrograms/cubic meter

Best Observed

Enhanced Green

Crisis Response
scores were

131% higher**

Information Usage
scores were

299% higher**

scores were

288% higher**