Investigating the effects of caffeine on executive functions using traditional Stroop and a new ecologically-valid virtual reality task, the Jansari assessment of Executive Functions (JEF(©))

Appetite. 2016 Oct 1:105:156-63. doi: 10.1016/j.appet.2016.05.021. Epub 2016 May 20.

Abstract

Objective: Caffeine has been shown to have effects on certain areas of cognition, but in executive functioning the research is limited and also inconsistent. One reason could be the need for a more sensitive measure to detect the effects of caffeine on executive function. This study used a new non-immersive virtual reality assessment of executive functions known as JEF(©) (the Jansari Assessment of Executive Function) alongside the 'classic' Stroop Colour-Word task to assess the effects of a normal dose of caffeinated coffee on executive function.

Method: Using a double-blind, counterbalanced within participants procedure 43 participants were administered either a caffeinated or decaffeinated coffee and completed the 'JEF(©)' and Stroop tasks, as well as a subjective mood scale and blood pressure pre- and post condition on two separate occasions a week apart. JEF(©) yields measures for eight separate aspects of executive functions, in addition to a total average score.

Results: Findings indicate that performance was significantly improved on the planning, creative thinking, event-, time- and action-based prospective memory, as well as total JEF(©) score following caffeinated coffee relative to the decaffeinated coffee. The caffeinated beverage significantly decreased reaction times on the Stroop task, but there was no effect on Stroop interference.

Conclusion: The results provide further support for the effects of a caffeinated beverage on cognitive functioning. In particular, it has demonstrated the ability of JEF(©) to detect the effects of caffeine across a number of executive functioning constructs, which weren't shown in the Stroop task, suggesting executive functioning improvements as a result of a 'typical' dose of caffeine may only be detected by the use of more real-world, ecologically valid tasks.

Keywords: Caffeine; Cognitive; Executive function; JEF(©); Mood; Stroop.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Caffeine / adverse effects
  • Caffeine / therapeutic use*
  • Central Nervous System Stimulants / adverse effects
  • Central Nervous System Stimulants / therapeutic use*
  • Coffee* / adverse effects
  • Double-Blind Method
  • Executive Function*
  • Female
  • Humans
  • Hypertension / etiology
  • Male
  • Mental Fatigue / diagnosis*
  • Mental Fatigue / diet therapy
  • Mental Fatigue / prevention & control*
  • Mood Disorders / etiology
  • Performance-Enhancing Substances / adverse effects
  • Performance-Enhancing Substances / therapeutic use*
  • Psychiatric Status Rating Scales
  • Task Performance and Analysis
  • Virtual Reality

Substances

  • Central Nervous System Stimulants
  • Coffee
  • Performance-Enhancing Substances
  • Caffeine