Introduction

The emergence of food supplements which hold no therapeutic claims but advertised as having great effects to health has prompted the researchers to conduct this experimental study. Since no medical or therapeutic claims are published, could it be that manufacturers are trying to use the placebo effect to sell their products? With this in mind, the researchers aim to determine if this effect extends to a person's mental performance. Placebos have been used in experiments mainly on the effectiveness of a drug being tested. In most cases the placebo whether a drug or a procedure, showed the same effectiveness as the treatment being tested. Placebos have an effect because they constitute suggestions in the minds of people taking them (Henderson, 2005). The researchers have incorporated suggestive reinforcement to placebo treatment in the study. There is little evidence of a placebo effect in mental performance as most researches have been on the field of medicine. But certain studies have shown that effective placebo treatment induces changes in brain function that are distinct from those associated with medication (Leuchter et al, 2002).