Hemoglobin refers to a heme- which contains protein in red blood cells that is responsible for transporting oxygen to tissues. Hemoglobin also serves as a weak buffer within red blood cells.

In psychology, hemoglobin is a protein in the blood that is essential for carrying oxygen from the lungs to the body's tissues and transporting carbon dioxide from the tissues to the lungs to be exhaled. Hemoglobin is also used as a biomarker for various psychological and neurological conditions.

For example, researchers have found that levels of hemoglobin in the brain are associated with cognitive functioning, with lower levels being linked to poorer cognitive performance. Abnormal levels of hemoglobin have also been linked to conditions such as depression, bipolar disorder, and schizophrenia.

Additionally, studies have shown that individuals with traumatic brain injuries (TBI) often experience changes in hemoglobin levels, which can affect brain function and lead to cognitive deficits. Understanding these changes in hemoglobin levels and their effects on brain function can help researchers develop better treatments for TBI and other neurological disorders.

Overall, hemoglobin is an important biomarker in the field of psychology and neuroscience, as it can provide valuable insights into the functioning of the brain and various psychological conditions.