Authentication or uniquely identifying a person is a very crucial aspect and has vivid applications worldwide. The most robust being biometric, which has its own pros and cons inherent. Since they are hard to refute, effective utilization of these can effectively identify a person. Hence governing the negative issues is of paramount importance. This paper makes a survey of the challenges met in two biometric based approaches: face recognition and authentication via neuro-signals. It is found that the key challenges in the former are less complex when compared to the latter.