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The neurocognitive sequelae of a sport-related concussion and its management are poorly defined. Detecting deficits are vital in making a decision about the treatment plan as it can persist one year or more following a brain injury. The reliability of traditional cognitive assessment tools is debatable, and thus attention has turned to assessments based on electroencephalogram (EEG) to evaluate subtle post-concussive alterations. In this study, we calculated neurocognitive deficits combining EEG analysis with three standard post-concussive assessment tools. Data were collected for all testing modalities from 21 adolescent athletes (seven concussive and fourteen healthy) in three different trials. For EEG assessment, along with linear frequency-based features, we introduced a set of time-frequency (Hjorth Parameters) and nonlinear features (approximate entropy and Hurst exponent) for the first time to explore post-concussive deficits. Besides traditional frequency-band analysis, we also presented a new individual frequency-based approach for EEG assessment. While EEG analysis exhibited significant discrepancies between the groups, none of the cognitive assessment resulted in significant deficits. Therefore, the evidence from the study highlights that our proposed EEG analysis and markers are more efficient at deciphering post-concussion residual neurocognitive deficits and thus has a potential clinical utility of proper concussion assessment and management.

Researchers in the fields of marketing or management may find themselves in situations where they would like to make use of existing theory to guide their investigations. However, they may also see the research developing rather than testing theory, in which case the data may need to be gathered on an inductive/qualitative basis. The use of theory with qualitative method may appear to be a dichotomy.Indeed, existing texts in research methods seem to suggest that it is not possible to use existing theories, or elements of them, to drive an investigation when the aim is to develop theory.Drawing upon a study of the ways in which entrepreneurs use trust to mediate customer-perceived risk at the start of a venture, this paper argues that researchers can combine elements of both approaches, in an epistemologically consistent way.Specifically, researchers seeking to use an inductivist/qualitative approach can start with an a priori specification of constructs, perhaps in the form of a model. One of the ways in which this can help researchers is to identify where they should look in order to find the phenomena of interest to them. We argue that the difference between inductivist and deductivist research is how they draw upon existing research: in inductivist research theory can be used where it is composed of constructs while theory represented in the form of variables is more appropriate in hypotheticodeductive research.Similarly we argue that although existing theory can be used to formulate the questions which the inductivist/qualitative researcher asks of the respondent, what is important is that such questions are atheoretical, and this should also be a characteristic of the tabulation of the data.We acknowledge that using existing theory to drive a qualitative/ inductivist investigation can compromise the researcher ability to pay attention to the respondent's point of view. It can also limit the extent to which the investigation is truly inductive. However we feel that these losses can be minimised and can be more than compensated by gains in other areas. The implication for inductivist/qualitative researchers is that they need not feel guilty about using existing research -what matters is how they use it.3

The primary purpose of this chapter is to demonstrate one of the applications of P300 event-related potential (ERP), i.e., brain-computer interface (BCI). Researchers and students will find the chapter appealing with a preliminary description of P300 ERP. This chapter also appreciates the importance and advantages of noninvasive ERP technique.In noninvasive BCI, the P300 ERPs are extracted from brain electrical activities [electroencephalogram (EEG)] as a signature of the underlying electrophysiological mechanism of brain responses to the external or internal changes and events. As the chapter proceeds, topics are covered on more relevant scholarly works about challenges and new directions in P300 BCI. Along with these, articles with the references on the advancement of this technique will be presented to ensure that the scholarly reviews are accessible to people who are new to this field. To enhance fundamental understanding, stimulation as well as signal processing methods will be discussed from some novel works with a comparison of the associated results. This chapter will meet the need for a concise and practical description of basic, as well as advanced P300 ERP techniques, which is suitable for a broad range of researchers extending from today's novice to an experienced cognitive researcher.

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