Introduction In 1987 Oatley and Johnson-Laird (cited in Mogg & Bradley, 1998) supposed the evolutionary source to be the major consideration in the analysis of emotions. For instance the primary role of the mechanism responsible for the fear emotion are to allow the identification of threat in the surrounding and to assist the organism react promptly an efficiently to the situation. The attention system in the brain facilitates the pathway for sensing and tracking environmental and interceptive signal which are related with the excitement of the organism. Cognitive theory Based on the current theories, biases in information encoding contribute considerably in the etiology and sustenance of emotional disturbances, including generalized anxiety disorders (GAD) and significant depressive disturbances (Beck, 1976; Eysenck, 1992; Matthews & MacLeod, 1994). Particularly, dysfunctional schemata are responsible for information failure or loss characteristics of depression, while the schemata are receptive to danger or threat associated with anxiety, (Beck, 1976; Beck et al., 1979, 1986). The stimulation of the schemata produces bias encoding of congruent information. Furthermore, he stipulated that susceptibility to emotional disturbances is an attribute of individual variation in the function of the schemata. For instance, an anxiety-prone person would present a hyperactive threat-schema which translates to elevated attention to external threat cues, an inclination to translate ambiguous stimuli to threat, and an amplified propensity to recall threatening incidents (Mogg & Bradley, 1998). In 1981, Bower postulated a “semantic network theory of emotion,” wherein every emotion is denoted with a node in the corresponding network system in memory, limbic system. All the nodes are interconnected with other representation within the memory network, including the memory of happy or sad experiences. Stimulation of a certain node elevates the stimulation of the connected nodes, resulting in encoding bias in favor of information that is harmonious with the emotion. This for instance translates to an increase in stimulation of a corresponding threat-relevant material in the network due to an increase in anxious emotions. William et al. (1988) postulated a reviewed cognitive formulation of depression and anxiety, with the following prominent attributes;  1. Anxiety is majorly characterized by bias for threat signal in preattentive pathway and in selective attention. Based on Graf and Mandler (1984) model of memory, anxiety is related with a bias in automatic stimulation.  2. Persons who are prone to preattentive, habitual vigilance for threat excitation are more vulnerable to developing anxiety disturbances when subjected to stress.  3. Trait anxiety determines the course of attentional and preattentive biases to threat motivation. High trait anxious individuals have a chronic inclination to focus attention towards threat, while low trait individuals have an inclination towards avoidant of threat stimuli. Such focus biases are augmented by escalated anxiety. In other words, HTA persons tend to be more vigilant, while LTA tend to be more avoidant of threat. Thus, attentional and preattentive biases are an interrelated function of trait and stat