One of the controversies tied to the definition of emotion is whether it can exist without cognition. Is cognition a precursor to emotion? Some theorists have argued that the process of experiencing emotion relies to great extent on appraising our environment. According to Lazarus, emotions arise from 'how a person construes the outcome, actual or anticipated, of a transaction or a bit of commerce with the environment'. In order to experience anxiety, for example, we need to attribute anxiety-provoking properties to an object, event or person in the environment. We need, in short, to think about the object/event/person, and this leads to the emotion. Seeing a spider, for example, involves first being able to identify the creature as a spider, a cognitive process. Based on this attribution, and then some combination of evolution or learned behaviour, people(arachnophobes) become frightened. At the core of response is a person's cognitive operations - attributions and appraisals - but not all theorists agree that the precursor model explains all emotion. Zajonc, for example, provided some evidence to show that we can respond emotionally to events that we were not capable of consciously perceiving. The solution is the act of perception, then it is almost unarguable that cognition does not precede emotion. If perception is not regarded as a cognitive operation, then the view that emotions are not preceded by cognition is justified