Pain is a personal experience that widely varies between people and even within an individual. It dependson numerous factors which can change over the time. The psychological state of the person, such as cognitive and emotional factors, has an important influence on pain perception. In chronic pain it can occur anatomical and functional alterations in regions involved both in pain control and cognitive or emotional functioning.

The authors aim to clarify the role of cognition and emotion in pain modulation and its disruption in chronic pain.

Literature review in PubMed database using the following key words: 'pain”, 'chronic pain”, 'pain modulation”,'emotion” and 'cognition”.

Recent studies demonstrate that cognitive – attentional variations – and emotional factors can modulate pain perception. The attentional state changes the perceived intensity of pain, while emotional state changes the perceived unpleasantness of the pain without changing its intensity. Such evidence takes usback to that cognition and emotion modulates pain by different mechanisms. Emotional state activates anterior cingulatecortex, prefrontal cortex and periaqueductal gray. On the other hand, attention activates projections from the superiorparietal lobe to the primary somatosensory cortex and insula. Cross-sectional studies have demonstrated that chronicpain can change these modulatory pathways.

Despite the personal and interpersonal differences in pain perception, it is established that cognitive and emotional factors are important in pain modulation and perception. However, in chronic pain there are changes in these mechanisms which need to be clarified.