Affect is the experience of feeling or emotion.

Affect is a key part of the process of an organism's interaction with stimuli. The word also refers sometimes to affect display, which is “a facial, vocal, or gestural behavior that serves as an indicator of affect” (APA 2006).

The affective domain represents one of the three divisions described in modern psychology: the cognitive, the conative, and the affective. Classically, these divisions have also been referred to as the “ABC of psychology”, in that case using the terms “affect”, “behavior”, and “cognition”. In certain views, the cognitive may be considered as a part of the affective, or the affective as a part of the cognitive.

Three hundred twenty-three moderate traumatic brain injury to severe traumatic brain injury survivors received 2 to 16 years post-trauma an aftercare survey with seven questions asking for changes in behavior and affect, presented both to patients and their proxies. One hundred eighty-six patients (59%) answered the behavioral questions; 42% had frontal lesions on CT. Ordinal common factor analysis on proxy scores yielded two factors, with behavior and affective items clearly separated and the anger item mediocre related to both factors. Three scales were created: Behavior, Affective and Anger. Frontal patients scored significantly higher on the Behavior and Anger scales. Logistic regression analysis showed a fourfold increase of long-term neurobehavioral problems in patients with frontal lesions. Long-term neurobehavioral problems were significantly correlated to one-year outcome and return to work in the long term.

Patients with moderate to severe TBI neurobehavioral and affective problems can be distinguished. Early CT frontal abnormalities predict long-term neurobehavioral problems, but not affective problems ¹⁾.