Mood-Related Impairments in Learning and Memory

Cognitive tasks carry according to the degree to which they require our attention. Some tasks require little attention control for successful performance; many of the cognitive processes involved in these tasks are relatively automatic, which means that they are well practiced and can occur simultaneously with other cognitive processes. Other tasks require more effortful and deliberate focus of attention if good performance is to be achieved. The degree to which focused attention is required for good performance is a characteristic of tasks that are performed during initial exposure or learning and tasks that reveal memory for past events. Reading a long list of unrelated words for the first time, for example, requires little attention by fluent readers, but organizing them in ways that will be useful during later attempts to remember them clearly requires more effortful and deliberate focus. Similarly, tests of memory for those words vary in the degree of focused attention that they require. Rereading the same words is one index of memory (in that the old words can be read faster than new words) that involves processes which are relatively automatic. In contrast, trying to recall the words on the list is a deliberate task that can benefit from a great deal of attention and the use of special strategies. 

Separate assessments of learning and memory are not possible; any index of learning involves memory and vice versa. It is possible, however, to emphasize variations in one type of task by examining research in which the other type of task is held constant. When that is done, a pattern emerges: The learning and memory tasks that benefit from attention control are the tasks that present difficulties to depressed and anxious people; they perform less well than people who are not mood-impaired. Weingartner and his colleagues(1981), discovered that clinically depressed patients could learn lists of words organized into simple categories as well as could non-depressed people. However, when the same words were unorganized, the depressed patients learned less well. Similarly, college students who are experimentally induced to feel depressed do not learn words presented in the context of more elaborate or distinctive sentences as well as do students in neutral moods, but the two groups perform similarly when the contexts are less elaborate or distinctive (Ellis et al.,1984). Williams and his colleagues(1988) reviewed similar findings in the literature on anxiety and cognition. If people approach these types of leaning tasks by providing their own organization( a deliberate strategy) or by focusing attention on elaborations and distinctions, they learn at higher levels. Depressed and anxious people do not seem to attend in these ways. Similar conclusions can be reached in examining different types of memory tests. Hertel and Hardin(1990) found that depressed college students performed as well as nondepressed students when the test did not involve attention focus on a past event, but when the test required such focus, depressed students did not spontaneously use strategies for recognition that characterized the performance of the nondepressed students.

Mood-Congruent Memory

People pay attention to and subsequently remember episodes and materials that are consistent (or congruent) with their moods more often than they attend to and remember other occurrences. Mood congruent attention characterizes the performance of anxious people in particular. To the extent that anxiety is similar to a more general state of physiological arousal or alertness, attention to threat related events can be understood from an evolutionary perspective. Research conducted by Eysenck et al. (1987) illustrates anxiety-congruent attention. In that experiment anxious participants, more often than non-anxious participants, spelled spoken homophones such as die/dye to coincide with the more threatening concept. The results of another experiment by Mathews et al. (1989( showed similar mood-congruent attention on a test of memory. In this test, the participants were shown the first three letters of words and asked to complete them to form the first word that came to mind. The anxious subjects completed the stems of threat-related words that they had encountered in an earlier task more often than other types of old and new words; non-anxious subjects did not show this bias.

On more traditional tests of memory, such as tests of deliberate recall, anxious people do not always remember anxiety-related episodes better than other episodes (Williams 1988).

Yet research concerned with other emotional states (including depression, happiness, and anger) shows more consistent evidence

Mood-Dependent Memory (State-Dependent Memory)

There is evidence for the claim of better memory when one's mood at the time of remembering is the same as one's mood during the original encounter. This phenomenal, so called mood-dependent memory or state-dependent memory

Summary

Individual differences in emotional states and transitory moods correspond to differences in leaning and remembering. The research findings are consistent with the theoretical framework: attention deficits or attention biases toward mood-related aspects of experience can be difficulties in remembering emotionally irrelevant events or can be beneficial in retaining the memory in emotionally aroused events.