AUTOBIOGRAPHICAL MEMORY IN MAJOR DEPRESSION:
DIFFERENT RESPONSES TO VERBAL AND VISUAL EMOTIONAL CUES?
4.1.3. The Visually Cued ABM Test
A primary concern, in terms of the development of the proposed visually cued autobiographical memory test, was the type of visual stimuli to be presented to the participants in order to elicit retrieval of personal memories. In traditional cueing tasks (e.g. Williams & Dritschel, 1988; Williams & Scott, 1988) the words have tended to describe either distinct emotions (e.g. happiness, surprise, anger) or concepts (mood-congruent & mood-incongruent) that are highly salient to people suffering from depression (e.g. lonely, successful). Emotional facial expressions could be considered to be the visual equivalent of the first type of word cue (i.e. they represent distinct emotions). Furthermore, photographic images depicting emotional scenes and social interactions could be considered suitable to represent concepts that would be salient to a person suffering from depression. Evidence supporting this
notion comes from a study conducted by Lang, Greenwald, Bradley and Hamm (1993), who argued that, although individuals are able to make the psychological distinction between pictures and reality, the information contained within pictorial stimuli corresponds with the properties of “real life” objects and events, and as such lead to activation of cognitive representations that are associated with powerful affective reactions.
4,1,4. Major Depression and the Visually Cued ABM Test
As noted above, Williams and Dritschel (1988) suggested that depressed individuals might use the overgeneral retrieval style in order to avoid the negative consequences of accessing specific negative memories. However, as noted by Williams, Teasdale, Segal and Soulsby (2000), it is possible that the cognitive effort required to suppress these memories reduces the amount of available resources that can be utilised to move from general to specific memories.
If overgeneral ABM retrieval does represent a strategic avoidance of the emotive nature of specific memories, then one possible influence on the specificity of ABM retrieval in depressed individuals might be the ease with which the different forms of stimuli {yerbal cfe visual) are able to access emotional reactions. It would be expected that cues that lead to greater access of emotional content would be more likely to result in the strategic avoidance of specific retrieval. Therefore, based on the proposal of Williams et al (1997) that pictorial representations are more emotive than verbal descriptions, it would be expected that depressed individuals would demonstrate greater overgeneral retrieval to image cues than to words. Furthermore, as emotional facial expressions are by their nature emotive (see Lundqvist & Dimberg, 1995; Wild,
Erb & Bartels, 2001 for evidence of emotional contagion from faces) it might also be expected that, relative to word cues, emotional faces would result in the retrieval of a greater proportion of generic ABMs by the depressed patients. However, if overgeneral categorical retrieval does represent sti ategic avoidance of negative affect, on the part of the patients, then it would be expected that any observed increase in generic retrieval would be restricted to negative memories.
Differences in the emotive properties of the distinct forms of stimuli might also be expected to modify other aspects of autobiographical retrieval that are influenced by the valence of the memory cues, namely retrieval times and proportion of positive and negative memories retrieved. Teasdale and Barnard (1993) proposed that, according to their ICS model, different elements of a given event (e.g. visual, spatial, emotional, etc) are represented in multiple subsystems within the cognitive architecture. In line with Williams (1996), Teasdale and Barnard (1993) suggest that ABM retrieval requires constructing a “description” or summary of the required information with which to access these stored representations. They further suggested that mood congruent retrieval of autobiographical memories depends upon the mood at recall enhancing the availability of descriptions relating to material of a similar emotional tone. In particular they noted the importance of the distinction between “hot” and “cold” cognition in explaining mood-congruent memory. In terms of personal memory retrieval, “cold” cognition refers to the access of elements of a given event (e.g. its semantic meaning) without a re-experience of the relevant emotional reactions. In contrast “hot” cognition reflects the affective representation of the event, and hence will be accompanied by the appropriate emotional response. According to Teasdale and Barnard (1993) the presence of mood-congruent retrieval bias requires
access to representations in the Implicational sub-system, as (in the ICS model) this is the sub-system that represents affect-related “hot” themes from an individual’s past. With this in mind, it would be expected that memory cues that lead to greater access of emotional representations (i.e. Implicational representations) would result in stronger mood congruent effects. Therefore, based on the assumption that images and faces are more emotive than words, and presumably would be more likely to access the Implicational code, it would be expected that mood-congruent retrieval effects would be stronger for the visual stimuli than for word cues.
4.1,5. Overview and Predictions
Clinically depressed patients and healthy controls were presented with three different sets of affective memory cues {words, faces & images) and were asked to retrieve, as quickly as they could, a specific autobiographical memory (ABM) in response to each cue. The cues were presented in blocks (e.g. all words together etc). Participants were also asked to rate the pleasantness of each ABM they retrieved. The following predictions were made:
1. In line with Williams et al (1999) it was expected that images would lead to greater access to specific ABMs than would words or faces. With this in mind it was predicted that participants would be significantly faster to retrieve specific ABMs to images than to words or faces. However, in line with Williams and Dritschel (1988) it was predicted that depressed individuals would not demonstrate enlianced retrieval to images, therefore no differences were expected for the depressed individuals retrieval times to the different memory cues.
2. In line with previous findings (outlined in section L4.1.1, page 17) it was predicted that depressed patients would be significantly faster to produce negative than positive memories. Conversely, it was expected that the controls would be faster to produce positive than negative memories.
3. In line with Williams et al (1999), it was expected that, overall, participants would retrieve significantly more specific ABMs (as a first response) when cued with images than when cued with words or faces. However, it was not expected that depressed individuals would demonstrate this specificity advantage for the image cues.
4. In line with previous findings (outlined in section 1.4.1.1, page 17) it was expected that depressed patients would retrieve significantly fewer specific ABMs than would the controls. However, in line with previous findings it was also expected that depressed individuals would retrieve significantly fewer specific positive than negative ABMs.
5. Based on previous findings (outlined in section 1.4.1.1, page 17) it was expected that depressed individuals would make significantly more categorical retrieval errors than either omissions or extended errors. Furthermore, it was expected that depressed participants would retrieve significantly more categorical memories than would the controls.