If you study the multi-store model you will be familiar with evidence that supports the distinction between short- and long-term stores. For example evidence of differences in duration and capacity. There is also evidence related to encoding in memory – the most cited study is one by Baddeley which indicated that short-term memory is mainly acoustic and long-term memory is mainly semantic. However another study, by Maria Brandimonte and colleagues showed that this was not always true. For example if information is presented visually then STM is visual. The stimulus material used in this study was six picture pairs, composed so one picture of each pair is a component of the other. The six picture pairs are shown below.
Participants were asked to subtract the second picture from the first one for each pair, producing a ‘composite’ picture. The pictures were displayed for 2 seconds. Afterwards participants were asked to verbally recall the composite images in any order. Using an independent groups design, some participants were given an articulatory suppression task in the interval before recall (i.e. they had to say ‘la la la la’). This is done to prevent any verbal rehearsal in the retention interval. This suppression task had no effect on performance for the images that had no name but improved performance for images that could be named (a verbal activity). This shows that storage can be visual.
This is an interesting study to try yourself – let me know what you find out.