Short-term memory for pictures seen once or twice.

The present study is concerned with the effects of exposure time, repetition, spacing and lag on old/new recognition memory for generic visual scenes presented in a RSVP paradigm. Early memory studies with verbal material found that knowledge of total exposure time at study is sufficient to accurately predict memory performance at test (the Total Time Hypothesis), irrespective of number of repetitions, spacing or lag. However, other studies have disputed such simple dependence of memory strength on total study time, demonstrating super-additive facilitatory effects of spacing and lag, as well as inhibitory effects, such as the Ranschburg effect, Repetition Blindness and the Attentional Blink.

Implicit short-term memory and event frequency effects in visual search.

Numerous experiments have shown that animals and humans behave as if guided by an implicit knowledge of the relative frequency of occurrence of events in their environment. A well-known example of such trait is "Hick's Law" for reaction times: responses to more frequent stimuli are faster than to less frequent ones. In the present study, we demonstrate that an important source of the effects produced by Hick's law in the context of a visual search task is to be found in a form of implicit short-term memory, previously described as Priming of Pop-out.

Short-term memory for scenes with affective content.

The emotional content of visual images can be parameterized along two dimensions: valence (pleasantness) and arousal (intensity of emotion). In this study we ask how these distinct emotional dimensions affect the short-term memory of human observers viewing a rapid stream of images and trying to remember their content. We show that valence and arousal modulate short-term memory as independent factors.

Saccades require focal attention and are facilitated by a short-term memory system.

We performed two sets of experiments in which observers were instructed to make saccades to an odd colored target embedded in an array of distractors. First, we found that when the colors of the target and distractors switched unpredictably from trial to trial (the mixed condition), saccadic latencies decreased with increasing numbers of distractors. In contrast, saccadic latencies were independent of the number of distractors when the color of the target and distractors remained the same on each trial (the blocked condition).

Priming of pop-out: II. The role of position.

In an earlier paper (Maljkovic & Nakayama, 1994) we showed that repetition of an attention-driving feature primes the deployment of attention to the same feature on subsequent trials. Here we show that repetition of the target position also primes subsequent trials. Position priming shows a characteristic spatial pattern.