Intention, attention and long-term memory for visual scenes: It all depends on the scenes

Lower-Resolution Retrieval of Scenes in Older Adults With Subjective Cognitive Decline

Objective

Scenes with more perceptual detail can help detect subtle memory deficits more than scenes with less detail. Here, we investigated whether older adults with subjective cognitive decline (SCD) show less brain activation and more memory deficits to scenes with more (vs. scenes with less) perceptual detail compared to controls (CON).

Method

In 37 healthy older adults (SCD: 16), we measured blood oxygenation level-dependent-functional magnetic resonance imaging during encoding and behavioral performance during retrieval.

Results

During encoding, higher activation to scenes with more (vs. less) perceptual detail in the parahippocampal place area predicted better memory performance in SCD and CON. During retrieval, superior performance for new scenes with more (vs. less) perceptual detail was significantly more pronounced in CON than inSCD.

Conclusions

Together, these results suggest a present, but attenuated benefit from perceptual detail for memory retrieval in SCD. Memory complaints in SCD might, thus, refer to a decreased availability of perceptual detail of previously encoded stimuli.

Cross-Modal Interaction Between Auditory and Visual Input Impacts Memory Retrieval

How we perceive and learn about our environment is influenced by our prior experiences and existing representations of the world. Top-down cognitive processes, such as attention and expectations, can alter how we process sensory stimuli, both within a modality (e.g., effects of auditory experience on auditory perception), as well as across modalities (e.g., effects of visual feedback on sound localization). Here, we demonstrate that experience with different types of auditory input (spoken words vs. environmental sounds) modulates how humans remember concurrently-presented visual objects. Participants viewed a series of line drawings (e.g., picture of a cat) displayed in one of four quadrants while listening to a word or sound that was congruent (e.g., "cat" or ), incongruent (e.g., "motorcycle" or ), or neutral (e.g., a meaningless pseudoword or a tonal beep) relative to the picture. Following the encoding phase, participants were presented with the original drawings plus new drawings and asked to indicate whether each one was "old" or "new." If a drawing was designated as "old," participants then reported where it had been displayed. We find that words and sounds both elicit more accurate memory for what objects were previously seen, but only congruent environmental sounds enhance memory for where objects were positioned - this, despite the fact that the auditory stimuli were not meaningful spatial cues of the objects' locations on the screen. Given that during real-world listening conditions, environmental sounds, but not words, reliably originate from the location of their referents, listening to sounds may attune the visual dorsal pathway to facilitate attention and memory for objects' locations. We propose that audio-visual associations in the environment and in our previous experience jointly contribute to visual memory, strengthening visual memory through exposure to auditory input.

Detecting accelerated long-term forgetting: A problem and some solutions

While many memory disorders occur with normal rates of forgetting, an accelerated rate of long-term forgetting (ALF) may occur, sometimes in the absence of a learning deficit. Detecting ALF presents a problem as it is desirable that the learned material is re-tested after each of several delays. This may result in earlier retrievals confounding later tests, with evidence suggesting that both positive and negative interaction can occur between successive tests. An earlier study (Baddeley et al., 2019) tested cued recall of a series of four crimes or four visual scenes by probing a different sample of features from all four crimes/scenes at each delay. Even though no question was asked twice, the interpolated tests markedly reduced the rate of forgetting. We suggest that this decelerated forgetting effect may result from the retrieval of probed features activating other associated features within that episode, hence facilitating their recall on subsequent tests. If so, the effect should be removed when only single and separate episodes, or individual items, are tested at each delay. We test this by probing a separate episode at each delay (Experiment 1), or by replacing integrated episodes with recognition memory for isolated words (Experiments 2 and 3) or visual scenes (Experiments 4 and 5). As predicted, we find no reduction in the rate of forgetting, in contrast to our earlier studies. The theoretical and clinical implications of our results are discussed. We conclude that the previously developed Crimes and Four Doors Tests (Baddeley et al., 2019) and the present single item recognition tests are complementary and are both likely to be necessary to ensure the reliable detection of ALF.

The road to long-term memory: Top-down attention is more effective than bottom-up attention for forming long-term memories

Does the strength of representations in long-term memory (LTM) depend on which type of attention is engaged? We tested participants' memory for objects seen during visual search. We compared implicit memory for two types of objects-related-context nontargets that grabbed attention because they matched the target defining feature (i.e., color; top-down attention) and salient distractors that captured attention only because they were perceptually distracting (bottom-up attention). In Experiment 1, the salient distractor flickered, while in Experiment 2, the luminance of the salient distractor was alternated. Critically, salient and related-context nontargets produced equivalent attentional capture, yet related-context nontargets were remembered far better than salient distractors (and salient distractors were not remembered better than unrelated distractors). These results suggest that LTM depends not only on the amount of attention but also on the type of attention. Specifically, top-down attention is more effective in promoting the formation of memory traces than bottom-up attention.

The use of novel measures to detect Accelerated Long-term forgetting in people with epilepsy: The Crimes Test and Four Doors Test

Most patients with memory disorders appear to forget at a relatively normal rate. Hence testing retention beyond the initial test session becomes unnecessary. However, it is now well established that a subsample of patients, most notably people with epilepsy, can show substantially increased forgetting rates even when acquisition rate is normal, raising the need for new tests focused on the assessment of long-term forgetting. Our study is part of the process of developing two such tests. Both focus on the need to test the same person several times and address the problem that each successive test may interfere with the memory of the event being tested. Depending on conditions, such effects can be substantial and may be either positive or negative. The Crimes and Four Doors Tests tackle this problem by presenting easily memorised episodes or scenes, from which a different sample of features is tested at each delay by telephone. We apply these two novel tests to assess rates of forgetting in groups of people with epilepsy and a matched control group. Both the visual and verbal tests showed clear evidence of accelerated forgetting in the epilepsy group supporting the potential value of the tests as convenient and sensitive measures of the rate of long-term forgetting.

How does a threatening stimulus affect the memory of the display?

Ample research has suggested that visual attention is biased towards threat and it was argued that this bias is an essential component of survival and implicated in anxiety. However, it is less clear how this bias is translated into memory, and specifically into the memory of items presented near a threatening stimulus. Here, we investigated this issue by testing how well people remember neutral and threatening images presented under various task demands. On each trial, observers saw two images before performing a dot-probe task (Experiment 1), a colour discrimination task (Experiment 2), a global or local attention task (Experiment 3), or no task at all (Experiment 4). A recognition memory test was performed at the end of each experiment to assess how the presence of a threatening image influences the memory of both images presented in the display. In all experiments, overall memory was enhanced as more threatening images were presented in the display. However, this enhancement did not occur at the expense of the processing of the surroundings. That is, with the exception of the dot-probe task, memory performance was not affected by an adjacent threatening image. Together, these findings challenge trade-off accounts, which predict that the processing of a threatening stimulus should take place at the expense of the processing of nearby items. Instead, these findings suggest that any effect of threat on the visual processing of the display is short-lived and more limited than previously thought.

From short-term store to multicomponent working memory: The role of the modal model

The term "modal model" reflects the importance of Atkinson and Shiffrin's paper in capturing the major developments in the cognitive psychology of memory that were achieved over the previous decade, providing an integrated framework that has formed the basis for many future developments. The fact that it is still the most cited model from that period some 50 years later has, we suggest, implications for the model itself and for theorising in psychology more generally. We review the essential foundations of the model before going on to discuss briefly the way in which one of its components, the short-term store, had influenced our own concept of a multicomponent working memory. This is followed by a discussion of recent claims that the concept of a short-term store be replaced by an interpretation in terms of activated long-term memory. We present several reasons to question these proposals. We conclude with a brief discussion of the implications of the longevity of the modal model for styles of theorising in cognitive psychology.