Object memory and change detection: dissociation as a function of visual and conceptual similarity

People often fail to detect a change between two visual scenes, a phenomenon referred to as change blindness. This study investigates how a post-change object's similarity to the pre-change object influences memory of the pre-change object and affects change detection. The results of Experiment 1 showed that similarity lowered detection sensitivity but did not affect the speed of identifying the pre-change object, suggesting that similarity between the pre- and post-change objects does not degrade the pre-change representation. Identification speed for the pre-change object was faster than naming the new object regardless of detection accuracy. Similarity also decreased detection sensitivity in Experiment 2 but improved the recognition of the pre-change object under both correct detection and detection failure. The similarity effect on recognition was greatly reduced when 20% of each pre-change stimulus was masked by random dots in Experiment 3. Together the results suggest that the level of pre-change representation under detection failure is equivalent to the level under correct detection and that the pre-change representation is almost complete. Similarity lowers detection sensitivity but improves explicit access in recognition. Dissociation arises between recognition and change detection as the two judgments rely on the match-to-mismatch signal and mismatch-to-match signal, respectively.     

Visual long-term memory and change blindness: Different effects of pre- and post-change information on one-shot change detection using meaningless geometric objects

To clarify the relationship between visual long-term memory (VLTM) and online visual processing, we investigated whether and how VLTM involuntarily affects the performance of a one-shot change detection task using images consisting of six meaningless geometric objects. In the study phase, participants observed pre-change (Experiment 1), post-change (Experiment 2), or both pre- and post-change (Experiment 3) images appearing in the subsequent change detection phase. In the change detection phase, one object always changed between pre- and post-change images and participants reported which object was changed. Results showed that VLTM of pre-change images enhanced the performance of change detection, while that of post-change images decreased accuracy. Prior exposure to both pre- and post-change images did not influence performance. These results indicate that pre-change information plays an important role in change detection, and that information in VLTM related to the current task does not always have a positive effect on performance.     

To see dynamic change: continuous focused attention facilitates change detection,but the effect persists briefly

What is the role of continuously focused attention on an object in change detection? To ensure focused attention on one object, we conducted a single object change detection task, manipulating an object’s location between pre-change and post-change displays (same or different location), and also manipulating a blank duration (the FOD task) and a pre-change object presentation duration (the FBD task). If attention is continuously focused at the spatial location of the pre-change object, a location shift of the post-change object should interrupt change detection due to a cognitive cost of attentional shift. Results suggest attention is focused continuously for a brief blank duration, and attention can facilitate the detection of change occurring at the location of attentional focus. Additionally, although attention is focused continuously for a long time if a target is visible, the effect of attention declines with time. The results clarify the new temporal characteristics of focused attention.     

Is a pre-change object representation weakened under correct detection of a change?

We investigated whether a pre-change representation is inhibited or weakened under correct change detection. Two arrays of six objects were rapidly presented for change detection in three experiments. After detection, the perceptual identification of degraded stimuli was tested in Experiments 1 and 2. The weakening of a pre-change representation was not observed under correct detection. The repetition priming effect was observed for a pre-change object and the magnitude was equivalent to the effect for a post-change object. Under change blindness, repetition priming for a pre-change representation was observed when detection did not require report of location in Experiment 1 and was not observed when location was required to be reported in Experiment 2. The results of Experiment 3 showed that a pre-change representation was recognized at a higher rate under correct detection than under change blindness, reflecting a stronger rather than a weaker pre-change representation in the former context.     

On the prevalence of directly retrieved autobiographical memories

In this study, we used process measures to understand how people recall autobiographical memories in response to different word cues. In Experiment 1, participants provided verbal protocols when cued by object and emotion words. Participants also reported whether memories had come directly to mind. The self-reports and independent ratings of the verbal protocols indicated that directly recalled memories are much faster and more frequent than generated memories and are more prevalent when cued by objects than emotions. Experiment 2 replicated these results without protocols to eliminate any demand characteristics or output interference associated with the protocol method. In Experiment 3, we obtained converging results using a different method for assessing retrieval strategies by asking participants to assess the amount of information required to retrieve memories. The greater proportion of fast direct retrievals when memories are cued by objects accounts for reaction time differences between object and emotion cues, and not the commonly accepted explanation based on ease of retrieval. We argue for a dual-strategies approach that disputes generation as the canonical form of autobiographical memory retrieval and discuss the implication of these findings for the representation of personal events in autobiographical memory. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Improving metacognitive accuracy: How failing to retrieve practice items reduces overconfidence

People often exhibit inaccurate metacognitive monitoring. For example, overconfidence occurs when people judge that they will remember more information on a future test then they actually do. The present experiments examined whether a small number of retrieval practice opportunities would improve participants’ metacognitive accuracy by reducing overconfidence. Participants studied Lithuanian–English paired associates and predicted their performance on an upcoming memory test. Then they attempted to retrieve one or more practice items (or none in the control condition) and made a second prediction. Experiment 1 showed that failing to retrieve a single practice item lead to improved subsequent performance predictions – participants became less overconfident. Experiment 2 directly manipulated retrieval failure and showed that again failure to retrieve a single practice item significantly improved subsequent predictions, relative to when participants successfully retrieved the practice item. Finally, Experiment 3 showed that additional retrieval practice opportunities reduced overconfidence and improved prediction accuracy.     

Failures of retrieval and comparison constrain change detection in natural scenes

In a change detection paradigm, a target object in a natural scene either rotated in depth, was replaced by another object token, or remained the same. Change detection performance was reliably higher when a target postcue allowed participants to restrict retrieval and comparison processes to the target object (Experiment 1). Change detection performance remained excellent when the target object was not attended at change (Experiment 2) and when a concurrent verbal working memory load minimized the possibility of verbal encoding (Experiment 3). Together, these data demonstrate that visual representations accumulate in memory from attended objects as the eyes and attention are oriented within a scene and that change blindness derives, at least in part, from retrieval and comparison failure.     

Why don't we see changes?: The role of attentional bottlenecks and limited visual memory

Seven experiments explore the role of bottlenecks in selective attention and access to visual short-term memory in the failure of observers to identify clearly visible changes in otherwise stable visual displays. Experiment One shows that observers fail to register a color change in an object even if they are cued to the location of the object by a transient at that location as the change is occurring. Experiment Two shows the same for orientation change. In Experiments Three and Four, attention is directed to specific objects prior to making changes in those objects. Observers have only a very limited memory for the status of recently attended items. Experiment Five reveals that observers have no ability to detect changes that happen after attention has been directed to an object and before attention returns to that object. In Experiment Six, attention is cued at rates that more closely resemble natural rates and Experiment Seven uses natural images. Memory capacity remains very small (<4 items).     

Suppression in object-based attention

This study examines suppression in object-based attention in three experiments using an object-based attention task similar to Egly, R., Driver, J., & Rafal, R. D. (1994. Shifting visual attention between objects and locations: Evidence from normal and parietal lesion subjects. Journal of Experimental Psychology: General, 123(2), 161–177. doi:10.1037/0096-3445.123.2.161) with the addition of a distractor. In Experiment 1 participants identified a target object at one of four ends of two rectangles. The target location was validly cued on 72% of trials. The remaining 28% were located on the same or a different object. Sixty-eight percent of trials also included a distractor on one of the two objects. Experiment 1 failed to show suppression when a distractor was present, but did demonstrate the spread of attention across the attended object when no distractor was present. Experiment 2 added a mask to the paradigm to make the task more difficult and engage suppression. When suppression was engaged in the task, data showed suppression on the unattended (different) object, but not on the attended (same) object. Experiment 3 replicated findings from Experiment 1 and 2 using a within participants design. Findings are discussed in relation to the role of suppression in visual selective attention.     

Attending to objects: Endogenous cues can produce inhibition of return

Inhibition of Return (IOR) is effective in a wide range of experimental settings but has proven elusive under conditions of volitional (endogenous) attentional control. This result may be due to a continuing attentional bias towards the cued location. Here we ask whether IOR can be unmasked under endogenous cueing conditions when a predictive cue prevents such a bias. In Experiment 1, a central arrow directed attention endogenously to one end of a rectangular object. Attention initially radiated to an unpredicted location in the object but IOR later impaired target detection at that location. In Experiment 2, attention was directed endogenously to a dynamic object. While target detection was facilitated at a subsequent (and predicted) location of the rotating object, detection-latencies at its original location were slowed. Together the results show that it is possible to produce IOR using endogenous cues.     

Does expanded retrieval produce benefits over equal-interval spacing? Explorations of spacing effects in healthy aging and early stage Alzheimer's disease

Three experiments explored different schedules of retrieval practice in young adults, older adults, and individuals with dementia of the Alzheimer type. In each experiment, an initial acquisition phase was presented in which participants studied or attempted to retrieve response words to cues, followed by a later cued-recall test. Experiment 1 produced a benefit of expanded retrieval over equal-interval retrieval during acquisition, but this benefit was lost in final cued recall. In Experiments 2 and 3, participants received corrective feedback during acquisition and modified spacing schedules. There was again no evidence of a difference between expanded and equal-interval conditions in final cued recall. Discussion focuses on the potential benefits and costs of expanded retrieval on a theoretical and applied level.     

Attentional coding of categorical relations in scene perception: evidence from the flicker paradigm

The purpose of the present investigation was to determine whether the positions of objects in a scene are coded relative to one another categorically (i.e., above, below, or side of; Experiment 1) and to determine whether spatial position in scene perception is coded preattentively or only under focused attention (Experiment 2). In Experiment 1, participants viewed alternating versions of a scene in which one of the objects in the scene changed its categorical relationship to the closest object in the scene, changed only its metric relationship to the closest object in a scene, or appeared and disappeared. Participants were faster at detecting changes that disrupted categorical relations than at detecting changes that disrupted only metric relations. In Experiment 2, this categorical advantage still occurred even when participants were cued to the location of the change. These results suggest that categorical spatial relations are being coded in scene perception and that attention is required in order to encode spatial relations.     

Evidence for preserved representations in change blindness

People often fail to detect large changes to scenes, provided that the changes occur during a visual disruption. This phenomenon, known as "change blindness," occurs both in the laboratory and in real-world situations in which changes occur unexpectedly. The pervasiveness of the inability to detect changes is consistent with the theoretical notion that we internally represent relatively little information from our visual world from one glance at a scene to the next. However, evidence for change blindness does not necessarily imply the absence of such a representation---people could also miss changes if they fail to compare an existing representation of the pre-change scene to the post-change scene. In three experiments, we show that people often do have a representation of some aspects of the pre-change scene even when they fail to report the change. And, in fact, they appear to "discover" this memory and can explicitly report details of a changed object in response to probing questions. The results of these real-world change detection studies are discussed in the context of broader claims about change blindness.     

Subjective states associated with retrieval failures in Parkinson’s disease

Instances in which we cannot retrieve information immediately but know that the information might be retrieved later are subjective states that accompany retrieval failure. These are expressed in feeling-of-knowing (FOK) and Tip-of-the-tongue (TOT) experiences. In Experiment 1, participants with Parkinson’s disease (PD) and older adult controls were given general questions and asked to report when they experienced a TOT state and to give related information about the missing word. The PD group experienced similar levels of TOTs but provided less correct peripheral information related to the target when in a TOT state. In Experiment 2, participants were given a Semantic (general knowledge questions) and an Episodic (word pairs) FOK task. PD patients failed to accurately predict their future memory performance (FOK) in response to both episodic and semantic cues. Results are interpreted in the context of recent frameworks of memory and metacognition.     

Remembrance of remembrance past

Arnold and Lindsay (2002) found that individuals more often failed to remember they had previously recalled an item if that item had been cued in a qualitatively different way on two recall occasions: the “forgot-it-all-along” (FIA) effect. Experiment 1 was designed to determine if the FIA effect arises because participants incorrectly believe they have not been previously tested for an item, or because they incorrectly believe they have failed to recall the item when previously tested. Experiment 2 measured participants' confidence in their incorrect prior-recall judgements, and Experiment 3 tested participants' ability to “recover” their previous recollection when the prior-recall context was restored. Results indicated that participants usually believed they had not previously been cued for the items they failed to remember previously recalling; they were often confident in their incorrect judgements of prior non-remembering; and re-introducing the context of prior remembering sometimes enabled them to recapture their memories of previous recall.     

Remembrance of remembrance past

Arnold and Lindsay (2002) found that individuals more often failed to remember they had previously recalled an item if that item had been cued in a qualitatively different way on two recall occasions: the "forgot-it-all-along" (FIA) effect. Experiment 1 was designed to determine if the FIA effect arises because participants incorrectly believe they have not been previously tested for an item, or because they incorrectly believe they have failed to recall the item when previously tested. Experiment 2 measured participants' confidence in their incorrect prior-recall judgements, and Experiment 3 tested participants' ability to "recover" their previous recollection when the prior-recall context was restored. Results indicated that participants usually believed they had not previously been cued for the items they failed to remember previously recalling; they were often confident in their incorrect judgements of prior non-remembering; and re-introducing the context of prior remembering sometimes enabled them to recapture their memories of previous recall.     

Change blindness and priming: When it does and does not occur

In a series of three experiments, we explored the nature of implicit representations in change blindness (CB). Using 3 x 3 letter arrays, we asked subjects (Ss) to locate changes in paired arrays separated by 80 ms ISIs, in which one, two or three letters of a row in the second array changed. In one testing version, a tone followed the second array, signaling a row for partial report (PR). In the other version, no PR was required. After Ss reported whether a change had been detected and the PR had been completed (if required), they were asked to identify a degraded letter trigram that was either novel, or from a previously shown row (repetition priming). Our findings indicate that when CB occurs, both the pre-change and post-change stimulus information primes despite its unavailability to consciousness. Surprisingly, findings also indicate that when change detection occurs only the post-change information primes.     

Rumination and overgeneral autobiographical memory

Two studies investigated the effects of rumination on the retrieval of autobiographical memories in high-depressed and low-depressed individuals. Experiment 1 administered either a rumination or distraction task prior to a cued autobiographical memory task. High-depressed participants recalled more overgeneral memories following rumination relative to distraction, whereas experimental inductions did not influence low-depressed participants. Experiment 2 administered either a positive or negative rumination task prior to a cued autobiographical memory task. Negatively valenced rumination led high-depressed participants to recall more overgeneral memories than positively valenced rumination; this effect was not observed in low-depressed participants. These findings accord with the proposal that rumination is a mediating mechanism in the retrieval of overgeneral memories, and extends this proposal by indicating that negatively valenced ruminative content is particularly instrumental in inducing overgeneral retrieval.     

动态范式中基于客体的返回抑制 ——是客体抑制还是空间抑制的动态更新？

对动态范式中基于客体的返回抑制进行了考察。实验1在双侧客体改变和不改变条件下考察了返回抑制效应,结果表明,在双侧客体改变条件下返回抑制仍然存在。实验2采用单侧客体变化技术对动态范式中基于客体的返回抑制进行了测量,结果发现,在有效线索化条件下,单侧客体改变和不改变条件下对靶子的反应时没有显著差异（p > 0.90）。这些结果表明动态范式中基于客体的返回抑制的机制是空间抑制的动态更新,而不是客体表征受到抑制     

Voluntary Remembering: Elucidating the Mental Strategies Used to Recall the Past

This study investigated the possibility that people use multiple different types of voluntary retrieval strategies when they are attempting to recall past episodes. In two experiments, we used a retrieve out loud procedure where participants were required to verbalize their thoughts while attempting to retrieve personal memories in response to phrase cues. In Experiment 1, we hypothesized that three main types of voluntary retrieval strategies would be evident during the retrieve out loud procedure, repeating, temporal, and generative/hierarchical retrieval. The results confirmed our hypothesis, showing that the three strategies were used equally. In Experiment 2, we examined the retrieval speed and success rates of the three strategies. The results showed that the repeating strategy was statistically faster than the other two strategies, while also showing that the temporal strategy had the least success in generating memories.Copyright © 2017 John Wiley & Sons, Ltd.