Menstrual cycle effects on perceptual closure mediate changes in performance on a fragmented objects test of implicit memory

Healthy premenopausal women with regular menstrual cycles were assessed on a fragmented objects test of implicit memory. Testing took place at either the low estrogen (n=17) or the high estrogen (n=16) stages of the menstrual cycle. Concentrations of ovarian hormones were confirmed by saliva assays. Both groups of women exhibited a priming effect, in that primed objects were identified faster and at greater fragmentation than unprimed objects. There was no evidence that high estrogen inhibits perceptual object priming. However, women at the menstrual phase were able to identify both primed and unprimed objects at a more degraded level of fragmentation. Changes in perceptual closure over the menstrual cycle may be the basis for the changes in performance on the fragmented objects test observed in previous studies.     

Perceptual priming is not a necessary consequence of semantic classification of pictures

Four experiments investigated how repetition priming of object recognition is affected by the task performed in the prime and test phases. In Experiment 1 object recognition was tested using both vocal naming and two different semantic decision tasks (whether or not objects were manufactured, and whether or not they would be found inside the house). Some aspects of the data were inconsistent with contemporary models of object recognition. Specifically, object priming was eliminated with some combinations of prime and test tasks, and there was no evidence of perceptual (as opposed to conceptual or response) priming in either semantic classification task, even though perceptual identification of the objects is required for at least one of these tasks. Experiment 2 showed that even when perceptual demands were increased by brief presentation, the inside task showed no perceptual priming. Experiment 3 showed that the inside task did not appear to be based on conceptual priming either, as it was not primed significantly when the prime decisions were made to object labels. Experiment 4 showed that visual sensitivity could be restored to the inside task following practice on the task, supporting the suggestion that a critical factor is whether the semantic category is preformed or must be computed. The results show that the visual representational processes revealed by object priming depend crucially on the task chosen.     

Implicit and explicit memory bias for threat in post-traumatic stress disorder.

We investigated explicit (cued recall) and implicit (word completion) memory in Vietnam combat veterans with (n = 24) and without (n = 24) post-traumatic stress disorder (PTSD). Half of the subjects in each group encoded combat, social threat, positive, and neutral words elaboratively, whereas the others encoded these words nonelaboratively. On the cued recall test, under both encoding conditions, both groups recalled more combat words than other words. However, difference scores obtained by subtracting the mean recall for neutral words from the mean recall scores for the other words revealed that PTSD patients exhibited a relative explicit memory bias for combat words. That is, PTSD patients tended to exhibit poor memory for everything but combat words. On the word completion test, only PTSD subjects exhibited an implicit memory bias for combat words. This bias was greater for primed than for unprimed words, thereby ruling out a response bias. Such memory bias may underlie the 'reexperiencing' symptoms characteristic of PTSD (e.g. intrusive thoughts, nightmares).     

Repetition priming and the haptic recognition of familiar and unfamiliar objects

In four experiments, we examined the haptic recognition of 3-D objects. In Experiment 1, blindfolded participants named everyday objects presented haptically in two blocks. There was significant priming of naming, but no cost of an object changing orientation between blocks. However, typical orientations of objects were recognized more quickly than nonstandard orientations. In Experiment 2, participants accurately performed an unannounced test of memory for orientation. The lack of orientation-specific priming in Experiment 1, therefore, was not because participants could not remember the orientation at which they had first felt an object. In Experiment 3, we examined haptic naming of objects that were primed either haptically or visually. Haptic priming was greater than visual priming, although significant cross-modal priming was also observed. In Experiment 4, we tested recognition memory for familiar and unfamiliar objects using an old-new recognition task. Objects were recognized best when they were presented in the same orientation in both blocks, suggesting that haptic object recognition is orientation sensitive. Photographs of the unfamiliar objects may be downloaded from www.psychonomic.org/archive.     

Effects of verbal and nonverbal interference on spatial and object visual working memory

We tested the hypothesis that a verbal coding mechanism is necessarily engaged by object, but not spatial, visual working memory tasks. We employed a dual-task procedure that paired n-back working memory tasks with domain-specific distractor trials inserted into each interstimulus interval of the n-back tasks. In two experiments, object n-back performance demonstrated greater sensitivity to verbal distraction, whereas spatial n-back performance demonstrated greater sensitivity to motion distraction. Visual object and spatial working memory may differ fundamentally in that the mnemonic representation of featural characteristics of objects incorporates a verbal (perhaps semantic) code, whereas the mnemonic representation of the location of objects does not. Thus, the processes supporting working memory for these two types of information may differ in more ways than those dictated by the "what/where" organization of the visual system, a fact more easily reconciled with a component process than a memory systems account of working memory function.     

基于客体工作记忆内容的保持对时间判断的影响

本研究通过操作工作记忆内容的有效性,探讨了记忆内容的保持对时间判断的影响。采用不规则的客体作为实验材料,使时间任务中的刺激与工作记忆内容匹配或不匹配。实验1采用工作记忆和时间判断的双任务范式,要求被试首先记忆一个客体,然后在每个试次的最后判断测试刺激是否与记忆项相同。在延迟阶段,被试判断连续出现的两个刺激的时距哪个更长（或更短）。实验2中,要求被试忽略第一个刺激,仅完成时间判断任务。结果发现,相比单任务的计时,双任务条件下,工作记忆内容的保持延长了时间判断的时间。而且,在记忆匹配和知觉匹配条件下,匹配刺激呈现的时间越长,正确率越低,反应时越长。这说明记忆内容的保持增加了决策的难度,工作记忆内容对时间判断的可能是由记忆内容引起的注意定向造成的。     

Priming and semantic memory loss in Alzheimer's disease

Semantic memory (SM) was investigated in six patients with probable Alzheimer's disease (AD) by on-line measurement of semantic priming in a lexical decision task, and off-line tests of comprehension. Detailed assessment was carried out on naming, name comprehension, and probes of semantic knowledge with a battery of 150 items. The patients performed normally on perceptual tests and displayed an item-specific loss of knowledge on the semantic tests. In a primed lexical decision task, greater semantic priming was found relative to age-matched normals. The priming was substantially greater for items with "degraded" representations as determined by the off-line tests. Lexical decision was also performed more slowly on these items. These unexpected results demand a reevaluation of the concepts of the lexicon and semantic memory structure and their possible alteration in dementia.     

Priorities for representation: Task settings and object interaction both influence object memory

Following an active task, the memory representations for used and unused objects are different. However, it is not clear whether these differences arise due to prioritizing objects that are task-relevant, objects that are physically interacted with, or a combination of the two factors. The present study allowed us to tease apart the relative importance of task-relevance and physical manipulation on object memory. A paradigm was designed in which objects were either necessary to complete a task (target), moved out of the way (obstructing, but interacted with), or simply present in the environment (background). Participants’ eye movements were recorded with a portable tracker during the task, and they received a memory test on the objects after the task was completed. Results showed that manipulating an object is sufficient to change how information is extracted and retained from fixations, compared to background objects. Task-relevance provides an additional influence: information is accumulated and retained differently for manipulated target objects than manipulated obstructing objects. These findings demonstrate that object memory is influenced both by whether we physically interact with an object, and the relevance of that object to our behavioral goals.     

Differential age-related effects on conjunctive and relational visual short-term memory binding

An age-related associative deficit has been described in visual short-term binding memory tasks. However, separate studies have suggested that ageing disrupts relational binding (to associate distinct items or item and context) more than conjunctive binding (to integrate features within an object). The current study directly compared relational and conjunctive binding with a short-term memory task for object–colour associations in 30 young and 30 older adults. Participants studied a number of object–colour associations corresponding to their individual object span level in a relational task in which objects were associated to colour patches and a conjunctive task where colour was integrated into the object. Memory for individual items and for associations was tested with a recognition memory test. Evidence for an age-related associative deficit was observed in the relational binding task, but not in the conjunctive binding task. This differential impact of ageing on relational and conjunctive short-term binding is discussed by reference to two underlying age-related cognitive difficulties: diminished hippocampally dependent binding and attentional resources.     

Hunts,Heinz, and Fries Priming ‘Ketchup’: The Effects of Lexicality on Brand Name–Product Associations and Brand Memory

Brand names should be memorable and easy to associate with the product. The present study investigated how brand name lexicality affects accessibility in memory. In Experiment 1, participants completed a primed lexical decision task (LDT) in which primes were real‐word brands (RWB; e.g., SATURN), nonword brands (NWB; e.g., KIA), or semantic associates (e.g., TIRE) and targets were product categories (e.g., car). NWB primes resulted in equivalent priming as semantic primes and were recalled more than RWBs in a free‐recall task. In Experiment 2, participants completed an unprimed LDT or brand decision task (BDT). In LDT, high NWB error rates reflected greater familiarity. In BDT, many RWBs were not recognized as brands. In Experiment 3, a primed BDT with brand names as targets indicated that NWBs and RWBs are equally primed by a related category label. Overall, NWBs appear to be more familiar and memorable, possibly because of distinctiveness. Copyright © 2015 John Wiley & Sons, Ltd.     

Independent effects of colour on object identification and memory

We examined the effects of colour on object identification and memory using a study-test priming procedure with a coloured-object decision task at test (i.e., deciding whether an object is correctly coloured). Objects were selected to have a single associated colour and were either correctly or incorrectly coloured. In addition, object shape and colour were either spatially integrated (i.e., colour fell on the object surface) or spatially separated (i.e., colour formed the background to the object). Transforming the colour of an object from study to test (e.g., from a yellow banana to a purple banana) reduced priming of response times, as compared to when the object was untransformed. This utilization of colour information in object memory was not contingent upon colour falling on the object surface or whether the resulting configuration was of a correctly or incorrectly coloured object. In addition, we observed independent effects of colour on response times, whereby coloured-object decisions were more efficient for correctly than for incorrectly coloured objects but only when colour fell on the object surface. These findings provide evidence for two distinct mechanisms of shape-colour binding in object processing.     

Independent effects of colour on object identification and memory

We examined the effects of colour on object identification and memory using a study–test priming procedure with a coloured-object decision task at test (i.e., deciding whether an object is correctly coloured). Objects were selected to have a single associated colour and were either correctly or incorrectly coloured. In addition, object shape and colour were either spatially integrated (i.e., colour fell on the object surface) or spatially separated (i.e., colour formed the background to the object). Transforming the colour of an object from study to test (e.g., from a yellow banana to a purple banana) reduced priming of response times, as compared to when the object was untransformed. This utilization of colour information in object memory was not contingent upon colour falling on the object surface or whether the resulting configuration was of a correctly or incorrectly coloured object. In addition, we observed independent effects of colour on response times, whereby coloured-object decisions were more efficient for correctly than for incorrectly coloured objects but only when colour fell on the object surface. These findings provide evidence for two distinct mechanisms of shape–colour binding in object processing.     

Intuition in the context of object perception: intuitive gestalt judgments rest on the unconscious activation of semantic representations

Intuition denotes the ability to judge stimulus properties on the basis of information that is activated in memory, but not consciously retrieved. In three experiments we show that participants discriminated better than chance fragmented line drawings depicting meaningful objects (coherent fragments) from fragments consisting of randomly displaced line segments (incoherent fragments) or from fragments which were rotated by 180 degrees (inverted fragments), even if participants did not consciously recognize the objects. Unrecognized coherent, but not incoherent or inverted fragments produced reliable priming of correct object names in a lexical decision task, indicating that coherent fragments activated an unconscious semantic object representation. Priming effects were larger for coherent fragments judged as coherent compared to coherent fragments judged as incoherent. We conclude that intuitive gestalt judgments for coherent fragments rested on the activation of semantic object representations, which biased participants' intuitive impression of "gestalt-ness" even when the underlying object representations remained unconscious.     

Mechanisms of facilitation in primed perceptual identification

We investigated the mechanism that produces priming in perceptual identification. In Experiment 1, subjects studied a series of compound words (e.g.,outdoor,sideline); in Experiment 2, subjects studied a series of pictures (photographs) of objects. All subjects later received perceptual identification tests in which old (primed) and new (unprimed) words (Experiment 1) or pictures (Experiment 2) were presented for varying durations and masked. In both experiments, performance for primed and unprimed stimuli was predicted essentially perfectly by a model that assumes that prior exposure to a stimulus results in increased visual information-acquisition rate when it is subsequently encountered. An ancillary purpose of Experiment 1 was to test whether or not priming occurs for recombined words (e.g.,outline); there was no evidence for such priming at any exposure duration.     

Priming voluntary autobiographical memories: Implications for the organisation of autobiographical memory and voluntary recall processes

The goal of this study was to show that voluntary autobiographical memories could be primed by the prior activation of autobiographical memories. Three experiments demonstrated voluntary memory priming with three different approaches. In Experiment 1 primed participants were asked to recall memories from their elementary school years. In a subsequent memory task primed participants were asked to recall memories from any time period, and they produced significantly more memories from their elementary school years than unprimed participants. In Experiment 2 primed participants were asked to recall what they were doing when they had heard various news events occurring between 1998 and 2005. Subsequently these participants produced significantly more memories from this time period than unprimed participants. In Experiment 3 primed participants were asked to recall memories from their teenage years. Subsequently these participants were able to recall more memories from ages 13–15 than unprimed participants, where both had only 1 second to produce a memory. We argue that the results support the notion that episodic memories can activate one another and that some of them are organised according to lifetime periods. We further argue that the results have implications for the reminiscence bump and voluntary recall of the past.