Examining the lag effect under incidental encoding: Contributions of semantic priming and reminding

Memory is better when repeated learning events are spaced than when they are massed (spacing effect), as well as when material is processed semantically than when it is processed graphemically (levels-of-processing effect). Examination of the relationship between levels of processing and spacing for both deeply and shallowly encoded items has shown a spacing effect for items processed deeply, but not shallowly. A semantic priming account of spacing was proposed to explain the interaction between levels of processing and spacing on memory. The current study manipulated levels of processing and the amount of spacing (lag) that occurred between repetitions of items that were incidentally encoded. Results from Experiments 1A and 1B revealed lag effects in test performance when items were deeply and shallowly encoded. Although these findings are inconsistent with a semantic priming account, they can be interpreted within a reminding account, which is explored in Experiment 2. Results from the second experiment indicate that bringing reminding under conscious control benefited items that were presented at a long lag but not at a shorter lag. Together, this study provides evidence that is difficult to accommodate with a semantic priming account of spacing and instead provides additional support for a reminding account suggesting that automatic and controlled processes may both underlie the reminding process.     

Current versus past ambiguity in intertrial priming

Visual search is speeded when the target is repeated from trial to trial compared to when it changes, suggesting that selective attention learns from previous events. Such intertrial effects are stronger when there is more competition for selection, for example in ambiguous displays where the target is accompanied by a salient distractor. Here we investigate whether this is because the competition strengthens the learning itself, or because it allows for a learned representation to exert a greater effect. The results point to the latter. Observers looked for a colour-defined target that could repeat or change from trial to trial. A salient distractor could be present on the current trial, the previous trial, both, or neither. Intertrial effects were greater when a distractor was present on the current trial, suggesting that a primed target representation is more beneficial under conditions of competition. In contrast, distractor presence on the previous trial had no effects whatsoever, indicating that the learning process itself is not affected by competition. This suggests that the source of the learning resides at postselection stages, whereas the effects may occur at the perceptual level.     

Recognition advantage of happy faces in extrafoveal vision: Featural and affective processing

Happy, surprised, disgusted, angry, sad, fearful, and neutral facial expressions were presented extrafoveally (2.5° away from fixation) for 150 ms, followed by a probe word for recognition (Experiment 1) or a probe scene for affective valence evaluation (Experiment 2). Eye movements were recorded and gaze-contingent masking prevented foveal viewing of the faces. Results showed that (a) happy expressions were recognized faster than others in the absence of fixations on the faces, (b) the same pattern emerged when the faces were presented upright or upside-down, (c) happy prime faces facilitated the affective evaluation of emotionally congruent probe scenes, and (d) such priming effects occurred at 750 but not at 250 ms prime–probe stimulus–onset asynchrony. This reveals an advantage in the recognition of happy faces outside of overt visual attention, and suggests that this recognition advantage relies initially on featural processing and involves processing of positive affect at a later stage.     

Eye movement indices of memory reveal re-processing of visual information: Evidence from Chinese characters

ABSTRACT

This study examined the nature of the memory effect revealed in eye movements. Chinese characters were processed visually, phonologically or semantically during the study phase. The proportion of viewing time during the subsequent recognition test was compared between characters associated with different types of encoding. To eliminate the influence of response selection on eye movements, participants were asked to select the unstudied character and make the selection after the viewing period ended. Results showed that the proportion of viewing time in the recognition test was larger for visually encoded characters than it was for semantically (Experiment 1) and phonologically encoded (Experiment 3) characters, even after the participants had presumably made the decision. Moreover, there was no significant difference in the proportion of viewing time between phonologically and semantically encoded characters (Experiment 2). These findings suggest that the viewing time change in eye movements during the recognition test is an obligatory consequence of re-processing the visual information encoded during the study phase.     

Greater priming for previously distracting information in young than older adults when suppression is ruled out

The use of previously distracting information on memory tests with indirect instructions is usually age-equivalent, while young adults typically show greater explicit memory for such information. This could reflect qualitatively distinct initial processing (encoding) of distracting information by younger and older adults, but could also be caused by greater suppression of such information by younger adults on tasks with indirect instructions. In Experiment 1, young and older adults read stories containing distracting words, which they ignored, before studying a list of words containing previously distracting items for a free recall task. Half the participants were informed of the presence of previously distracting items in the study list prior to recall (direct instruction), and half were not (indirect instruction). Recall of previously distracting words was age-equivalent in the indirect condition, but young adults recalled more distracting words in the direct condition. In Experiment 2, participants performed the continuous identification with recognition task, which captures a measure of perceptual priming and recognition on each trial, and is immune to suppression. Priming and recognition of previously distracting words was greater in younger than older adults, suggesting that the young engage in more successful suppression of previously distracting information on tasks in which its relevance is not overtly signaled.     

Repetition priming within and between languages in semantic classification of concrete and abstract words

Although concrete nouns are generally agreed to have shared core conceptual representations across languages in bilinguals, it has been proposed that abstract nouns have separate representations or share fewer semantic components. Conceptual repetition priming methodology was used to evaluate whether translation equivalents of abstract nouns have shared conceptual representations and compare the degree of conceptual overlap for concrete and abstract nouns. Here 72 Spanish–English bilinguals made concrete–abstract decisions on English and Spanish nouns. Both concrete and abstract nouns elicited substantial between-language priming and these effects were of equivalent size, indicating that translation equivalents of both concrete and abstract nouns have shared conceptual representations and that abstract words do not share fewer components. The between-language priming effects and their attenuation relative to within-language priming indicate that the within-language effect is based on facilitation of both word comprehension and semantic decision processes.     

Category priming with aliens: Analysing the influence of targets' prototypicality on the centre surround inhibition mechanism

Marginally perceptible prototypes as primes lead to slowed reactions to related category exemplars as compared to unrelated ones. This at first glance counterintuitive finding has been interpreted as evidence for a particular mechanism of lateral inhibition, namely the centre surround inhibition mechanism. We investigated the semantic surround of category labels by experimentally manipulating the prototypicality of stimuli. Participants first learned two new categories of fantasy creatures in a 5-day-long learning phase before they worked through a semantic priming task with the category prototypes as primes and category exemplars as targets. For high-prototypical targets we observed benefit effects from related primes, whereas for low-prototypical targets we observed cost effects. The results define when the centre surround inhibition mechanism is applied, and furthermore might explain why previous studies with word stimuli (i.e., material that prevents experimental manipulation of prototypicality) observed mixed results concerning the prototypicality of targets.     

Dissociating word stem completion and cued recall as a function of divided attention at retrieval

The aim of this study was to investigate the widely held, but largely untested, view that implicit memory (repetition priming) reflects an automatic form of retrieval. Specifically, in Experiment 1 we explored whether a secondary task (syllable monitoring), performed during retrieval, would disrupt performance on explicit (cued recall) and implicit (stem completion) memory tasks equally. Surprisingly, despite substantial memory and secondary costs to cued recall when performed with a syllable-monitoring task, the same manipulation had no effect on stem completion priming or on secondary task performance. In Experiment 2 we demonstrated that even when using a particularly demanding version of the stem completion task that incurred secondary task costs, the corresponding disruption to implicit memory performance was minimal. Collectively, the results are consistent with the view that implicit memory retrieval requires little or no processing capacity and is not seemingly susceptible to the effects of dividing attention at retrieval.     

An examination of differential repetition priming effects for natural and man-made objects

It has been theorized that differential cognitive resources may be involved in the processing of information pertaining to natural and man-made categories, commonly referred to as category specificity. The present study used four experiments to assess whether a natural priming advantage exists and, if so, whether color, texture, color diagnosticity, object complexity, and familiarity could account for the categorical difference. To do so, a repetition priming paradigm was used in which masked primes were briefly presented, and targets were categorized as natural or man-made. Across four experiments, a greater degree of priming was observed for natural as opposed to man-made stimuli. Examination of stimulus characteristics that could account for the differences revealed that the natural priming advantage was in part driven by color diagnosticity and familiarity. Results of this study support the notion that different cognitive resources represent and/or are involved in the processing of natural and man-made categories.     

The Relationship Between Cognitive Ability and Positive and Negative Priming in Identity and Spatial Priming Tasks

The authors examined whether stimulus activation and inhibition in the identity priming task are related to the temporal lobe, and whether these processes in the spatial priming task are related to the parietal lobe. Forty participants performed spatial and identity positive and negative priming tasks, the Vandenberg Mental Rotation task, and the Digit Span task. Both men and women showed significant positive and negative priming in the identity and spatial tasks with no gender difference. The magnitude of identity positive priming was predicted by the Digit Span task, and the magnitude of spatial positive priming was predicted by the mental rotation task. Only women showed a correlation between spatial ability and spatial negative priming. The results are partially consistent with the dorsal-ventral model of cognitive inhibition.