Associative and repetition priming with the repeated masked prime technique: no priming found.

Wentura and Frings (2005) reported evidence of subliminal categorical priming on a lexical decision task, using a new method of visual masking in which the prime string consisted of the prime word flanked by random consonants and random letter masks alternated with the prime string on successive refresh cycles. We investigated associative and repetition priming on lexical decision, using the same method of visual masking. Three experiments failed to show any evidence of associative priming, (1) when the prime string was fixed at 10 characters (three to six flanking letters) and (2) when the number of flanking letters were reduced or absent. In all cases, prime detection was at chance level. Strong associative priming was observed with visible unmasked primes, but the addition of flanking letters restricted priming even though prime detection was still high. With repetition priming, no priming effects were found with the repeated masked technique, and prime detection was poor but just above chance levels. We conclude that with repeated masked primes, there is effective visual masking but that associative priming and repetition priming do not occur with experiment-unique prime-target pairs. Explanations for this apparent discrepancy across priming paradigms are discussed. The priming stimuli and prime-target pairs used in this study may be downloaded as supplemental materials from mc.psychonomic-journals.org/content/supplemental.

Using temporal order to identify spatial reference frames.

A new method for identifying spatial reference frames is described and applied to the study of spatial span. In this method, a spatial sequence is displayed in relation to two reference frames that move relative to each other, so that different temporal orders are described in each reference frame. As applied to spatial span, a sequence of dots was displayed on a rectangular template that moved relative to the computer screen and the observer. Three experiments showed that the choice of reference frame is influenced by prior conditions, the size of the template, and the presence of an alternative stationary reference frame. Recall was impaired (1) when the template moved, suggesting that movement interference occurred, and (2) with increasing template size, but only if the template was used as the reference frame.

Developmental changes in information central to artifact representation: evidence from 'functional fluency' tasks.

Research suggests that while information about design is a central feature of older children's artifact representations it may be less important in the artifact representations of younger children. Three experiments explore the pattern of responses that 5- and 7-year-old children generate when asked to produce multiple uses for familiar (Experiments 1, 2) and novel (Experiment 3) named objects. Results showed that while older children tended to produce responses based on the known design function of the object, younger children's responses were more flexible, though still constrained by the mechanical structure of the object. Only when ignorant of a novel object's design function did older children produce more varied functions than did younger children. These results suggest that representations supporting object function undergo change across this period of development, with information about design assuming more importance later than it does earlier.

Spatial span under translation: a study of reference frames.

The nature of the reference frame used to remember location sequences in a computer-presented version of spatial span was investigated by moving the template (a rectangular frame enclosing nine target squares) across the screen during presentation and/or during recall. Movement of the display during presentation substantially impaired memory in comparison with a stationary display (Experiment 1). However, there was no effect of template movement during recall (Experiment 2). In Experiments 3 and 4, the template was moved through the same screen locations during presentation and recall. When the extrinsic, or screen location, of each position was repeated identically on each trial but the sequence on the template varied, learning was not facilitated (Experiment 3). When the template sequences were repeated across trials but extrinsic location varied, the sequences were rapidly learned (Experiment 4). In this version of spatial span, location sequences appear to be encoded in an intrinsic frame of reference that is based on the template. Movement of the template during encoding impairs this process, possibly because concurrent attention shifts prevent the encoding of locations. The results are discussed with respect to recent studies of positional encoding in which multiple reference frames were available.

Reversing the picture superiority effect: a speed-accuracy trade-off study of recognition memory.

Speed-accuracy trade-off methods have been used to contrast single- and dual-process accounts of recognition memory. With these procedures, subjects are presented with individual test items and required to make recognition decisions under various time constraints. In three experiments, we presented words and pictures to be intentionally learned; test stimuli were always visually presented words. At test, we manipulated the interval between the presentation of each test stimulus and that of a response signal, thus controlling the amount of time available to retrieve target information. The standard picture superiority effect was significant in long response deadline conditions (i.e., > or = 2,000 msec). Conversely, a significant reverse picture superiority effect emerged at short response-signal deadlines (< 200 msec). The results are congruent with views suggesting that both fast familiarity and slower recollection processes contribute to recognition memory. Alternative accounts are also discussed.

Serial position curves in short-term memory: functional equivalence across modalities.

Four experiments investigated item and order memory for sequences of seen unfamiliar faces and heard nonwords. Experiments 1 and 3 found bowed serial position curves using the serial reconstruction test of order with faces and nonwords, respectively. Experiments 2 and 4 found limited recency, no primacy, and above chance performance on all items using a two-alternative forced choice (2AFC) test of item recognition, again with faces and nonwords. These results suggest that the different serial position curves typically found using traditional paradigms for exploring visual and verbal short-term memory are due to differences in the methods used rather than modality-specific mechanisms.

One process is not enough! A speed-accuracy tradeoff study of recognition memory.

Speed-accuracy tradeoff (SAT) methods have been used to contrast single- and dual-process accounts of recognition memory. In these procedures, subjects are presented with individual test items and are required to make recognition decisions under various time constraints. In this experiment, we presented word lists under incidental learning conditions, varying the modality of presentation and level of processing. At test, we manipulated the interval between each visually presented test item and a response signal, thus controlling the amount of time available to retrieve target information. Study-test modality match had a beneficial effect on recognition accuracy at short response-signal delays (< or =300 msec). Conversely, recognition accuracy benefited more from deep than from shallow processing at study only at relatively long response-signal delays (> or =300 msec). The results are congruent with views suggesting that both fast familiarity and slower recollection processes contribute to recognition memory.

Item and order memory for novel visual patterns assessed by two-choice recognition.

Five experiments examined item and order memory for short lists of novel visual patterns. Memory was tested either by an item recognition test, choosing between a target and a similar foil (Experiments 1, 3a, and 4), or by a relative recency decision between two patterns that occupied adjacent list positions (Experiments 2, 3b, and 5). For both item recognition and relative recency tasks, accuracy was in most cases constant across serial positions, except for a recency advantage that was usually restricted to the most recent item or recency decision. Only a small and marginally significant effect of list length was observed for item recognition. Relative recency was more sensitive to list length and fell to near-chance levels with lists of eight items. We conclude that for these materials, prerecency item recognition depends on stable, context-free descriptions of items. Relative recency judgements are sensitive to list properties, but fail to show evidence of primacy or extended recency that are observed when other techniques are used to study serial order memory. We discuss the results in relation to four current models of serial order memory that embody different assumptions in the way that serial order is represented.

Executive function assessed by memory updating and random generation in schizotypal individuals.

Individuals scoring high (N=32) and low (N=27) on the unusual experiences (UnEx) scale of the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) were selected from a large sample (N=265) of normal volunteer undergraduates. The high- and low-UnEx groups were compared on two tasks, random generation and memory updating, which target executive functions that inhibit prepotent responses and update current information. The groups differed only on the R measure of random generation that assesses inequality in the relative frequencies of response alternatives, a result attributed to superstitious behaviour rather than to executive deficit. The results suggest that the executive impairments previously observed in high schizotypal individuals using the Wisconsin Card Sorting Test and other measures are selective rather than global.

Toward a unified account of spacing effects in explicit cued-memory tasks.

Memory for repeated items improves when presentations are spaced during study. This effect is found in memory tasks using different types of material, paradigms, and participant populations. Although several explanations have been proposed, none explains the presence of spacing effects in cued-memory tasks for unfamiliar stimuli. Two experiments assessed the spacing effect on a yes-no recognition-memory task using nonwords and words as targets. The main results showed that changing the font between repeated occurrences of targets at study removed the spacing effect for nonwords only. A 3rd experiment using lexical decision showed that the font manipulation reduced repetition priming of nonwords when items were repeated at Lag 0. These results suggest that short-term perceptual priming supports spacing effects in cued-memory tasks for unfamiliar stimuli.

Spacing effects in cued-memory tasks for unfamiliar faces and nonwords.

Memory for repeated items improves as the interval between repetitions in a list increases (the spacing effect). This study investigated the spacing effect in recognition memory and in a frequency judgment task for unfamiliar target faces that were repeated in the same or in a different pose during incidental learning. Changing the pose between prime and probe trials reduced perceptual repetition priming in a structural discrimination task and also reduced the spacing effect in a subsequent unexpected recognition memory task. Three further experiments confirmed that the spacing effect inrecognition memory (Experiments 2 and 4) or frequency judgment (Experiment 3) was reduced when the pose was changed between repeated presentations at study. Similarly, with nonwords as targets (Experiment 5), changing the font between repeated occurrences of targets at study removed the spacing effect in a subsequent unexpected recognition memory test. These results are interpreted to support the view that short-term perceptual repetition priming underlies the spacing effect in explicit cued-memory tasks for unfamiliar nonsense material.

The word-length effect and disyllabic words.

Three experiments compared immediate serial recall of disyllabic words that differed on spoken duration. Two sets of long- and short-duration words were selected, in each case maximizing duration differences but matching for frequency, familiarity, phonological similarity, and number of phonemes, and controlling for semantic associations. Serial recall measures were obtained using auditory and visual presentation and spoken and picture-pointing recall. In Experiments 1a and 1b, using the first set of items, long words were better recalled than short words. In Experiments 2a and 2b, using the second set of items, no difference was found between long and short disyllabic words. Experiment 3 confirmed the large advantage for short-duration words in the word set originally selected by Baddeley, Thomson, and Buchanan (1975). These findings suggest that there is no reliable advantage for short-duration disyllables in span tasks, and that previous accounts of a word-length effect in disyllables are based on accidental differences between list items. The failure to find an effect of word duration casts doubt on theories that propose that the capacity of memory span is determined by the duration of list items or the decay rate of phonological information in short-term memory.

Response bias in visual serial order memory.

The recency-to-primacy shift represents a major challenge for all theories that attempt to explain the effects of serial order on memory. At short retention intervals, strong recency and no primacy effects occur, but as the retention interval increases, recency is attenuated and primacy increases. In 2 experiments, 24 participants were presented with sets of 4 unfamiliar faces and were asked to state the serial position of a probe face after 0 or 10 s. The predicted recency-to-primacy shift was obtained with accuracy responses. However, the distribution of responses also showed that there was a change in response bias with retention interval. When this was corrected for, the recency-to-primacy shift was eliminated. Response bias is suggested as the underlying cause of the recency-to-primacy shift in this task.

Serial report and item recognition of novel visual patterns.

Previous studies of memory for novel visual patterns have reported how item recognition varies across serial positions, but have neglected serial order memory. In Expts 1 and 2 participants reported the order in which short series of novel patterns had been presented. The results showed markedly bowed serial position curves similar to those reported for sequences of verbal items or spatial locations. Concurrent articulation reduced performance in the serial report task relative to the memory task alone (Expt 2) or concurrent tapping (Expt 3) suggesting that a verbal component was involved. When two-alternative forced choice tests were used to test memory for the configuration of each pattern in the series, no primacy or recency was found (Expt 4). In Expt 5 the presentation of a series of five items was followed at random by either a serial report or the two-choice item recognition task. The serial position curves for the two tasks remained different, suggesting that encoding strategies were not responsible. The results show that bowed serial position curves are found when judgments of serial order are required, even when phonological coding is discouraged, whereas memory for item descriptions is independent of serial position. The implications for current conceptualizations of short-term memory are discussed.

The role of assembled phonology in reading comprehension.

The contribution of assembled phonology to phonological effects in reading comprehension was assessed. In Experiment 1, subjects judged the acceptability of sentences with regular, exception, and nonword homophone substitutions and orthographic controls. Significantly more errors occurred to sentences with regular-word homophones than to exception words, and error rates for nonword homophones were low and not significant. Experiment 2 showed that this was not due to differences in the sentence frames. In Experiment 3, the subjects judged as unacceptable those sentences containing an exception word that sounded correct when read according to spelling-to-sound rules. Significantly higher error rates occurred only for low-frequency exception words. Experiment 4 showed that task conditions affect semantic-categorization error rates for nonword homophones. These results indicate that both assembled and addressed phonology contribute to sentence and word comprehension, but the low error rate for nonwords suggests that an early lexical check may be applied.

Visualization and memorization as a function of display time and poststimulus processing time.

Three experiments investigated the relationship of short- and long-term components of visual memory to the processing time at presentation. The components were isolated by measuring the recognition of novel visual patterns after a short, unfilled retention interval (STVM) or after interference (LTVM). Experiment 1 showed a dissociation of STVM and LTVM when display time of the target was varied. STVM increased rapily as the display time increased from 60 msec to 200 msec, a result confirmed in Experiment 2 for patterns at two levels of complexity. LTVM increased slowly and irratically as display time increased from 60 msec to 2.6 sec. No increase in LTVM was seen when poststimulus processing time was extended from 400 msec to 2.7 sec. The results post severe problems for single trace theories of visual memory and for serial models that claim that all information in LTVM Is derived from STVM. The distinction between maintenance and elaboration is used to explain the occurrence of visualization without memorization.