Bias effects in word fragment completion in young and older adults

Young and older adults were tested on a word fragment completion task in which correct solutions were studied words, words orthographically similar to studied words, or new words. In Experiments 1 and 2, the standard production version of the word fragment completion task was used; older adults had reduced benefits of prior exposure to target words and slightly decreased costs. However, costs and benefits did not differ across age in a forced-choice version of the task (Experiment 3). At a behavioral level, the results are contrary to predictions that age differences in word fragment completion priming effects will be greater when there is a strong competitor for the correct solution and that age differences in both costs and benefits will be smaller for identification than for production tasks. Theoretical implications of these findings are considered.     

In search of perceptual priming in a semantic classification task

Four experiments tested for perceptual priming for written words in a semantic categorization task. Repetition priming was obtained for low-frequency words when unrelated categorizations were performed at study and test (Experiment 1), but it was not orthographically mediated given that written-to-written and spoken-to-written word priming was equivalent (Experiments 2 and 3). Furthermore, no priming was obtained between pictures and words (Experiment 4), suggesting that the nonorthographic priming was largely phonological rather than semantic. These results pose a challenge to standard perceptual theories of priming that should expect orthographic priming when words are presented in a visual format at study and test.     

Now you see it, now you don't: repetition blindness for nonwords

Repetition blindness (RB) for nonwords has been found in some studies, but not in others. The authors propose that the discrepancy in results is fueled by participant strategy; specifically, when rapid serial visual presentation lists are short and participants are explicitly informed that some trials will contain repetitions, participants are able to use partial orthographic information to correctly guess repetitions on repetition trials while avoiding spurious repetition reports on control trials. The authors first replicated V. Coltheart and R. Langdon's (2003) finding of RB for words but repetition advantage for nonwords (Experiment 1). When all participants were encouraged to utilize partial information in a same/different matching task along with an identification task, a repetition advantage was observed for both words and nonwords (Experiment 2). When guessing of repetitions was made detectable by including non-identical but orthographically similar items in the experiments, the repetition advantage disappeared; instead, RB was found for both words and nonwords (Experiments 3 and 4). Finally, when experiments did not contain any identical items, participants almost never reported repetitions, and reliable RB was found for orthographically similar words and nonwords (Experiments 5 and 6).     

Repetition blindness: out of sight or out of mind?

Does repetition blindness represent a failure of perception or of memory? In Experiment 1, participants viewed rapid serial visual presentation (RSVP) sentences. When critical words (C1 and C2) were orthographically similar, C2 was frequently omitted from serial report; however, repetition priming for C2 on a postsentence lexical decision task was equivalent whether or not C1 was similar to C2. In Experiment 2, participants monitored RSVP sentences for a predetermined target. Participants frequently failed to detect the target when it was preceded by an orthographically similar word. In Experiment 3, the authors investigated the role of the attentional blink in this effect. These experiments suggest that repetition blindness is a failure of conscious perception, consistent with predictions of the token-individuation hypothesis.     

Mechanisms of source confusion and discounting in short-term priming: 1. Effects of prime duration and prime recognition

Huber, Shriffrin, Lyle, and Ruys (2001) measured short-term repetition priming effects in perceptual identification with two-alternative forced-choice testing. There was a preference to choose repeated words following passive viewing of primes and a preference against choosing repeated words following active responding to primes. In this present study, we explored conditions of prime processing that produce this pattern of results. Experiment 1 revealed that increased prime duration under passive viewing instructions produces the active priming pattern. Experiment 2 assessed memory for primes: With poor recognition of primes, there was a strong preference for repeated words; however, with good recognition of primes, this preference was eliminated. These results are modeled by a computational theory of optimal decision making, responding optimally with unknown sources of evidence (ROUSE). In ROUSE, a preference for repeated words results from source confusion between primes and choice words. A reversal in the direction of preference arises from the discounting of words known to have also appeared as primes.     

Priming the Identification of Environmental Sounds

Three experiments were conducted using a repetition priming paradigm: Auditory word or environmental sound stimuli were identified by subjects in a pre-test phase, which was followed by a perceptual identification task using either sounds or words in the test phase. Identification of an environmental sound was facilitated by prior presentation of the same sound, but not by prior presentation of a spoken label (Experiments 1 and 2). Similarly, spoken word identification was facilitated by previous presentation of the same word, but not when the word had been used to label an environmental sound (Experiment 1). A degree of abstraction was demonstrated in Experiment 3, which revealed a facilitation effect between similar sounds produced by the same type of source. These results are discussed in terms of the Transfer Appropriate Processing, activation, and systems approaches.     

Mechanisms of source confusion and discounting in short-term priming 2: effects of prime similarity and target duration

D. E. Huber, R. M. Shiffrin, K. B. Lyle, and K. I. Ruys (2001) tested two-alternative, forced-choice (2-AFC) perceptual identification in a short-term priming task. For repetition priming, passive viewing of primes resulted in a preference to choose repeated words, but actively responding to primes resulted in a preference against choosing repeated words. These results were explained with a computational model, responding optimally with unknown sources of evidence (ROUSE), using the offsetting mechanisms of source confusion and discounting. An analysis of ROUSE revealed conditions under which discounting efficacy should diminish, causing a preference for primed words even with active prime processing. Two new studies confirm 2 such conditions: very short target flash durations and very low similarity between primes and primed choice words. These a priori predictions contrast with the a posteriori data fits of a multinomial model developed by R. Ratcliff and G. McKoon (2001).     

Perception and preference in short-term word priming

Responding optimally with unknown sources of evidence (ROUSE) is a theory of short-term priming applied to associative, orthographic-phonemic, and repetition priming. In our studies, perceptual identification is measured with two-alternative forced-choice testing. ROUSE assumes features activated by primes are confused with those activated by the target. A near-optimal decision discounts evidence arising from such shared features. Too little discounting explains the finding that primed words were preferred after passive viewing of primes. Too much discounting explains the findings of reverse preference after active processing of primes. These preference changes highlight the need to use paradigms (like the present ones) capable of separating preferential and perceptual components of priming. Evidence of enhanced perception was found only with associative priming and was very small in magnitude compared with preference effects.     

Associative priming in perceptual identification: Effects of prime-processing requirements

Three experiments assessed the effects of prime-processing instructions on associative-priming in word identification and episodic memory for primes. In Experiment 1, groups instructed to read the prime silently or generate silently an associate of the prime showed a larger accuracy benefit for related over unrelated targets than did a group that decided whether an asterisk was to the right or left of the prime. The asterisk-search group showed a weaker repetition effect on a subsequent identification test of primes, indicating that the weaker priming in this group was a result of poorer perceptual processing. On a cued-recall test for primes, the generate group was superior to the other groups. In Experiment 2, we found that with weak prime-target associations, priming was comparable for read and generate groups and stronger than estimated for a guessing strategy, on the basis of single predictions made from each prime by an additional group. In Experiment 3, we demonstrated that the read and generate instructions produced similar mispriming and inhibitory effects. The results suggest that the depths of prime-processing manipulations do not have parallel effects on priming and episodic memory, and that associative priming in word identification, as in other tasks, may involve an expectancy process.     

Perceptual and response components in repetition priming of spoken words and pseudowords

Two experiments explored repetition priming effects for spoken words and pseudowords in order to investigate abstractionist and episodic accounts of spoken word recognition and repetition priming. In Experiment 1, lexical decisions were made on spoken words and pseudowords with half of the items presented twice (～12 intervening items). Half of all repetitions were spoken in a “different voice” from the first presentations. Experiment 2 used the same procedure but with stimuli embedded in noise to slow responses. Results showed greater priming for words than for pseudowords and no effect of voice change in both normal and effortful processing conditions. Additional analyses showed that for slower participants, priming is more equivalent for words and pseudowords, suggesting episodic stimulus–response associations that suppress familiarity-based mechanisms that ordinarily enhance word priming. By relating behavioural priming to the time-course of pseudoword identification we showed that under normal listening conditions (Experiment 1) priming reflects facilitation of both perceptual and decision components, whereas in effortful listening conditions (Experiment 2) priming effects primarily reflect enhanced decision/response generation processes. Both stimulus–response associations and enhanced processing of sensory input seem to be voice independent, providing novel evidence concerning the degree of perceptual abstraction in the recognition of spoken words and pseudowords.     

Perceptual representations in false recognition and priming of pictures

Using a new procedure, we investigate whether imagination can induce false memory by creating a perceptual representation. Participants studied pictures and words with and without an imagery task and at test performed both a direct recognition test and an indirect perceptual identification test on pictorial stimuli. Corrected false recognition rates were 7% for pictures studied in word form (Experiment 1), 26% for pictures imagined once (Experiment 2), and 48% for pictures imagined multiple times (Experiment 3), although on the indirect test, no priming was found for these items. Furthermore, a perceptual/conceptual imagery manipulation did not affect the tendency to claim that imagined items had been studied as pictures (Experiment 4). These results suggest that the false memories reported on direct tests are not driven by perceptual representations.     

Do priming effects in perceptual identification and word judgment reflect different underlying mechanisms?

We examined priming of orthographically illegal nonwords in a perceptual identification task and a word judgment task in undergraduate participants. In perceptual identification, priming was significant and equivalent after structural or phonological encoding. In word judgment, priming was significant after phonological encoding but not structural encoding. In a follow-up experiment in older control participants and amnesic participants, priming in word judgment was not significant. Older control participants found the stimuli more difficult to pronounce than did undergraduate participants, and word judgment priming in undergaduate participants was significant only for the stimuli that were judged easy to pronounce. These findings demonstrate that priming in perceptual identification and word judgment extends to novel stimuli that are not linked to preexisting lexical or sublexical representations but that priming occurs at different levels in the two tasks: at a featural or orthographic level in perceptual identification and at a phonological level in word judgment.     

The word frequency effect in recognition memory versus repetition priming

The role of word frequency in recognition memory and repetition priming was investigated by using a manipulation of attention. In Experiment 1, the lexical decision task produced greater repetition priming for low-frequency words than for high-frequency words following either the attended or the unattended study condition. The recognition memory test, on the other hand, showed a low-frequency word advantage only following the attended study condition. Furthermore, this advantage was limited to the measure of recognition memory based on conscious recollection of the study episode. In Experiment 2, a speeded recognition memory test replicated the pattern obtained with the unspeeded recognition memory test in Experiment 1. These results argue against the view that the word frequency effects in recognition memory and repetition priming have the same origin. Instead, the results suggest that the word frequency effect in recognition memory has its locus in conscious recollection.     

Orthographic similarity: The case of “reversed anagrams”

How orthographically similar are words such as paws and swap, flow and wolf, or live and evil? According to the letter position coding schemes used in models of visual word recognition, these reversed anagrams are considered to be less similar than words that share letters in the same absolute or relative positions (such as home and hose or plan and lane). Therefore, reversed anagrams should not produce the standard orthographic similarity effects found using substitution neighbors (e.g., home, hose). Simulations using the spatial coding model (Davis, Psychological Review 117, 713-758, 2010), for example, predict an inhibitory masked-priming effect for substitution neighbor word pairs but a null effect for reversed anagrams. Nevertheless, we obtained significant inhibitory priming using both stimulus types (Experiment 1). We also demonstrated that robust repetition blindness can be obtained for reversed anagrams (Experiment 2). Reversed anagrams therefore provide a new test for models of visual word recognition and orthographic similarity.     

Repetition priming is not purely episodic in origin

The sufficiency of similarity among surface attributes of prime-target pairs to account for the pattern of facilitation obtained in the repetition priming paradigm was evaluated. In Experiment 1, morphological primes were singular, inflected case forms of Serbo-Croatian words and visual similarity of prime and target was manipulated by alternating the two alphabets in which the Serbo-Croatian language is written. Results indicated that the magnitude of facilitation in the alphabetically alternating condition was not reduced relative to the nonalternating condition (RUPI-RUPI vs. RUPI-RUPI) which suggested that visual similarity is not a necessary condition for facilitation in the present task. In Experiment 2, related pairs included (a) base forms with diminutives, a class of highly productive and semantically predictable derivations marked in Serbo-Croatian by suffixes and (b) base words with morphologically unrelated monomorphemic words whose orthographic pattern encompassed the target in initial position and a sequence of letters in final position that elsewhere functions as a diminutive suffix. No facilitation of word targets by orthographically similar but morphologically unrelated primes was observed although there was a tendency toward facilitation among structurally similar pseudowords. Collectively, the experiments suggested that structural similarity of prime and target is not a sufficient condition for facilitation in the repetition priming paradigm.     

Priming on verbal perceptual tests: Roles of lexical,surface, and conceptual processes

According to a lexical-access hypothesis, priming on verbal-completion tests requires previous access to higher-order nodes such as morphemes or words. In two experiments, subjects studied words presented in printed color, either by reading the words or by naming the printed colors. In Experiment 2, some of the words were to be ignored in both study conditions. The words presented in Experiment 2 were either conceptually related or unrelated to each other. And the cues in the test phase for repeated targets were either printed in the studied color or in a different color. In both experiments, the word stems of nouns studied and of new targets were presented with word-completion instructions (implicit test of memory). Consistent with the hypothesis, the amount of priming obtained was greater in the reading than in the color-naming condition. The least amount of priming was observed for targets that were to be ignored at study. In addition, Experiment 2 showed considerable effects of surface similarity (i.e., stronger priming effects with cues whose color was not changed from the study to the test phase) and some effects of conceptual processing, as was indicated by different amounts of priming for unrelated and for related nouns. Because these two effects were observed with both types of study task, it is concluded that perceptual and conceptual processes may make independent contributions to priming effects in verbal perceptual tests. This conclusion modifies and extends the original hypothesis, according to which previous lexical access is required in order to obtain effects of perceptual or conceptual processes on the priming scores.     

联想启动与知觉启动的比较研究

采用快速命名方法探讨不同加工水平对联想启动效应的影响。被试分别在深、浅加工条件下学习一系列颜色词,然后完成颜色命名和再认任务,并设立词命名任务,以比较联想启动和知觉启动的异同。结果表明,在颜色命名任务中,深、浅加工条件下均可形成对颜色词的启动效应,但浅加工条件下的再认成绩明显低于深加工,出现了联想启动和再认的分离现象。词命名表现出与颜色命名相似的结果,但它们在有意识回忆方面仍存在一定的差异,提示知觉表征系统单独并不能支持联想启动,联想启动可能是多个记忆系统共同作用的结果。     

Eliminating the memory blocking effect

Six experiments investigated the memory blocking effect (MBE) in which exposure to orthographically similar words (e.g., BALLOON) impairs one's ability to complete a similar fragment (e.g., BAL_ON_, solution is BALCONY). Experiments 1 and 2 demonstrated that blocking is not observed after a 72-hour delay; however, repetition priming was observed after the same delay. Experiments 3 and 4 showed that presenting unrelated semantic information during the fragment completion test eliminates blocking. Experiment 5 demonstrated that the MBE persists despite directed-forgetting instructions, and Experiments 5 and 6 demonstrated that activating both the solutions and blocking words for a particular fragment at study eliminates blocking. Collectively, the data demonstrate that reading orthographically similar primes automatically triggers retrieval of the blocking word and an executive control process works to manage this interference. A working framework that describes how an executive control mechanism could govern memory retrieval in the memory-blocking paradigm is presented to stimulate development of more advanced theoretical models that can explain blocking.     

A criterion-shift model for enhanced discriminability in perceptual identification: A note on the counter model

The original version of the counter model for perceptual identification (Ratcliff & McKoon, 1997) assumed that word frequency and prior study act solely to bias the identification process (i.e., subjects have a tendency to prefer high-frequency and studied low-frequency words, irrespective of the presented word). In a recent study, using a two-alternative forced-choice paradigm, we showed an enhanced discriminability effect for high-frequency and studied low-frequency words (Wagenmakers, Zeelenberg, & Raaijmakers, 2000). These results have led to a fundamental modification of the counter model: Prior study and high frequency not only result in bias, but presumably also result in a higher rate of feature extraction (i.e., better perception). We demonstrate that a criterion-shift model, assuming limited perceptual information extracted from the flash as well as a reduced distance to an identification threshold for high-frequency and studied low-frequency words, can also account for enhanced discriminability.     

Priming of new associations in reading time: What is learned?

The priming of new associations has been a controversial topic, with some studies finding significant effects but others failing to replicate these results. Three studies investigated the priming of new associations in a reading time task, presenting lists of word pairs that were read aloud as quickly as possible. In Experiment 1, significant priming of new associations was found after two study presentations, replicating similar results by Moscovitch, Winocur, and MacLachan (1986). In Experiment 2, reading time was facilitated for intact pairs when word positions remained constant relative to when word positions were reversed. This suggested that the associative priming effect was related to specific lower level features of the word pairs rather than to abstract associations. In Experiment 3, the insertion of the wordand between test words eliminated the pairing-specific effect, placing the locus of new association priming at the transition between words within pairs. These findings demonstrate that the knowledge that supports priming of new associations in the reading time task involves perceptual or articulatory information about the transitions between words rather than abstract associative knowledge.