Is unconscious identity priming lexical or sublexical?

We examined unconscious priming in a stem-completion task with both identity and form-related primes. Participants were given exclusion instructions to avoid completing a stem (e.g., ca---) with a briefly flashed masked word (e.g., candy). In Experiment 1, priming of around 7% occurred for both identity (e.g., candy) and form-based (e.g., windy) primes at a 33 ms exposure duration. When examining only trials in which the participants failed to identify the prime, this effect increased to 12% for identity primes, but remained the same for form-based primes. In Experiment 2, priming without prime identification was 9% for identity primes, 4% for homophone primes, and 3% for orthographic control primes. Although identity priming was greater than form priming in both experiments, regression analyses revealed that orthographic and phonological overlap alone between the flashed primes and targets could completely account for unconscious identity priming. Hence, we conclude that masked words may only activate their sublexical orthographic and phonological representations and not their lexical representations.     

Lexical guidance in sentence processing?

An eyetracking experiment was conducted to explore a self-paced reading effect reported by Mitchell (1987). Mitchell found that a noun phrase (NP) was read slowly when it immediately followed an intransitive verb, as long as the verb and NP appeared in the same presentation region. This effect has been used to support the claim that verb subcategorization information is not used initially in sentence parsing. However, the effect did not appear in the eyetracking experiment reported in the present paper, supporting criticisms that Mitchell’s segmentation procedure distorted the parsing process.     

The plausibility effect: Lexical priming or sentential processing?

Five experiments are reported that investigated whether the plausibility effect is caused by lexical priming resulting from the higher proportion of related words in plausible than in implausible sentences. In Experiment 1, a plausibility effect was demonstrated that was entirely attributable to the way in which lexical items were combined rather than to the properties of individual lexical items. In Experiment 2, the content words from the sentences used in Experiment 1 were shown to produce a similar reaction-time difference in a task in which syntactic processing was disrupted, supporting a lexical priming explanation of the plausibility effect. However, Experiments 3 and 4 demonstrated that, in another task less prone to task-specific strategies but sensitive to plausibility, the disruption of syntactic processing eliminated the effect. In Experiment 5, it was shown that when lexical priming was eliminated, a plausibility effect still occurred. Thus, two separate lines of evidence suggested that the plausibility effect cannot be fully explained in terms of lexical priming.     

Lexical processing of ambiguous words: dominance or associative strength?

Four experiments examined the role of meaning frequency (dominance) and associative strength (measured by associative norms) in the processing of ambiguous words in isolation. Participants made lexical decisions to targets words that were associates of the more frequent (dominant) or less frequent (subordinate) meaning of a homograph prime. The first two experiments investigated the role of associative strength at long SOAs (Stimulus Onset Asynchrony) (750 ms.), showing that meaning is facilitated by the targets' associative strength and not by their dominance. The last two experiments traced the role associative strength at short SOAs (250 ms), showing that the manipulation of the associative strength has no effect in the semantic priming. The conclusions are: on the one hand, semantic priming for homographs is due to associative strength manipulations at long SOAs. On the other hand, the manipulation of the associative strength has no effect when automatic processes (short SOAs) are engaged for homographs.     

Short-term memory limitations in children: Capacity or processing deficits?

This paper evaluates the assertion that short-term memory (STM) capacity increases with age. Initially an analysis is made of the STM system in terms of its parameters and control processes. No evidence was found that can suggest conclusively that either the capacity or the rate of information loss from STM varies with age. On the other hand, substantial evidence exists to show that the processing strategies used by adults are unavailable or deficient in children. Furthermore, considerable differences in the contents and complexity of the long-term memory (LTM) knowledge base (semantic and recognition networks can produce grossly different STM performance between age groups. The second half of this paper reviews three STM-related paradigms-memory span, serial probed recall, and recognition under limited exposure-that have consistently shown performance deficits in children. These deficits are explained in terms of the lack of proper control processes (or processing strategies), as well as an impoverished LTM knowledge base rather than a limitation in STM capacity.     

Biased cognitive operations in anxiety: artefact, processing priorities or attentional search?

It has been shown that, under certain circumstances, anxiety is associated with a processing bias favouring threatening information. To explain why this bias is apparent only on certain cognitive tasks, it has recently been proposed that the bias operates only when there is competition for processing resources. The present study sought to replicate previous evidence for the 'competition' hypothesis, while taking into account a potential confounding factor of word categorization in the stimulus materials. Anxious patients and normal controls were compared on their lexical decision times for threatening, categorized neutral and uncategorized neutral words that were presented either alone or accompanied by irrelevant nonword stimuli (i.e. absence vs presence of competition). The results were only partially consistent with previous findings and highlighted the importance of considering separately the effects of word valence and word categorization. When the latter was taken into account, the results indicated that an anxiety-related bias was only evident when there was competition for processing resources and when the information was presented outside the focus of Ss' attention. A modified version of the competition hypothesis was proposed in the light of these results and previous research into attentional biases in anxiety.     

Lexical and Metrical Stress in Word Recognition: Lexical or Pre-lexical Influences?

The influence of lexical stress and/or metrical stress on spoken word recognition was examined. Two experiments were designed to determine whether response times in lexical decision or shadowing tasks are influenced when primes and targets share lexical stress patterns (JUVenile–BIBlical [Syllables printed in capital letters indicate those syllables receiving primary lexical stress.]). The results did not support an effect of lexical stress on the organization of lexical memory. In Experiment 3 primes and targets whose first syllables shared lexical stress only (MUDdy–PASta), metrical stress only (alTHOUGH–PASta), both cues (LECtern–PASta), or neither cue (conTROL–PASta) revealed no priming effect. However, targets whose first syllables were strong were responded to faster than targets whose first syllables were weak. Experiment 4 manipulated the metrical stress patterns of bi-syllabic primes and targets. Targets with strong–weak metrical stress patterns were responded to more quickly than those with strong–strong or weak–strong patterns. Although the priming paradigm did not reveal an influence of lexical and metrical stress on the organization of lexical memory, the data do support an influence of strong syllables on the processing of auditorily presented words.     

Does interword spacing influence lexical processing in Chinese reading?

This study investigated how inserting spaces between Chinese words affected word recognition in Chinese reading. Eye movements of Chinese readers were recorded in a sentence reading task where high- and low-frequency target words were presented in both the spaced and normally unspaced texts. We found that fixation durations on target words were shorter in the high- than low-frequency conditions, and shorter in the spaced than unspaced conditions. The survival analysis revealed that interword spacing advanced the temporal onset of word frequency effects relative to the normally unspaced condition. However, inconsistent with the findings in English reading, there was no interaction between word frequency and interword spacing on all fixation duration measures, and the Bayes factor analyses also favoured the hypothesis of null interaction. These data suggest that interword spacing facilitates visual rather than lexical processing in Chinese reading, and thus improves our understanding on the roles of interword spacing across different writing systems.     

Recognition and lexical decision without detection: unconscious perception?

Stimulus detection and concurrent measures of stimulus recognition were compared to establish whether perception occurs in the absence of detection. The target stimuli were familiar words (Experiments 1 and 2), nonwords (Experiment 3), or both words and nonwords (Experiment 4). On each trial, either a stimulus or a blank field was presented. Ss first decided whether a stimulus had been presented and then made either a forced-choice recognition decision (Experiments 1, 2, and 3) or a lexical decision (Experiment 4). Both words and nonwords were recognized and discriminated following correct detections (i.e., hits). However, in the absence of stimulus detection (i.e., misses), only words were recognized or discriminated. These qualitatively different patterns of results following hits and misses for words and nonwords suggest that stimulus detection may provide an adequate measure of conscious awareness.     

A word’s meaning affects the decision in lexical decision

The influence of an isolated word’s meaning on lexical decision reaction time (RT) was demonstrated through four experiments. Subjects in two experiments made lexical decision judgments, those in a third experiment pronounced the words used in the lexical decision task, and those in a fourth experiment quickly pronounced their first associative response to the words. Differences in lexical access time for the words were measured with the pronunciation task, and differences in meaning were assessed with the association task. Multiple regression analyses of lexical decision RT were conducted using associative RT, pronunciation RT, and other target word properties (printed frequency, length, instance dominance, and number of dictionary meanings) as predictor variables. These analyses revealed a relationship between lexical decision RT and associative RT after the effects of other variables had been partialed out. In addition, word frequency continued to have a significant relationship to lexical decision RT beyond that shared with pronunciation RT and the other variables. The results of these experiments indicate that at least some of the effect of word meaning and word frequency in lexical decision is attributable to a decision stage following lexical access.     

Sequential lineups: shift in criterion or decision strategy?

R. C. L. Lindsay and G. L. Wells (1985) argued that a sequential lineup enhanced discriminability because it elicited use of an absolute decision strategy. E. B. Ebbesen and H. D. Flowe (2002) argued that a sequential lineup led witnesses to adopt a more conservative response criterion, thereby affecting bias, not discriminability. Height was encoded as absolute (e.g., 6 ft [1.83 m] tall) or relative (e.g., taller than). If a sequential lineup elicited an absolute decision strategy, the principle of transfer-appropriate processing predicted that performance should be best when height was encoded absolutely. Conversely, if a simultaneous lineup elicited a relative decision strategy, performance should be best when height was encoded relatively. The predicted interaction was observed, providing direct evidence for the decision strategies explanation of what happens when witnesses view a sequential lineup.     

What causes the effect of age of acquisition in lexical processing?

Three hypotheses for effects of age of acquisition (AoA) in lexical processing are compared: the cumulative frequency hypothesis (frequency and AoA both influence the number of encounters with a word, which influences processing speed), the semantic hypothesis (early-acquired words are processed faster because they are more central in the semantic network), and the neural network model (early-acquired words are faster because they are acquired when a network has maximum plasticity). In a regression study of lexical decision (LD) and semantic categorization (SC) in Italian and Dutch, contrary to the cumulative frequency hypothesis, AoA coefficients were larger than frequency coefficients, and, contrary to the semantic hypothesis, the effect of AoA was not larger in SC than in LD. The neural network model was supported.     

Preattentive processing or prefocal processing?

The concept of preattentive processing is analyzed and alternative views of it are presented. A basic question is whether processing required for preattentive input selection is qualitatively different from post-selection processing. In order to study this, subjects were presented in one set of conditions with one stimulus at either of two locations, and in another set of conditions, simultaneously with two stimuli. The stimuli could be green or red, or large or small. Subjects were asked to indicate the location (or the color, or the size) of the single stimulus in the single-stimulus conditions, or of a predesignated stimulus (say, the red one) in the dual-stimulus conditions. Responses were generally slower in the dual-stimulus conditions. The increases in reaction time were accounted for by the times it takes to process for response selection the properties by which the target stimulus could be selected, as indicated by the results of two control conditions. The results as well as some other considerations do not support the view that preattentive processing is necessarily of a type that qualitatively differs from post-selection processing.     

What causes the effect of age of acquisition in lexical processing?

Three hypotheses for effects of age of acquisition (AoA) in lexical processing are compared: the cumulative frequency hypothesis (frequency and AoA both influence the number of encounters with a word, which influences processing speed), the semantic hypothesis (early-acquired words are processed faster because they are more central in the semantic network), and the neural network model (early-acquired words are faster because they are acquired when a network has maximum plasticity). In a regression study of lexical decision (LD) and semantic categorization (SC) in Italian and Dutch, contrary to the cumulative frequency hypothesis, AoA coefficients were larger than frequency coefficients, and, contrary to the semantic hypothesis, the effect of AoA was not larger in SC than in LD. The neural network model was supported.     

Attentional bias in anxiety: selective search or defective filtering?

Two experimental tasks were used to investigate the nature of a previously documented bias in attention associated with anxiety. Results from the first task failed to reveal any differences between anxious and nonanxious subjects, either in attention focusing or selective search for letters. The second task, with words as targets and distractors, suggested that selective search was less efficient in anxious subjects when distractors were present. Currently anxious subjects were slower than controls when required to search for the target among distractors of any type, whereas both currently anxious and recovered subjects were slower when the distractors were threatening words. It was therefore suggested that a bias favoring threat cues during perceptual search is an enduring feature of individuals vulnerable to anxiety, rather than a transient consequence of current mood state alone.     

Amodal completion in visual search: preemption or context effects?

In a previous study, search for a notched-disk target abutting a square among complete-disk nontargets and squares was inefficient in 250-ms exposures, but relatively efficient in 100-ms exposures. This finding was interpreted as evidence that amodal completion proceeds through a mosaic and then a completion stage, with the latter preempting the former. We used the same target but changed its context: Nontargets were instead notched disks near squares. Task set was also different: Participants searched for a complete disk. Contrary to the prediction of the preemption model, search was efficient in the 100-ms condition and inefficient in the 250-ms condition. We propose that in both the present and the previous studies, the target was ambiguous, and task set and context affected how it was perceived. In both experiments, set effects were evident for 100-ms exposures; context effects were evident for 250-ms exposures.     

Precue effects in visual search: Data or resource limited?

Precuing an observer as to where a target is more likely to occur in a subsequent visual array can increase the detectability (d′) of a target at that location. This is often attributed to the observer’s increased allocation of some limited cognitive resource (“attention”) to the cued location. Two experiments are reported which are difficult to interpret in this way even though they involve similar cue effects. The first involves postcuing a location well after the array but before the observer responds, so that the cue can influence the response but not the observation. The second involves precuing, but with slow sequential presentation of array elements prior to the response, so the observer need not share any limited resource while processing each element in turn. Enhanced detectability similar to that produced with precues and simultaneous presentation of elements is shown to occur in each experiment. An alternative data-limited (rather than resource-limited) interpretation of these effects is provided by a mathematical model in which the observer integrates equally noisy or degraded internal representations of the array elements, but gives more weight to cued elements in selecting a response. Theoretical parameters of the model are shown to provide separate measures of both an observer’s overall sensitivity and precue effects in cost-benefit analyses of cuing data.     

Detection of cryptic prey: search image or search rate?

Animals' improvement in capturing cryptic prey with experience has long been attributed to a perceptual mechanism, the specific search image. Detection could also be improved by adjusting rate of search. In a series of studies using both naturalistic and operant search tasks, pigeons searched for wheat, dyed to produce 1 conspicuous and 2 equally cryptic prey types. Contrary to the predictions of the search-rate hypothesis, pigeons given a choice between the 2 cryptic types took the type experienced most recently. However, experience with 1 cryptic type improved accuracy on the other cryptic type, a result inconsistent with a search image specific to 1 prey type. Search image may better be thought of as priming of attention to those features of the prey type that best distinguish the prey from the background.     

Is the go/no-go lexical decision task an alternative to the yes/no lexical decision task?

In the go/no-go lexical decision task (LDT), participants are instructed to respond as quickly as they can when a word is presented and not to respond if a nonword is presented. By minimizing part of the response selection process in the experimental task, the impact of response decision time on the obtained lexical decision time is probably reduced relative to the standard yes/no LDT (Gordon, 1983). Experiments 1 and 2 show that the go/no-go LDT is sensitive to the effects of word frequency and associative priming--the magnitude of these effects is similar with the two tasks. More important, the go/no-go LDT has a number of advantages with respect to the "standard" yes/no LDT: It offers faster response times, more accurate responding, and fewer processing demands than does the yes/no task. Accordingly, the go/no-go task appears to be an excellent alternative to the standard yes/no task.     

On the relation between feeling of knowing and lexical decision: persistent subthreshold activation or topic familiarity?

Experiment 1 replicated Yaniv and Meyer's (1987) finding that lexical decision and episodic recognition performance was better for words previously yielding high-accessibility levels (a combination of feeling-of-knowing and tip-of-the-tongue ratings) in comparison with those yielding low-accessibility levels in a rare word definition task. Experiment 2 yielded the same pattern even though lexical decisions preceded accessibility estimates by a full week. Experiment 3 dismissed the possibility that the Experiment 2 results may have been due to a long-term influence from the lexical decision task to the rare word judgment task. These results support a model in which Ss (a) retrieve topic familiarity information in making accessibility estimates in the rare word definition task and (b) use this information to modulate lexical decision performance.