On the interaction between linguistic and pictorial systems in the absence of semantic mediation: Evidence from a priming paradigm

Use of the letter search task in the context of the priming paradigm has proved to be an invaluable tool for the investigation of the strategic control of processes involved in word recognition. In particular, previous findings that letter search on a prime word interferes with the priming of semantically/associatively related targets, but not with the priming of either identical or morphologically related targets, suggests that letter search may selectively interfere with semantic processing, leaving other levels of processing intact. In the present experiments, this investigation was extended by exploring the priming of pictures following letter search of either a same-concept word (repetition priming) or a semantically/associatively related word (semantic priming). There was significant repetition priming of picture categorization following both silent reading and letter search of the prime word (Experiments 1 and 2). In contrast, semantic priming of pictures was found only following silent reading of the prime; there was no semantic priming following letter search of the prime (Experiment 2). This pattern of results suggests that focusing attention at the letter level during prime processing selectively attenuates activation of the semantic system by the prime. It does not prevent the spread of activation between the lexical and pictogen levels of representation of a given concept.     

On the relationship between visual imagery and visual perception: Evidence from priming studies

Two priming experiments using a perceptual identification task were conducted to explore the functional and representational overlap between visual imagery and visual perception. The first experiment included a study phase in which primes were either perceived or imaged objects and a perceptual identification test task in which targets were parts of studied and non-studied objects. Imagery primed identification when subjects were instructed to count the parts of the imaged objects in the study phase but not when they were instructed to focus on the global shape of the imaged objects. This result suggests that imagery involves perceptual representations identical to those involved in perception. It also suggests that the representational overlap between imagery and perception depends on the type of images generated, as some images may consist in global shapes only, whereas others may consist in detailed, multi-part shapes. In the second experiment, we used whole objects as target stimuli which provided subjects with more information to identify masked targets and thereby reduced top-down processing. Priming from imagery fell beneath significance, suggesting that this sort of priming is elicited in a large part by a transfer of top-down processes from study to test.     

On the relationship between negative affective priming and prefrontal cognitive control mechanisms

Although several studies have examined inhibition of affective stimuli, valence-dependent cognitive control effects remain poorly understood. Behavioural and functional imaging (functional magnetic resonance imaging) data were collected from 17 healthy participants to examine neural correlates of the Negative Affective Priming (NAP) task. We created relative ratio scores considering the reaction times of prime trials in order to assess the amount of interference after the presentation of negative and positive distracter words. Behavioural results showed an attenuated NAP effect for negative distracters compared to neutral stimuli. Furthermore, priming negative distracters generated more interference by reacting to the probe target than positive distracters. Neuroimaging data revealed a stronger prefrontal activation during negative NAP trials compared to positive NAP and neutral control trials, which was reflected in a heightened activation of superior and middle frontal gyrus as well as parietal cortex. The findings show the impact of negative distracters on prefrontal response, contributing to the understanding of NAP effects in healthy subjects.     

Understanding the relationship between repetition priming and mere exposure

Over the last two decades interest in implicit memory, most notably repetition priming, has grown considerably. During the same period, research has also focused on the mere exposure effect. Although the two areas have developed relatively independently, a number of studies has described the mere exposure effect as an example of implicit memory. Tacit in their comparisons is the assumption that the effect is more specifically a demonstration of repetition priming. Having noted that this assumption has attracted relatively little attention, this paper reviews current evidence and shows that it is by no means conclusive. Although some evidence is suggestive of a common underlying mechanism, even a modified repetition priming (perceptual fluency/attribution) framework cannot accommodate all of the differences between the two phenomena. Notwithstanding this, it seems likely that a version of this theoretical framework still offers the best hope of a comprehensive explanation for the mere exposure effect and its relationship to repetition priming. As such, the paper finishes by offering some initial guidance as to ways in which the perceptual fluency/attribution framework might be extended, as well as outlining important areas for future research.     

On the relationship between Fortier's simultaneous linear prediction and van den Wollenberg's redundancy analysis

The purpose of this note is to show that Van den Wollenberg's method of redundancy analysis is a special case of a simultaneous linear prediction method offered by Fortier.     

On the relation between conceptual priming, neural priming, and novelty assessment

A consistently reported finding in functional neuroimaging studies which compare processing of new information to processing of old information is a reduction in blood flow, and hence neural activity, associated with the old condition. This deactivation has been labeled neural priming. Some investigators have hypothesized that neural priming is the physiological mechanism underlying conceptual priming—a facilitation in the semantic processing of repeated information. Others, however, have hypothesized that neural priming reflects novelty assessment—a mechanism which minimizes the probability that redundant information will be stored in long‐term memory. In this paper, the conceptual priming and novelty assessment hypotheses are compared and contrasted in order to ask, and tentatively answer, the question: Are conceptual priming and novelty assessment cognitively and neurophysiologically distinct? Based on a review of the literature, it is suggested that whereas novelty assessment and conceptual priming are distinct cognitive entities, they cannot be presently separated neurophysiologically. That is, some novelty assessment deactivations may in fact reflect priming, and some priming deactivations may in fact reflect novelty assessment.     

On the discriminability of stimulus duration.

The performance of pigeons trained to detect differences in the duration of stimuli was analysed using a matching model of signal detection. Two white stimuli, S1 and S2, differing in duration, were arranged with equal probability on the center key of a three-key chamber. S1 was systematically varied from 5 seconds to 25 seconds while S2 remained constant at 30 seconds. On completion of the center-key stimulus, a peck on the center key turned on the two red side keys. A left-key response was "correct" when S1 had been in effect on the center key and a right-key response was "correct" on S2 trials. A correct response produced a 3-second magazine light accompanied intermittently by food. Incorrect responses produced 3-second blackouts. Detection performance was measured under two procedures. In the first, the obtained reinforcement ratio was uncontrolled by allowing the number of food reinforcements obtained for correct left- and right-key responses to vary as the stimuli were changed. In the second procedure, the presentation of food reinforcement was controlled by holding the obtained reinforcement ratio constant. Discriminability changed as a function of stimulus differences under both procedures. No such trend was found in response bias.     

On the relation between perceptual priming and recognition memory

Two experiments evaluated the hypothesis that perceptual fluency is used to infer prior occurrence. Subjects heard (Experiment 1) or saw (Experiment 2) a list of words and then were presented in the same modality with both these and other words twice in succession: first in a more or less impoverished fashion, and then in clear fashion. For the first of these two presentations, the subjects tried to identify the word; for the second, they gave a recognition judgement. As predicted by the perceptual fluency hypothesis, and as has been found in previous research, the recognition judgments were more positive for identified words than for unidentified words. However, degree of impoverishment, by which apparent perceptual fluency was brought under experimental control, did not affect the recognition judgments. The perceptual fluency hypothesis was therefore not supported, and the observed relation between identification and recognition was attributed to an item selection effect.     

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.     

A single-system account of the relationship between priming, recognition, and fluency

A single-system computational model of priming and recognition was applied to studies that have looked at the relationship between priming, recognition, and fluency in continuous identification paradigms. The model was applied to 3 findings that have been interpreted as evidence for a multiple-systems account: (a) priming can occur for items not recognized; (b) the pattern of identification reaction times (RTs) to hits, misses, correct rejections, and false alarms can change as a function of recognition performance; and (c) fluency effects (shorter RTs to words judged old vs. judged new) and priming effects (shorter RTs to old vs. new words) can be observed in amnesic patients at levels comparable with healthy adults despite impaired or near-chance recognition. The authors' simulations suggest, contrary to previous interpretations, that these results are consistent with a single-system account.     

The relationship between binocular brightness matches and luminance difference discriminability of successively presented light flashes1

Measurements of monocular ΔI and PSE as a function of the ISI between two 2-deg foveal fields successively presented to the same retinal area were obtained for two Standard durations, using the method of constant stimuli. Binocular brightness matches of the stimuli revealed that detection of a difference occurred whenever a constant difference (in log mL) in matching luminance existed. The implication of the results was that ΔI is related to the rate of change of brightness with changes in test-field luminance.     

Effects of priming, discriminability, and reinforcement on reaction-time components of pigeon visual search

Pigeons searched computer screens for 1 of 4 letter targets among 55 alphanumeric distractors. In Experiment 1, valid-cue trials used distinctive patterns to signal the subsequent appearance of specific targets, whereas ambiguous-cue trials used a signal common to all targets. Search reaction times (RTs) after valid cues were shorter than after the ambiguous cue; increased target discriminability also reduced RT. In Experiment 2, when reinforcement for 2 targets shifted from 10% to 20%, RTs to those targets dropped, whereas RTs to the other 2 targets rose. RT distributions suggested that precues and discriminability both affect the momentary probability of finding a target, as embodied in the decay constant of an underlying exponentially distributed RT component. Reinforcement changes appeared to affect different components of the response process, embodied in changes in the mean of an underlying lognormal distribution.     

On the locus of priming and inverse priming effects

Visual stimuli that are made invisible by a following mask can affect overt motor responses and nonmotor processing. Previous studies have compared the effects of primes that were perceptually similar to the subsequent stimulus with those of primes that were perceptually similar to an alternative stimulus. The present study examined the effect of congruent primes that are perceptually dissimilar to the target (or the cue) but are nonetheless associated with the same response (or the same task) as the later stimulus. Positive and inverse priming effects (negative compatibility effects) were studied in a target priming paradigm (Experiments 1 and 2) and in a cue priming paradigm (Experiments 3 and 4). The results showed stronger priming effects with similar primes than with dissimilar congruent primes. However, the effects of perceptually dissimilar congruent primes differed from those of dissimilar incongruent primes. These findings suggest that a substantial part of both positive target and cue priming effects is produced at levels of processing that are not affected by perceptual similarity. The version of inverse priming effects examined in this study, however, seems to arise from perceptual processing that is affected by the similarity between a prime and the stimulus that follows the mask.     

Intact conceptual priming in the absence of declarative memory

Priming is an unconscious (nondeclarative) form of memory whereby identification or production of an item is improved by an earlier encounter. It has been proposed that declarative memory and priming might be related-for example, that conceptual priming results in more fluent processing, thereby providing a basis for familiarity judgments. In two experiments, we assessed conceptual priming and recognition memory across a 5-min interval in 5 memory-impaired patients. All patients exhibited fully intact priming in tests of both free association (study tent; at test, provide an association to canvas) and category verification (study lemon; at test, decide: Is lemon a type of fruit?). Yet the 2 most severely amnesic patients performed at chance on matched tests of recognition memory. These findings count against the notion that conceptual priming provides feelings of familiarity that can support accurate recognition judgments. We suggest that priming is inaccessible to conscious awareness and does not influence declarative memory.     

Unconscious semantic priming in the absence of partial awareness

In a recent paper in Psychological Science, Kouider and Dupoux reported obtaining unconscious Stroop priming only when subjects had partial awareness of the masked distractor words (i.e., could consciously perceive subword features that enabled reconstruction of whole words). Kouider and Dupoux conjectured that semantic priming occurs only when such partial awareness is present. The present experiments tested this conjecture in an affective categorization priming task that differed from Kouider and Dupoux’s in using masked distractors that subjects had practiced earlier as visible words. Experiment 1 showed priming from practiced words when subjects had no partial awareness of those words. Experiment 2 showed that, in the absence of partial awareness, practiced words yielded priming but not-practiced words did not. Experiment 3 corroborated Experiment 1 and 2s results using a different test of partial awareness. These results suggest that unconscious processing (rather than partial awareness) of subword elements drives masked semantic priming by practiced words.