Prime-target Interval Research Articles

How does language affect spatial attention? Deconstructing the prime-target relationship.

It is still unclear how spatially associated concepts (e.g., directional expressions, object names, metaphors) shape our cognitive experience. Here, two experiments (N = 156) investigated the mechanisms by which words with either explicit or implicit spatial meaning induce spatial attention shifts. Participants performed a visual target-discrimination task according to response rules that required different degrees of prime and target processing depth. For explicit prime words, we found spatial congruency effects independent of processing depth, while implicit prime words generated congruency effects only when participants had to compute the congruency relationship. These results were robust across different prime-target intervals and imply that spatial connotations alone do not automatically activate spatial attention shifts. Instead, explicit semantic analysis is a prerequisite for conceptual cueing.

Dissociating the time courses of the cross-modal semantic priming effects elicited by naturalistic sounds and spoken words

The present study compared the time courses of the cross-modal semantic priming effects elicited by naturalistic sounds and spoken words on visual picture processing. Following an auditory prime, a picture (or blank frame) was briefly presented and then immediately masked. The participants had to judge whether or not a picture had been presented. Naturalistic sounds consistently elicited a cross-modal semantic priming effect on visual sensitivity (d') for pictures (higher d' in the congruent than in the incongruent condition) at the 350-ms rather than at the 1,000-ms stimulus onset asynchrony (SOA). Spoken words mainly elicited a cross-modal semantic priming effect at the 1,000-ms rather than at the 350-ms SOA, but this effect was modulated by the order of testing these two SOAs. It would therefore appear that visual picture processing can be rapidly primed by naturalistic sounds via cross-modal associations, and this effect is short lived. In contrast, spoken words prime visual picture processing over a wider range of prime-target intervals, though this effect was conditioned by the prior context.

Voxel-Based Lesion Symptom Mapping of Coarse Coding and Suppression Deficits in Patients With Right Hemisphere Damage.

This study examined right hemisphere (RH) neuroanatomical correlates of lexical-semantic deficits that predict narrative comprehension in adults with RH brain damage. Coarse semantic coding and suppression deficits were related to lesions by voxel-based lesion symptom mapping. Participants were 20 adults with RH cerebrovascular accidents. Measures of coarse coding and suppression deficits were computed from lexical decision reaction times at short (175 ms) and long (1000 ms) prime-target intervals. Lesions were drawn on magnetic resonance imaging images and through normalization were registered on an age-matched brain template. Voxel-based lesion symptom mapping analysis was applied to build a general linear model at each voxel. Z score maps were generated for each deficit, and results were interpreted using automated anatomical labeling procedures. A deficit in coarse semantic activation was associated with lesions to the RH posterior middle temporal gyrus, dorsolateral prefrontal cortex, and lenticular nuclei. A maintenance deficit for coarsely coded representations involved the RH temporal pole and dorsolateral prefrontal cortex more medially. Ineffective suppression implicated lesions to the RH inferior frontal gyrus and subcortical regions, as hypothesized, along with the rostral temporal pole. Beyond their scientific implications, these lesion-deficit correspondences may help inform the clinical diagnosis and enhance decisions about candidacy for deficit-focused treatment to improve narrative comprehension in individuals with RH damage.

Mask-triggered thrust reversal in the negative compatibility effect.

Rapid motor responses to visual stimuli can involve both the activation and inhibition of motor responses. Here, we trace the early processing dynamics of response generation, examining whether activation and inhibition events form a strict sequence when elicited by sequential stimuli, as we would expect if motor events are driven by fast, stimulus-triggered feedforward sweeps. We employed identical stimuli in two complementary paradigms. In response priming, responses to a target stimulus are speeded or slowed by a masked prime triggering the same or an alternative response, respectively. By prolonging the prime-target interval, the response-priming effect can reverse to form the negative compatibility effect (NCE), especially when the mask contains response-relevant features. We report two experiments in which primed pointing movements going in ten possible directions were measured with response-relevant, response-irrelevant, or no masks interleaved between the primes and targets, while selective visual attention was varied. We showed that in response priming, initial responses are controlled exclusively by the prime. In the NCE, however, even the earliest movement phase is controlled jointly by the prime, mask, and target information, and a massive force in counterdirection to the primed response reverses the priming effects specifically for slow responses. We conclude that response priming reflects a strict sequence of feedforward response activations, whereas the activation/inhibition events in the NCE are not strictly serial, but integrate information from the different stimuli over time. Even though the mask features and visual attention modulate the NCE, its major source is a mask-induced, direction-specific thrust reversal of the initial response.

Eye movements are primed toward the center of multiple stimuli even when the interstimulus distances are too large to generate saccade averaging.

Prior oculomotor research has established that saccades tend to land near the center of multiple saccade targets when they are near each other. This saccade averaging phenomenon (or global effect) has been ascribed to short-distance lateral excitation between neurons in the superior colliculus. Further, at greater inter-stimulus distances, eye movements tend toward the individual elements. This transition to control by local elements (individuation) with inter-stimulus distance has been attributed to long-range lateral inhibition between neurons in winner-take-all models of oculomotor behavior. We hypothesized that the traditional method of requiring a saccade to an array of multiple, simultaneous targets may entail response ambiguity that intensifies with distance. We resolved the ambiguity by focussing on reaction time of our human participants to a single saccade target after one or more simultaneous priming stimuli. At a 50-ms prime-target interval, saccadic reaction time was shortest for targets closer to the center of the prime stimuli independent of the distance between the primes. This effect was gone at 400 ms. These findings challenge the typical inferences about the neural control of oculomotor behavior that have been derived from the boundary between saccade averaging and individuation and provide a new method to explore eye movements with lessened impact from decision processes.

The time course of temporal attention effects on nonconscious prime processing

We presented a masked prime at various prime-target intervals (PTIs) before a target that required a speeded motor response and investigated the impact of temporal attention on the nonconscious prime processing. The allocation of temporal attention to the target was manipulated by presenting an accessory tone and comparing that condition with a no-tone condition. The results showed that, independently of the visibility of the prime, temporal attention led to an enhanced effect of prime-target congruency on the reaction times, and that the amount of the enhancement increased with increasing PTIs. This effect pattern is consistent with the assumption of increasing influences of temporal attention and of the increasing PTI on nonconscious prime processing; it argues against the hypothesis that temporal attention narrows the time period in which the prime may affect target processing. An accumulator model is proposed assuming that target-related temporal attention increases the accumulation rate for masked primes and, thus, enhances the impact of the prime on the speed of choice decisions.

Rapid processing of closure and viewpoint-invariant symmetry: behavioral criteria for feedforward processing

To pin down the processing characteristics of symmetry and closure in contour processing, we investigated their ability to activate rapid motor responses in a primed flanker task. In three experiments, participants selected as quickly and accurately as possible the one of two target contours possessing symmetry or closure. Target pairs were preceded by prime pairs whose spatial arrangement was consistent or inconsistent with respect to the required response. We tested for the efficiency and automaticity of symmetry and closure processing. For both cues, priming effects were present in full magnitude in the fastest motor responses consistent with a simple feedforward model. Priming effects from symmetry cues were independent of skewing and the orientation of their symmetry axis but sometimes failed to increase with increasing prime-target interval. We conclude that closure and (possibly) viewpoint-independent symmetry cues are extracted rapidly during the first feedforward wave of neuronal processing.

No evidence for subliminal affective priming with emotional facial expression primes

The present study investigated whether facial expressions of emotion presented outside consciousness awareness will elicit evaluative responses as assessed in affective priming. Participants were asked to evaluate pleasant and unpleasant target words that were preceded by masked or unmasked schematic (Experiment 1) or photographic faces (Experiments 1 and 2) with happy or angry expressions. They were either required to perform the target evaluation only or to perform the target evaluation and to name the emotion expressed by the face prime. Prime-target interval was 300 ms in Experiment 1 and 80 ms in Experiment 2. Naming performance confirmed the effectiveness of the masking procedure. Affective priming was evident after unmasked primes in tasks that required naming of the facial expressions for schematic and photographic faces and after unmasked primes in tasks that did not require naming for photographic faces. No affective priming was found after masked primes. The present study failed to provide evidence for affective priming with masked face primes, however, it indicates that voluntary attention to the primes enhances affective priming.

A prospective view of the impact of prime validity on response speed and selection in the arrow classification task with free choice trials

Bodner and Masson (2001, 2003, 2004) demonstrated that masked priming effects in many cognitive tasks become larger when the proportion of related trials increases (prime validity effects). Those authors claimed that these effects are due to participants' recruiting prime information to aid target processing when it is useful to do so (e.g., there are a large number of related trials-the memory recruitment account). Bodner and Mulji (in press) recently reported similar effects in an arrow classification task with free choice trials. In the present research, we examined whether the memory recruitment account can adequately explain prime validity effects in that task. In this experiment, participants classified arrow direction (i.e., left-right) and responded to free choice stimuli (i.e., two-sided arrows that allow either a left or right response) following arrow primes when the prime-target relationship for the arrow target trials was always congruent, always incongruent, or unpredictive. Prime validity effects for the either-way targets emerged with both 77- and 165-msec prime-target intervals. The results in the unpredictive conditions, however, suggest that those effects were due to the impact of automatic response biases initially created by the prime, which participants attempt to suppress when it is advantageous to do so.

Evidence from the attentional blink for different sources of word repetition effects

T2 in an attentional blink paradigm served as a high- or low-frequency prime word for a subsequent repeated target. Consistent with research in visual word identification, only reported primes facilitated the identification of a target repeated approximately 8s after RSVP. Priming was greater for low- than high-frequency words. Analogous with masked priming, a blinked T2 facilitated report of a repeated target occurring 318ms after T2 in RSVP. The blinked repetition priming effect was additive with target frequency. These results indicate that: (1) the outcomes of processing prime words are a key factor in repetition priming effects, with blinked and reported T2s behaving like masked and unmasked primes, respectively, (2) there may be different sources of repetition effects, (3) there is a consistent cross-paradigm pattern of repetition effects that occurs as a function of prime–target interval and the ability to identify the word on its first and second presentation.

Episodic accessibility and morphological processing: Evidence from long-term auditory priming

Long-term priming studies of lexical processing have yielded conflicting claims as to whether abstract versus episodic representations are involved during word recognition. A critical piece of evidence that could separate the two accounts rests on the existence of full morphological priming, where morphologically related words yield the same amount of priming as repeated words. In this study, participants performed speeded lexical decision on lists of auditory words and non-words, which contained repeated, morphologically related, semantically related and phonologically related pairs of items. In order to minimize the involvement of episodic factors, we increased the prime–target interval and decreased their physical similarity by introducing a change in speaker’s voice. We show that under conditions that minimize access to episodic features, the magnitude of repetition priming decreased to attain that of morphological priming. Importantly, morphological and repetition priming for words were always observed in the absence of any semantic and phonological priming, suggesting that they cannot be reduced to formal or meaning overlap. Our results support the view that long-term priming taps both abstract lexical codes with a morphological format and episodic memory components. Further, they show that episodic influences on priming can be modulated by prime–target interval and physical similarity.

Subliminal speech perception and auditory streaming

Current theories of consciousness assume a qualitative dissociation between conscious and unconscious processing: while subliminal stimuli only elicit a transient activity, supraliminal stimuli have long-lasting influences. Nevertheless, the existence of this qualitative distinction remains controversial, as past studies confounded awareness and stimulus strength (energy, duration). Here, we used a masked speech priming method in conjunction with a submillisecond interaural delay manipulation to contrast subliminal and supraliminal processing at constant prime, mask and target strength. This delay induced a perceptual streaming effect, with the prime popping out in the supraliminal condition. By manipulating the prime-target interval (ISI), we show a qualitatively distinct profile of priming longevity as a function of prime awareness. While subliminal priming disappeared after half a second, supraliminal priming was independent of ISI. This shows that the distinction between conscious and unconscious processing depends on high-level perceptual streaming factors rather than low-level features (energy, duration).

Visual attention amplifies response priming of pointing movements to color targets

We studied the influence of spatial visual attention on the time course of primed pointing movements. We measured pointing responses to color targets preceded by color stimuli priming either the same response as the target or the opposite response. The effects of visual attention at the prime and target locations were studied by varying both the cue-prime and prime-target intervals when presenting either exogenous attentional cues or, in a separate experiment, endogenous cues whose processing was a precondition for performing the task. Pointing trajectories revealed large priming effects in which pointing responses were first controlled by prime signals and then captured in midflight by target signals. Priming effects were strongly amplified when the relevant prime locations were visually attended at optimal cue-prime SOAs, with attention modulating the entire time course of the primed pointing movements. We propose that visual attention amplifies the earliest waves of visuomotor feedforward information, elicited in turn by primes and by targets.

Effects of Prime Task on Affective Priming By Facial Expressions of Emotion

Priming of affective word evaluation by pictures of faces showing positive and negative emotional expressions was investigated in two experiments that used a double task procedure where participants were asked to respond to the prime or to the target on different trials. The experiments varied between-subjects the prime task assignment and the prime-target interval (SOA, stimulus onset asynchrony). Significant congruency effects (that is, faster word evaluation when prime and target had the same valence than when they were of opposite valence) were observed in both experiments. When the prime task oriented the subjects to an affectively irrelevant property of the faces (their gender), priming was observed at SOA 300 ms but not at SOA 1000 ms (Experiment 1). However, when the prime task assignment explicitly oriented the subjects to the valence of the face, priming was observed at both SOA durations (Experiment 2). These results show, first, that affective priming by pictures of facial emotion can be obtained even when the subject has an explicit goal to process a non-affective property of the prime. Second, sensitivity of the priming effect to SOA duration seems to depend on whether it is mediated by intentional or unintentional activation of the valence of the face prime.

Further evidence of gender stereotype priming in language: Semantic facilitation and inhibition in Italian role nouns

Two experiments tested the activation of gender stereotypes for Italian role nouns (e.g.,teacher). The experimental paradigm was modeled on the one proposed by a study by Banaji and Hardin: participants were shown a prime word followed by a target pronoun (heorshe) on which they performed a gender decision task. The prime words were Italian role nouns that had an associated female stereotype, an associated male stereotype, or no associated stereotype (control condition). The results of Experiment 1 showed no influence of stereotypes on the gender decision response to personal pronouns. However, when, in Experiment 2, the prime-target interval and the prime presentation times were prolonged, a stereotypical gender priming effect did emerge. A different inhibition pattern was found when the pronoun was preceded by a noun associated with a male stereotype instead of a female one.

The effect of nonmasking distractors on the priming of motor responses.

Masked stimuli (primes) can affect the preparation of a motor response to subsequently presented target. In numerous studies, it has been shown that the compatibility effect is biphasic as it develops over time: positive (benefits for compatible trials and costs for incompatible trials) for short prime-target temporal distances and negative (benefits for incompatible trials and costs for compatible trials) for long ones. What triggers the 2nd phase is the matter of the current debate. According to the self-inhibition hypothesis, the motor response elicited by a prime is automatically followed by an inhibition phase. The object-updating and mask-triggered inhibition hypotheses assume that this phase is triggered by the mask, provided that it contains features calling for the alternative response. In the present study, the author shows that the compatibility effect is modulated on the temporal position of a nonmasking distractor presented after the prime and before the target. With a distractor possessing task-relevant features, the compatibility effect was found to be negative for short prime- distractor intervals and for moderate prime-target intervals. The consequences of these results for the 3 hypotheses are discussed.

How a PINT can hurt you now but help you later: The time course of priming for word body neighbors

The process of naming an exception word prime (e.g., PINT) delays subsequent naming of a nonrhyming regular-inconsistent word body neighbor target (e.g., TINT). Both an activation account ( Taraban & McClelland, 1987) and a learning account ( Burt & Humphreys, 1993) have been offered to explain this interference effect. We investigated how long these effects last in naming tasks, using prime-target intervals ranging from 3 to 51 s. We also explored whether such effects are longer lasting in more difficult phonological lexical decision tasks (PLDT, does it sound like a word?). The results showed that phonologically based interference effects were present only at relatively short (3–5 s) prime-target intervals in naming tasks but that the same items produced longer term facilitation effects in PLDT. We invoke both activation and memory mechanisms to explain the full pattern of results.

Motor Control in Old Age: Evidence of Impaired Low-Level Inhibition

In the masked prime task, responses to supraliminal targets are influenced by previously presented subliminal primes. When targets follow primes immediately, positive compatibility effects are obtained such that performance is better when prime and target are compatible (mapped to the same response) than when they are incompatible (mapped to opposite responses). In young adults, this pattern reverses with longer interstimulus intervals (negative compatibility effect). These effects reflect an activation-followed-by-inhibition process: Primes trigger an initial activation of their corresponding motor response, which is subsequently inhibited. The present study demonstrates that healthy older adults (M = 76 years) show a substantial positive compatibility effect with a short prime-target interval, but they fail to produce reliable negative compatibility effects with longer intervals, indicating an age-related impairment in low-level motor control.

Automatic activation of the semantic network in schizophrenia: evidence from event-related brain potentials

Background Language disorder associated with schizophrenia might be due to disturbances in both automatic activation and mechanisms of controlled attention. The contribution of each process to semantic memory dysfunction has not been determined for schizophrenia, and the semantic priming paradigm is well-suited for addressing this question. In the present report, event-related potentials (ERPs) elicited under conditions assumed to reveal automatic activation (short prime-target interval and low proportion of related words) are compared directly with ERPs elicited under conditions associated with controlled processing (long prime-target interval and high proportion of related words). Methods Visual ERPs were recorded during a lexical decision task, in which semantic relationship (associated and unassociated words), expectancy (relatedness proportions), and prime-target interval (250- and 850-msec inter-stimulus intervals [ISIs]) were varied. Diagnosis and expectancy were between-subjects factors; semantic relationship and ISI were repeated measures. The N400 priming effect (enhanced negativity to unassociated words) was compared between 34 male normal control subjects tested once and 37 male schizophrenia inpatients evaluated during their participation in a double-blind haloperidol maintenance therapy and placebo replacement protocol. Results The N400 priming effect for patients was significantly reduced during both pharmacologic phases, compared with controls. During haloperidol treatment, however, patients showed a significant N400 priming effect over the anterior scalp region and additionally under the automatic activation condition. The N400 priming effect was enhanced under the controlled processing condition for control subjects; this effect was not observed for patients. N400 amplitude elicited under the rapid presentation rate (250-msec ISI) differed between medicated patients and controls; groups did not differ for the 850-msec ISI. Conclusions Findings suggest that automatic activation and mechanisms of controlled attention are both disrupted during semantic memory access for schizophrenia patients. Pharmacologic agents, such as haloperidol, might enhance automatic activation of the semantic network in this patient population, as indexed by the N400 component of the ERP.

Competition between automatic and controlled processes

We investigated the competition between automatic and controlled processes in a word stem completion task. Prime-display duration and the prime-target interval were manipulated. On each trial a masked prime was displayed briefly, followed either immediately or after a delay by a word stem. The subjects were required to complete each stem with the first word that came to mind, to report any prime they could identify, and not to give as completion any identified prime. By the assumption that automatic processes require less stimulus input and can be completed faster than consciously controlled processes we expected a stronger performance contribution from automatic processes with the shorter prime-display durations and in the immediate stems condition. The results confirmed this expectation. The findings highlight that consciously controlled processes require more time to run their course than unconscious automatic processes.