An anxiety-related bias in semantic activation when processing threat/neutral homographs

Three experiments are reported comparing high and low-trait anxious subjects in terms of their patterns of semantic activation in response to ambiguous primes, with one threat-related and one neutral meaning. Such primes were followed by targets related to either their threat or neutral meaning, or by unrelated targets, in a lexical decision task. Experiments 1 to 3 employed stimulus onset asynchronies (SOAs) of 750 msec, 500 msec, and 1250 msec, respectively. At 500-msec SOA all subjects showed facilitation for both meanings. At 750-msec SOA the only significant priming effect was that for the threat-related meaning in the high-anxiety group, and a similar trend was found at 1250-msec SOA. Consideration of the patterns of priming for targets following ambiguous threat/neutral primes suggest that at the longer SOAs, high-anxiety subjects consciously “lock on” to a threatening interpretation if one has been made available by earlier automatic spreading activation.     

Cognate status and cross-script translation priming

Greek-French bilinguals were tested in three masked priming experiments with Greek primes and French targets. Related primes were the translation equivalents of target words, morphologically related to targets, or phonologically related to targets. In Experiment 1, cognate translation equivalents (phonologically similar translations) showed facilitatory priming, relative to matched phonologically related primes, in conditions in which morphologically related primes showed no effect (50-msec prime exposure). Cross-language morphological priming emerged at longer prime exposure durations (66 msec), but cognate primes continued to generate more priming than did those in the morphological condition. In Experiments 2 and 3, the level of phonological overlap across translation equivalents was varied, and priming effects were measured against those for matched phonologically related primes and those in an unrelated prime condition. When measured against the unrelated baseline, cognate primes showed the typical advantage over noncognate primes. However, this cognate advantage disappeared when priming was measured against the phonologically related prime condition. The results are discussed in terms of how translation equivalents are represented in bilingual memory.     

Effects of time and event uncertainty upon sequential information processing

Two experiments were conducted to investigate the psychological refractory period (PRP), a delay induced into the second of two reaction times (RT) when the interstimulus interval (ISI) is short. In Experiment1, time and event uncertainty were factorially varied by providing or not providing S with foreknowledge of the ISI and the order in which the two events would occur, respectively. ISIs of0, 50, 100, 200, and400 msec were used. Time and event uncertainty produced independent degradation of both RTs. Also, the second RT (RT ₂ ) was delayed at50 msec ISI when both time and event certainty were present. Experiment 2 attempted to replicate this latter finding using ISIs of0, 25, 50, 75, and100 msec. Delays in RT ₂ were found for the middle three values of ISI. These results were interpreted as supporting a modified single channel theory of the PRP.     

Effects of paradigm and inter-stimulus interval on age differences in eyeblink classical conditioning in rabbits

The aim of this study was to examine parameters affecting age differences in eyeblink classical conditioning in a large sample of young and middle-aged rabbits. A total of 122 rabbits of mean ages of 4 or 26 mo were tested at inter-stimulus intervals (ISIs) of 600 or 750 msec in the delay or trace paradigms. Paradigm affected both age groups dramatically, with superior performance in the delay paradigm. ISI was salient as middle-aged rabbits were significantly impaired in 750-msec compared with 600-msec delays, and young rabbits were significantly less impaired in 600-msec than in 750-msec trace. Young rabbits performed equally well at both delay ISIs, and consequently, there were significant age differences in 750-msec but not in 600-msec delays. Middle-aged rabbits performed poorly at both 600- and 750-msec trace, resulting in significant age differences in 600-msec but not in 750-msec trace. Timing of the conditioned response has been associated with cerebellar cortical function. Normal aging of the cerebellar cortex likely contributed to the magnitude of the effect of ISI in delay conditioning in middle-aged rabbits. Results demonstrate that the magnitude of age differences in eyeblink conditioning can be enlarged or eliminated by ISI and paradigm.     

Parameters affecting gap detection in the rat

The present research used a startle amplitude reduction paradigm to investigate the ability of the rat’s auditory system to track rapidly changing acoustic transients. Specifically examined was the ability of brief gaps in otherwise continuous noise to reduce the amplitude of a subsequently elicited acoustic startle reflex. The duration of the gap, time between gap offsetand startle elicitation (the interstimulus interval or ISI), and rise-fall characteristics of the gap were systematically varied. Consistent with previous research, gaps reliably reduced startle amplitude. Gaps 2 msec long were reliably detected, and a 50-msec ISI resulted in the greatest amplitude reduction. Gaps presented at short ISIs produced amplitude reduction that followed a different time course than did gaps presented at longer ISIs. These results may reflect differences in the length oftime available for the processing of the stimulus and may involve two different processes.     

Semantic priming of familiar faces

A series of experiments to explore the effect of priming by semantically related items in familiarity judgement tasks using faces and names that are analogous to lexical decision tasks is reported. In the first experiment, the semantic priming effect in face recognition reported by Bruce (1983) was explored in more detail by including neutral as well as associated and unrelated primes and by varying the prime-target SOA from 250 to 1,000 msec. Significant facilitation effects, with no inhibition, were found at all three SOAs. To explore the analogy between the processing of faces and verbal materials, a second experiment used names rather than faces. The difference between related and unrelated conditions at 250- and 1,000-msec SOA was similar to that found for faces in Experiment 1, but for names there was some evidence of inhibition. To investigate the locus of the priming effect with faces, in Experiment 3 the effect of degrading face targets was examined. An interaction between stimulus quality and semantic priming was observed, suggesting that the locus of the facilitation might lie at a relatively early stage in face processing. The results of these experiments illustrate further similarities between the processing of faces and verbal materials (cf. Bruce 1979, 1981).     

Semantic priming and identification of near threshold primes in a lexical decision task

Three experiments examined both the impact of semantic analysis of 50-msec, masked visual primes on a target response and the impact of semantic analysis of the target on a prime response. The first two experiments used a prime-target interval of 1000 msec. In Experiment 1, subjects reported the identity of each prime: (a) after a lexical decision about the target, (b) both before and after a lexical decision, or (c) after a target detection response. Prime report after both types of target response showed retroactive priming in which report was facilitated by related targets and inhibited by unrelated targets. Analyses of lexical decision latency and accuracy conditionalized on prime report showed that semantic priming was restricted to reported related primes. In Experiment 2, subjects made no overt response to the primes. Priming was conditionalized on recognition of the primes on a subsequent test. The pattern was the same as Experiment 1: There was priming only for recognized primes; recognition memory showed a pattern consistent with retroactive priming. Experiment 3 also conditionalized priming on recognition performance but used a prime-target interval of only 250 msec. Again, semantic priming was found only for recognized primes, and recognition memory revealed retroactive priming. Retroactive priming indicates an interdependency between prime and target processing that needs to be incorporated into models of semantic priming.     

Strategic reliance on phonological mediation in lexical access

The present study investigated strategic variation in reliance on phonological mediation in visual word recognition. In Experiment 1, semantically related or unrelated word primes preceded word, pseudohomophone (e.g.,trane), or nonpseudohomophone (e.g.,trank) targets in a lexical decision task. Semantic priming effects were found for words, and response latencies to pseudohomophones were longer in related than in unrelated prime conditions. In Experiment 2, related or unrelated word primes preceded word or pseudohomophone targets. A relatedness effect was found for words, although it was significant at a 600-msec prime-target stimulus onset asynchrony (SOA) and not at a 200-msec SOA. There was no relatedness effect for pseudohomophones. Experiment 3 was a replication of Experiment 2, except that pseudohomophones were replaced by nonpseudohomophonic orthographic controls. Facilitation effects for related target words were greater in Experiment 3 than in Experiment 2. The results reflect apparent variations in the expectation that a related prime reliably indicates that a target is a word. Although reliance on phonological mediation might be strategically contingent, there could be a brief time period in which phonologically mediated lexical access occurs automatically. Whether phonological information is maintained or suppressed subsequently depends on its overall usefulness for the task.     

汉语双音节同音词词汇歧义消解过程的研究

使用跨通道词汇判断任务和语义启动技术,两个实验分别考察了孤立状态下和句子语境中汉语双音节同音词意义通达的情况,结果发现(1)在孤立状态下,无论ISI为0毫秒还是-150毫秒,与同音词主要或次要意义有关的探测词都受到了促进;(2)当ISI为0毫秒时,在语境一致的条件下,与同音词主要或次要意义有关的探测词均受到了促进,在语境不一致的条件下,则未发现任何促进效应;(3)当ISI为-150毫秒时,只是在语境一致并且探测词与同音词的主要意义有关的条件下才观察到促进效应。     

The role of visual short-term memory in empty cell localization

Three experiments examined the visual memory representation supporting performance at long interstimulus intervals (ISIs) in an empty cell localization task. Two arrays of dots within a 4 x 4 grid were displayed briefly in succession. One grid cell did not contain a dot in either array, and the task was to localize the empty cell. In Experiment 1, we replicated previous findings of recovery to high levels of performance at long ISIs. In Experiment 2, we tested whether figural grouping in visual short-term memory (VSTM) supports long-ISI performance by manipulating the complexity of the array pattern. Pattern complexity had no effect on empty cell localization at 0-msec ISI, suggesting dependence on high-capacity visible persistence, but there was a large simple pattern advantage at long ISIs, suggesting dependence on figural grouping in VSTM. Experiment 3 demonstrated that participants typically remember the empty cells of the first array, and not the dots, for comparison with Array 2.     

Slow potential changes and choice reaction time as a function of interstimulus interval

Slow potential changes were recorded over the vertex (C_z) during a choice reaction task. The constant interstimulus interval (ISI) between the visual warning (S₁) and the visual imperative signal (S₂) was either 200, 400, 1000 or 2000 msec. The contingent negative variation (CNV) was not only measured between S₁ and S₂ (CNV₂), but also before S₁ (CNV₁).The main results were: (1) The CNV₂ amplitude showed significant variation as a function of ISI. It reached its maximum with an ISI of 1000 msec. (2) CNV₁ developed only before the short ISIs (200 and 400 msec). (3) When CNV₁ and CNV₂ were summed the differences in CNV amplitudes and durations between different ISIs became smaller. (4) The peak-to-peak amplitude P₁-N₁ of the potential evoked by S₁ was enhanced with short ISIs. (5) The correlations between mean CNV and median reaction time (RT) were low but significant for ISIs of 400, 1000 and 2000 msec. When, however, the effect of subjects was partialized out these correlations were drastically reduced, whereas the partialization of session and block effects had no noticeable influence on these correlations. (6) The correlations between single RT and single CNV (measured for the ISI of 1000 msec, individually for two subjects) were weak or even completely lacking.The main conclusion was that CNV coincides with preparedness to react to a stimulus in a choice RT-task, but its amplitude at the moment of onset of the imperative stimulus does not reflect, or reflects weakly, the degree of preparedness (as indicated by RTs) at that moment.     

The facilitation of lexical decisions by a prime occurring after the target

Three experiments are reported that investigate priming effects in a lexical decision task. when the prime was presented after the target. In Experiment 1, the lexical decision target was presented for 50 msec, followed 80 msec later by the prime. No significant facilitation of responses was observed in the related prime condition. In Experiment 2, the target was presented for 30 msec, followed 35 msec later by the prime. Targets followed by related primes were responded to significantly faster than targets with unrelated primes. Experiment 3 replicated the result of Experiment 2. The data are interpreted as supporting parallel processing of the prime and target in semantic priming experiments. The theoretical implications of the “backward” priming effect are discussed.     

Reaction time to the second of two shortly spaced auditory signals both varying in intensity

Six subjects participated in a reaction time (RT) task in which the stimulus events consisted of two sinusoidal waves presented in close succession. The leading stimulus (S₁) had a duration of 25 msec while the binary reaction stimulus (S₂) was 250 msec. Presentation of the interstimulus interval (ISI) was irregular. S₁ as well as S₂ varied in intensity and were assigned randomly the values of 45, 68, 85 and 105 db (SPL). RT to S₂ was examined as a function of the intensity of both stimuli. Generally RT varied inversely with the intensity of S₁ and the downward gradient of RT with ISI became steepened at least for ISIs shorter than 200–250 msec. Concerning S₂, RT grew shorter as the intensity increased up to 85 db. Probably due to startle, RT tended to lengthen at S₂ = 105 db. When both S₁ and S₂ were 105 db the startle effect upon RT seemed most evident. Then the elevation in RT took place at especially those ISIs for which he fastest RTs might have been expected (about 200 msec). For the remaining intensities no interaction between S₁ and S₂ upon RT was found even for the shortest ISIs, implying that the effects of S₁ and S₂ intensities upon RT were independent.     

Common response processing and psychological refractoriness

This experiment examined whether structural considerations, that is the functional closeness of limb control centres (Kinsbourne and Hicks 1978), have a role to play in common processing models of psychological refractoriness. A typical double stimulation paradigm was used (Kantowitz 1974). On experimental trials, subjects responded with the right hand (RT1) to an auditory signal (0.80 probability). After a varied interstimulus interval (ISI) of 100, 200, 300 or 700 msec, one of three lights corresponding to one of the other limbs provided the signal for the second response (RT2). Control trials for RT1 and RT2 involved both stimuli, but subjects were required to make only one response. Results indicated that experimental RT1 was lengthened considerably over control values. While typical double stimulation effects were found at short ISIs, that is RT2 was lengthened, RT2 at long ISIs was actually faster than double stimulation control values. Although the RT results were not in a pattern that would be predicted by functional distance (Kinsbourne and Hicks 1978), within subject correlations of RT1 and RT2 by limb condition suggest that structural considerations may have a role to play. While within subject correlations were positive at all levels of ISI, they decreased as the interval between the two signals increased. The implications of these results for common processing models are discussed.     

Spare the rod and spoil the icon

Short-term visual storage was investigated with a successive field paradigm, so that correct performance depended upon combining visual information from two targets that were never on simultaneously. In the first two experiments, the stimuli consisted of two slides, each containing a 10' red dot on a gray surround, and separated by an interstimulus interval (ISI) from 20 to 400 msec. Subjects had to determine if the dots were vertically or horizontally aligned. In Experiment 1, the stimuli had either no contrast for the rods or no luminance contrast for the cones or high contrast. At short ISIs the cone contrast determined performance, whereas at long ISIs the rod contrast determined performance. In fact, when the dots were invisible to the rods, the task was impossible for long ISIs. In Experiment 2, performance was compared for zero log rod contrast and for small departures from zero. Even a small departure from zero log rod contrast resulted in above-chance performance. In Experiment 3, the stimuli were luminous rectangles and the task was to decide whether or not a 4' spatial gap was present between the two successively presented rectangles. Wavelength, luminance, and ISI were varied under both photopic and scotopic adapting conditions. The result was that the rods performed the task for ISIs of 150 msec or longer under scotopic conditions and under the photopic conditions that we were able to test. The results of the experiments taken together are consistent with the hypothesis that the cone icon is short, whereas the rod icon is robust and long lasting.     

Grammatical Priming of Visual Word Recognition in Fourth grade Children

Previous work examining context effects in children has been limited to semantic context. The current research examined the effects of grammatical priming of word-naming in fourth-grade children. In Experiment 1, children named both inflected and uninflected noun and verb target words faster when they were preceded by grammatically constraining primes than when they were preceded by neutral primes. Experiment 1 used a long stimulus onset asynchrony (SOA) interval of 750 msec. Experiment 2 replicated the grammatical priming effect at two SOA intervals (400 msec and 700 msec), suggesting that the grammatical priming effect does not reflect the operation of any gross strategic effects directly attributable to the long SOA interval employed in Experiment 1. Grammatical context appears to facilitate target word naming by constraining target word class. Further work is required to elucidate the loci of this effect.     

Phonology and orthography in visual word recognition: Evidence from masked non-word priming

Three lexical decision experiments in French investigated the effects of briefly presented forward-masked non-word primes on latencies to phonologically and/or orthographically related targets. At 64-msec prime presentation durations, primes that are pseudohomophones of the target produced facilitatory effects compared to orthographic controls, but these orthographically similar non-word primes did not facilitate target recognition compared to unrelated controls. These results were obtained independently of target word frequency and independently of the presence or absence of pseudohomophone targets in the experimental lists. With a 32-msec prime duration, on the other hand, pseudohomophone and orthographic primes had similar effects on target recognition, both producing facilitation relative to unrelated controls. The results are discussed in terms of the time course of phonological and orthographic code activation in the processing of pronounceable strings of letters.     

Primed-lexical decision: The effect of varying the stimulus-onset asynchrony of prime and target

Lexical decisions to word targets are usually faster when they are preceded by associatively related word primes than when they follow a neutral prime. Also; it has been shown that, under certain circumstances, lexical decisions to words preceded by unassociated word primes are slower than those to words following a neutral prime. The present study explores the influence of the stimulus-onset asynchrony (SOA) of prime and target on these priming effects. Eleven SOAs were investigated ranging from 100 msec to 1240 msec. The facilitatory effect of related primes was reliable in all SOA conditions. The inhibitory effect of unrelated primes was reliable in all but one SOA condition. Furthermore, it was found that, up to the longest SOA, facilitation increases with SOA, whereas inhibition remains virtually constant. In the longest SOA condition both facilitation and inhibition decrease. Yet another finding was that pseudowords following non-neutral primes were processed faster than those preceded by neutral primes, except with the two shortest SOAs. It appears that the SOA data cannot be satisfactorily interpreted in terms of actual priming processes, that is, processes that prepare subsequent word recognition, and that some experimental artifacts may partly have been responsible for the observed pattern of results.     

Cleaving automatic processes from strategic biases in phonological priming

In a phonological priming experiment using spoken Dutch words, Dutch listeners were taught varying expectancies and relatedness relations about the phonological form of target words, given particular primes. They learned to expect that, after a particular prime, if the target was a word, it would be from a specific phonological category. The expectancy either involved phonological overlap (e.g., honk-vonk, "base-spark"; expected related) or did not (e.g., nest-galm, "nest-boom"; expected unrelated, where the learned expectation after hearing nest was a word rhyming in -alm). Targets were occasionally inconsistent with expectations. In these inconsistent expectancy trials, targets were either unrelated (e.g., honk-mest, "base-manure"; unexpected unrelated), where the listener was expecting a related target, or related (e.g., nest-pest, "nest-plague"; unexpected related), where the listener was expecting an unrelated target. Participant expectations and phonological relatedness were thus manipulated factorially for three types of phonological overlap (rhyme, one onset phoneme, and three onset phonemes) at three interstimulus intervals (ISIs; 50, 500, and 2,000 msec). Lexical decisions to targets revealed evidence of expectancy-based strategies for all three types of overlap (e.g., faster responses to expected than to unexpected targets, irrespective of phonological relatedness) and evidence of automatic phonological processes, but only for the rhyme and three-phoneme onset overlap conditions and, most strongly, at the shortest ISI (e.g., faster responses to related than to unrelated targets, irrespective of expectations). Although phonological priming thus has both automatic and strategic components, it is possible to cleave them apart.