Longer Short Stimulus Onset Asynchronies Research Articles

Do visible semantic primes preactivate lexical representations?

Considerable research effort has been devoted to investigating semantic priming effects, particularly, the locus of those effects. Semantically related primes might activate their target's lexical representation (through automatic spreading activation at short stimulus onset asynchronies (SOAs), or through generation of words expected to follow the prime at longer SOAs). Alternately, semantically related primes might aid responding after target identification (i.e., postlexically). In contrast, masked orthographic priming effects appear to be lexical and automatic. Lexical processing of targets is facilitated by orthographically similar nonword primes and often inhibited by orthographically similar word primes (Davis & Lupker, 2006). Using the lexical-decision task (LDT), we found additivity between the facilitative effects of visible semantic primes and the facilitative effects of masked orthographically similar nonword primes at long and short SOAs, consistent with a postlexical locus of the semantic priming effects. Also consistent with this conclusion, semantic primes affected the skew of the distribution (larger effects on longer latency trials), whereas masked orthographic primes did not. In a final experiment, visible primes that were semantically related to the masked orthographic word primes did not make those primes more effective lexical inhibitors of orthographically similar targets (independent of SOA). Taken together, our findings suggest that the impact of a semantic prime is not to increase the lexical activation of related concepts. Rather, they suggest that the locus of semantic priming effects in LDTs is postlexical, in that discovering the existence of a relationship between the prime and target biases participants to make a "word" response. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Response Priming with Horizontally and Vertically Moving Primes: A Comparison of German, Malaysian, and Japanese Subjects.

Response priming refers to the finding that a prime preceding a target influences the response to the target. With German subjects, horizontally moving dots as primes, and static arrows as targets, there are typically faster responses to compatible (i.e., prime and target are associated with the same response) as compared to incompatible targets (i.e., positive compatibility effect, PCE) with short stimulus onset asynchronies (SOAs). In contrast, with longer SOAs, subjects respond faster to incompatible as compared to compatible targets (i.e., negative compatibility effect, NCE). In the present study, we extended the evidence by adding vertically oriented materials. Furthermore, we tested subjects from Malaysia and Japan, where the vertical orientation is more present in daily life, and compared them to German subjects to investigate whether the amount of experience with one orientation influences the compatibility effects on this orientation. Overall, we found pronounced PCEs in the short SOA (i.e., 150 ms) but only reduced PCEs in the longer SOAs (i.e., 350, 550, and 750 ms) across all countries and orientations. There were no differences between the German and Malaysian samples, but the Japanese sample showed larger PCEs in the longer SOAs compared to both other samples. Furthermore, we found larger PCEs for horizontal than vertical materials in the short SOA and larger PCEs for vertical than horizontal materials in the longer SOAs. We discuss our findings in light of theories and findings on compatibility effects as well as attentional mechanisms.

Activation, Inhibition, or Something Else: An Exploratory Study on Response Priming Using Moving Dots as Primes in Middle-Aged and Old Adults.

Response priming refers to the finding that a prime stimulus preceding a target stimulus influences the response to the following target stimulus. With young subjects, using moving dot stimuli as primes indicated faster responses to compatible targets (i.e., prime and target are associated with the same response) with short stimulus onset asynchronies (SOAs). In contrast, with longer SOAs, participants responded faster to incompatible targets. In the present study, we extended the evidence by comparing middle-aged (50–65 years) and old (66–87 years) adults. With two different motion types, the result found in young participants was replicated in the middle-aged adults. In contrast, old adults showed large positive compatibility effects with the short SOA but neither activation nor inhibition effects with the longer SOA. We discuss our findings in light of several theoretical accounts (i.e., inhibitory deficit, deautomatization, evaluation window account, attention, rapid decay).

The head turn cueing effect is sustained at longer SOA's in the presence of an object distractor

In social cueing studies, participants are asked to discriminate a target object cued by social signals, such as eye gaze or head turns. Knowing that the cues are not predictive, participants nevertheless respond faster to the target presented at the cued than uncued location at short Stimulus Onset Asynchrony (SOA) intervals of 300 to 600 ms. However, as the SOA between the cue and target increases (1005 ms), the cueing effect diminishes indicating that the reflexivity of social cues can be overridden by voluntary, controlled processes.In the current study, we tested the reflexive and voluntary characteristics of social cues in an object recognition task. In our paradigm, participants were asked to discriminate a circle or square target object appearing in the left or right hand of a human model. On half of the trials, a distractor triangle object appeared in the opposite hand and on the other half of the trials, no distractor object was presented in the opposite hand. The target object was cued by a head turn that appeared at SOA's of 0, 105, 300, 600 or 1005 ms. Participants had to report which target they saw by key press and were told to ignore the head turn because it had no predictive validity. Without a distractor, the typical results were found where a cueing effect was evident at SOAs of 300 and 600 ms and disappeared at the longer 1005 ms SOA. However, in the distractor present condition, a cueing effect was found at the 300, 600 and critically, remained potent at the SOA of 1005 ms. These results call into the question of the reflexive-voluntary account of social cueing effect and suggest that, in the presence of a distractor object, head turn cues cannot be voluntarily inhibited at the long SOA. Meeting abstract presented at VSS 2012

Gaze and Arrow Distractors Influence Saccade Trajectories Similarly

Perceiving someone's averted eye-gaze is thought to result in an automatic shift of attention and in the preparation of an oculomotor response in the direction of perceived gaze. Although gaze cues have been regarded as being special in this respect, recent studies have found evidence for automatic attention shifts with nonsocial stimuli, such as arrow cues. Here, we directly compared the effects of social and nonsocial cues on eye movement preparation by examining the modulation of saccade trajectories made in the presence of eye-gaze, arrows, or peripheral distractors. At a short stimulus onset asynchrony (SOA) between the distractor and the target, saccades deviated towards the direction of centrally presented arrow distractors, but away from the peripheral distractors. No significant trajectory deviations were found for gaze distractors. At the longer SOA, saccades deviated away from the direction of the distractor for all three distractor types, but deviations were smaller for the centrally presented gaze and arrow distractors. These effects were independent of whether line-drawings or photos of faces were used and could not be explained by differences in the spatial properties of the peripheral distractor. The results suggest that all three types of distractors (gaze, arrow, peripheral) can induce the automatic programming of an eye movement. Moreover, the findings suggest that gaze and arrow distractors affect oculomotor preparation similarly, whereas peripheral distractors, which are classically regarded as eliciting an automatic shift of attention and an oculomotor response, induce a stronger and faster acting influence on response preparation and the corresponding inhibition of that response.

Modulation of reflexive orienting to gaze direction by facial expressions

Facial expression and gaze perception are thought to share brain mechanisms but behavioural interactions, especially from gaze-cueing paradigms, are inconsistent. We conducted a series of gaze-cueing studies using dynamic facial cues to examine orienting across different emotional expression and task conditions, including face inversion. Across experiments, at a short stimulus–onset asynchrony (SOA) we observed both an expression effect (i.e., faster responses when the face was emotional versus neutral) and a cue validity effect (i.e., faster responses when the target was gazed-at), but no interaction between validity and emotion. Results from face inversion suggest that the emotion effect may have been due to both facial expression and stimulus motion. At longer SOAs, validity and emotion interacted such that cueing by emotional faces, fearful faces in particular, was enhanced relative to neutral faces. These results converge with a growing body of evidence that suggests that gaze and expression are initially processed independently and interact at later stages to direct attentional orienting.

Orienting of spatial attention in Huntington's Disease

To explore the functioning of spatial attention in Huntington's Disease (HD), 14 HD patients and 14 age-matched controls performed a cued response time (RT) task with peripheral cues. In Experiment 1, cues were not informative about the future target location, thus eliciting a purely exogenous orienting of attention. At short stimulus-onset asynchrony (SOA), controls showed an initial facilitation for cued locations, later replaced by a cost (inhibition of return, IOR). Patients had a larger and more persistent validity effect, with delayed IOR, resulting from a larger cost for uncued targets. This suggests an impairment of attentional disengaging from cued locations. In Experiment 2, 80% of the cues were valid, thus inducing an initially exogenous, and later endogenous, attentional shift towards the cued box. The validity effect was larger in patients than in controls, again as a result of a disproportionate cost for uncued targets. In Experiment 3, 80% of the cues were invalid, thus inviting participants to endogenously re-orient attention towards the uncued box. Patients could take advantage of invalid cues to re-orient their attention towards the uncued targets but at a longer SOA than controls, thus suggesting that endogenous orienting is preserved in HD, but slowed down by the disengage deficit. The disengage deficit correlated with several radiological and biological markers of HD, thus suggesting a causal relationship between HD and attentional impairments. Cued RT tasks are promising tools for the clinical monitoring of HD and of its potential treatments.

Reconfiguration and the bottleneck: Does task switching affect the refractory period effect?

If two stimuli are presented with a short stimulus–onset asynchrony (SOA), the response to the second stimulus is usually slower than on longer SOAs. Bottleneck theories attribute these dual-task costs, also known as the psychological refractory period (PRP) effect, to an inability for carrying out two central processes simultaneously. A delay of the second response is also observed if the instruction of the current single task is different from that of the previous single task. These costs of task switching are typically attributed to the costs of control operations. The current study investigated how task-switching costs relate to the PRP effect. In the first experiment, dual-task trials were preceded by prime tasks. In the dual task, the second task was or was not the same as the prime task. The latency of the second response was substantially reduced if the second task was primed, and the priming effect was independent of SOA. A second experiment compared the PRP effect on dual tasks with and without a task switch. Task selection was complicated by requiring the participant to vocalise a word that was compatible, incompatible, or neutral with respect to the currently relevant stimulus dimension. Again, the switch costs and the compatibility effect were constant across SOA. These experiments corroborate the conclusion of Lien, Schweickert, and Proctor (2003) that control operations involved in task switching are sensitive to capacity limitations that also give rise to the PRP effect, and show that it also applies to endogenous switch processes and ambiguous stimuli.

A central-peripheral asymmetry in masked priming.

Masked primes presented prior to a target result in behavioral benefits on incompatible trials (in which the prime and the target are mapped onto opposite responses) when they appear at fixation, but in behavioral benefits on compatible trials (in which the prime and the target are mapped onto the same response) when appearing peripherally. In Experiment 1, the time course of this central-peripheral asymmetry (CPA) was investigated. For central primes, compatible-trial benefits at short stimulus onset asynchronies (SOAs) turned into incompatible-trial benefits at longer SOAs. For peripheral primes, compatible-trial benefits at short SOAs increased in size with longer SOAs. Experiment 2 showed that these effects also occur when primes and targets are physically dissimilar, ruling out an interpretation in terms of the perceptual properties of the stimulus material. In Experiments 3 and 4, the question was investigated as to whether the CPA is related to visual-spatial attention and/or retinal eccentricity per se. The results indicate that the CPA is independent of attentional factors but strongly related to the physiological inhomogeneity of the retina. It is argued that central and peripheral primes trigger an initial motor activation, which is inhibited only if primes are presented at retinal locations of sufficiently high perceptual sensitivity. The results are discussed in terms of an activation threshold model.

Sequential effects in rudimentary auditory and visual tasks.

Three experiments examined sequential effects in choice reaction time tasks. On each trial, a right/left positional judgment was made to a either a pure tone or a luminance increment in a visual array of box elements. In the first two experiments, a preparatory signal was presented prior to each imperative signal to indicate the relevant stimulus modality. At a short stimulus onset asynchrony (SOA) between the preparatory and the imperative signal (i.e., 60 msec), subjects were quicker to repeat the same response than to change their response when presented with successive tones, although no such repetition effect occurred on the visual target trials. Subjects were impaired if the stimulus modality changed across successive trials regardless of the modality of the target. At a longer SOA (i.e., 500 msec), these sequential effects were abolished; subjects were assumed to be able to prepare for the relevant modality because of the presentation of the preparatory signal. When the preparatory signals were omitted, in a final experiment, the modality-switching costs were still evident, but now inhibition of return occurred on both the auditory and the visual target trials-subjects were now impaired in responding when the target reappeared at its immediately previous location. It seems, therefore, that the repetition effect and modality-switching effects do dissociate. The data revealed clear differences between orienting attention to a particular spatial locale and focusing attention to a particular sensory modality.

Implicit knowledge versus psychoacoustic similarity in priming of chords.

A chord-priming paradigm was used to test predictions of a neural net model (MUSACT). The model makes a nonintuitive prediction: Following a prime chord, expectations for the target chord are based on psychoacoustic similarity at short stimulus onset asynchronies (SOAs) but on implicit knowledge of conventional relationships at longer SOAs. In a critical test, 2 targets were selected for each prime. One was more psychoacoustically similar to the prime, and the other was more closely related on the basis of convention. With an SOA of 50 ms, priming favored the psychoacoustically similar target; with SOAs of 500 ms and longer, the effect reversed, and priming favored conventional relatedness. The results underscore the limitations of models of harmony based on psychoacoustic factors alone. These studies demonstrate how neural net learning models that are appropriately constrained can be subject to strong empirical verification. It is an age-old question whether relationships between musical chords are driven by the physical structure of periodic sounds or by implicit knowledge of cultural convention. In advancing the former view, Helmholtz (1885/1954) suggested a measure of acoustic similarity based on the number of frequencies in common between two chords. A contemporary descendent of this approach (Parncutt, 1989; Terhardt, 1974, 1979) uses a measure of psychoacoustic similarity based on the number of evoked pitches in common. The implicit knowledge hypothesis receives support from the priming of chords, which seems to be based on conventional associations rather than shared frequencies (Bharucha & Stoeckig, 1987). In this article, we explore some of the boundary conditions of these two views. Priming tasks reveal that people have substantial implicit knowledge of conventional relationships between chords, even if they have had no formal musical training and cannot verbalize this knowledge (Bharucha & Stoeckig, 1986, 1987). In particular, for Western participants with or without formal musical training, a chord primes other chords that have high transition probabilities in the most prevalent (i.e., popular) forms of Western music. These priming effects have been simulated by a neural net model (MUSACT) that has passively internalized the grouping of tones typical of the Western musical environment (Bharucha, 1987a, 1987b). It has been suggested that pervasive tonal patterns become

Prefrontal cortical function and schizophrenia

To explore the functioning of spatial attention in Huntington's Disease (HD), 14 HD patients and 14 age-matched controls performed a cued response time (RT) task with peripheral cues. In Experiment 1, cues were not informative about the future target location, thus eliciting a purely exogenous orienting of attention. At short stimulus-onset asynchrony (SOA), controls showed an initial facilitation for cued locations, later replaced by a cost (inhibition of return, IOR). Patients had a larger and more persistent validity effect, with delayed IOR, resulting from a larger cost for uncued targets. This suggests an impairment of attentional disengaging from cued locations. In Experiment 2, 80% of the cues were valid, thus inducing an initially exogenous, and later endogenous, attentional shift towards the cued box. The validity effect was larger in patients than in controls, again as a result of a disproportionate cost for uncued targets. In Experiment 3, 80% of the cues were invalid, thus inviting participants to endogenously re-orient attention towards the uncued box. Patients could take advantage of invalid cues to re-orient their attention towards the uncued targets but at a longer SOA than controls, thus suggesting that endogenous orienting is preserved in HD, but slowed down by the disengage deficit. The disengage deficit correlated with several radiological and biological markers of HD, thus suggesting a causal relationship between HD and attentional impairments. Cued RT tasks are promising tools for the clinical monitoring of HD and of its potential treatments.

Temporal integration of acoustic and cutaneous stimuli shown in the blink reflex.

Temporal integration of pairs of brief blink-eliciting acoustic and cutaneous stimuli was investigated to determine if there was integration of stimuli from different modalities. Reflexes elicited by a tone burst or by a brief electrical shock to the supraorbital nerve followed by a second tone burst or shock at short stimulus onset asynchronies (SOAs) were larger and faster than control reflexes elicited by a single stimulus identical to the lead stimulus of the stimulus pairs. Reflex amplitude was augmented at longer SOAs where there was no effect on latency. Temporal integration was evident for all stimulus pairs, showing that it is due, at least in part, to processes that occur outside specific sensory pathways. Heterogeneous stimulus pairs produced greater reflex enhancement than did homogeneous stimulus pairs. This finding was examined further in Experiment 2, which showed that reflex enhancement with pairs of acoustic pulses was unaffected by the frequency of the second stimulus, suggesting that sensory masking was not acting to suppress reflex expression with acoustic pulse pairs. Integration of reflexogenic acoustic stimuli shown in the blink reflex is restricted to shorter intervals than is integration of acoustic stimuli shown by psychophysical procedures, suggesting that the two methods reflect different aspects of stimulus processing. Integration of reflexogenic stimuli may result from summation of activity associated more directly with reflex expression than with perceptual awareness.

Automatic and expectancy-based priming effects in a digit naming task.

In a voice reaction time task, subjects named target digits that were horizontally flanked by noise digits or by a neutral symbol (#). For the control subjects, the noise digits were uncorrelated with the target digit, whereas for three experimental groups, the value of the noise digit predicted the target digit by an arithmetic rule (target = noise, target = noise + 1, target = noise - 1) on 75% of the trials. Patterns of reaction time facilitation and inhibition relative to the control condition among the four subject groups illustrated differing time courses of involuntary and expectancy-based priming. For prediction rules requiring an arithmetic transformation (expect N = 1 and expect N - 1), responses to predicted targets were slowed by response competition at short stimulus-onset asynchrony (SOAs) but greatly facilitated by expectancy at longer SOAs.