Sakinah S. J. Alhadad

Modality-specific attentional startle modulation during continuous performance tasks: A brief time is sufficient

Attentional startle modulation has been found to be modality specific in continuous performance tasks (CPTs) and modality nonspecific in trial-structured tasks. Experiment 1 investigated whether attentional blink modulation in a CPT would change if a trial structure was imposed. Participants performed a visual CPT either continuously (CONT), or during brief periods of time signaled by a change in screen color with stimuli either presented all the time (MIXED) or only during the trial segments (DISC). Contrary to expectation, evidence for modality-specific attentional startle modulation-smaller acoustic startle during targets than during nontargets-was strongest in Groups MIXED and DISC. Experiment 2 confirmed that this pattern of results was present during the first stimulus of the task period in group DISC. This suggests that the continuous nature of a task is not critical in determining the attentional mechanisms engaged.

Inferring Learning from Big Data: The Importance of a Transdisciplinary and Multidimensional Approach

The use of big data in higher education has evolved rapidly with a focus on the practical application of new tools and methods for supporting learning. In this paper, we depart from the core emphasis on application and delve into a mostly neglected aspect of the big data conversation in higher education. Drawing on developments in cognate disciplines, we analyse the inherent difficulties in inferring the complex phenomenon that is learning from big datasets. This forms the basis of a discussion about the possibilities for systematic collaboration across different paradigms and disciplinary backgrounds in interpreting big data for enhancing learning. The aim of this paper is to provide the foundation for a research agenda, where differing conceptualisations of learning become a strength in interpreting patterns in big datasets, rather than a point of contention.

Startle blink facilitation during the go signal of a reaction time task is not affected by movement preparation or attention to the go signal

Startle reflex eliciting stimuli presented at the onset of the go signal in a simple forewarned reaction time (RT) task (at a SOA of 0 ms) elicit larger blink reflexes than do stimuli presented later (e.g., at a SOA of 150 ms) or during inter trial intervals. The present study investigated whether this facilitation is affected by attention to the go signal or motor preparation. Participants performed a forewarned reaction time task that crossed the requirements for a speeded response (Hold versus Move) and for a discrimination task performed with the go signal (Report versus No report). Relative to control reflexes, blinks elicited at a SOA of 0 ms were facilitated and blinks elicited at a SOA of 150 ms were inhibited. RTs were slower on trials that required attention to the go signal and in both attention conditions and at both SOAs shortened in the presence of a blink-eliciting stimulus. However, neither attention to the go signal nor motor preparation affected blink facilitation at the 0 ms SOA. This finding suggests that the blink reflex facilitation observed at a SOA of 0 ms with the onset of a go signal reflects on the summation of sub- and supra-threshold activations of the startle pathway.

Enhanced sensitization to animal, interpersonal, and intergroup fear‐relevant stimuli (but no evidence for selective one‐trial fear learning)

Selective sensitization has been proposed as an alternative explanation for enhanced responding to animal fear-relevant stimuli--snakes and spiders--during extinction of Pavlovian fear conditioning. The current study sought to replicate the phenomenon using a shock workup procedure as the sensitizing manipulation and to extend it to interpersonal and intergroup fear-relevant stimuli--angry faces and other-race faces. Assessment of selective sensitization was followed by a one-trial fear learning procedure. Selective sensitization, larger electrodermal responses to fear-relevant than to control stimuli after sensitization, or a larger increase in electrodermal responding to fear-relevant than to control stimuli after sensitization was observed across stimulus domains. However, the one-trial fear learning procedure failed to provide evidence for enhanced fear conditioning to fear-relevant stimuli. One-trial fear learning was either absent or present for fear-relevant and nonfear-relevant stimuli. The current study confirms that electrodermal responses to fear-relevant stimuli across stimulus domains are subject to selective sensitization.

The Foreperiod Effect: Acoustic Startle Magnitude as An Index of Anticipatory Attentional and Motor Response Processes

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Startle inhibition at long lead intervals in a spatial cueing task

It is believed that our attentional systems are hard-wired to attend to threat; however, an alternative explanation is simply that attention is quickly drawn to the stimulus of most personal relevance in the environment. We used an eye tracker to monitor attention to threat stimuli (spiders) and to positive stimuli with no biological or evolutionary relevance (pictures from the television program Dr. Who) during a target search task. We found that distracter pictures from Dr. Who were fixated on more quickly and were allocated more attention in terms of overall dwell time than were pictures of spiders by participants who had a strong interest in Dr. Who. As such, allocation of attention was guided by the personal relevance of the images, rather than their threat content per se. The attentional system believed to have a causal role in anxiety disordersmay therefore be a general system that responds to stimulus relevance rather than being specific to threat; hence, non-evolutionary images, such as those from Dr Who, are allocated attention in a similar manner as are fear relevant, spider, images. For people with an interest in Dr.Who and a fear of spiders therefore, the Empress of Racnoss (a spider-like creature who features in the program) might be the ultimate attention-grabbing stimulus.Blink startle is said to be inhibited at short lead intervals; an effect that decreases with increasing lead interval. Experiment 1 assessed startle modulation in a modified spatial cueing task with directional or neutral cues. Directional cues were valid on 80% of the trials. Acoustic startle was elicited 120 and 800 ms after the onset of the 1 s cues. Startle inhibition did not differ between cues and neutral stimuli. Unexpectedly, startle inhibition was larger at the 800 ms lead interval than at the 120 ms lead interval. Maximal inhibition of acoustic startle during visual stimuli has been shown to occur later (180 ms) than during acoustic stimuli (120ms), though no evidence of enhanced inhibition has been shown to occur as late as 800ms. Experiment 2 assessed whether this pattern of results reflected two distinct inhibitory processes, prepulse inhibition and target anticipation, or a unitary extended inhibition and whether it covaries with task demands. Startles were elicited at 120, 600, and 800 ms after stimulus onset during directional and neutral cues and during ‘‘NoGo’’ cues that did not require a response. Startle magnitude decreased linearly across lead intervals during directional and neutral cues, but remained unchanged across the lead intervals during the ‘‘NoGo’’ cues. These results indicate that target anticipation in a demanding task can result in extended blink startle inhibition that extends well beyond the time window in which prepulse inhibition is usually observed.

No evidence for a role of startle in the startreac effect or for an effect of attention on blink facilitation at very short lead intervals

Presentation of an accessory intense acoustic stimulus coinciding with the onset of the visual imperative stimulus (IS) in a forewarned simple RT task facilitates RTrelative to IS alone trials (StartReac effect) and elicits blinks larger than those seen on control trials. In Experiment 1, 95 or 105 dBA noise bursts of 0 or 30 ms rise time were presented during half the 5 s ISs in a simpleRTtask at lead intervals of 0, 50 and 150 ms and during intertrial intervals. RT was facilitated in the presence of an accessory acoustic stimulus and the extent of RT facilitation decreasedwith increasing lead interval. Blinks were larger at the 0 ms lead interval than at longer lead intervals or during intertrial intervals. However, blink startle magnitude or blink facilitation were not related to RT or RT facilitation suggesting that, contrary to previous suggestions, startle does not mediate the Start- Reac effect. Experiment 2 varied the reporting and response requirements to the IS to assess whether attention to the IS or motor preparation affected blink facilitation at 0 ms. Blinks were elicited 0 or 150 ms after IS onset. RT was shortest in the presence of an accessory acoustic stimulus at 0 ms and slower if presentation of the IS required additional report. Neither motor preparation nor the additional attention requirement to the IS affected the extent of blink facilitation at 0 ms. Thus, blink facilitation at 0 ms seems to reflect on the summation of sub-reflex threshold excitation by the IS and super-reflex threshold excitation by the reflex eliciting stimulus in the motor pathway.The pattern of attentional startle is modulated when the lead stimulus and startle eliciting stimulus are presented in different modalities. Startle modulation is said to be modality specific if startles are inhibited and modality non specific if startles are facilitated relative to baseline. This finding is of theoretical interest as modality specificity is indicative of early selection and modality non-specificity of late selection mechanisms. Previous research provided evidence for modality specificity in continuous performance tasks, and modality non-specificity in tasks that assessed attention to discrete stimuli. The present research investigated experimental conditions that may determine the engagement of early or late selection mechanisms. Participants were given a target detection task under conditions that approximated continuous performance (Group 1), discrete trials(Group 3), and continuous performance with discrete trials (Group 2). Blink startles elicited with a burst of white noise were recorded at 120 ms or 1200 ms, during targets, non-targets and baseline. Blink startle was inhibited relative to baseline in all three groups. Contrary to expectations, greater inhibition during targets compared to non targets was found in Groups 2 and 3 but not inGroup 1. The current results are consistent with a modality specific account of attentional startle modulation. Moreover, we propose on the basis of the current results that within the early selection mechanism, attention may be more or less engaged depending on the overall context of the task.

Modality non specific attentional startle is modulated by task demands

Presentation of an accessory intense acoustic stimulus coinciding with the onset of the visual imperative stimulus (IS) in a forewarned simple RT task facilitates RTrelative to IS alone trials (StartReac effect) and elicits blinks larger than those seen on control trials. In Experiment 1, 95 or 105 dBA noise bursts of 0 or 30 ms rise time were presented during half the 5 s ISs in a simpleRTtask at lead intervals of 0, 50 and 150 ms and during intertrial intervals. RT was facilitated in the presence of an accessory acoustic stimulus and the extent of RT facilitation decreasedwith increasing lead interval. Blinks were larger at the 0 ms lead interval than at longer lead intervals or during intertrial intervals. However, blink startle magnitude or blink facilitation were not related to RT or RT facilitation suggesting that, contrary to previous suggestions, startle does not mediate the Start- Reac effect. Experiment 2 varied the reporting and response requirements to the IS to assess whether attention to the IS or motor preparation affected blink facilitation at 0 ms. Blinks were elicited 0 or 150 ms after IS onset. RT was shortest in the presence of an accessory acoustic stimulus at 0 ms and slower if presentation of the IS required additional report. Neither motor preparation nor the additional attention requirement to the IS affected the extent of blink facilitation at 0 ms. Thus, blink facilitation at 0 ms seems to reflect on the summation of sub-reflex threshold excitation by the IS and super-reflex threshold excitation by the reflex eliciting stimulus in the motor pathway.The pattern of attentional startle is modulated when the lead stimulus and startle eliciting stimulus are presented in different modalities. Startle modulation is said to be modality specific if startles are inhibited and modality non specific if startles are facilitated relative to baseline. This finding is of theoretical interest as modality specificity is indicative of early selection and modality non-specificity of late selection mechanisms. Previous research provided evidence for modality specificity in continuous performance tasks, and modality non-specificity in tasks that assessed attention to discrete stimuli. The present research investigated experimental conditions that may determine the engagement of early or late selection mechanisms. Participants were given a target detection task under conditions that approximated continuous performance (Group 1), discrete trials(Group 3), and continuous performance with discrete trials (Group 2). Blink startles elicited with a burst of white noise were recorded at 120 ms or 1200 ms, during targets, non-targets and baseline. Blink startle was inhibited relative to baseline in all three groups. Contrary to expectations, greater inhibition during targets compared to non targets was found in Groups 2 and 3 but not inGroup 1. The current results are consistent with a modality specific account of attentional startle modulation. Moreover, we propose on the basis of the current results that within the early selection mechanism, attention may be more or less engaged depending on the overall context of the task.