Behavioural Dissociation between Exogenous and Endogenous Temporal Orienting of Attention

BACKGROUND: In the current study we compared the effects of temporal orienting of attention based on predictions carried by the intrinsic temporal structure of events (rhythm) and by instructive symbolic cues; and tested the degree of cognitive, strategic control that could be exerted over each type of temporal expectation. The experiments tested whether the distinction between exogenous and endogenous orienting made in spatial attention may extend to the temporal domain. TASK DESIGN AND MAIN RESULTS: In this task, a ball moved across the screen in discrete steps and disappeared temporarily under an occluding band. Participants were required to make a perceptual discrimination on the target upon its reappearance. The regularity of the speed (rhythmic cue) or colour (symbolic cue) of the moving stimulus could predict the exact time at which a target would reappear after a brief occlusion (valid trials) or provide no temporal information (neutral trials). The predictive nature of rhythmic and symbolic cues was manipulated factorially in a symmetrical and orthogonal fashion. To test for the effects of strategic control over temporal orienting based on rhythmic or symbolic cues, participants were instructed either to "attend-to-speed" (rhythm) or "attend-to-colour". Our results indicated that both rhythmic and symbolic (colour) cues speeded reaction times in an independent fashion. However, whilst the rhythmic cueing effects were impervious to instruction, the effects of symbolic cues were contingent on the instruction to attend to colour. FINAL CONCLUSIONS: Taken together, our results provide evidence for the existence of qualitatively separable types of temporal orienting of attention, akin to exogenous and endogenous mechanisms

A transcranial magnetic stimulation study on the role of the left intraparietal sulcus in temporal orienting of attention

likely to occur. Temporal orienting of attention has been consistently associated with activation of the left intraparietal sulcus (IPS) in prior fMRI studies. However, a direct test of its causal involvement in temporal orienting is still lacking. The present study tackled this issue by transiently perturbing left IPS activity with either online (Experiment 1) or offline (Experiment 2) transcranial magnetic stimulation (TMS). In both experiments, participants performed a temporal orienting task, alternating between blocks in which a temporal cue predicted when a subsequent target would appear and blocks in which a neutral cue provided no information about target timing. In Experiment 1 we used an online TMS protocol, aiming to interfere specifically with cue-related temporal processes, whereas in Experiment 2 we employed an offline protocol whereby participants performed the temporal orienting task before and after receiving TMS. The right IPS and/or the vertex were stimulated as active control regions. While results replicated the canonical pattern of temporal orienting effects on reaction time, with faster responses for temporal than neutral trials, these effects were not modulated by TMS over the left IPS (as compared to the right IPS and/or vertex regions) regardless of the online or offline protocol used. Overall, these findings challenge the causal role of the left IPS in temporal orienting of attention inviting further research on its underlying neural substratesFrench National Research Agency (ANR) ANR-18-CE28-0009-01MCIN/AEI/10.13039/501100011033 PID2021- 128696NA-I00"ERDF A way of making Europe"Spanish GovernmentEuropean Union Next GenerationMinistry of Economy, Knowledge, EnterpriseUniversities of AndalusiaMinistry of Science and Innovation, Spain (MICINN) Spanish Government PSI2017-88136EDER-Junta de AndaluciaUniversidad de Granada/CBU

Neural Substrates of Mounting Temporal Expectation

A cognitive and neuroanatomical perspective on how timing and expectation are represented in the human brain

Increasing conditional probabilities over time speed responses.

<p>(A) If an event is likely to occur after one of four possible delays with equal probability, then the conditional probability that the event will occur at one of these delays evolves over time. For example, after a delay of 1 s, the probability of the event occurring is 1 in 4 (i.e., 0.25). If it does not occur at 1 s, then there are three possible delays left, now giving a 1 in 3 (i.e., 0.33) chance of occurring at the next delay. But, if it does not occur after 2 s either, there is now a 1 in 2 (i.e., 0.50) chance of it occurring at the next delay. Finally, if it has still not occurred by 3 s, then the subject can be sure that it must certainly occur (i.e., 1.0) at the final (4 s) delay. In other words, the objective probability of event occurrence combines with the predictive power of time's arrow to produce changing conditional probabilities over time. (B) As the time (or “foreperiod”) before an event occurs gets longer, so responses to that event get faster. The speeding of reaction time typically parallels increasing conditional probabilities over time, reflecting a state of increased preparedness to respond with passing time.</p

Implicit, Predictive Timing Draws upon the Same Scalar Representation of Time as Explicit Timing

It is not yet known whether the scalar properties of explicit timing are also displayed by more implicit, predictive forms of timing. We investigated whether performance in both explicit and predictive timing tasks conformed to the two psychophysical properties of scalar timing: the Psychophysical law and Weber’s law. Our explicit temporal generalization task required overt estimation of the duration of an empty interval bounded by visual markers, whereas our temporal expectancy task presented visual stimuli at temporally predictable intervals, which facilitated motor preparation thus speeding target detection. The Psychophysical Law and Weber’s Law were modeled, respectively, by (1) the functional dependence between mean subjective time and real time (2) the linearity of the relationship between timing variability and duration. Results showed that performance for predictive, as well as explicit, timing conformed to both psychophysical properties of interval timing. Both tasks showed the same linear relationship between subjective and real time, demonstrating that the same representational mechanism is engaged whether it is transferred into an overt estimate of duration or used to optimise sensorimotor behavior. Moreover, variability increased with increasing duration during both tasks, consistent with a scalar representation of time in both predictive and explicit timing. However, timing variability was greater during predictive timing, at least for durations greater than 200 msec, and ascribable to temporal, rather than nontemporal, mechanisms engaged by the task. These results suggest that although the same internal representation of tim

Temporal expectation in the brain.

<p>Fixed temporal expectations of when a visual event is likely to occur are underpinned by activity in left premotor and parietal areas <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1000166#pbio.1000166-Coull1" target="_blank">[7]</a>,<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1000166#pbio.1000166-Sakai1" target="_blank">[26]</a>. However, if the event has still not appeared by the expected delay, the right prefrontal cortex (PFC) <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1000166#pbio.1000166-Coull2" target="_blank">[21]</a>–<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1000166#pbio.1000166-Vallesi4" target="_blank">[25]</a> makes use of neural indices of elapsed time (represented in functionally specialized regions of the brain e.g., in visual cortex for visual events <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1000166#pbio.1000166-Ghose1" target="_blank">[15]</a>) to update current temporal expectations (i.e., the hazard function). Once the event occurs, an integrated sum of the probability that the event would have occurred at that time (i.e., the cumulative hazard function) is represented by the magnitude of activity in SMA and right STG <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1000166#pbio.1000166-Cui1" target="_blank">[14]</a>, and allows expectations about the onset time of future events to be updated.</p

Using time-to-contact information to assess potential collision modulates both visual and temporal prediction networks

Accurate estimates of the time-to-contact (TTC) of approaching objects are crucial for survival. We used an ecologically valid driving simulation to compare and contrast the neural substrates of egocentric (head-on approach) and allocentric (lateral approach) TTC tasks in a fully factorial, event-related fMRI design. Compared to colour control tasks, both egocentric and allocentric TTC tasks activated left ventral premotor cortex/frontal operculum and inferior parietal cortex, the same areas that have previously been implicated in temporal attentional orienting. Despite differences in visual and cognitive demands, both TTC and temporal orienting paradigms encourage the use of temporally predictive information to guide behaviour, suggesting these areas may form a core network for temporal prediction. We also demonstrated that the temporal derivative of the perceptual index tau (tau-dot) held predictive value for making collision judgements and varied inversely with activity in primary visual cortex (V1). Specifically, V1 activity increased with the increasing likelihood of reporting a collision, suggesting top-down attentional modulation of early visual processing areas as a function of subjective collision. Finally, egocentric viewpoints provoked a response bias for reporting collisions, rather than no-collisions, reflecting increased caution for head-on approaches. Associated increases in SMA activity suggest motor preparation mechanisms were engaged, despite the perceptual nature of the task