Investigating dimensional organization in scripts using the pupillary response

Using network science to provide insights into the structure of event knowledge

The structure of event knowledge plays a critical role in prediction, reconstruction of memory for personal events, construction of possible future events, action, language usage, and social interactions. Despite numerous theoretical proposals such as scripts, schemas, and stories, the highly variable and rich nature of events and event knowledge have been formidable barriers to characterizing the structure of event knowledge in memory. We used network science to provide insights into the temporal structure of common events. Based on participants' production and ordering of the activities that make up events, we established empirical profiles for 80 common events to characterize the temporal structure of activities. We used the event networks to investigate multiple issues regarding the variability in the richness and complexity of people's knowledge of common events, including: the temporal structure of events; event prototypes that might emerge from learning across many experiential instances and be expressed by people; the degree to which scenes (communities) are present in various events; the degree to which people believe certain activities are central to an event; how centrality might be distributed across an event's activities; and similarities among events in terms of their content and their temporal structure. Thus, we provide novel insights into human event knowledge, and describe 18 predictions for future human studies.

Tracing embodied word production in persons with Parkinson's disease in distinct motor conditions

Embodied cognition theories posit direct interactions between sensorimotor and mental processing. Various clinical observations have been interpreted in this controversial framework, amongst others, low verb generation in word production tasks performed by persons with Parkinson's disease (PD). If this were the consequence of reduced motor simulation of prevalent action semantics in this word class, reduced PD pathophysiology should result in increased verb production and a general shift of lexical contents towards particular movement-related meanings. 17 persons with PD and bilateral deep brain stimulation (DBS) of the subhtalamic nucleus (STN) and 17 healthy control persons engaged in a semantically unconstrained, phonemic verbal fluency task, the former in both DBS-off and DBS-on states. The analysis referred to the number of words produced, verb use, and the occurrence of different dimensions of movement-related semantics in the lexical output. Persons with PD produced fewer words than controls. In the DBS-off, but not in the DBS-on condition, the proportion of verbs within this reduced output was lower than in controls. Lowered verb production went in parallel with a semantic shift: in persons with PD in the DBS-off, but not the DBS-on condition, the relatedness of produced words to own body-movement was lower than in controls. In persons with PD, DBS induced-changes of the motor condition appear to go along with formal and semantic shifts in word production. The results are compatible with the idea of some impact of motor system states on lexical processing.

Altered event processing in persons with Parkinson's disease

Persons with Parkinson's disease (PD) often show particular problems in seemingly simple routines despite relatively preserved cognitive function. We therefore investigated the processing of everyday events on behavioral and neurophysiological levels in a PD and control group. The participants had to indicate via button press whether three sequentially presented sub-events described a previously defined event (e.g., going grocery shopping). Sub-event sequences were either correct or included an event that did not belong to the event (content violation), or events were chronologically wrong (temporal violation). During task execution event-related potentials (ERPs) were recorded. Generally, the PD group showed less accurate performance independently from task conditions, and reaction times to temporal violations were particularly slow compared to the control group. Regarding ERP results, the control group showed a right lateralized N400 effect in response to content violations, which was absent in the PD group indicating altered content event processing. Concerning the reanalysis of content event violations, the expression of late positive components (LPCs) was similar between both groups. Upon temporal violations, both groups also showed a LPC with a tendentially earlier onset in the PD group, resembling positive components indicative of novelty processing. Together, these findings suggest poor event prediction in PD, which may originate from weak event representation or retrieval and possibly relate to prevalent behavioral dysfunctions in everyday life in PD.

Quantifying evidential value and selective reporting in recent and 10-year past psychophysiological literature: A pre-registered P-curve analysis

Selective reporting (i.e., only reporting significant findings as opposed to all analyses or results) is a questionable research practice that undermines the integrity of published research. Psychophysiology research may be susceptible to selective reporting, given the high number of decision points and methodological complexity in analyses of psychophysiology data. We aimed to assess the presence of selective reporting and evidential value (i.e., that significant results are due to true underlying effects) in recent and past psychophysiological research by utilizing p-curve analyses. Study protocols and methods were pre-registered on the Open Science Framework (OSF). P-values and the associated test statistics were extracted from articles in the most recent issue (as of January 2018) and 10-year previous counterpart issue of three major psychophysiology journals: Psychophysiology, International Journal of Psychophysiology, and Journal of Psychophysiology. Using the p-curve application, 10 primary p-curves were conducted: all recent articles, all past articles, recent articles split by journal, past articles split by journal, recent cognitive electrophysiology articles, and past cognitive electrophysiology articles. Evidential value and generally adequate average power (≥78% average power) were present in all p-curves, except those that only included articles from the Journal of Psychophysiology because of the small number of articles published in the journal. Findings provide some positive news and indicate that, generally, results were not selectively reported, and selective reporting may not be a primary issue for this sample of psychophysiological research. Future p-curve analyses examining sub-disciplines of psychophysiology are recommended.

Cortical modulation of pupillary function: systematic review

BACKGROUND

The pupillary light reflex is the main mechanism that regulates the pupillary diameter; it is controlled by the autonomic system and mediated by subcortical pathways. In addition, cognitive and emotional processes influence pupillary function due to input from cortical innervation, but the exact circuits remain poorly understood. We performed a systematic review to evaluate the mechanisms behind pupillary changes associated with cognitive efforts and processing of emotions and to investigate the cerebral areas involved in cortical modulation of the pupillary light reflex.

METHODOLOGY

We searched multiple databases until November 2018 for studies on cortical modulation of pupillary function in humans and non-human primates. Of 8,809 papers screened, 258 studies were included.

RESULTS

Most investigators focused on pupillary dilatation and/or constriction as an index of cognitive and emotional processing, evaluating how changes in pupillary diameter reflect levels of attention and arousal. Only few tried to correlate specific cerebral areas to pupillary changes, using either cortical activation models (employing micro-stimulation of cortical structures in non-human primates) or cortical lesion models (e.g., investigating patients with stroke and damage to salient cortical and/or subcortical areas). Results suggest the involvement of several cortical regions, including the insular cortex (Brodmann areas 13 and 16), the frontal eye field (Brodmann area 8) and the prefrontal cortex (Brodmann areas 11 and 25), and of subcortical structures such as the locus coeruleus and the superior colliculus.

CONCLUSIONS

Pupillary dilatation occurs with many kinds of mental or emotional processes, following sympathetic activation or parasympathetic inhibition. Conversely, pupillary constriction may occur with anticipation of a bright stimulus (even in its absence) and relies on a parasympathetic activation. All these reactions are controlled by subcortical and cortical structures that are directly or indirectly connected to the brainstem pupillary innervation system.

Pupil dilation tracks the dynamics of mnemonic interference resolution

Mnemonic interference refers to the inability to retrieve a goal-relevant memory due to interference from goal-irrelevant memories. Understanding the causes of such interference and how it is overcome has been a central goal in the science of memory for more than a century. Here, we shed new light on this fundamental issue by tracking participants' pupil response when they encode and retrieve memories in the face of competing goal-irrelevant memories. We show that pupil dilation systematically increased in accordance with interference from competing memory traces when participants retrieved previously learned information. Moreover, our results dissociate two main components in the pupillary response signal: an early component, which peaked in a time window where the pupillary waveform on average had its maximum peak, and a late component, which peaked towards the end of the retrieval task. We provide evidence that the early component is specifically modulated by the cognitive effort needed to handle interference from competing memory traces whereas the late component reflects general task engagement. This is the first demonstration that mnemonic interference resolution can be tracked online in the pupil signal and offers novel insight into the underlying dynamics.

Foggy windows: Pupillary responses during task preparation

We investigated pupil dilation in 96 subjects during task preparation and during a post-trial interval in a visual search task and an auditory working memory task. Completely informative difficulty cues (easy, medium, or hard) were presented right before task preparation to examine whether pupil dilation indicated advance mobilisation of attentional resources; functional magnetic resonance imaging (fMRI) studies have argued for the existence of such task preparation, and the literature shows that pupil dilation tracks attentional effort during task performance. We found, however, little evidence for such task preparation. In the working memory task, pupil size was identical across cues, and although pupil dilation in the visual search task tracked the cue, pupil dilation predicted subsequent performance in neither task. Pupil dilation patterns in the post-trial interval were more consistent with an effect of emotional reactivity. Our findings suggest that the mobilisation of attentional resources in the service of the task does not occur during the preparatory interval, but is delayed until the task itself is initiated.

Exploring Temporal Progression of Events Using Eye Tracking

This study investigates the representation of the temporal progression of events by means of the causal change in a patient. Subjects were asked to verify the relationship between adjectives denoting a source and resulting feature of a patient. The features were presented either chronologically or inversely to a primed event context given by a verb (to cut: long-short vs. short-long). Effects on response time and on eye movement data show that the relationship between features presented chronologically is verified more easily than that between features presented inversely. Post hoc, however, we found that the effects of temporal order occurred only when subjects read the features more than once. Then, the relationship between the features is matched with the causal change implied by the event context (contextual strategy). When subjects read the features only once, subjects respond to the relationship between the features without taking into account the event context.

Semantic priming of progression features in events

Event knowledge includes persons and objects and their roles in the event. This study investigated whether the progression of patients from a source to a resulting feature, such as the progression of hair that is cut from long to short, forms part of event representations. Subjects were presented with an event prime followed by two adjectives and asked to judge whether the adjectives were interrelated. Results showed that the semantic interrelation of two adjectives is recognized faster and more accurately when the adjectives denote source and resulting features of the patient of the primed event ("cutting": long-short). Furthermore, we found that presenting an event-related adjective in combination with an unrelated adjective makes it more difficult to recognize that the two adjectives are not interrelated, but only when the event-related adjective denotes a source feature. We argue that an inference mechanism automatically completes the representation of the event. We conclude that source and resulting features are represented in a goal-directed and chronological way.

Impact of chronotype and time perspective on the processing of scripts

Little is known about the impact of temporal orientation (chronotype; time perspective) on cognitive performance. This study adopted a psychophysiological approach to explore how chronotype (morningness-eveningness) and time perspective (present; future) influence time succession as another aspect of psychological time that is entailed within script knowledge. In a temporal judgment task, participants decided which of the two presented sub-events (e.g., get new batteries-set right time on alarm clock) comes earlier (or later) within a given script (e.g., changing batteries in an alarm clock). Behavioral and pupillary data suggest a differential impact of chronotype and time perspective on script knowledge and cognitive performance. The impact of time perspective on the processing of temporal information entailed in script knowledge appears linked to match or mismatch conditions between a strong focus on future outcomes associated with future time perspective and the task of identifying either the later (future-oriented) or the earlier (past-oriented) sub-event. Concerning the chronotype, evening types process items in which chronological time succession is violated (i.e., reversely presented items) more accurately than morning types. Indexed by pupillary data, the impact of chronotype may relate to more general cognitive abilities. The psychophysiological data derived in this study suggests that evening types typically outperform morning types in various measures such working memory capacity and verbal intelligence simply because they invest more cognitive resources than morning types.

Systematic influence of gaze position on pupil size measurement: analysis and correction

Cognitive effort is reflected in pupil dilation, but the assessment of pupil size is potentially susceptible to changes in gaze position. This study exemplarily used sentence reading as a stand-in for paradigms that assess pupil size in tasks during which changes in gaze position are unavoidable. The influence of gaze position on pupil size was first investigated by an artificial eye model with a fixed pupil size. Despite its fixed pupil size, the systematic measurements of the artificial eye model revealed substantial gaze-position-dependent changes in the measured pupil size. We evaluated two functions and showed that they can accurately capture and correct the gaze-dependent measurement error of pupil size recorded during a sentence-reading and an effortless z-string-scanning task. Implications for previous studies are discussed, and recommendations for future studies are provided.

Discerning temporal expectancy effects in script processing: evidence from pupillary and eye movement recordings

Accessing the temporal position of events (early or late in the event sequence) can influence the generation of predictions about upcoming events. However, it is unclear how the temporal position is processed strategically. To investigate this, we presented event pairs to 23 healthy volunteers manipulating temporal order (chronological, inverse) and temporal position (early, late). Pupil dilation, eye movements, and behavioral data, showed that chronological and early event pairs are processed with more ease than inverse and late event pairs. Indexed by the pupillary response late events and inversely presented event pairs elicited greater cognitive processing demands than early events and chronologically presented event pairs. Regarding eye movements, fixation duration was less sensitive to temporal position than to temporal order. Looking at each item of the event sequence only once was behaviorally more effective than looking multiple times at each event regardless of whether temporal position or temporal order was processed. These results emphasize that accessing temporal position and temporal order information results in dissociable behavioral patterns. While more cognitive resources are necessary for processing late and inverse items, change of information acquisition strategies turns out to be most effective when temporal order processing is required.

In the eye of the listener: pupil dilation elucidates discourse processing

The current study investigated cognitive resource allocation in discourse processing by means of pupil dilation and behavioral measures. Short question-answer dialogs were presented to listeners. Either the context question queried a new information focus in the successive answer, or else the context query was corrected in the answer sentence (correction information). The information foci contained in the answer sentences were either adequately highlighted by prosodic means or not. Participants had to judge the adequacy of the focus prosody with respect to the preceding context question. Prosodic judgment accuracy was higher in the conditions bearing adequate focus prosody than in the conditions with inadequate focus prosody. Latency to peak pupil dilation was longer when new information foci were perceived compared to correction foci. Moreover, for the peak dilation, an interaction of focus type and prosody was found. Post hoc statistical tests revealed that prosodically adequate correction focus positions were processed with smaller peak dilation in comparison to all other dialog conditions. Thus, pupil dilation and results of a principal component analysis suggest an interaction of focus type and focus prosody in discourse processing.

Establishing causal coherence across sentences: an ERP study

This study examined neural activity associated with establishing causal relationships across sentences during on-line comprehension. ERPs were measured while participants read and judged the relatedness of three-sentence scenarios in which the final sentence was highly causally related, intermediately related, and causally unrelated to its context. Lexico-semantic co-occurrence was matched across the three conditions using a Latent Semantic Analysis. Critical words in causally unrelated scenarios evoked a larger N400 than words in both highly causally related and intermediately related scenarios, regardless of whether they appeared before or at the sentence-final position. At midline sites, the N400 to intermediately related sentence-final words was attenuated to the same degree as to highly causally related words, but otherwise the N400 to intermediately related words fell in between that evoked by highly causally related and intermediately related words. No modulation of the late positivity/P600 component was observed across conditions. These results indicate that both simple and complex causal inferences can influence the earliest stages of semantically processing an incoming word. Further, they suggest that causal coherence, at the situation level, can influence incremental word-by-word discourse comprehension, even when semantic relationships between individual words are matched.

I spy with my little eye: detection of temporal violations in event sequences and the pupillary response

Scripts of familiar activities store the temporal order of events. This enables us to generate predictions about which event will follow another. When an event does not unfold in the chronological order, a mismatch arises between the predictions and the external sensory input which is perceived as a conflict. The detection of this mismatch is accomplished by a comparison mechanism (Zacks et al., 2007; Barsalou, 2009). We have applied pupillometry to investigate the nature of this comparison process. We further tested for individual differences in the efficiency of the mismatch detection. Participants were presented the title of an event sequence to trigger predictions about the order in which events would unfold. Subsequently, three script events were presented one at a time. The events either unfolded in the correct chronological order or included temporal violations at different points within the event triplet. Violations of the temporal order had to be detected. As soon as it was detected, the trial had to be terminated. We found that a temporal violation elicited a large pupillary response in all individuals indicating that the comparison between the predictions and the external sensory input was accomplished online and worked equally well for all individuals. However, not all individuals terminated the trial after having detected the violation. Results showed that efficient individuals who responded adequately had a greater pupillary response than inefficient individuals suggesting that they invested more cognitive resources. The results are discussed in light of theories of behavioral performance and conflict-monitoring.