Brief Report: Which Came First? Exploring Crossmodal Temporal Order Judgements and Their Relationship with Sensory Reactivity in Autism and Neurotypicals

Previous studies have indicated that visual-auditory temporal acuity is reduced in children with autism spectrum conditions (ASC) in comparison to neurotypicals. In the present study we investigated temporal acuity for all possible bimodal pairings of visual, tactile and auditory information in adults with ASC (n = 18) and a matched control group (n = 18). No group differences in temporal acuity for crossmodal stimuli were observed, suggesting that this may be typical in adults with ASC. However, visual-tactile temporal acuity and bias towards vision when presented with visual-auditory information were both predictors of self-reported sensory reactivity. This suggests that reduced multisensory temporal acuity and/or attention towards vision may contribute to atypical sensory reactivity

“No Way Out Except From External Intervention”: First-Hand Accounts of Autistic Inertia

This study, called for by autistic people and led by an autistic researcher, is the first to explore ‘autistic inertia,’ a widespread and often debilitating difficulty acting on their intentions. Previous research has considered initiation only in the context of social interaction or experimental conditions. This study is unique in considering difficulty initiating tasks of any type in real life settings, and by gathering qualitative data directly from autistic people. Four face-to-face and 2 online (text) focus groups were conducted with 32 autistic adults (19 female, 8 male, and 5 other), aged 23–64 who were able to express their internal experiences in words. They articulate in detail the actions they have difficulty with, what makes it easier or harder to act, and the impact on their lives. Thematic analysis of the transcripts found four overarching themes: descriptions of inertia, scaffolding to support action, the influence of wellbeing, and the impact on day-to-day activities. Participants described difficulty starting, stopping and changing activities that was not within their conscious control. While difficulty with planning was common, a subset of participants described a profound impairment in initiating even simple actions more suggestive of a movement disorder. Prompting and compatible activity in the environment promoted action, while mental health difficulties and stress exacerbated difficulties. Inertia had pervasive effects on participants’ day-to-day activities and wellbeing. This overdue research opens the door to many areas of further investigation to better understand autistic inertia and effective support strategies

Turning the periodic table upside down

The periodic table is immensely powerful for rationalizing many different properties of the chemical elements, but would turning it on its head make some important aspects easier to understand and give everyone a new perspective on chemistry

Interoceptive and exteroceptive attention have opposite effects on subsequent somatosensory perceptual decision making

Evidence suggests that interoceptive and exteroceptive attention might have different perceptual effects. However, the effects of these different types of body-focused attention have never been directly compared. The current research investigated how interoceptive and exteroceptive attention affect subsequent performance on the somatic signal detection task (SSDT). In Experiment 1, 37 participants completed the SSDT under usual testing conditions and after performing an interoceptive heartbeat perception task. This task led to a more liberal response criterion, leading to increased touch reports in the presence and absence of a target vibration. This finding is consistent with suggestions that attending internally contributes to physical symptom reporting in patients with medically unexplained symptoms (MUS). In Experiment 2, 40 participants completed the SSDT before and after an exteroceptive grating orientation task. This task led to a more stringent response criterion, leading to decreased touch reports in the presence and absence of the target, possibly via a reduction in sensory noise. This work demonstrates that internal and external body-focused attention can have opposite effects on subsequent somatic perceptual decision making and suggests that attentional training could be useful for patients reporting MUS. </jats:p

A third-person perspective on co-speech action gestures in Parkinson's disease

A combination of impaired motor and cognitive function in Parkinson’s disease (PD) can impact on language and communication, with patients exhibiting a particular difficulty processing action verbs. Co-speech gestures embody a link between action and language and contribute significantly to communication in healthy people. Here, we investigated how co-speech gestures depicting actions are affected in PD, in particular with respect to the visual perspective—or the viewpoint – they depict. Gestures are closely related to mental imagery and motor simulations, but people with PD may be impaired in the way they simulate actions from a first-person perspective and may compensate for this by relying more on third-person visual features. We analysed the action-depicting gestures produced by mild-moderate PD patients and age-matched controls on an action description task and examined the relationship between gesture-viewpoint, action-naming, and performance on an action observation task (weight judgement). Healthy controls produced the majority of their action-gestures from a first person perspective, whereas PD patients produced a greater proportion of gestures produced from a third person perspective. We propose that this reflects a compensatory reliance on third-person visual features in the simulation of actions in PD. Performance was also impaired in action-naming and weight judgement, although this was unrelated to gesture viewpoint. Our findings provide a more comprehensive understanding of how action-language impairments in PD impact on action communication, on the cognitive underpinnings of this impairment, as well as elucidating the role of action simulation in gesture production

Spontaneous Ocular Scanning of Visual Symmetry Is Similar During Classification and Evaluation Tasks

Visual symmetry perception and symmetry preference have been studied extensively. However, less is known about how people spontaneously scan symmetrical stimuli with their eyes. We thus examined spontaneous saccadic eye movements when participants (N = 20) observed patterns with horizontal or vertical mirror reflection. We found that participants tend to make saccades along the axis of reflection and that this oculomotor behaviour was similar during objective classification and subjective evaluation tasks. The axis-scanning behaviour generates a dynamic sequence of novel symmetrical images from a single static stimulus. This could aid symmetry perception and evaluation by enhancing the neural response to symmetry

Shifting attention between modalities: revisiting the modality-shift effect in autism

Selective attention to a sensory modality has been observed experimentally in studies of the modality-shift effect – a relative performance benefit for targets preceded by a target in the same modality, compared to a different modality. Differences in selective attention are commonly observed in autism and we investigated whether exogenous (automatic) shift costs between modalities are increased. Autistic adults and neurotypical controls made speeded discrimination responses to simple visual, tactile and auditory targets. Shift costs were observed for each target modality in participant response times and were largest for auditory targets, reflective of fast responses on auditory repeat trials. Critically, shift costs were similar between the groups. However, integrating speed and accuracy data using drift-diffusion modelling revealed that shift costs in drift rates (reflecting the quality of information extracted from the stimulus) were reduced for autistic participants compared with neurotypicals. It may be that, unlike neurotypicals, there is little difference between attention within and between sensory modalities for autistic people. This finding also highlights the benefit of combining reaction time and accuracy data using decision models to better characterise selective attention in autism