Visual working memory and sensory processing in autistic children.

While atypical sensory processing is one of the more ubiquitous symptoms in autism spectrum disorder, the exact nature of these sensory issues remains unclear, with different studies showing either enhanced or deficient sensory processing. Using a well-established continuous cued-recall task that assesses visual working memory, the current study provides novel evidence reconciling these apparently discrepant findings. Autistic children exhibited perceptual advantages in both likelihood of recall and recall precision relative to their typically-developed peers. When autistic children did make errors, however, they showed a higher probability of erroneously binding a given colour with the incorrect spatial location. These data align with neural-architecture models for feature binding in visual working memory, suggesting that atypical population-level neural noise in the report dimension (colour) and cue dimension (spatial location) may drive both the increase in probability of recall and precision of colour recall as well as the increase in proportion of binding errors when making an error, respectively. These changes are likely to impact core symptomatology associated with autism, as perceptual binding and working memory play significant roles in higher-order tasks, such as communication.

Seeing the Forest and the Trees: Default Local Processing in Individuals with High Autistic Traits Does Not Come at the Expense of Global Attention.

Atypical sensory perception is one of the most ubiquitous symptoms of autism, including a tendency towards a local-processing bias. We investigated whether local-processing biases were associated with global-processing impairments on a global/local attentional-scope paradigm in conjunction with a composite-face task. Behavioural results were related to individuals' levels of autistic traits, specifically the Attention to Detail subscale of the Autism Quotient, and the Sensory Profile Questionnaire. Individuals showing high rates of Attention to Detail were more susceptible to global attentional-scope manipulations, suggesting that local-processing biases associated with Attention to Detail do not come at the cost of a global-processing deficit, but reflect a difference in default global versus local bias. This relationship operated at the attentional/perceptual level, but not response criterion.

Erasing and blurring memories: The differential impact of interference on separate aspects of forgetting.

Interference disrupts information processing across many timescales, from immediate perception to memory over short and long durations. The widely held similarity assumption states that as similarity between interfering information and memory contents increases, so too does the degree of impairment. However, information is lost from memory in different ways. For instance, studied content might be erased in an all-or-nothing manner. Alternatively, information may be retained but the precision might be degraded or blurred. Here, we asked whether the similarity of interfering information to memory contents might differentially impact these 2 aspects of forgetting. Observers studied colored images of real-world objects, each followed by a stream of interfering objects. Across 4 experiments, we manipulated the similarity between the studied object and the interfering objects in circular color space. After interference, memory for object color was tested continuously on a color wheel, which in combination with mixture modeling, allowed for estimation of how erasing and blurring differentially contribute to forgetting. In contrast to the similarity assumption, we show that highly dissimilar interfering items caused the greatest increase in random guess responses, suggesting a greater frequency of memory erasure (Experiments 1-3). Moreover, we found that observers were generally able to resist interference from highly similar items, perhaps through surround suppression (Experiments 1 and 4). Finally, we report that interference from items of intermediate similarity tended to blur or decrease memory precision (Experiments 3 and 4). These results reveal that the nature of visual similarity can differentially alter how information is lost from memory. (PsycINFO Database Record

Linking Anxiety and Insistence on Sameness in Autistic Children: The Role of Sensory Hypersensitivity.

Sensory hypersensitivity and insistence on sameness (I/S) are common, co-occurring features of autism, yet the relationship between them is poorly understood. This study assessed the impact of sensory hypersensitivity on the clinical symptoms of specific phobia, separation anxiety, social anxiety and I/S for autistic and typically developing (TD) children. Parents of 79 children completed questionnaires on their child's difficulties related to sensory processing, I/S, and anxiety. Results demonstrated that sensory hypersensitivity mediated 67% of the relationship between symptoms of specific phobia and I/S and 57% of the relationship between separation anxiety and I/S. No relationship was observed between sensory hypersensitivity and social anxiety. These mediation effects of sensory hypersensitivity were found only in autistic children, not in TD children.

A global attentional scope setting prioritizes faces for conscious detection.

The scope of visual attention is known to affect conscious object perception, with recent studies showing that a global attentional scope boosts holistic face processing, relative to a local scope. Here we show that attentional scope settings can also modulate the availability of information for conscious visual awareness. In an initial experiment, we show that adopting a global attentional scope accelerates conscious detection of initially invisible faces, presented under continuous flash suppression (CFS). Furthermore, face detection time was not modulated by attentional scope in a nonrivalrous control condition, which emulated the experience of CFS without inducing binocular rivalry. In a follow-up experiment, we report an exact replication of the original effect, as well as data suggesting that this effect is specific to upright faces, and is abolished when using both inverted faces and images of houses in an otherwise identical task. Thus, attentional scope settings can modulate the availability of information to conscious awareness, fundamentally altering the contents of our subjective visual experience.

Pop-out and pop-in: Visual working memory advantages for unique items.

Attentional control is thought to play a critical role in determining the amount of information that can be stored and retrieved from visual working memory (VWM). We tested whether and how task-irrelevant feature-based salience, known to affect the control of visual attention, affects VWM performance. Our results show that features of a task-irrelevant color singleton are more likely to be recalled from VWM than non-singleton items and that this increased memorability comes at a cost to the other items in the display. Furthermore, the singleton effect in VWM was negatively correlated with an individual's baseline VWM capacity. Taken together, these results suggest that individual differences in VWM storage capacity may be partially attributable to the ability to ignore differences in task-irrelevant physical salience.

Distinct cognitive mechanisms involved in the processing of single objects and object ensembles.

Behavioral research has demonstrated that the shape and texture of single objects can be processed independently. Similarly, neuroimaging results have shown that an object's shape and texture are processed in distinct brain regions with shape in the lateral occipital area and texture in parahippocampal cortex. Meanwhile, objects are not always seen in isolation and are often grouped together as an ensemble. We recently showed that the processing of ensembles also involves parahippocampal cortex and that the shape and texture of ensemble elements are processed together within this region. These neural data suggest that the independence seen between shape and texture in single-object perception would not be observed in object-ensemble perception. Here we tested this prediction by examining whether observers could attend to the shape of ensemble elements while ignoring changes in an unattended texture feature and vice versa. Across six behavioral experiments, we replicated previous findings of independence between shape and texture in single-object perception. In contrast, we observed that changes in an unattended ensemble feature negatively impacted the processing of an attended ensemble feature only when ensemble features were attended globally. When they were attended locally, thereby making ensemble processing similar to single-object processing, interference was abolished. Overall, these findings confirm previous neuroimaging results and suggest that distinct cognitive mechanisms may be involved in single-object and object-ensemble perception. Additionally, they show that the scope of visual attention plays a critical role in determining which type of object processing (ensemble or single object) is engaged by the visual system.

Automatic capture of attention by conceptually generated working memory templates.

Many theories of attention propose that the contents of working memory (WM) can act as an attentional template, which biases processing in favor of perceptually similar inputs. While support has been found for this claim, it is unclear how attentional templates are generated when searching real-world environments. We hypothesized that in naturalistic settings, attentional templates are commonly generated from conceptual knowledge, an idea consistent with sensorimotor models of knowledge representation. Participants performed a visual search task in the delay period of a WM task, where the item in memory was either a colored disk or a word associated with a color concept (e.g., "Rose," associated with red). During search, we manipulated whether a singleton distractor in the array matched the contents of WM. Overall, we found that search times were impaired in the presence of a memory-matching distractor. Furthermore, the degree of impairment did not differ based on the contents of WM. Put differently, regardless of whether participants were maintaining a perceptually colored disk identical to the singleton distractor, or whether they were simply maintaining a word associated with the color of the distractor, the magnitude of attentional capture was the same. Our results suggest that attentional templates can be generated from conceptual knowledge, in the physical absence of the visual feature.