Does Sound Influence Perceived Duration of Visual Motion?

Multimodal perception is a key factor in obtaining a rich and meaningful representation of the world. However, how each stimulus combines to determine the overall percept remains a matter of research. The present work investigates the effect of sound on the bimodal perception of motion. A visual moving target was presented to the participants, associated with a concurrent sound, in a time reproduction task. Particular attention was paid to the structure of both the auditory and the visual stimuli. Four different laws of motion were tested for the visual motion, one of which is biological. Nine different sound profiles were tested, from an easier constant sound to more variable and complex pitch profiles, always presented synchronously with motion. Participants’ responses show that constant sounds produce the worst duration estimation performance, even worse than the silent condition; more complex sounds, instead, guarantee significantly better performance. The structure of the visual stimulus and that of the auditory stimulus appear to condition the performance independently. Biological motion provides the best performance, while the motion featured by a constant-velocity profile provides the worst performance. Results clearly show that a concurrent sound influences the unified perception of motion; the type and magnitude of the bias depends on the structure of the sound stimulus. Contrary to expectations, the best performance is not generated by the simplest stimuli, but rather by more complex stimuli that are richer in information.

EXPRESS: Do cognitive load and ADHD traits affect the tendency to prioritise social information in scenes?

We report two experiments investigating the effect of working memory (WM) load on selective attention. Experiment 1 was a modified version of Lavie et al. (2004) and confirmed that increasing memory load disrupted performance in the classic flanker task. Experiment 2 used the same manipulation of WM load to probe attention during the viewing of complex scenes, while also investigating individual differences in ADHD traits. In the image viewing task, we measured the degree to which fixations targeted each of two crucial objects: (1) a social object (a person in the scene) and (2) a non-social object of higher or lower physical salience. We compared the extent to which increasing WM load would change the pattern of viewing of the physically salient and socially salient objects. If attending to the social item requires greater default voluntary top-down resources, then the viewing of social objects should show stronger modulation by WM load compared to viewing of physically salient objects. The results showed that the social object was fixated to a greater degree than the other object (regardless of physical saliency). Increased saliency drew fixations away from the background leading to slightly increased fixations on the non-social object, without changing fixations on the social object. Increased levels of ADHD-like traits were associated with fewer fixations on the social object, but only in the high salient, low load condition. Importantly, WM load did not affect number of fixations on the social object. Such findings suggest rather surprisingly that attending to a social area in complex stimuli is not dependent on the availability of voluntary topdown resources.

Premise typicality as feature inference decision-making in perceptual categories

Making property inferences for category instances is important and has been studied in two largely separate areas—categorical induction and perceptual categorization. Categorical induction has a corpus of well-established effects using complex, real-world categories; however, the representational basis of these effects is unclear. In contrast, the perceptual categorization paradigm has fostered the assessment of well-specified representation models due to its controlled stimuli and categories. In categorical induction, evaluations of premise typicality effects, stronger attribute generalization from typical category instances than from atypical, have tried to control the similarity between instances to be distinct from premise–conclusion similarity effects, stronger generalization from greater similarity. However, the extent to which similarity has been controlled is unclear for these complex stimuli. Our research embedded analogues of categorical induction effects in perceptual categories, notably premise typicality and premise conclusion similarity, in an attempt to clarify the category representation underlying feature inference. These experiments controlled similarity between instances using overlap of a small number of constrained features. Participants made inferences for test cases using displayed sets of category instances. The results showed typicality effects, premise–conclusion similarity effects, but no evidence of premise typicality effects (i.e., no preference for generalizing features from typical over atypical category instances when similarity was controlled for), with significant Bayesian support for the null. As typicality effects occurred and occur widely in the perceptual categorization paradigm, why was premise typicality absent? We discuss possible reasons. For attribute inference, is premise typicality distinct from instance similarity? These initial results suggest not.

Temporal lobe activation during episodic memory encoding following traumatic brain injury

The temporal lobes are critical for encoding and retrieving episodic memories. The temporal lobes are preferentially disrupted following a traumatic brain injury (TBI), likely contributing to the difficulties observed in episodic memory. However, the underlying neural changes that precipitate or maintain these difficulties in individuals with TBI remains poorly understood. Here, we use functional magnetic resonance imaging (fMRI) to interrogate the relationship between temporal lobe activation and encoding of episodic stimuli. Participants encoded face, scene, and animal stimuli during an fMRI run. In an out-of-scanner task, participants were required to correctly identify previously displayed stimuli over two presentation runs (each in-scanner stimuli presented twice). Forty-three patients with moderate-severe TBI were recruited and compared with 38 demographically similar healthy controls. The pattern of behavioural performance between groups depended on the stimuli presentation run. The TBI group demonstrated poorer episodic memory for faces and scenes during the first presentation, but not the second presentation. When episodic memory was analysed across all presentation runs, behavioural deficits were only apparent for faces. Interestingly, processing of faces emerged as the only between group-difference on fMRI, whereby TBI participants had an increased signal in the middle temporal gyrus extending to the superior temporal sulcus. These findings provide evidence to suggest that following TBI: (a) episodic memory is preferentially impaired for complex stimuli such as faces, and (b) robust behavioural inefficiencies are reflected in increased activation in specific temporal lobe structures during encoding.

Working memory performance is tied to stimulus complexity

1.SummaryWorking memory is the cognitive capability to maintain and process information over short periods. Recent behavioral and computational studies have shown that increased visual information of the presented stimulus material is associated with enhanced working memory performance. However, the underlying neural correlates of this association are unknown. To identify how stimuli of different visual information levels affect working memory performance, we conducted behavioral experiments and single unit recordings in the avian analog of the prefrontal cortex, the nidopallium caudolaterale (NCL). On the behavioral level, we confirmed that feature-rich complex stimuli demonstrated higher working memory performance compared to feature-poor simple stimuli. This difference was reflected by distinct neural coding patterns at the single unit level. For complex stimuli, we found a highly multiplexed neuronal code. During the sample presentation, NCL neurons initially reflected both visual and value-related features of the presented stimuli that switched to a representation of the upcoming choice during a delay period. When processing simple stimuli, NCL neurons did not multiplex and represented the upcoming choice already during stimulus presentation and throughout the delay period. It is conceivable that the maintenance of the upcoming choice in working memory was prolonged for simple stimuli due to the early choice representation. This possibly resulted in increased decay of the working memory trace ultimately leading to a decrease in performance. In conclusion, we found that increases in stimulus complexity are associated with increased neuronal multiplexing of the working memory representation. This could possibly allow for a facilitated read-out of the neural code resulting in further enhancements of working memory performance.

An Analytical Framework of Tonal and Rhythmic Hierarchy in Natural Music Using the Multivariate Temporal Response Function

Even without formal training, humans experience a wide range of emotions in response to changes in musical features, such as tonality and rhythm, during music listening. While many studies have investigated how isolated elements of tonal and rhythmic properties are processed in the human brain, it remains unclear whether these findings with such controlled stimuli are generalizable to complex stimuli in the real world. In the current study, we present an analytical framework of a linearized encoding analysis based on a set of music information retrieval features to investigate the rapid cortical encoding of tonal and rhythmic hierarchies in natural music. We applied this framework to a public domain EEG dataset (OpenMIIR) to deconvolve overlapping EEG responses to various musical features in continuous music. In particular, the proposed framework investigated the EEG encoding of the following features: tonal stability, key clarity, beat, and meter. This analysis revealed a differential spatiotemporal neural encoding of beat and meter, but not of tonal stability and key clarity. The results demonstrate that this framework can uncover associations of ongoing brain activity with relevant musical features, which could be further extended to other relevant measures such as time-resolved emotional responses in future studies.

Cognitive Biases in Criminal Case Evaluation: A Review of the Research

Psychological heuristics are an adaptive part of human cognition, helping us operate efficiently in a world full of complex stimuli. However, these mental shortcuts also have the potential to undermine the search for truth in a criminal investigation. We reviewed 30 social science research papers on cognitive biases in criminal case evaluations (i.e., integrating and drawing conclusions based on the totality of the evidence in a criminal case), 18 of which were based on police participants or an examination of police documents. Only two of these police participant studies were done in the USA, with the remainder conducted in various European countries. The studies provide supporting evidence that lay people and law enforcement professionals alike are vulnerable to confirmation bias, and there are other environmental, individual, and case-specific factors that may exacerbate this risk. Six studies described or evaluated the efficacy of intervention strategies, with varying evidence of success. Further research, particularly in the USA, is needed to evaluate different approaches to protect criminal investigations from cognitive biases.

The locus of recognition memory signals in human cortex depends on the complexity of the memory representations

Representational theories predict that brain regions contribute to cognition according to the information they represent (e.g., simple versus complex), contradicting the traditional notion that brain regions are specialized for cognitive functions (e.g., perception versus memory). In support of representational accounts, substantial evidence now attests that the Medial Temporal Lobe (MTL) is not specialized solely for long-term declarative memory, but underpins other functions including perception and future-imagining for complex stimuli and events. However, a complementary prediction has been less well explored, namely that the cortical locus of declarative memory may fall outside the MTL if the to-be-remembered content is sufficiently simple. Specifically, the locus should coincide with the optimal neural code for the representations being retrieved. To test this prediction, we manipulated the complexity of the to-be-remembered representations in a recognition memory task. First, participants in the scanner viewed novel 3D objects and scenes, and we used multivariate analyses to identify regions in the ventral visual-MTL pathway that preferentially coded for either simple features of the stimuli, or complex conjunctions of those features. Next, in a separate scan, we tested recognition memory for these stimuli and performed neuroimaging contrasts that revealed two memory signals ‒ feature memory and conjunction memory. Feature memory signals were found in visual cortex, while conjunction memory signals emerged in MTL. Further, the regions optimally representing features via preferential feature-coding coincided with those exhibiting feature memory signals. These findings suggest that representational content, rather than cognitive function, is the primary organizing principle in the ventral visual-MTL pathway.

Evaluation of Diadochokinesis in Greek Preschoolers With Speech Sound Disorders Using a Diadochokinetic Rates Protocol

The study aimed at evaluating the diadochokinetic (DDK) skills of Greek-speaking preschool children with Phonological Disorder (PD) by means of a structured evaluation protocol and at proposing cut-off points for children at risk of speech impairment. The participants were 36 children with PD and 60 typically developing (TD) peers. The groups were matched on age and gender. The PD group performed significantly slower than the TD group in all speech DDK tasks, but not in the oral-motor tasks. The ROC analysis showed a statistically significant positive discrimination for all speech tasks. The internal consistency of the protocol was excellent (Cronbach’s α = .844), while complex stimuli showed a better discriminatory ability. The obtained results agree with Dodd’s classification for Speech Sound Disorders (SSDs). Different types of speech stimuli must be included in the evaluation of DDK performance which can be used as a clinical predictor for preschoolers with SSDs who face difficulties in speech maturation.

Transcranial theta-burst stimulation of primary sensory cortex attenuates somatosensory threat memory in humans

Sensory cortices are required for learning to discriminate complex stimuli that predict threat from those that predict safety in rodents. Yet, sensory cortices may not be needed to learn threat associations to simple stimuli. It is unknown whether these findings apply in humans. Here, we investigated the role of primary sensory cortex in discriminative threat conditioning with simple and complex somatosensory conditioned stimuli (CS) in healthy humans. Immediately before conditioning, participants received continuous theta-burst transcranial magnetic stimulation (cTBS) to primary somatosensory cortex either in the CS-contralateral or CS-ipsilateral hemisphere. After overnight consolidation, threat memory was attenuated in the contralateral compared to the ipsilateral group, as indicated by reduced startle eye-blink potentiation. There was no evidence for a difference between simple and complex stimuli, or that CS identification or conditioning was affected, suggesting a stronger effect of cTBS on consolidation than on initial stimulus processing. We propose that non-invasive stimulation of sensory cortex may provide a new avenue for interfering with threat memories in humans.