Stimulus Selection Research Articles

Strategies for constructing harmonious colour combinations by art students with autism spectrum disorders

Introduction. The survey discussed in the article represents the first experience of an empirical study of the peculiarities characterising the ways of construction and perception of colour harmony by students with autism spectrum disorders – professional art education learners. The relevance of the study is conditioned by new trends in education related to the need to create an inclusive and favourable environment for people with autism. This environment is necessary for their successful integration and professional training in art specialities that are considered a promising area for professional realisation of people with autism. Methods. The survey was carried out using the experimental method involving 21 participants with autism spectrum disorders (mean age = 20.4 years; SD = 2.4; 9 males, 12 females). The participants’ answers in the experimental group were compared with those of an age-, gender-, and education-matched control group (N=21). The participants’ task was to match two given shades with a third one in the palette, for the colour combination to be as harmonious as possible. The experimental palette allowed to change the hue, lightness and chroma of shades. Results. The participants with autism spectrum disorders were twice as likely to choose yellow (23.8% compared to 12.4% in the control group) and purple shades (16.2% compared to 9.5%); hardly used orange (1.9%) and blue (4.8%) and preferred lighter shades (the mean L value was 67.8 compared to the control group’s 63.0). The chroma of the selected shades correlated with their hue and lightness. The stimulus selection strategy depended on the distance (∆E*00) between the given (upper and lower) shades in the CIELAB colour space and was based on a specific “geometry” (a particular ratio of values characterising the angles and side lengths formed by the given and selected shades, as well as a preference for a particular triangle area and its type). Discussion. The experiment showed that the students with autism spectrum disorders differed markedly from neurotypical students in a number of indicators when constructing a colour harmony. The experimental group participants’ responses showed a “preference for sameness” characteristic of autism. The significant inter-group differences were applied more to the lightness and chroma of the chosen shades than to their hue. The shades preferred by the participants with autism spectrum disorders better matched the conditions of the habitual “chromatic diet” and the colour’s statistics in nature. The observed specificity may also reflect the reduced ability to generalise and average out colours in terms of holistic perception, specific to autism. Conclusion. The survey results make an important contribution to the improvement of the professional training methodology for art students, and for the development of scientifically based educational approaches to teaching people with autism spectrum disorders, primarily in the context of the formation of colour-related competencies; in addition, they may provide new impulses for investigating the fundamental mechanisms of cognitive processing of colour-related information.

Mapping punishment avoidance learning deficits in non-suicidal self-injury in young adults with and without borderline personality disorder: An fMRI study

IntroductionNon-suicidal self-injury (NSSI) is a growing public health concern among young adults in both clinical and non-clinical settings. Despite evidence linking NSSI to alterations in learning from reward and punishment, this area remains understudied, especially in non-clinical populations without borderline personality disorder (BPD). MethodsWe employed a modified version of the Probabilistic Stimulus Selection (PSS) task in two groups of young adults with recurrent NSSI, with (NSSI+BPD) and without BPD (NSSI), and an additional group of healthy controls (HC). While undergoing functional magnetic resonance imaging (fMRI), participants were asked to choose between pairs of stimuli with different reward probabilities. In the training phase, they received probabilistic feedback and learned to identify the most rewarding option within fixed pairs. In the test phase, these learned stimuli were recombined into novel pairs, where participants' accuracy in selecting the most rewarding and avoiding the most punishing options reflected their ability to learn from reward and punishment, respectively. ResultsCompared to HC, participants in the NSSI and NSSI+BPD groups were less accurate at avoiding the most punishing options than at choosing the most rewarding options, and showed reduced activity in the nucleus accumbens (NAcc) during punishment avoidance relative to reward selection. LimitationsThe modest sample size, descriptive rather than modeling approach, and absence of ecological momentary assessments may limit the results. ConclusionFindings suggest that reduced activation of the NAcc when avoiding loss may underlie difficulties in learning to avoid punishment in young adults with NSSI, regardless of the presence of BPD.

Auditory competition and stimulus selection across spatial locations from midbrain to forebrain in barn owls

Barn owls enable investigation of neural mechanisms underlying stimulus selection of concurrent stimuli. The audio-visual space map in the optic tectum (OT), avian homologue of the superior colliculus, encodes relative strength of concurrent auditory stimuli through spike response rate and interneuronal spike train synchrony (STS). Open questions remain regarding stimulus selection in downstream forebrain regions lacking topographic coding of auditory space, including the functional consequences of interneuronal STS on interregional signaling. To this end, we presented concurrent stimuli at different locations and manipulated relative strength while simultaneously recording neural responses from OT and its downstream thalamic target, nucleus rotundus (nRt), in awake barn owls of both sexes. Results demonstrated that broadly spatially tuned nRt units exhibit different spike response patterns to competition depending on spatial tuning preferences. Modeling suggests nRt units integrate convergent inputs from distant locations across midbrain map regions. Additionally, STS within nRt reflects the temporal properties of the strongest stimulus. Furthermore, interregional STS between OT and nRt was strongest when spatial tuning overlap between units across regions was large and when the strongest stimulus location during competition was favorable for units in both regions. Additionally, though gamma oscillations synthesized within OT are weakly propagated within nRt, average gamma power across regions correlates with strength of interregional STS. Overall, we demonstrate that nRt integrates inputs across distant areas of OT, retains spatial information through differences in strength of inputs from various locations of the midbrain map across neurons, and prioritizes coding of identity features to the strongest sound.Significance StatementThe brain strategically selects and preferentially processes salient stimuli. A critical function to this process involves transferring salient information across regions that may exhibit drastic transformations in coding schemes. Our study in barn owls investigates bottom-up signaling between the midbrain space map and its downstream thalamic target, which lacks spatial topography as also observed in mammalian auditory forebrain regions to elucidate general mechanisms underlying how spatial location information and other properties of the strongest sound are relayed between regions. Results show that the thalamus integrates neural responses widely across the midbrain map, retains coding of spatial location through varying strength of inputs of the map across neurons, and prioritizes further coding of identity features only to the strongest sound.

Neural correlates of category learning in monkey inferior temporal cortex.

Area TE is required for normal learning of visual categories based on perceptual similarity. To evaluate whether category learning changes neural activity in area TE, we trained two monkeys (both male) implanted with multi-electrode arrays to categorize natural images of cats and dogs. Neural activity during a passive viewing task was compared pre- and post-training. After the category training, the accuracy of abstract category decoding improved. Single units became more category-selective, the proportion of single units with category-selectivity increased, and units sustained their category-specific responses for longer. Visual category learning thus appears to enhance category separability in area TE by driving changes in the stimulus selectivity of individual neurons and by recruiting more units to the active network.Significance statement Neurons in Area TE are known to respond selectively to a small number of visual stimuli. Here we demonstrate that the neural activity in area TE is modulated by category learning of natural images (cats and dogs), thus demonstrating that this region is capable of undergoing rapid plastic changes in adult primates.

Deprivation of visual input alters specific subset of inhibitory neurons and affect thalamic afferent terminals in V1 of rd1 mouse.

Retinitis Pigmentosa (RP) is a heterogenous group of inherited disorder, and its progression not only affects the retina but also the primary visual cortex. This manifests imbalances in the excitatory and inhibitory neurotransmission. Here, we investigated if changes in cortical functioning is linked to alterations in GABAergic population of neurons and its two important subsets, somatostatin (SST) and parvalbumin (PV) neuron in rd1 model of retinal degeneration (RD). We demonstrate marked decrease in the proportion of SST neurons in different layers of cortex whereas PV neurons were less affected. Moreover, we found reduced expression of glutamatergic thalamic afferents (VGLUT2) due to lack of visual activity. These results suggest PV neurons are likely recruited by the cortical circuitry to increase the inhibitory drive and compensate the disrupted inhibition-excitation balance. However, reduced SST expression perhaps results in weakening of stimulus selectivity. Delineating their functional role during RD will provide insights for acquisition of high-resolution vision thereby improving current state of vision restoration.

Functional role of area 8A in the posterior dorsolateral frontal region of the human brain: A single case study.

Area 8A has traditionally been considered to be the frontal eye field (FEF), i.e. the area for the motor production of eye movements. However, recent research has shown that the FEF lies posteriorly in premotor area 6. Research in macaque monkeys has demonstrated that, in contrast to premotor area 6, which is involved in the production of motor actions, area 8A is implicated in the cognitive allocation of attention to stimuli based on instruction cues. The aim of the present study was to elucidate the specific cognitive role of area 8A by examining a unique patient with a lesion restricted to area 8A, i.e. sparing the premotor cortex. This right-handed male patient underwent neuropsychological assessment and testing on two conditional associative-learning tasks: the motor hand conditional associative-learning task (MCALT) assessing the selection of motor actions based on instruction cues and the visual conditional associative-learning task (VCALT) assessing the selection of visual stimuli based on instruction cues. The patient's performance on the VCALT was significantly impaired compared to control subjects, but performance on the MCALT and on an Eye Movement Control Task was preserved. The present study provides evidence that area 8A is critical for the cognitive process regulating the allocation of attention to different stimuli in the environment, but not in the production of eye movements. These findings enhance understanding of the functional organization of the posterior dorsolateral frontal region in the human brain and suggest a specialized role of area 8A in high-level cognitive processes.

A chromatic feature detector in the retina signals visual context changes.

The retina transforms patterns of light into visual feature representations supporting behaviour. These representations are distributed across various types of retinal ganglion cells (RGCs), whose spatial and temporal tuning properties have been studied extensively in many model organisms, including the mouse. However, it has been difficult to link the potentially nonlinear retinal transformations of natural visual inputs to specific ethological purposes. Here, we discover a nonlinear selectivity to chromatic contrast in an RGC type that allows the detection of changes in visual context. We trained a convolutional neural network (CNN) model on large-scale functional recordings of RGC responses to natural mouse movies, and then used this model to search in silico for stimuli that maximally excite distinct types of RGCs. This procedure predicted centre colour opponency in transient suppressed-by-contrast (tSbC) RGCs, a cell type whose function is being debated. We confirmed experimentally that these cells indeed responded very selectively to Green-OFF, UV-ON contrasts. This type of chromatic contrast was characteristic of transitions from ground to sky in the visual scene, as might be elicited by head or eye movements across the horizon. Because tSbC cells performed best among all RGC types at reliably detecting these transitions, we suggest a role for this RGC type in providing contextual information (i.e. sky or ground) necessary for the selection of appropriate behavioural responses to other stimuli, such as looming objects. Our work showcases how a combination of experiments with natural stimuli and computational modelling allows discovering novel types of stimulus selectivity and identifying their potential ethological relevance.

Characterization of the temporal stability of ToM and pain functional brain networks carry distinct developmental signatures during naturalistic viewing

A temporally stable functional brain network pattern among coordinated brain regions is fundamental to stimulus selectivity and functional specificity during the critical period of brain development. Brain networks that are recruited in time to process internal states of others’ bodies (like hunger and pain) versus internal mental states (like beliefs, desires, and emotions) of others’ minds allow us to ask whether a quantitative characterization of the stability of these networks carries meaning during early development and constrain cognition in a specific way. Previous research provides critical insight into the early development of the theory-of-mind (ToM) network and its segregation from the Pain network throughout normal development using functional connectivity. However, a quantitative characterization of the temporal stability of ToM networks from early childhood to adulthood remains unexplored. In this work, reusing a large sample of children (n = 122, 3–12 years) and adults (n = 33) dataset that is available on the OpenfMRI database under the accession number ds000228, we addressed this question based on their fMRI data during a short and engaging naturalistic movie-watching task. The movie highlights the characters’ bodily sensations (often pain) and mental states (beliefs, desires, emotions), and is a feasible experiment for young children. Our results tracked the change in temporal stability using an unsupervised characterization of ToM and Pain networks DFC patterns using Angular and Mahalanobis distances between dominant dynamic functional connectivity subspaces. Our findings reveal that both ToM and Pain networks exhibit lower temporal stability as early as 3-years and gradually stabilize by 5-years, which continues till adolescence and late adulthood (often sharing similarity with adult DFC stability patterns). Furthermore, we find that the temporal stability of ToM brain networks is associated with the performance of participants in the false belief task to access mentalization at an early age. Interestingly, higher temporal stability is associated with the pass group, and similarly, moderate and low temporal stability are associated with the inconsistent group and the fail group. Our findings open an avenue for applying the temporal stability of large-scale functional brain networks during cortical development to act as a biomarker for multiple developmental disorders concerning impairment and discontinuity in the neural basis of social cognition.

Tracking neurons across days with high-density probes.

Neural activity spans multiple time scales, from milliseconds to months. Its evolution can be recorded with chronic high-density arrays such as Neuropixels probes, which can measure each spike at tens of sites and record hundreds of neurons. These probes produce vast amounts of data that require different approaches for tracking neurons across recordings. Here, to meet this need, we developed UnitMatch, a pipeline that operates after spike sorting, based only on each unit's average spike waveform. We tested UnitMatch in Neuropixels recordings from the mouse brain, where it tracked neurons across weeks. Across the brain, neurons had distinctive inter-spike interval distributions. Their correlations with other neurons remained stable over weeks. In the visual cortex, the neurons' selectivity for visual stimuli remained similarly stable. In the striatum, however, neuronal responses changed across days during learning of a task. UnitMatch is thus a promising tool to reveal both invariance and plasticity in neural activity across days.

Audiogram Estimation Performance Using Auditory Evoked Potentials and Gaussian Processes.

Auditory evoked potentials (AEPs) play an important role in evaluating hearing in infants and others who are unable to participate reliably in behavioral testing. Discriminating the AEP from the much larger background activity, however, can be challenging and time-consuming, especially when several AEP measurements are needed, as is the case for audiogram estimation. This task is usually entrusted to clinicians, who visually inspect the AEP waveforms to determine if a response is present or absent. The drawback is that this introduces a subjective element to the test, compromising quality control of the examination. Various objective methods have therefore been developed to aid clinicians with response detection. In recent work, the authors introduced Gaussian processes (GPs) with active learning for hearing threshold estimation using auditory brainstem responses (ABRs). The GP is attractive for this task, as it can exploit the correlation structure underlying AEP waveforms across different stimulus levels and frequencies, which is often overlooked by conventional detection methods. GPs with active learning previously proved effective for ABR hearing threshold estimation in simulations, but have not yet been evaluated for audiogram estimation in subject data. The present work evaluates GPs with active learning for ABR audiogram estimation in a sample of normal-hearing and hearing-impaired adults. This involves introducing an additional dimension to the GP (i.e., stimulus frequency) along with real-time implementations and active learning rules for automated stimulus selection. The GP's accuracy was evaluated using the "hearing threshold estimation error," defined as the difference between the GP-estimated hearing threshold and the behavioral hearing threshold to the same stimuli. Test time was evaluated using the number of preprocessed and artifact-free epochs (i.e., the sample size) required for locating hearing threshold at each frequency. Comparisons were drawn with visual inspection by examiners who followed strict guidelines provided by the British Society of Audiology. Twenty-two normal hearing and nine hearing-impaired adults were tested (one ear per subject). For each subject, the audiogram was estimated three times: once using the GP approach, once using visual inspection by examiners, and once using a standard behavioral hearing test. The GP's median estimation error was approximately 0 dB hearing level (dB HL), demonstrating an unbiased test performance relative to the behavioral hearing thresholds. The GP additionally reduced test time by approximately 50% relative to the examiners. The hearing thresholds estimated by the examiners were 5 to 15 dB HL higher than the behavioral thresholds, which was consistent with the literature. Further testing is still needed to determine the extent to which these results generalize to the clinic. GPs with active learning enable automatic, real-time ABR audiogram estimation with relatively low test time and high accuracy. The GP could be used to automate ABR audiogram estimation or to guide clinicians with this task, who may choose to override the GP's decisions if deemed necessary. Results suggest that GPs hold potential for next-generation ABR hearing threshold and audiogram-seeking devices.

Adhesion Evolution: Designing Smart Polymeric Adhesive Systems with On-Demand Reversible Switchability.

Smart polymeric switchable adhesives represent a rapidly emerging class of advanced materials, exhibiting the ability to undergo on-demand transitioning between "On" and "Off" adhesion states. By selectively tuning external stimuli triggers (including temperature, light, electricity, magnetism, and chemical agents), we can engineer these materials to undergo reversible changes in their bonding capabilities. The strategic design selection of stimuli is a pivotal factor in the design of switchable adhesive systems. This review outlines recent advancements in the field of smart switchable polymeric adhesives over the past decade with a focus on the selection of stimulus triggers. These systems are further categorized into one of four adhesion switching mechanisms upon initiation by a specific stimuli-trigger: (i) interfacial adhesion, (ii) stiffness, (iii) contact area, or (iv) suction-based switching. Evaluation of adhesion switching performance across systems is primarily made based on three key metrics: (i) maximum adhesion strength, (ii) switch ratio, and (iii) switch time. Different stimuli and mechanisms offer distinct advantages and limitations, influencing the performance characteristics and applicability of these materials across domains such as detachable biomedical devices, robotic grippers, and climbing robots. This review thus offers a perspective on the present advancements and challenges in this emerging field, along with insights into future directions.

Multi-timescale neural dynamics for multisensory integration.

Carrying out any everyday task, be it driving in traffic, conversing with friends or playing basketball, requires rapid selection, integration and segregation of stimuli from different sensory modalities. At present, even the most advanced artificial intelligence-based systems are unable to replicate the multisensory processes that the human brain routinely performs, but how neural circuits in the brain carry out these processes is still not well understood. In this Perspective, we discuss recent findings that shed fresh light on the oscillatory neural mechanisms thatmediate multisensory integration (MI), including power modulations, phase resetting, phase-amplitude coupling and dynamic functional connectivity. We then consider studies that also suggest multi-timescale dynamics in intrinsic ongoing neural activity and during stimulus-driven bottom-up and cognitive top-down neural network processing in the context of MI. We propose a new concept of MI that emphasizes the critical role of neural dynamics at multiple timescales within and across brain networks, enabling the simultaneous integration, segregation, hierarchical structuring and selection of information in different time windows. To highlight predictions from our multi-timescale concept of MI, real-world scenarios in which multi-timescale processes may coordinate MI in a flexible and adaptive manner are considered.

Striatal GABA levels correlate with risk sensitivity in monetary loss.

Decision-making under risk is a common challenge. It is known that risk-taking behavior varies between contexts of reward and punishment, yet the mechanisms underlying this asymmetry in risk sensitivity remain unclear. This study used a monetary task to investigate neurochemical mechanisms and brain dynamics underpinning risk sensitivity. Twenty-eight participants engaged in a task requiring selection of visual stimuli to maximize monetary gains and minimize monetary losses. We modeled participant trial-and-error processes using reinforcement learning. Participants with higher subjective utility parameters showed risk preference in the gain domain (r = -0.59) and risk avoidance in the loss domain (r = -0.77). Magnetic resonance spectroscopy (MRS) revealed that risk avoidance in the loss domain was associated with γ-aminobutyric acid (GABA) levels in the ventral striatum (r = -0.42), but not in the insula (r = -0.15). Using functional magnetic resonance imaging (fMRI), we tested whether risk-sensitive brain dynamics contribute to participant risky choices. Energy landscape analyses demonstrated that higher switching rates between brain states, including the striatum and insula, were correlated with risk avoidance in the loss domain (r = -0.59), a relationship not observed in the gain domain (r = -0.02). These findings from MRS and fMRI suggest that distinct mechanisms are involved in gain/loss decision making, mediated by subcortical neurometabolite levels and brain dynamic transitions.

Meniscal Allograft versus Synthetic Graft in Treatment Outcomes of Meniscus Repair: A Mini-review and Meta-analysis.

Meniscal injuries are highly correlated with osteoarthritis (OA) onset and progression. Although meniscal allograft transplantation (MAT) is a therapeutic option to restore meniscal anatomy, a shortage of donor material and the donor-derived infectious risk may be concerns in clinics. This review summarizes the literature reporting meniscus repair status in preclinical models and clinical practice using allografts or synthetic grafts. The advantages and limitations of biodegradable polymer-based meniscal scaffolds, applied in preclinical studies, are discussed. Then, the long-term treatment outcomes of patients with allografts or commercial synthetic scaffolds are compared. A total of 47 studies are included in our network meta-analysis. Compared with the meniscal allografts, the commercial synthetic products significantly improved clinical treatment outcomes in terms of the Knee Injury and Osteoarthritis Outcome Score (KOOS), Visual Analog Scale (VAS) scores, and Lysholm scores. In addition, development strategies for the next generation of novel synthetic scaffolds are proposed through optimization of structural design and fabrication, and selection of cell sources, external stimuli, and active ingredients. This review may inspire researchers and surgeons to design and fabricate clinic-orientated grafts with improved treatment outcomes.

Measuring attentional selection of object categories using hierarchical frequency tagging.

In the present study, we used Hierarchical Frequency Tagging (Gordon etal., 2017) to investigate in electroencephalography how different levels of the neural processing hierarchy interact with category-selective attention during visual object recognition. We constructed stimulus sequences of cyclic wavelet scrambled face and house stimuli at two different frequencies (f1 = 0.8Hz and f2 = 1Hz). For each trial, two stimulus sequences of different frequencies were superimposed and additionally augmented by a sinusoidal contrast modulation with f3 = 12.5Hz. This allowed us to simultaneously assess higher level processing using semantic wavelet-induced frequency-tagging (SWIFT) and processing in earlier visual levels using steady-state visually evoked potentials (SSVEPs), along with their intermodulation (IM) components. To investigate the category specificity of the SWIFT signal, we manipulated the category congruence between target and distractor by superimposing two sequences containing stimuli from the same or different object categories. Participants attended to one stimulus (target) and ignored the other (distractor). Our results showed successful tagging of different levels of the cortical hierarchy. Using linear mixed-effects modeling, we detected different attentional modulation effects on lower versus higher processing levels. SWIFT and IM components were substantially increased for target versus distractor stimuli, reflecting attentional selection of the target stimuli. In addition, distractor stimuli from the same category as targets elicited stronger SWIFT signals than distractor stimuli from a different category indicating category-selective attention. In contrast, for IM components, this category-selective attention effect was largely absent, indicating that IM components probably reflect more stimulus-specific processing.

Toward parametric Bayesian adaptive procedures for multi-frequency categorical loudness scaling.

A series of Bayesian adaptive procedures to estimate loudness growth across a wide frequency range from individual listeners was developed, and these procedures were compared. Simulation experiments were conducted based on multinomial psychometric functions for categorical loudness scaling across ten test frequencies estimated from 61 listeners with normal hearing and 87 listeners with sensorineural hearing loss. Adaptive procedures that optimized the stimulus selection based on the interim estimates of two types of category-boundary models were tested. The first type of model was a phenomenological model of category boundaries adopted from previous research studies, while the other type was a data-driven model derived from a previously collected set of categorical loudness scaling data. An adaptive procedure without Bayesian active learning was also implemented. Results showed that all adaptive procedures provided convergent estimates of the loudness category boundaries and equal-loudness contours between 250 and 8000 Hz. Performing post hoc model fitting, using the data-driven model, on the collected data led to satisfactory accuracies, such that all adaptive procedures tested in the current study, independent of modeling approach and stimulus-selection rules, were able to provide estimates of the equal-loudness-level contours between 20 and 100 phons with root-mean-square errors typically under 6 dB after 100 trials.

Reading Reshapes Stimulus Selectivity in the Visual Word Form Area.

Reading depends on a brain region known as the "visual word form area" (VWFA) in the left ventral occipitotemporal cortex. This region's function is debated because its stimulus selectivity is not absolute, it is modulated by a variety of task demands, and it is inconsistently localized. We used fMRI to characterize the combination of sensory and cognitive factors that activate word-responsive regions that we precisely localized in 16 adult humans (4 male). We then presented three types of character strings: English words, pseudowords, and unfamiliar characters with matched visual features. Participants performed three different tasks while viewing those stimuli: detecting real words, detecting color in the characters, and detecting color in the fixation mark. There were three primary findings about the VWFA's response: (1) It preferred letter strings over unfamiliar characters even when the stimuli were ignored during the fixation task. (2) Compared with those baseline responses, engaging in the word reading task enhanced the response to words but suppressed the response to unfamiliar characters. (3) Attending to the stimuli to judge their color had little effect on the response magnitudes. Thus, the VWFA is uniquely modulated by a cognitive signal that is specific to voluntary linguistic processing and is not additive. Functional connectivity analyses revealed that communication between the VWFA and a left frontal language area increased when the participant engaged in the linguistic task. We conclude that the VWFA is inherently selective for familiar orthography, but it falls under control of the language network when the task demands it.

The effects of cognitive bias, examiner expertise, and stimulus material on forensic evidence analysis.

Forensic examiners have come under scrutiny due to high-profile exonerations, highlighting the consequences that contextual bias can have on investigations. Researchers have proposed solutions to reduce the effects of bias including blind testing and redacting task-irrelevant information. Practitioners have concerns over the limitations of some of this research that uses untrained students to examine complex pieces of forensic evidence (e.g., fingerprints) (1; but see 2 for studies including trained experts and/or actual casework). This study sought to (a) examine the effect of contextual bias on examiners' evaluation of forensic evidence by varying the amount of pre-comparison information available to participants, (b) compare student and expert examiners' performance and their vulnerability to contextual bias, and (c) examine the effects of contextual bias on examiners' evaluation of different types of forensic evidence. Expert fingerprint examiners and student participants were presented with varying amounts of pre-comparison case information and compared matching and non-matching fingerprint and footwear impression evidence. Results suggest no effects of blinding examiners from case information or redacting task-irrelevant information. As expected, expert fingerprint examiners were more likely to correctly identify matching fingerprints and correctly exclude non-matching fingerprints than students. However, expert fingerprint examiners were no better than student participants at comparing footwear impression evidence. These findings suggest that sample, stimulus selection, and discipline-specific training matter when investigating bias in forensic decision making. These findings suggest caution when using forensic stimuli with student samples to investigate forensic decision-making and highlight the need for more research on redaction procedures.

Reading reshapes stimulus selectivity in the visual word form area.

Reading depends on a brain region known as the "visual word form area" (VWFA) in left ventral occipito-temporal cortex. This region's function is debated because its stimulus selectivity is not absolute, it is modulated by a variety of task demands, and it is inconsistently localized. We used fMRI to characterize the combination of sensory and cognitive factors that activate word-responsive regions that we precisely localized in 16 adult humans (4 male). We then presented three types of character strings: English words, pseudowords, and unfamiliar characters with matched visual features. Participants performed three different tasks while viewing those stimuli: detecting real words, detecting color in the characters, and detecting color in the fixation mark. There were three primary findings about the VWFA's response: (1) It preferred letter strings over unfamiliar characters even when the stimuli were ignored during the fixation task; (2) Compared to those baseline responses, engaging in the word reading task enhanced the response to words but suppressed the response to unfamiliar characters. (3) Attending to the stimuli to judge their font color had little effect on the response magnitudes. Thus, the VWFA is uniquely modulated by a cognitive signal that is specific to voluntary linguistic processing and is not additive. Functional connectivity analyses revealed that communication between the VWFA and a left frontal language area increased when the participant engaged in the linguistic task. We conclude that the VWFA is inherently selective for familiar orthography, but it falls under control of the language network when the task demands it.

Comparing child word associations to adult associative norms: Evidence for child-specific associations with a strong priming effect in 3-year-olds

Investigating how infants first establish relationships between words is a necessary step towards understanding how an interconnected network of semantic relationships develops in the adult lexical-semantic system. Stimuli selection for these child studies is critical since words must be both familiar and highly imageable. However, there has been a reliance on adult word association norms to inform stimuli selection in English infant studies to date, as no resource currently exists for child-specific word associations. We present three experiments that explore the strength of word–word relationships in 3-year-olds. Experiment 1 collected children’s word associations (WA) (N = 150; female = 84, L1 = British English) and compared them to adult associative norms (Moss & Older, 1996; Nelson et al., 2004 (Behavior Research Methods, Instruments, & Computers, 36(3), 402–407)). Experiment 2 replicated WAs from Experiment 1 in an online adaptation of the task (N = 24: 13 female, L1 = British English). Both experiments indicated a high proportion of child-specific WAs not represented in adult norms (Moss & Older, 1996; Nelson et al., 2004 (Behavior Research Methods, Instruments, & Computers, 36(3), 402–407)). Experiment 3 tested noun–noun WAs from these responses in an online semantic priming study (N = 40: 19 female, L1 = British English) and found that association type modulated priming (F(2.57, 100.1) = 13.13, p <. 0001, generalized η2 = .19). This research presents a resource of child-specific imageable noun–noun word pair stimuli suitable for testing young children in word recognition and semantic priming studies.