The effects of internal representations on performance and fluidity in a motor task.

Individuals can differ in the mode in which they experience conscious thought. These differences in visualisation and verbalisation can also be evident during motor control. The Internal Representation Questionnaire (IRQ) was developed to measure propensity to engage certain types of representations, but its ability to predict motor control and links to reinvestment and motor imagery have not been tested. 159 included participants completed the IRQ, movement specific reinvestment scale (MSRS), and a novel online motor task before and after a period of practice. Results showed that the IRQ Verbal and Orthographic factors were significant predictors of scores on the MSRS. The IRQ factor of Manipulational Representations predicted motor performance both before and after practice. The fluidity of executed movements were predicted by the IRQ verbalisation factor where higher propensity to verbalise was associated with higher levels of jitter, but only after a period of practice. Results suggest there may be some informative conceptual overlap between internal verbalisations and reinvestment and that the propensity to manipulate internal representations may be predictive of motor performance in new tasks. The IRQ has potential to be a valuable tool for predicting motor performance.

Processing time not modality dominates shift costs in the modality-shifting effect.

Shifting attention between visual and auditory targets is associated with reaction time costs, known as the modality-shifting effect. The type of modality shifted from, e.g., auditory or visual is suggested to have an effect on the degree of cost. Studies report greater costs shifting from visual stimuli, yet notably used visual stimuli that are also identified slower than the auditory. It is not clear whether the cost is specific to modality effects, or with identification speed independent of modality. Here, to interpret whether the effects are due to modality or identification time, switch costs are instead compared with auditory stimuli that are identified slower than the visual (inverse of tested previously). A second condition used the same auditory stimuli at a low intensity, allowing comparison of semantically identical stimuli that are even slower to process. The current findings contradicted suggestions of a general difficulty in shifting from visual stimuli (as previously reported), and instead suggest that cost is reduced when targets are preceded by a more rapidly processed stimulus. 'Modality-Shifting' as it is often termed induces shifting costs, but the costs are not because of a change of modality per se, but because of a change in identification speed, where the degree of cost is dependent on the processing time of the surrounding stimuli.

The Internal Representations Questionnaire: Measuring modes of thinking.

Does the format in which we experience our moment-to-moment thoughts vary from person to person? Many people claim that their thinking takes place in an inner voice and that using language outside of interpersonal communication is a regular experience for them. Other people disagree. We present a novel measure, the Internal Representation Questionnaire (IRQ) designed to assess people's subjective mode of internal representations, and to quantify individual differences in "modes of thinking" along multiple factors in a single questionnaire. Exploratory factor analysis identified four factors: Internal Verbalization, Visual Imagery, Orthographic Imagery, and Representational Manipulation. All four factors were positively correlated with one another, but accounted for unique predictions. We describe the properties of the IRQ and report a test of its ability to predict patterns of interference in a speeded word-picture verification task. Taken together, the results suggest that self-reported differences in how people internally represent their thoughts relates to differences in processing familiar images and written words.

The Role of Language in Nonlinguistic Stimuli: Comparing Inhibition in Children With Language Impairment.

Purpose: There is conflicting evidence regarding if and how a deficit in executive function may be associated with developmental language impairment (LI). Nonlinguistic stimuli are now frequently used when testing executive function to avoid a language confound. However, it is possible that increased stimulus processing demands for nonlinguistic stimuli may also compound the complexity of the relationship between executive function and LI. The current study examined whether variability across nonlinguistic auditory stimuli might differentially affect inhibition and whether performance differs between children with and without language difficulties. Method: Sixty children, aged 8-14 years, took part in the study: 20 typically developing children, 20 children with autism spectrum disorder, and 20 children with specific LI. For the purposes of assessing the role of language, children were further categorized based on language ability: 33 children with normal-language (NL) ability and 27 children with LI. Children completed a go/no-go task with 2 conditions comparing nonlinguistic auditory stimuli: 2 abstract sounds and 2 familiar sounds (duck quack and dog bark). Results: There was no significant difference for diagnostic category. However, there was a significant interaction between language ability and condition. There was no significant difference in the NL group performance in the abstract and familiar sound conditions. In contrast, the group with LI made significantly more errors in the abstract condition compared with the familiar condition. There was no significant difference in inhibition between the NL group and the group with LI in the familiar condition; however, the group with LI made significantly more errors than the NL group in the abstract condition. Conclusions: Caution is needed in stimuli selection when examining executive function skills because, although stimuli may be selected on the basis of being "nonlinguistic and auditory," the type of stimuli chosen can differentially affect performance. The findings have implications for the interpretation of deficits in executive function as well as the selection of stimuli in future studies.

Parental perception of listening difficulties: an interaction between weaknesses in language processing and ability to sustain attention.

(Central) auditory processing disorder ((C)APD) is a controversial diagnostic category which may be an artefact of referral route. Yet referral route must, to some extent, be influenced by a child's profile of presenting symptoms. This study tested the hypothesis that parental perception of listening difficulty is associated with weaknesses in ability to sustain attention while listening to speech. Forty-four children (24 with listening difficulties) detected targets embedded in a 16-minute story. The targets were either mispronunciations or nonsense words. Sentence context was modulated to separate out effects due to deficits in language processing from effects due to deficits in attention. Children with listening difficulties missed more targets than children with typical listening abilities. Both groups of children were initially sensitive to sentence context, but this declined over time in the children with listening difficulties. A report-based measure of language abilities captured the majority of variance in a measure capturing time-related changes in sensitivity to context. Overall, the findings suggest parents perceive children to have listening, not language difficulties, because weaknesses in language processing only emerge when stressed by the additional demands associated with attending to, and processing, speech over extended periods of time.

Hearing without listening: Attending to a quiet audiobook.

Careful systematic tests of hearing ability may miss the cognitive consequences of sub-optimal hearing when listening in the real world. In Experiment 1, sub-optimal hearing is simulated by presenting an audiobook at a quiet but discriminable level over 50 min. Recall of facts, words and inferences are assessed and performance compared to another group at a comfortable listening volume. At the quiet intensity, participants are able to detect, discriminate and identify spoken words but do so at a cost to sequential accuracy and fact recall when attention must be sustained over time. To exclude other interpretations, the effects are studied in Experiment 2 by comparing recall to the same sentences presented in isolation. Here, the differences disappear. The results demonstrate that the cognitive consequences of listening at low volume arise when sustained attention is demanded over time.

The role of nonverbal working memory in morphosyntactic processing by children with specific language impairment and autism spectrum disorders.

BACKGROUND: Both children with autism spectrum disorders (ASD) and children with specific language impairment (SLI) have been shown to have difficulties with grammatical processing. A comparison of these two populations with neurodevelopmental disorders was undertaken to examine similarities and differences in the mechanisms that may underlie grammatical processing. Research has shown that working memory (WM) is recruited during grammatical processing. The goal of this study was to examine morphosyntactic processing on a grammatical judgment task in children who varied in clinical diagnosis and language abilities and to assess the extent to which performance is predicted by nonverbal working memory (WM). Two theoretical perspectives were evaluated relative to performance on the grammatical judgment task-the "working memory" account and the "wrap-up" account. These accounts make contrasting predictions about the detection of grammatical errors occurring early versus late in the sentence. METHODS: Participants were 84 school-age children with SLI (n = 21), ASD (n = 27), and typical development (TD, n = 36). Performance was analyzed based on diagnostic group as well as language status (normal language, NL, n = 54, and language impairment, LI, n = 30). A grammatical judgment task was used in which the position of the error in the sentence (early versus late) was manipulated. A visual WM task (N-back) was administered and the ability of WM to predict morphosyntactic processing was assessed. RESULTS: Groups differed significantly in their sensitivity to grammatical errors (TD > SLI and NL > LI) but did not differ in nonverbal WM. Overall, children in all groups were more sensitive and quicker at detecting errors occurring late in the sentence than early in the sentence. Nonverbal WM predicted morphosyntactic processing across groups, but the specific profile of association between WM and early versus late error detection was reversed for children with and without language impairment. CONCLUSIONS: Findings primarily support a "wrap up" account whereby the accumulating sentence context for errors positioned late in the sentence (rather than early) appeared to facilitate morphosyntactic processing. Although none of the groups displayed deficits in visual WM, individual differences in these nonverbal WM resources predicted proficiency in morphosyntactic processing.

Continuous Performance Tasks: Not Just About Sustaining Attention.

PURPOSE: Continuous performance tasks (CPTs) are used to measure individual differences in sustained attention. Many different stimuli have been used as response targets without consideration of their impact on task performance. Here, we compared CPT performance in typically developing adults and children to assess the role of stimulus processing on error rates and reaction times. METHOD: Participants completed a CPT that was based on response to infrequent targets, while monitoring and withholding responses to regular nontargets. Performance on 3 stimulus conditions was compared: visual letters (X and O), their auditory analogs, and auditory pure tones. RESULTS: Adults showed no difference in error propensity across the 3 conditions but had slower reaction times for auditory stimuli. Children had slower overall reaction times. They responded most quickly to the visual target and most slowly to the tone target. They also made more errors in the tone condition than in either the visual or the auditory spoken CPT conditions. CONCLUSIONS: The results suggest error propensity and reaction time variations on CPTs cannot solely be interpreted as evidence of inattention. They also reflect stimulus-specific influences that must be considered when testing hypotheses about modality-specific deficits in sustained attention in populations with different developmental disorders.

Attending at a Low Intensity Increases Impulsivity in an Auditory Sustained Attention to Response Task.

Why attention lapses during prolonged tasks is debated, specifically whether errors are a consequence of under-arousal or exerted effort. To explore this, we investigated whether increased impulsivity is associated with effortful processing by modifying the demand of a task by presenting it at a quiet intensity. Here, we consider whether attending at low but detectable levels affects impulsivity in a population with intact hearing. A modification of the Sustained Attention to Response Task was used with auditory stimuli at two levels: the participants' personal "lowest detectable" level and a "normal speaking" level. At the quiet intensity, we found that more impulsive responses were made compared with listening at a normal speaking level. These errors were not due to a failure in discrimination. The findings suggest an increase in processing time for auditory stimuli at low levels that exceeds the time needed to interrupt a planned habitual motor response. This leads to a more impulsive and erroneous response style. These findings have important implications for understanding the nature of impulsivity in relation to effortful processing. They may explain why a high proportion of individuals with hearing loss are also diagnosed with Attention Deficit Hyperactivity Disorder.

ERP evidence for human early visual sensitivity to co-linearity compared to co-circularity.

Our complex visual environment is constrained by natural geometric regularities, including spatiotemporal regularity, co-linearity and co-circularity. To investigate human visual processing associated with these regularities we directly compared the neural processes in encoding dynamic co-linearity and co-circularity using event-related potentials (ERPs). By recording ERPs to a target bar presented alone (no context) or in a dynamic sequence of bars following a co-linear or co-circular path, we observed earlier ERPs to targets embedded in co-linear sequence at early (66ms) and later stages (197ms) of post-target processing. In contrast, targets in co-circular sequence only modulated ERPs at later stages of processing. It is proposed that early visual processing may have adapted to efficiently process co-linearity to improve target identification, whereas sensitivity to co-circularity does not occur until later stages of processing. These results have significant impact for understanding brain-behaviour relationships when processing natural geometric regularities.

Social interactions through the eyes of macaques and humans.

Group-living primates frequently interact with each other to maintain social bonds as well as to compete for valuable resources. Observing such social interactions between group members provides individuals with essential information (e.g. on the fighting ability or altruistic attitude of group companions) to guide their social tactics and choice of social partners. This process requires individuals to selectively attend to the most informative content within a social scene. It is unclear how non-human primates allocate attention to social interactions in different contexts, and whether they share similar patterns of social attention to humans. Here we compared the gaze behaviour of rhesus macaques and humans when free-viewing the same set of naturalistic images. The images contained positive or negative social interactions between two conspecifics of different phylogenetic distance from the observer; i.e. affiliation or aggression exchanged by two humans, rhesus macaques, Barbary macaques, baboons or lions. Monkeys directed a variable amount of gaze at the two conspecific individuals in the images according to their roles in the interaction (i.e. giver or receiver of affiliation/aggression). Their gaze distribution to non-conspecific individuals was systematically varied according to the viewed species and the nature of interactions, suggesting a contribution of both prior experience and innate bias in guiding social attention. Furthermore, the monkeys' gaze behavior was qualitatively similar to that of humans, especially when viewing negative interactions. Detailed analysis revealed that both species directed more gaze at the face than the body region when inspecting individuals, and attended more to the body region in negative than in positive social interactions. Our study suggests that monkeys and humans share a similar pattern of role-sensitive, species- and context-dependent social attention, implying a homologous cognitive mechanism of social attention between rhesus macaques and humans.

I know you are beautiful even without looking at you: discrimination of facial beauty in peripheral vision.

Earlier research suggests that facial attractiveness may capture attention at parafovea. However, little is known about how well facial beauty can be detected at parafoveal and peripheral vision. Participants in this study judged relative attractiveness of a face pair presented simultaneously at several eccentricities from the central fixation. The results show that beauty is not only detectable at parafovea but also at periphery. The discrimination performance at parafovea was indistinguishable from the performance around the fovea. Moreover, performance was well above chance even at the periphery. The results show that the visual system is able to use the low-spatial-frequency information to appraise attractiveness. These findings not only provide an explanation why a beautiful face could capture attention when central vision is already engaged elsewhere, but also reveal the potential means by which a crowd of faces is quickly scanned for attractiveness.

Human spontaneous gaze patterns in viewing of faces of different species.

Clear differences in perceptual and neural processing of faces of different species have been reported, implying the contribution of visual experience to face perception. Can these differences be revealed by our eye scanning patterns while we extract salient facial information? Here, we systematically compared non-pet-owners' gaze patterns while exploring human, monkey, dog, and cat faces in a passive viewing task. Our analysis revealed that the faces of different species induced similar patterns of fixation distribution between left and right hemiface, and among key local facial features, with the eyes attracting the highest proportion of fixations and viewing times, followed by the nose, and then the mouth. Only the proportion of fixations directed at the mouth region was species-dependent and could be differentiated at the earliest stage of face viewing. Our spontaneous eye-scanning patterns associated with face exploration appear to have been mainly constrained by general facial configurations; the species affiliation of the inspected faces had limited impact on gaze allocation, at least under free-viewing conditions.