Examining the Spatiotemporal Disruption to Gaze When Using a Myoelectric Prosthetic Hand

The aim of this study was to provide a detailed account of the spatial and temporal disruptions to eye-hand coordination when using a prosthetic hand during a sequential fine motor skill. Twenty-one able-bodied participants performed 15 trials of the picking up coins task derived from the Southampton Hand Assessment Procedure with their anatomic hand and with a prosthesis simulator while wearing eye-tracking equipment. Gaze behavior results revealed that when using the prosthesis, performance detriments were accompanied by significantly greater hand-focused gaze and a significantly longer time to disengage gaze from manipulations to plan upcoming movements. The study findings highlight key metrics that distinguish disruptions to eye-hand coordination that may have implications for the training of prosthesis use.     

Excitatory and inhibitory priming by attended and ignored non-recycled words with monolinguals and bilinguals

Experiments examining identity priming from attended and ignored novel words (words that are used only once except when repetition is required due to experimental manipulation) in a lexical decision task are reported. Experiment 1 tested English monolinguals whereas Experiment 2 tested Twi (a native language of Ghana, Africa)-English bilinguals. Participants were presented with sequential pairs of stimuli composed of a prime followed by a probe, with each containing two items. The participants were required to name the target word in the prime display, and to make a lexical decision to the target item in the probe display. On attended repetition (AR) trials the probe target item was identical to the target word on the preceding attentional display. On ignored repetition (IR) trials the probe target item was the same as the distractor word in the preceding attentional display. The experiments produced facilitated (positive) priming in the AR trials and delayed (negative) priming in the IR trials. Significantly, the positive and negative priming effects also replicated across both monolingual and bilingual groups of participants, despite the fact that the bilinguals were responding to the task in their non-dominant language.     

A Brief Argument For Consciousness Without Access

This paper proposes a new argument in favour of the claim that phenomenal consciousness overflows – that is, has a far higher capacity than – cognitive access. It shows that opponents of overflow implicate a necessary role for visual imagery in the change detection paradigm. However, empirical evidence suggests that there is no correlation between visual imagery abilities and performance in this paradigm. Since the use of imagery is not implicated in the performance strategy of subjects, we find a new argument for consciousness without access.     

Examining the visual processing patterns of lonely adults

Prior research has shown that loneliness is associated with hypervigilance to social threats, with eye‐tracking research showing lonely people display a specific attentional bias when viewing social rejection and social exclusion video footage (Bangee, Harris, Bridges, Rotenberg & Qualter, 2014; Qualter, Rotenberg, Barrett et al ., 2013). The current study uses eye‐tracker methodology to examine whether that attentional bias extends to negative emotional faces and negative social non‐rejecting stimuli, or whether it could be explained only as a specific bias to social rejection/exclusion. It is important to establish whether loneliness relates to a specific or general attention bias because it may explain the maintenance of loneliness. Participants (N = 43, F = 35, M age = 20 years and 2 months, SD = 3 months) took part in three tasks, where they viewed different social information: Task 1 – slides displaying four faces each with different emotions (anger, afraid, happy and neutral), Task 2 – slides displaying sixteen faces with varying ratios expressing happiness and anger, and Task 3 – slides displaying four visual scenes (socially rejecting, physically threatening, socially positive, neutral). For all three tasks, eye movements were recorded in real time with an eye‐tracker. Results showed no association between loneliness and viewing patterns of facial expressions, but an association between loneliness and hypervigilant viewing of social rejecting stimuli. The findings indicate that lonely adults do not have a generalised hypervigilance to social threat, but have, instead, a specific attentional bias to rejection information in social contexts. Implications of the findings for interventions are discussed.     

A progressive model for teaching children with autism to follow gaze shift

Gunby, Rapp, Bottoni, Marchese and Wu (2017) taught three children with autism spectrum disorder to follow an instructor's gaze shift to select a specific item; however, Gunby et al. used different types of prompts with each participant. To address this limitation, we used a progressive training model for increasing gaze shift for three children with autism spectrum disorder. Results show that each participant learned to follow an adult's shift in gaze to make a correct selection. In addition, two participants displayed the skill in response to a parent's gaze shift and with only social consequences; however, the third participant required verbal instruction and tangible reinforcement to demonstrate the skill outside of training sessions.     

Higher visuo-Attentional Demands of Multiple Object Tracking (MOT) Lead to A Lower Precision in Pointing Movements

Multiple object tracking (MOT) requires visually attending to dynamically moving targets and distractors. This cognitive ability is based on perceptual-attentional processes that are also involved in goal-directed movements. This study aimed to test the hypothesis that MOT affects the motor performance of aiming movements. Therefore, the participants performed pointing movements using their fingers or a computer mouse that controlled the movements of a cursor directed at the targets in the MOT task. The precision of the pointing movements was measured, and it was predicted that a higher number of targets and distractors in the MOT task would result in a lower pointing precision. The results confirmed this hypothesis, indicating that MOT might influence the performance of motor actions. The potential factors underlying this influence are discussed.     

Shifts of spatial attention cued by irrelevant numbers: Electrophysiological evidence from a target discrimination task

Fischer et al. demonstrated that a centrally presented number can shift attention to the left/right when its magnitude is small/large. Two electrophysiological studies described these attentional effects as event-related potentials (ERPs) at centro-parietal sites. Since both studies used target detection tasks, it remains currently unknown whether similar results would be obtained with a discrimination task. We used ERPs to test whether digit cues also induce attention shifts when participants perform a feature-discrimination task on targets. ERPs were recorded whereas subjects discriminated the colour of lateral targets that were preceded by a central non-predictive digit. Analysis of cue-locked controlateral vs. ipsilateral ERP activity showed the emergence of early preparatory attention-directing components in parietal and frontal regions. Moreover, target-locked P1 components at occipito-parietal sites were significantly modulated by digit magnitude-target side congruency. These results demonstrate that irrelevant digit cues also bias sensory processing when embedded in a feature-discrimination task.     

Central load reduces peripheral processing: Evidence from incidental memory of background speech

Is there a trade‐off between central (working memory) load and peripheral (perceptual) processing? To address this question, participants were requested to undertake an n‐back task in one of two levels of central/cognitive load (i.e., 1‐back or 2‐back) in the presence of a to‐be‐ignored story presented via headphones. Participants were told to ignore the background story, but they were given a surprise memory test of what had been said in the background story, immediately after the n‐back task was completed. Memory was poorer in the high central load (2‐back) condition in comparison with the low central load (1‐back) condition. Hence, when people compensate for higher central load, by increasing attentional engagement, peripheral processing is constrained. Moreover, participants with high working memory capacity (WMC) – with a superior ability for attentional engagement – remembered less of the background story, but only in the low central load condition. Taken together, peripheral processing – as indexed by incidental memory of background speech – is constrained when task engagement is high.     

How the Eyes Tell Lies: Social Gaze During a Preference Task

Social attention is thought to require detecting the eyes of others and following their gaze. To be effective, observers must also be able to infer the person's thoughts and feelings about what he or she is looking at, but this has only rarely been investigated in laboratory studies. In this study, participants' eye movements were recorded while they chose which of four patterns they preferred. New observers were subsequently able to reliably guess the preference response by watching a replay of the fixations. Moreover, when asked to mislead the person guessing, participants changed their looking behavior and guessing success was reduced. In a second experiment, naïve participants could also guess the preference of the original observers but were unable to identify trials which were lies. These results confirm that people can spontaneously use the gaze of others to infer their judgments, but also that these inferences are open to deception.     

Failure to Obtain Reinstatement of an Olfactory Representation

It has long been suspected that attentional processes differ between olfaction and the other senses. Here, we test whether voluntary dishabituation, seen, for example, when we re‐attend to the ticking of a clock, can occur in olfaction. Participants were seated in an odorized room, where at various intervals they had to evaluate what they could smell. An experimental group had one nostril open and the other closed, except during the evaluations, so that the closed side was subject to centrally driven habituation, but not peripheral adaptation. A control group had both nostrils closed except during evaluations. Following exposure, the experimental group could not report the room's odor in either the centrally habituated nostril (i.e., that remained closed) or the nostril that remained open, while the control group could. This effect could result from a number of causes, including olfaction's unique neuroanatomy, functional constraints imposed by detecting volatile chemicals, and as a consequence of limited cortical resources, with implications for the functional value of consciousness.