Face matching impairment in developmental prosopagnosia

Developmental prosopagnosia (DP) is commonly referred to as ‘face blindness’, a term that implies a perceptual basis to the condition. However, DP presents as a deficit in face recognition and is diagnosed using memory-based tasks. Here, we test face identification ability in six people with DP, who are severely impaired on face memory tasks, using tasks that do not rely on memory. First, we compared DP to control participants on a standardised test of unfamiliar face matching using facial images taken on the same day and under standardised studio conditions (Glasgow Face Matching Test; GFMT). DP participants did not differ from normative accuracy scores on the GFMT. Second, we tested face matching performance on a test created using images that were sourced from the Internet and so vary substantially due to changes in viewing conditions and in a person’s appearance (Local Heroes Test; LHT). DP participants show significantly poorer matching accuracy on the LHT relative to control participants, for both unfamiliar and familiar face matching. Interestingly, this deficit is specific to ‘match’ trials, suggesting that people with DP may have particular difficulty in matching images of the same person that contain natural day-to-day variations in appearance. We discuss these results in the broader context of individual differences in face matching ability

Adaptive Motor Imagery: A Multimodal Study of Immobilization-Induced Brain Plasticity.

The consequences of losing the ability to move a limb are traumatic. One approach that examines the impact of pathological limb nonuse on the brain involves temporary immobilization of a healthy limb. Here, we investigated immobilization-induced plasticity in the motor imagery (MI) circuitry during hand immobilization. We assessed these changes with a multimodal paradigm, using functional magnetic resonance imaging (fMRI) to measure neural activation, magnetoencephalography (MEG) to track neuronal oscillatory dynamics, and transcranial magnetic stimulation (TMS) to assess corticospinal excitability. fMRI results show a significant decrease in neural activation for MI of the constrained hand, localized to sensorimotor areas contralateral to the immobilized hand. MEG results show a significant decrease in beta desynchronization and faster resynchronization in sensorimotor areas contralateral to the immobilized hand. TMS results show a significant increase in resting motor threshold in motor cortex contralateral to the constrained hand, suggesting a decrease in corticospinal excitability in the projections to the constrained hand. These results demonstrate a direct and rapid effect of immobilization on MI processes of the constrained hand, suggesting that limb nonuse may not only affect motor execution, as evidenced by previous studies, but also MI. These findings have important implications for the effectiveness of therapeutic approaches that use MI as a rehabilitation tool to ameliorate the negative effects of limb nonuse

Do people have insight into their face recognition abilities?

Diagnosis of developmental or congenital prosopagnosia (CP) involves self-report of everyday face recognition difficulties, which are corroborated with poor performance on behavioural tests. This approach requires accurate self-evaluation. We examine the extent to which typical adults have insight into their face recognition abilities across four studies involving nearly 300 participants. The studies used five tests of face recognition ability: two that tap into the ability to learn and recognise previously unfamiliar faces (the Cambridge Face Memory Test, CFMT, Duchaine & Nakayama, 2006 and a newly devised test based on the CFMT but where the study phases involve watching short movies rather than viewing static faces – the CFMT-Films) and three that tap face matching (Benton Facial Recognition Test, BFRT, Benton, Sivan, Hamsher, Varney, & Spreen, 1983; and two recently devised sequential face matching tests). Self-reported ability was measured with the 15-item Kennerknecht et al. (2008) questionnaire; two single-item questions assessing face recognition ability; and a new 77-item meta-cognition questionnaire). Overall, we find that adults with typical face recognition abilities have only modest insight into their ability to recognise faces on behavioural tests. In a fifth study, we assess self-reported face recognition ability in people with CP and find that some people who expect to perform poorly on behavioural tests of face recognition do indeed perform poorly. However, it is not yet clear whether individuals within this group of poor performers have greater levels of insight (i.e., into their degree of impairment) than those with more typical levels of performance

Constraints on attentional orienting by symbolic and abrupt onset cues as revealed through masking

Thesis by publication."Department of Cognitive Science, Perception in Action Research Centre, ARC Centre of Excellence in Cogniion and its Disorders, Faculty of Human Sciences. Macquarie University, Sydney, Australia" -- title page.Includes bibliographical references.Previous research suggests that the exogenous orienting of spatial attention is an involuntary process; that is, it can occur without intent, effort or awareness. Recent studies, however, have shown that exogenous shifts of attention may, at least to some extent, be reliant on these three factors. On the basis of this finding, the purpose of the present thesis was to tease apart the relative contribution of intentions and conscious awareness, in particular, on the orienting of attention by abrupt onset cues in the periphery and symbolic (i.e., averted eye-gaze and arrow) cues at fixation. To investigate this issue, a visual masking paradigm was used and the task-relevance of cues was manipulated. It was found in Study 1 that both masked and unmasked abrupt onset cues produce a validity effect even when they are uninformative of target location. This pattern of results indicates that abrupt onset cues can exogenously shift attention regardless of intentions and conscious awareness. It was found in Studies 2 – 4 that masked symbolic cues also produce a validity effect when they are uninformative of target location. This effect, however, was restricted to experimental contexts that favoured cue utilization and tasks that allowed for the formation of stimulus-response mappings. Intriguingly, however, this pattern of results did not hold for unmasked symbolic cues. Those cues produced a validity effect regardless of task-relevance and task-type. The findings of Studies 2 – 4, therefore, suggest that the propensity to which symbolic cues shift attention relies on participants having a conscious appreciation of the orienting stimulus. Thus, the findings of the present thesis serve to further our understanding of the constraints imposed on the orienting of visual attention generated by masked abrupt onset and symbolic cues.Mode of access: World wide web1 online resource (182 pages) diagrams, graph

Effective processing of masked eye gaze requires volitional control

The purpose of the present study was to establish whether the validity effect produced by masked eye gaze cues should be attributed to strictly reflexive mechanisms or to volitional top-down mechanisms. While we find that masked eye gaze cues are effective in producing a validity effect in a central cueing paradigm, we also find that the efficacy of masked gaze cues is sharply constrained by the experimental context. Specifically, masked gaze cues only produced a validity effect when they appeared in the context of unmasked and predictive gaze cues. Unmasked gaze cues, in contrast, produced reliable validity effects across a range of experimental contexts, including Experiment 4 where 80% of the cues were invalid (counter-predictive). Taken together, these results suggest that the effective processing of masked gaze cues requires volitional control, whereas the processing of unmasked (clearly visible) gaze cues appears to benefit from both reflexive and top-down mechanisms.11 page(s

Responding to the direction of the eyes : in search of the masked gaze-cueing effect

Recent studies have demonstrated that masked gaze cues can produce a cueing effect. Those studies, however, all utilized a localization task and, hence, are ambiguous with respect to whether the previously observed masked gaze-cueing effect reflects the orienting of attention or the preparation of a motor response. The aim of the present study was to investigate this issue by determining whether masked gaze cues can modulate responses in detection and discrimination tasks, both of which isolate spatial attention from response priming. First, we found a gaze-cueing effect for unmasked cues in detection, discrimination, and localization tasks, which suggests that the gaze-cueing effect for visible cues is not task dependent. Second, and in contrast, we found a gaze-cueing effect for masked cues in a localization task, but not in detection or discrimination tasks, which suggests that the gaze-cueing effect for masked cues is task dependent. Therefore, the present study shows that the masked gaze-cueing effect is attributed to response priming, as opposed to the orienting of spatial attention.14 page(s

Direct evidence of cognitive control without perceptual awareness

A central question within the domain of human cognition is whether or not the ability to replace a current action with a new one (i.e., cognitive control) depends on a conscious appreciation of the environmental change that necessitates the new behavior. Specifically, it is not yet known if non-consciously perceived stimuli can trigger the modification of a currently ongoing action. We show for the first time that individuals are able to use non-consciously perceived information to modify the course and outcome of an ongoing action. Participants were presented with a masked (i.e., subliminal) ‘stop’ or ‘go-on’ prime stimulus whilst performing a routine reach-to-touch action. Despite being invisible to participants, the stop primes produced more hesitations mid-flight and more movement reversals than the go-on primes. This new evidence directly establishes that cognitive control (i.e., the ability to modify a currently ongoing action) does not depend on a conscious appreciation of the environmental trigger.6 page(s

Non-threatening other-race faces capture visual attention: evidence from a dot-probe task.

Visual attentional biases towards other-race faces have been attributed to the perceived threat value of such faces. It is possible, however, that they reflect the relative visual novelty of other-race faces. Here we demonstrate an attentional bias to other-race faces in the absence of perceived threat. White participants rated female East Asian faces as no more threatening than female own-race faces. Nevertheless, using a new dot-probe paradigm that can distinguish attentional capture and hold effects, we found that these other-race faces selectively captured visual attention. Importantly, this demonstration challenges previous interpretations of attentional biases to other-race faces as threat responses. Future studies will need to determine whether perceived threat increases attentional biases to other-race faces, beyond the levels seen here

Foreword: Special Issue on Trends in Artificial Intelligence and Data Analytics for an Ethical and Inclusive Digitalized Society

Artificial Intelligence (AI) and Data Analytics play a crucial role in building a digitalized society that is ethical and inclusive. AI is a simulation that is trained to learn and mimic human behaviour. These AI algorithms are capable of learning from their mistakes and doing tasks that are comparable to those performed by humans. AI will have a significant impact on our quality of life as it develops. The main aim of any tool and approach is to simplify human effort and aid us in making better decisions. Data Analytics helps in analyzing raw data in order to draw inferences from it. These techniques and processes have been automated in order to deal with raw data, which is intended for human consumption. The combination of both these techniques will help humans to evolve further in field of research and will enhance the decision making process... Byline: Mamoun Alazab, Ameer Al-Nemrat, Mohammad Shojafar, Shahd Al-Janab

Using reaching trajectories to reveal the dynamics of stimulus categorisation

In categorisation tasks, such as lexical decision, the standard dependent measure in cognitive psychology is mean reaction time (RT). While mean RTs are certainly informative, they are relatively insensitive to the dynamics of the categorisation process under investigation. To address this, some researchers have begun using reaching trajectories as their dependent measure. The promise of this continuous measure is that it can reveal effects while stimulus processing is still unfolding. In this talk I will discuss a series of experiments in which we use reaching trajectories to investigate the effects of spatial and temporal attention in two different categorisation tasks: lexical decision and face (male/female) categorisation. Replicating earlier work, our results indicate strong modulatory effects of attention on stimulus categorisation. Looking at the time course of these modulatory effects, we see that they arise very early (~200 ms) and that they are remarkably short-lived.1 page(s