Why is “blindsight” blind? A new perspective on primary visual cortex,recurrent activity and visual awareness

The neuropsychological phenomenon of blindsight has been taken to suggest that the primary visual cortex (V1) plays a unique role in visual awareness, and that extrastriate activation needs to be fed back to V1 in order for the content of that activation to be consciously perceived. The aim of this review is to evaluate this theoretical framework and to revisit its key tenets. Firstly, is blindsight truly a dissociation of awareness and visual detection? Secondly, is there sufficient evidence to rule out the possibility that the loss of awareness resulting from a V1 lesion simply reflects reduced extrastriate responsiveness, rather than a unique role of V1 in conscious experience? Evaluation of these arguments and the empirical evidence leads to the conclusion that the loss of phenomenal awareness in blindsight may not be due to feedback activity in V1 being the hallmark awareness. On the basis of existing literature, an alternative explanation of blindsight is proposed. In this view, visual awareness is a “global” cognitive function as its hallmark is the availability of information to a large number of perceptual and cognitive systems; this requires inter-areal long-range synchronous oscillatory activity. For these oscillations to arise, a specific temporal profile of neuronal activity is required, which is established through recurrent feedback activity involving V1 and the extrastriate cortex. When V1 is lesioned, the loss of recurrent activity prevents inter-areal networks on the basis of oscillatory activity. However, as limited amount of input can reach extrastriate cortex and some extrastriate neuronal selectivity is preserved, computations involving comparison of neural firing rates within a cortical area remain possible. This enables “local” read-out from specific brain regions, allowing for the detection and discrimination of basic visual attributes. Thus blindsight is blind due to lack of “global” long-range synchrony, and it functions via “local” neural readout from extrastriate areas.     

Learning in the visual association of novice and expert designers

Designers are adept at determining similarities between previously seen objects and new creations using visual association. However, extant research on the visual association of designers and the differences between expert and novice designers when they engage in the visual association task are scant. Using electroencephalography (EEG), this study attempted to narrow this research gap. Sixteen healthy designers—eight experts and eight novices—were recruited, and asked to perform visual association while EEG signals were acquired, subsequently analysed using independent component analysis. The results indicated that strong connectivity was observed among the prefrontal, frontal, and cingulate cortices, and the default mode network. The experts used both hemispheres and executive functions to support their association tasks, whereas the novices mainly used their right hemisphere and memory retrieval functions. The visual association of experts appeared to be more goal-directed than that of the novices. Accordingly, designing and implementing authentic and goal-directed activities for improving the executive functions of the prefrontal cortex and default mode network are critical for design educators and creativity researchers.     

Testing attitudes,social desirability and behavioral regulations as moderators of implicit-explicit exercise discrepancies: A replication study in Iranian students

IntroductionThere is mixed evidence regarding moderators of the relationship between implicitly and explicitly measured constructs. This study examined this issue with evaluations of exercise relative to health or appearance in a sample of Iranian adolescents. Investigaing automatic associations and reflective constructs might provide important implications for developing interventions targeting exercise behavior in a population with different cultural, social, and economic barriers to exercise than European or North American adolescents.MethodsParticipants were 471 students enrolled in grades 9 to 12, of whom 269 (54.9%) were female. Behavioral regulations, explicit attitudes, and social desirability were investigated as possible moderators. All students completed questionnaire measures of physical activity behavior, attitudes, social desieality and behavioral regulation. They also completed two Go/No Go Association tasks to measure automatic associations of exercise with health and apperarance.ResultsAttitude was a significant moderator of discrepancies between automatic associations of exercise with health and health motives. Interjected regulation moderated implicit-explicit appearance discrepancies. Participants with low social desirability and negative automatic appearance associations had the highest appearance motivation.ConclusionsParticipants focused on the potential of achieving positive health outcomes of exercise rather than physical appearance outcomes, which differs from research from other countries. It is possible that, health was strongly linked with exercise by the pervasive societal pressures in Iran to have a healthy body.     

Corpus-based estimates of word association predict biases in judgment of word co-occurrence likelihood

This paper draws a connection between statistical word association measures used in linguistics and confirmation measures from epistemology. Having theoretically established the connection, we replicate, in the new context of the judgments of word co-occurrence, an intriguing finding from the psychology of reasoning, namely that confirmation values affect intuitions about likelihood. We show that the effect, despite being based in this case on very subtle statistical insights about thousands of words, is stable across three different experimental settings. Our theoretical and empirical results suggest that factors affecting traditional reasoning tasks are also at play when linguistic knowledge is probed, and they provide further evidence for the importance of confirmation in a new domain.     

Association between the arginine vasopressin receptor 1A (AVPR1A) gene and preschoolers’ executive functioning

Recent evidence implicates the arginine vasopressin (AVP) system in complex neuropsychological disorders which are characterized by deficits in executive functioning (EF). Despite the genetic contribution to EF, little is currently known about its molecular genetic basis. Drawing on research from social neuroscience and the role of related physiological systems in psychopathology, the current study hypothesized that variability in the AVP receptor 1a gene (AVPR1A) would be associated with EF in an epidemiological sample of 323 normally developing preschool-aged children. Using a family-based association design, the current study found that variability in the rs7298346 marker, located in the 5′-flanking region, was significantly related to a composite measure of EF in 4-year-old children after controlling for a variety of covariates and children’s theory of mind. The converse association between AVPR1A and theory of mind (after controlling for EF) was not significant, suggesting a level of specificity in this relationship. The results are discussed in terms of the difficulties faced by genetic association studies in teasing apart the behavioral phenotypes that characterize complex psychological diseases and the involvement of multiple physiological systems in human behavior.     

The minimal self hypothesis

For millennia self has been conjectured to be necessary for consciousness. But scant empirical evidence has been adduced to support this hypothesis. Inconsistent explications of “self” and failure to design apt experiments have impeded progress. Advocates of phenomenological psychiatry, however, have helped explicate “self,” and employed it to explain some psychopathological symptoms. In those studies, “self” is understood in a minimalist sense, sheer “for-me-ness.” Unfortunately, explication of the “minimal self” (MS) has relied on conceptual analysis, and applications to psychopathology have been hermeneutic, allowing for many degrees of interpretive latitude. The result is that MS’s current scientific status is analogous to that of the “atom,” at the time when “atom” was just beginning to undergo transformation from a philosophical to a scientific concept. Fortunately, there is now an opportunity to promote a similar transformation for “MS.” Discovery of the brain’s Default Mode Network (DMN) opened the door to neuroimaging investigations of self. Taking the DMN and other forms of intrinsic activity as a starting point, an empirical foothold can be established, one that spurs experimental research and that enables extension of research into multiple phenomena. New experimental protocols that posit “MS” can help explain phenomena hitherto not thought to be related to self, thereby hastening development of a mature science of self. In particular, targeting phenomena wherein consciousness is lost and recovered, as in some cases of Unresponsive Wakefulness Syndrome (UWS), allow for design of neuroimaging probes that enable detection of MS during non-conscious states. These probes, as well as other experimental protocols applied to NREM Sleep, General Anesthesia (GA), and the waking state, provide some evidence to suggest that not only can self and consciousness dissociate, MS might be a necessary precondition for conscious experience. Finally, these findings have implications for the science of consciousness: it has been suggested that “levels of consciousness” (LoC) is not a legitimate concept for the science of consciousness. But because we have the conceptual and methodological tools with which to refine investigations of MS, we have the means to identify a possible foundation—a bifurcation point—for consciousness, as well as the means by which to measure degrees of distance from that foundation. These neuroimaging investigations of MS position us to better assess whether LoC has a role to play in a mature science of consciousness.