http://www.mdpi.com/journal/brainsci Latest open access articles published in Brain Sci. at http://www.mdpi.com/journal/brainsci http://www.mdpi.com/2076-3425/2/2/203 The mammalian brain varies in size by a factor of 100,000 and is composed of anatomically and functionally distinct structures. Theoretically, the manner in which brain composition can evolve is limited, ranging from highly modular (“mosaic evolution”) to coordinated changes in brain structure size (“concerted evolution”) or anything between these two extremes. There is a debate about the relative importance of these distinct evolutionary trends. It is shown here that the presence of taxa-specific allometric relationships between brain structures makes a taxa-specific approach obligatory. In some taxa, the evolution of the size of brain structures follows a unique, coordinated pattern, which, in addition to other characteristics at different anatomical levels, defines what has been called here a “taxon cerebrotype”. In other taxa, no clear pattern is found, reflecting heterogeneity of the species’ lifestyles. These results suggest that the evolution of brain size and composition depends on the complex interplay between selection pressures and constraints that have changed constantly during mammalian evolution. Therefore the variability in brain composition between species should not be considered as deviations from the normal, concerted mammalian trend, but in taxa and species-specific versions of the mammalian brain. Because it forms homogenous groups of species within this complex “space” of constraints and selection pressures, the cerebrotype approach developed here could constitute an adequate level of analysis for evo-devo studies, and by extension, for a wide range of disciplines related to brain evolution. http://www.mdpi.com/2076-3425/2/2/203 Fri, 18 May 2012 00:00:00 CEST Brain Sciences 2012-05-18 2 2 Article 203 224 2076-3425 Understanding the Evolution of Mammalian Brain Structures; the Need for a (New) Cerebrotype Approach 2012-05-18 doi: 10.3390/brainsci2020203 Romain Willemet http://www.mdpi.com/2076-3425/2/2/176 Considerable evidence has argued in favor of multiple neural systems supporting human category learning, one based on conscious rule inference and one based on implicit information integration. However, there have been few attempts to study potential system interactions during category learning. The PINNACLE (Parallel Interactive Neural Networks Active in Category Learning) model incorporates multiple categorization systems that compete to provide categorization judgments about visual stimuli. Incorporating competing systems requires inclusion of cognitive mechanisms associated with resolving this competition and creates a potential credit assignment problem in handling feedback. The hypothesized mechanisms make predictions about internal mental states that are not always reflected in choice behavior, but may be reflected in neural activity. Two prior functional magnetic resonance imaging (fMRI) studies of category learning were re-analyzed using PINNACLE to identify neural correlates of internal cognitive states on each trial. These analyses identified additional brain regions supporting the two types of category learning, regions particularly active when the systems are hypothesized to be in maximal competition, and found evidence of covert learning activity in the “off system” (the category learning system not currently driving behavior). These results suggest that PINNACLE provides a plausible framework for how competing multiple category learning systems are organized in the brain and shows how computational modeling approaches and fMRI can be used synergistically to gain access to cognitive processes that support complex decision-making machinery. http://www.mdpi.com/2076-3425/2/2/176 Mon, 23 Apr 2012 00:00:00 CEST Brain Sciences 2012-04-23 2 2 Article 176 202 2076-3425 Combining Computational Modeling and Neuroimaging to Examine Multiple Category Learning Systems in the Brain 2012-04-23 doi: 10.3390/brainsci2020176 Emi M. Nomura Paul J. Reber http://www.mdpi.com/2076-3425/2/2/147 It is commonly believed that consciousness is a higher brain function. Here we consider the likelihood, based on abundant neuroevolutionary data that lower brain affective phenomenal experiences provide the “energy” for the developmental construction of higher forms of cognitive consciousness. This view is concordant with many of the theoretical formulations of Sigmund Freud. In this reconceptualization, all of consciousness may be dependent on the original evolution of affective phenomenal experiences that coded survival values. These subcortical energies provided a foundation that could be used for the epigenetic construction of perceptual and other higher forms of consciousness. From this perspective, perceptual experiences were initially affective at the primary-process brainstem level, but capable of being elaborated by secondary learning and memory processes into tertiary-cognitive forms of consciousness. Within this view, although all individual neural activities are unconscious, perhaps along with secondary-process learning and memory mechanisms, the primal sub-neocortical networks of emotions and other primal affects may have served as the sentient scaffolding for the construction of resolved perceptual and higher mental activities within the neocortex. The data supporting this neuro-psycho-evolutionary vision of the emergence of mind is discussed in relation to classical psychoanalytical models. http://www.mdpi.com/2076-3425/2/2/147 Tue, 17 Apr 2012 00:00:00 CEST Brain Sciences 2012-04-17 2 2 Review 147 175 2076-3425 The “Id” Knows More than the “Ego” Admits: Neuropsychoanalytic and Primal Consciousness Perspectives on the Interface Between Affective and Cognitive Neuroscience 2012-04-17 doi: 10.3390/brainsci2020147 Mark Solms Jaak Panksepp http://www.mdpi.com/2076-3425/2/2/130 We spend much of our life predicting the future. This involves developing theories and making predictions about others’ intentions, goals and about the consequences of the actions we are observing. Adapting our actions and behaviours to the environment is required for achieving our goals, and to do this the motor system relies on input from sensory modalities. However, recent theories suggest that the link between motor and perceptual areas is bidirectional, and that predictions based on planned or intended actions can unconsciously influence and modify our perception. In the following review we describe current theories on the link between action and perception, and examine the ways in which the motor system can unconsciously alter our perception. http://www.mdpi.com/2076-3425/2/2/130 Mon, 16 Apr 2012 00:00:00 CEST Brain Sciences 2012-04-16 2 2 Review 130 146 2076-3425 Unconscious Effects of Action on Perception 2012-04-16 doi: 10.3390/brainsci2020130 Veronika Halász Ross Cunnington http://www.mdpi.com/2076-3425/2/2/101 Memory is not a unity, but is divided along a content axis and a time axis, respectively. Along the content dimension, five long-term memory systems are described, according to their hierarchical ontogenetic and phylogenetic organization. These memory systems are assumed to be accompanied by different levels of consciousness. While encoding is based on a hierarchical arrangement of memory systems from procedural to episodic-autobiographical memory, retrieval allows independence in the sense that no matter how information is encoded, it can be retrieved in any memory system. Thus, we illustrate the relations between various long-term memory systems by reviewing the spectrum of abnormalities in mnemonic processing that may arise in the dissociative amnesia—a condition that is usually characterized by a retrieval blockade of episodic-autobiographical memories and occurs in the context of psychological trauma, without evidence of brain damage on conventional structural imaging. Furthermore, we comment on the functions of implicit memories in guiding and even adaptively molding the behavior of patients with dissociative amnesia and preserving, in the absence of autonoetic consciousness, the so-called “internal coherence of life”. http://www.mdpi.com/2076-3425/2/2/101 Tue, 10 Apr 2012 00:00:00 CEST Brain Sciences 2012-04-10 2 2 Review 101 129 2076-3425 The Remains of the Day in Dissociative Amnesia 2012-04-10 doi: 10.3390/brainsci2020101 Angelica Staniloiu Hans J. Markowitsch http://www.mdpi.com/2076-3425/2/2/85 The unconscious effects of an emotional stimulus have been highlighted by a vast amount of research, whereover it remains questionable whether it is possible to assign a specific function to cortical brain oscillations in the unconscious perception of facial expressions of emotions. Alpha band variation was monitored within the right- and left-cortical side when subjects consciously (supraliminal stimulation) or unconsciously (subliminal stimulation) processed facial patterns. Twenty subjects looked at six facial expressions of emotions (anger, fear, surprise, disgust, happiness, sadness, and neutral) under two different conditions: supraliminal (200 ms) vs. subliminal (30 ms) stimulation (140 target-mask pairs for each condition). The results showed that conscious/unconscious processing and the significance of the stimulus can modulate the alpha power. Moreover, it was found that there was an increased right frontal activity for negative emotions vs. an increased left response for positive emotion. The significance of facial expressions was adduced to elucidate cortical different responses to emotional types. http://www.mdpi.com/2076-3425/2/2/85 Mon, 26 Mar 2012 00:00:00 CEST Brain Sciences 2012-03-26 2 2 Article 85 100 2076-3425 Subliminal and Supraliminal Processing of Facial Expression of Emotions: Brain Oscillation in the Left/Right Frontal Area 2012-03-26 doi: 10.3390/brainsci2020085 Michela Balconi Chiara Ferrari http://www.mdpi.com/2076-3425/2/1/61 The latency of startle reflex potentiation may shed light on the aware and unaware processes underlying associative learning, especially associative fear learning. We review research suggesting that single-cue delay classical conditioning is independent of awareness of the contingency between the conditioned stimulus (CS) and the unconditioned stimulus (US). Moreover, we discuss research that argues that conditioning independent of awareness has not been proven. Subsequently, three studies from our lab are presented that have investigated the role of awareness in classical conditioning, by measuring the minimum latency from CS onset to observed changes in reflexive behavior. In sum, research using this method shows that startle is potentiated 30 to 100 ms after CS onset following delay conditioning. Following trace fear conditioning, startle is potentiated 1500 ms after CS presentation. These results indicate that the process underlying delay conditioned responding is independent of awareness, and that trace fear conditioned responding is dependent on awareness. Finally, this method of investigating the role of awareness is discussed and future research possibilities are proposed. http://www.mdpi.com/2076-3425/2/1/61 Thu, 16 Feb 2012 00:00:00 CET Brain Sciences 2012-02-16 2 1 Review 61 84 2076-3425 In the Blink of an Eye: Investigating the Role of Awareness  in Fear Responding by Measuring the Latency of  Startle Potentiation 2012-02-16 doi: 10.3390/brainsci2010061 Ole Åsli Magne A. Flaten http://www.mdpi.com/2076-3425/2/1/33 According to the bottom-up theory of attention, unconscious abrupt onsets are highly salient and capture attention via the Superior Colliculi (SC). Crucially, abrupt onsets increase the perceived contrast. In line with the SC hypothesis, unconscious abrupt-onset cues capture attention regardless of the cue color when participants search for abrupt-onset targets (Experiment 1). Also, stronger cueing effects occur for higher than lower contrast cues (Experiment 2) and for temporally, rather than nasally, presented stimuli (Experiment 3). However, in line with the known color-insensitivity of the SC, the SC pathway is shunted and unconscious abrupt-onset cues no longer capture attention when the participants have to search for color-defined targets (Experiment 4) or color-singleton targets (Experiment 5). When using color change cues instead of abrupt-onset cues, the cueing effect also vanishes (Experiment 6). Together the results support the assumption that unconscious cues can capture attention in different ways, depending on the exact task of the participants, but that one way is attentional capture via the SC. The present findings also offer a reconciliation of conflicting results in the domain of unconscious attention. http://www.mdpi.com/2076-3425/2/1/33 Wed, 15 Feb 2012 00:00:00 CET Brain Sciences 2012-02-15 2 1 Article 33 60 2076-3425 Unconscious Cueing via the Superior Colliculi: Evidence from Searching for Onset and Color Targets 2012-02-15 doi: 10.3390/brainsci2010033 Isabella Fuchs Ulrich Ansorge http://www.mdpi.com/2076-3425/2/1/22 In some circumstances, accurate recognition of repeated images in an explicit memory test is driven by implicit memory. We propose that this “implicit recognition” results from perceptual fluency that influences responding without awareness of memory retrieval. Here we examined whether recognition would vary if images appeared in the same or different visual hemifield during learning and testing. Kaleidoscope images were briefly presented left or right of fixation during divided-attention encoding. Presentation in the same visual hemifield at test produced higher recognition accuracy than presentation in the opposite visual hemifield, but only for guess responses. These correct guesses likely reflect a contribution from implicit recognition, given that when the stimulated visual hemifield was the same at study and test, recognition accuracy was higher for guess responses than for responses with any level of confidence. The dramatic difference in guessing accuracy as a function of lateralized perceptual overlap between study and test suggests that implicit recognition arises from memory storage in visual cortical networks that mediate repetition-induced fluency increments. http://www.mdpi.com/2076-3425/2/1/22 Mon, 06 Feb 2012 00:00:00 CET Brain Sciences 2012-02-06 2 1 Article 22 32 2076-3425 Implicit Recognition Based on Lateralized Perceptual Fluency 2012-02-06 doi: 10.3390/brainsci2010022 Iliana M. Vargas Joel L. Voss Ken A. Paller http://www.mdpi.com/2076-3425/2/1/1 Scientific studies have shown that non-conscious stimuli and representations influence information processing during conscious experience. In the light of such evidence, questions about potential functional links between non-conscious brain representations and conscious experience arise. This article discusses neural model capable of explaining how statistical learning mechanisms in dedicated resonant circuits could generate specific temporal activity traces of non-conscious representations in the brain. How reentrant signaling, top-down matching, and statistical coincidence of such activity traces may lead to the progressive consolidation of temporal patterns that constitute the neural signatures of conscious experience in networks extending across large distances beyond functionally specialized brain regions is then explained. http://www.mdpi.com/2076-3425/2/1/1 Tue, 27 Dec 2011 00:00:00 CET Brain Sciences 2011-12-27 2 1 Review 1 21 2076-3425 Why the Brain Knows More than We Do: Non-Conscious Representations and Their Role in the Construction of Conscious Experience 2011-12-27 doi: 10.3390/brainsci2010001 Birgitta Dresp-Langley http://www.mdpi.com/2076-3425/1/1/3 Our study provides evidence that Mild Cognitive Impairment (MCI) is associated with olfactory dysfunction on both conscious and non-conscious levels. MCI patients and age-matched controls underwent a face processing task during which sympathy decisions had to be made via button presses. Incidentally, some of the faces were associated with a simultaneously presented odour. Although attention was paid to faces, brain activities were analysed with respect to odour versus no-odour conditions. Behavioural differences were found related to overall face recognition performance, but these were not statistically significant. However, odour-related neurophysiology differed between both groups. Normal controls demonstrated brain activity differences between odour and no-odour conditions that resemble difference activity patterns in healthy young participants as described in a previous magnetoencephalography (MEG) study [1]. They showed odour-related activity patterns between about 160 ms and 320 ms after stimulus onset and between about 640 ms and 720 ms. On the other hand, the patient group did not show any such difference activities. Based on previous research we interpret the early odour-related brain activity pattern in controls as being associated with subliminal olfaction and the later activity pattern with conscious olfaction. None of these were found in MCI patients, although it has to be emphasised that our sample size was rather small. We confirm previous findings about olfactory related dysfunction in patients with MCI and conclude from our findings that even subliminal odour-related information processing is impaired. http://www.mdpi.com/2076-3425/1/1/3 Fri, 28 Oct 2011 00:00:00 CEST Brain Sciences 2011-10-28 1 1 Article 3 15 2076-3425 Dysfunctional Incidental Olfaction in Mild Cognitive Impairment (MCI): An Electroencephalography (EEG) Study 2011-10-28 doi: 10.3390/brainsci1010003 Peter Walla Cornelia Duregger Lüder Deecke Peter Dal-Bianco http://www.mdpi.com/2076-3425/1/1/1 During the first ten years that followed “The Decade of the Brain”, the quest of neuroscience for understanding brain function in health and disease has greatly expanded to include molecular, developmental, cognitive and evolutionary aspects of the nervous system. This increased multidisciplinary effort has been complemented by the spectacular development of highly sophisticated experimental methods. Neuroscientists can now perform studies ranging from molecular and imaging analysis of single pre- and postsynaptic neuronal processes to imaging of neural activity in the whole brain during perceptual and motor behavioral tasks. At the same time, theoretical advances in neuroscience have been aided by the rapid development of mathematical and computational simulations of biologically and functionally realistic single cells and complex neural networks across multiple spatiotemporal scales. Therefore, neuroscientists are more than ever in a position to deliver answers to basic, medical and biotechnological questions related to brain function and dysfunction. [...] http://www.mdpi.com/2076-3425/1/1/1 Thu, 15 Jul 2010 00:00:00 CEST Brain Sciences 2010-07-15 1 1 Editorial 1 2 2076-3425 Brain Sciences – An Open Access Journal 2010-07-15 doi: 10.3390/brainsci1010001 Germán Barrionuevo