Brian F. O'Donnell, Dean F. Salisbury, Margaret A. Niznikiewicz, Colleen A. Brenner, and Jenifer L. Vohs
Schizophrenia is a disabling psychotic illness that has been associated with alterations in synaptic connectivity and neurotransmission. Since event-related potential (ERP) components are typically generated by the summation of postsynaptic potentials produced by neural populations, these measures are well suited to assess such pathophysiological alterations. This chapter reviews the utility of ERP components in the investigation of the cognitive and neural mechanisms affected by schizophrenia. It focuses on five components: mismatch negativity (MMN), P50 measures of sensory gating, N100 and P300 in the oddball discrimination paradigms, and the N400 component elicited during language processing. These components test key cognitive systems affected by schizophrenia: sensory memory (MMN), sensory processing and inhibition (P50, N1), selective attention and working memory (P300), and semantic processing (N400). These components are discussed with respect to the following issues: (1) cognitive and neural systems indexed by the component, (2) abnormalities in schizophrenia, (3) sensitivity and specificity to schizophrenia, (4) clinical correlates, and (5) relationship to genetic variation. ERP components are well validated biomarkers for schizophrenia which have significant promise in the characterization of genomic and epigenomic factors, pharmacological response in humans and animal models, and the developmental and cognitive expression of the illness.
William J. Davies
This article provides an overview of what shapes the acoustic signals that arrive at the ear. There are three physical processes which are capable of generating audible sound: a vibrating surface, a turbulent fluid, and a rapid pressure change. It is structured as an account of the journey of a sound wave, from first generation, then propagation outdoors, followed by transmission into a building and indoor reverberation to its final reception, perception, and assessment. It throws light on how the signals that arrive at the ear are generated; how environment influences these signals; and how sound is perceived, controlled, and assessed in the environment. It gives information on basic principles, common measurements and current modelling techniques. Finally, it suggests that the external environment is complex and the acoustic signals arriving the ear reflect this complexity by carrying information about their production, their interaction with the environment, and their transmission through it.
Music’s continual temporal changes make it a useful stimulus for studying cognitive and neural processes unfolding over time. Although this dynamic nature is widely recognized on a macro level, the importance of temporal changes in individual notes is less widely discussed. For example, textbooks often focus on power spectra—time invariant summaries of spectral information—to explain differences in timbre between musical instruments. Unfortunately, this approach overlooks the importance of dynamic fluctuations in individual notes’ overtones. This chapter highlights the under-recognized importance of temporal structure in musical sounds by synthesizing a diverse range of research on musical acoustics and perception. It concludes by contrasting the rich temporal dynamics of musical sounds with the temporally invariant tones common in auditory perception research—which exhibit significant shortcomings regarding ecological validity. Although this creates barriers for generalizing outcomes from experiments with simplistic tones, it also offers exciting new topics for future research.
Christian Mühl, Dirk Heylen, and Anton Nijholt
This chapter is from the forthcoming The Oxford Handbook of Affective Computing edited by Rafael Calvo, Sidney K. D'Mello, Jonathan Gratch, and Arvid Kappas. The brain is involved in the registration, evaluation, and representation of emotional events and in the subsequent planning and execution of appropriate actions. Novel interface technologies—so-called affective brain-computer interfaces (aBCI)—can use this rich neural information, occurring in response to affective stimulation, for the detection of the user’s affective state. This chapter gives an overview of the promises and challenges that arise from the possibility of neurophysiology-based affect detection, with a special focus on electrophysiological signals. After outlining the potential of aBCI relative to other sensing modalities, the reader is introduced to the neurophysiological and neurotechnological background of this interface technology. Potential application scenarios are situated in a general framework of brain-computer interfaces. Finally, the main scientific and technological challenges that have yet to be solved on the way toward reliable affective brain-computer interfaces are discussed.
This article introduces a number of critical features of the afferent synapse with particular reference to mammalian hearing. The auditory synapse is the first relay point for the input of sound into the nervous system and the properties of this synapse determine how well a signal from the hair cells is relayed up the auditory brainstem. This information is re-encoded as a pattern in the auditory nerve for subsequent analysis by the brain. The design of the afferent synapse ensures that the information content is not degraded. The article describes the structure and physiology of the afferent synapse and explains the presynaptic and postsynaptic mechanisms. Furthermore, it reveals the paired presynaptic and postsynaptic responses. In addition, it also describes the concept of synaptic adaptation and the genetics of the synapse. It also states that it is sometimes necessary to extrapolate from non-mammalian systems.
Sander Daselaar and Roberto Cabeza
Memory is one of the cognitive functions that deteriorate most with age. The types of memory most affected by aging are working memory, the short-term memory maintenance and simultaneous manipulation of information, and episodic memory, our memory for personally experienced past events. Functional neuroimaging studies indicate important roles in age-related memory decline for the medial temporal lobe (MTL) and prefrontal cortex (PFC) regions, which have been linked to two major cognitive aging theories, the resource and binding deficit hypotheses, respectively. Interestingly, functional neuroimaging findings also indicate that aging is not exclusively associated with decline. Some older adults seem to deal with PFC and MTL decline by shifting to alternative brain resources that can compensate for their memory deficits. In the future, these findings may help to distinguish normal aging from early Alzheimer’s dementia and the development of memory remediation therapies.
Robert D. Frisina
This article examines age-related changes in the central auditory system from anatomical and neurochemical vantage points, and then the functional consequences of these structural changes are presented in the context of human perception and the underlying physiology of animal model systems. Neural processing in the central auditory system is dependent on the magnitude and timing of excitatory and inhibitory inputs to auditory neurons. Recent evidence suggests that there may be aging changes in other neurotransmitters at the level of the inferior colliculus. The molecular, anatomical, and neurochemical changes occurring with age in the auditory system have functional consequences for central auditory sound processing. Many of these are due to reduced cochlear outputs with age, and others appear to be somewhat independent of these peripheral changes, in line with neurodegenerative deficits of the aging brain. The article reveals that plasticity in the central auditory system often occurs well into old age, which is interesting from the perspectives of both basic neuroscience and future clinical interventions.
Sylvie Berthoz, Lydia Pouga, and Michele Wessa
Alexithymia is a multifaceted personality construct characterized by the impaired ability to reflect on and regulate one’s own emotions. This chapter refers to a wide range of domains of investigation in the field of social neuroscience to capture and specify the processes that could account for the observed associations between such an inability to monitor and self-regulate emotions and altered social understanding and interactions. To this end, it provides empirical support for considering alexithymia as a relevant model to investigate the links between brain, cognition and behavior, notably not only to delineate potential pathways between dysfunctional cerebral circuits, poor emotional insight, and intersubjectivity, but also to further explore their links with self-oriented and other-oriented harming behaviors.
Simon Garrod and Martin J. Pickering
This article argues that psycholinguists need to think in a different way to understand processing in dialogue. According to this view, interlocutors do not use language to encode and decode messages, but rather as a means by which they can align their mental states, so that they come to have the same ideas about the topic under discussion. It would in principle be possible to decompose this task into discrete acts of comprehension and production, but in practice real dialogue involves constant overlaying of production and comprehension. It is much better to understand dialogue as a joint activity, like ballroom dancing or using a two-handed saw, and to assume that alignment follows from this inherently interactive process. On the assumption that the goal of dialogue is alignment, this article discusses ways in which interlocutors come to achieve this state. First, it considers alignment via beliefs about one's interlocutor, and then discusses alignment via imitation. The article also looks at alignment via agreements between interlocutors, alignment via feedback, and alignment via physical co-presence.
This chapter reviews event-related potential (ERP) studies in patients suffering from neurodegenerative diseases. Such studies have been conducted from two different points of view: using ERPs to learn something about the disease and using the disease to learn something about ERPs. This review focuses on the former aspect: the utility of ERPs in the clinic. Thus, ERP research in neurodegenerative diseases will be discussed from the perspective of the insights gained from ERPs (1) for diagnosis, (2) for delineating and understanding the consequences of the disease for cognition, and (3) for determining the prognosis about the course of the disease.