Out on a limb? On multiple cognitive systems within the octopus nervous system

The idea that there can be only one cognitive system within any single given cognitive organism is an established albeit implicit one within cognitive science and related studies of the mind. The firm foothold of this notion is due largely to the immense corpus of empirical evidence for the correlation of a high level of cognitive sophistication with a centralized nervous system. However, it must be pointed out that these findings are sourced in large part from studies on vertebrates. This paper presents a potential counterexample to the notion that only one cognitive system can be realized within any single genuine cognitive organism. This counterexample is the octopus, an invertebrate with what initially appears to be a paradoxical combination of vertebrate-like cognitive and behavioral capacities and a functionally decentralized nervous system. The extensive relegation of sensorimotor processing and control responsibilities to the peripheral nervous system which controls the arms of the octopus raises principled reasons to believe that the octopus is an organism that may house multiple independent cognitive systems.     

Memory systems within a cognitive architecture

This article addresses the division of memory systems in relation to an overall cognitive architecture. As understanding the architecture is essential to understanding the mind, developing computational cognitive architectures is an important enterprise in computational psychology (computational cognitive modeling). The article proposes a set of hypotheses concerning memory systems from the standpoint of a cognitive architecture, in particular, the four-way division of memory (including explicit and implicit procedural memory and explicit and implicit declarative memory). It then discusses in detail how these hypotheses may be validated through examining qualitatively the literature on memory. A quick review follows of computational simulations of a variety of quantitative data (which are not limited to narrowly conceived “memory tasks”). Results of accounting for both qualitative and quantitative data point to the promise of this approach.     

The changing relations of representation and cognitive structure during the development of a cognitive map

In recent years, workers in cognitive science have come to recognize that cognitive structures should not be equated with computational ones. This realization has often been experienced as confusing. It is argued that cognitive science is moving closer to positions defended by genetic epistemologists. The course of development of a cognitive structure consists of two phases. During the first (Piaget's “phenotypic” adaptation), knowledge about successful ways of interacting with the environment is encoded in a relatively unspecialized format. Selected structural aspects of the resulting data base may later form the basis for a specifically appropriate format. It is during the first phase that knowledge about the environment is manifested in a behavioural structure which does not correspond to any computational entity. In the second phase, the internalized structure becomes computationally defined, which improves the system's efficiency. These ideas are illustrated with the Traveller, a detailed computational model of cognitive map development.     

Building blocks for a cognitive science-led epistemology of arithmetic

Philosophical Studies - In recent years philosophers have used results from cognitive science to formulate epistemologies of arithmetic (e.g. Giaquinto in J Philos 98(1):5–18, 2001). Such...     

Dynamic modulation of an orientation preference map by GABA responsible for age-related cognitive performance

Accumulating evidence suggests that cognitive declines in old (healthy) animals could arise from depression of intracortical inhibition, for which a decreased ability to produce GABA during senescence might be responsible. By simulating a neural network model of a primary visual cortical (V1) area, we investigated whether and how a lack of GABA affects cognitive performance of the network: detection of the orientation of a visual bar-stimulus. The network was composed of pyramidal (P) cells and GABAergic interneurons such as small (S) and large (L) basket cells. Intrasynaptic GABA-release from presynaptic S or L cells contributed to reducing ongoing-spontaneous (background) neuronal activity in a different manner. Namely, the former exerted feedback (S-to-P) inhibition and reduced the frequency (firing rate) of action potentials evoked in P cells. The latter reduced the number of saliently firing P cells through lateral (L-to-P) inhibition. Non-vesicular GABA-release, presumably from glia and/or neurons, into the extracellular space reduced the both, activating extrasynaptic GABAa receptors and providing P cells with tonic inhibitory currents. By this combinatorial, spatiotemporal inhibitory mechanism, the background activity as noise was significantly reduced, compared to the stimulus-evoked activity as signal, thereby improving signal-to-noise (S/N) ratio. Interestingly, GABA-spillover from the intrasynaptic cleft into the extracellular space was effective for improving orientation selectivity (orientation bias), especially when distractors interfered with detecting the bar-stimulus. These simulation results may provide some insight into how the depression of intracortical inhibition due to a reduction in GABA content in the brain leads to age-related cognitive decline.     

Hand laterality and cognitive ability: a multiple regression approach

Several different associations between hand laterality and cognitive ability have been proposed. Studies reporting different conclusions vary in their procedures for defining laterality, and several of them rely on measures which are statistically problematic. Previous methods for measuring relative hand skill have not satisfactorily separated the overall level of hand skill, which is a known correlate of cognitive ability, from the asymmetry of its distribution. This paper uses a multiple regression paradigm that separates these two components. Support is found for Leask and Crow's [Trends in Cognitive Sciences, 5 (2001) 513] proposal that average cognitive ability increases monotonically with increasing strength of laterality, regardless of its direction. The small average advantage to dextrals stems from them being more strongly lateralised than sinistrals. The paucity of strong dextrals amongst the very gifted is due to a smaller variance in cognitive ability in this group.     

Dissociating conflict adaptation from feature integration: a multiple regression approach

Congruency effects are typically smaller after incongruent than after congruent trials. One explanation is in terms of higher levels of cognitive control after detection of conflict (conflict adaptation; e.g., M. M. Botvinick, T. S. Braver, D. M. Barch, C. S. Carter, & J. D. Cohen, 2001). An alternative explanation for these results is based on feature repetition and/or integration effects (e.g., B. Hommel, R. W. Proctor, & K.-P. Vu, 2004; U. Mayr, E. Awh, & P. Laurey, 2003). Previous attempts to dissociate feature integration from conflict adaptation focused on a particular subset of the data in which feature transitions were held constant (J. G. Kerns et al., 2004) or in which congruency transitions were held constant (C. Akcay & E. Hazeltine, in press), but this has a number of disadvantages. In this article, the authors present a multiple regression solution for this problem and discuss its possibilities and pitfalls.     

Multitasking: multiple,domain-specific cognitive functions in a virtual environment

Multitasking among three or more different tasks is a ubiquitous requirement of everyday cognition, yet rarely is it addressed in research on healthy adults who have had no specific training in multitasking skills. Participants completed a set of diverse subtasks within a simulated shopping mall and office environment, the Edinburgh Virtual Errands Test (EVET). The aim was to investigate how different cognitive functions, such as planning, retrospective and prospective memory, and visuospatial and verbal working memory, contribute to everyday multitasking. Subtasks were chosen to be diverse, and predictions were derived from a statistical model of everyday multitasking impairments associated with frontal-lobe lesions (Burgess, Veitch, de Lacy Costello, & Shallice, 2000b). Multiple regression indicated significant independent contributions from measures of retrospective memory, visuospatial working memory, and online planning, but not from independent measures of prospective memory or verbal working memory. Structural equation modelling showed that the best fit to the data arose from three underlying constructs, with Memory and Planning having a weak link, but with both having a strong directional pathway to an Intent construct that reflected implementation of intentions. Participants who followed their preprepared plan achieved higher scores than those who altered their plan during multitask performance. This was true regardless of whether the plan was efficient or poor. These results substantially develop and extend the Burgess et al. (2000b) model to healthy adults and yield new insight into the poorly understood area of everyday multitasking. The findings also point to the utility of using virtual environments for investigating this form of complex human cognition.     

Information integration in multiple cue judgment: a division of labor hypothesis

There is considerable evidence that judgment is constrained to additive integration of information. The authors propose an explanation of why serial and additive cognitive integration can produce accurate multiple cue judgment both in additive and non-additive environments in terms of an adaptive division of labor between multiple representations. It is hypothesized that, whereas the additive, independent linear effect of each cue can be explicitly abstracted and integrated by a serial, additive judgment process, a variety of sophisticated task properties, like non-additive cue combination, non-linear relations, and inter-cue correlation, are carried implicitly by exemplar memory. Three experiments investigating the effect of additive versus non-additive cue combination verify the predicted shift in cognitive representations as a function of the underlying combination rule.     

Building a controllable expressive speech synthesis system with multiple emotion strengths

Emotion is considered to be an essential element in the performance of human-computer interactions. In expressive synthesis speech, it is important to generate emotional speech that reflects subtle and complex emotional states. However, there has been limited research on how to effectively synthesize emotional speech using different levels of emotion strength with intuitive control, which is difficult to be modeled effectively. In this paper, we explore an expressive speech synthesis model that can be used to produce speech with multiple emotion strengths. Unlike previous studies that encoded emotions into discrete codes, we propose an embedding vector to continuously control the emotion strength, which is a data-driven method to synthesize speech with a fine control over the emotions. Compared with the models using the retraining technique or a one-hot vector, our proposed model using an embedding vector can explicitly learn the high-level emotion strength from the low-level acoustic features. As a result, we can control the emotion strength of synthetic speech in a relatively predictable and globally consistent way. The objective and subjective evaluation tests show that our proposed model achieves state-of-the-art performance in terms of model flexibility and controllability.     

Mindfulness-based cognitive therapy to treat multiple chemical sensitivities: a randomized pilot trial

Skovbjerg, S., Hauge, C. R., Rasmussen, A., Winkel, P. & Elberling, J. (2012). Mindfulness‐based cognitive therapy to treat multiple chemical sensitivities: A randomized pilot trial. Scandinavian Journal of Psychology 53, 233–238. Multiple chemical sensitivities (MCS) is a medically unexplained and socially disabling disorder characterized by negative health effects attributed to exposure to common airborne chemicals. Currently, there is no evidence‐based treatment. The objectives of the study were to assess the feasibility of an 8‐week mindfulness‐based cognitive therapy program (MBCT) for adults with MCS and to evaluate possible effects on psychological distress and illness perception. The study design was a randomized clinical trial. The MBCT programme comprised 8 weekly sessions of 2½ hours. Forty‐two adults were screened for eligibility and 37 were included. Mean age of the participants was 51.6 years, 35 (94.6%) were female and 21 (56.8%) were unemployed. Measures of psychological distress and illness perceptions were assessed at baseline, 4 weeks, 8 weeks and at 3 months follow‐up. No significant differences in effect measures were found between the groups. However, those who completed the MBCT program generally reported benefiting in terms of improved coping strategies and sleep quality. The positive verbal feedback from the participants in the MBCT group suggests that a larger randomized clinical trial on the effect of MBCT for MCS could be considered.     

Multiple systems for cognitive control: evidence from a hybrid prime-Simon task

Cognitive control resolves conflicts between appropriate and inappropriate response tendencies. Is this achieved by a unitary all-purpose conflict control system, or do independent subsystems deal with different aspects of conflicting information? In a fully factorial hybrid prime-Simon task, participants responded to the identity of targets displayed at different nominally irrelevant screen locations, preceded by nominally irrelevant, consciously or nonconsciously perceived primes. The response required by the target's identity could match or mismatch (a) the target's location, and (b) the prime's identity, resulting in potential conflict (a) across and (b) within stimulus domains. Conflict effects were investigated within and across trials. Results suggest that (i) nonconsciously perceived information elicits within-trial control, but--unlike consciously perceived information--no across-trial behavioral modulation; (ii) separate subsystems deal with conflicts arising from different stimulus domains; and (iii) occasional apparent interactions between domains reflect a particular difficulty in reactivating a just-discarded response (reactivation aversion effect, RAE).     

The relationship between social-cultural attitudes and behavioral measures of cognitive style: a meta-analytic integration of studies

The present meta-analysis investigates the relationship between social-cultural right-wing attitudes and objective measures of cognitive style on a set of 124 unique samples, with a total of 29,209 participants. Intolerance of ambiguity and cognitive ability yielded relationships of moderate strength with right-wing attitudes, whereas only mixed evidence was obtained for rigidity, complexity, and field dependence. In the discussion, we compare the present weak to moderate relationships with a meta-analysis conducted by Jost, Glaser, Kruglanski, and Sulloway (2003b), included predominantly self-report measures of cognitive style, reporting moderate to strong relationships between conservatism. The need to study cognitive ability as a basis of ideological attitudes is also discussed.     

Evidence of a role for multiple memory systems in behavioral extinction

The acquisition of learned behavior involves multiple memory systems, and hippocampal system damage impairs cognitive learning while leaving stimulus-response habit learning intact. In view of evidence that extinction also involves new learning, the present experiments examined whether multiple memory systems theory may be applicable to the neural bases of extinction. Adult Long-Evans rats were trained to run in a straight-alley maze for food reward. Twenty-four hours later, rats matched for runway latencies during acquisition received extinction training. In a response extinction condition conducive to habit learning, rats performed a runway approach response to an empty food cup. In a latent extinction condition conducive to cognitive learning, rats were placed at an empty food cup without performing a runway approach response. Prior to daily extinction training, neural activity of the dorsal hippocampus was reversibly inactivated via infusion of bupivacaine (0.75%, 0.5 microl/side). Control rats receiving saline infusions displayed extinction behavior in both the response and latent training conditions. In contrast, rats receiving bupivacaine extinguished normally in the response condition, but did not display latent extinction. The findings (1) confirm that learning underlying extinction of the same overt behavior can occur with or without explicit performance of the previously acquired response, (2) indicate that extinction learning produced by response and latent training procedures can be neuroanatomically dissociated, and (3) suggest that similarly to initial task acquisition, the hippocampus may critically mediate extinction in situations requiring the use of cognitive learning, such as when performance of a previously acquired response habit is prevented.     

Level of cognitive performance as a correlate and predictor of health behaviors that protect against cognitive decline in late life: The path through life study

There is a lack of information on how cognitive ability relates to both health behaviors and change in health behaviors over time. This study examined verbal ability and processing speed as predictors of health behaviors in the PATH Through Life Study that includes cohorts aged in their 20s, 40s and 60s. Higher cognitive scores were associated with higher levels of physical activity, greater likelihood of taking vitamin and mineral supplements, reduced likelihood of current smoking and not abstaining from alcohol. However, lower level of verbal ability and processing speed were associated with higher levels of use of cholesterol lowering medication in the 60s cohort. Physical activity, consumption of vitamins and minerals and taking cholesterol lowering and antihypertensive medication over the four-year follow-up period increased in this cohort. The likelihood of adopting healthier behaviors was greatest for those with the lowest cognitive scores. We conclude that while higher levels of cognitive performance are associated with health promoting behaviors, improvements in health behavior are more likely to be due to non-cognitive, contextual and societal factors.