Understanding the emergence of modularity in neural systems

Modularity in the human brain remains a controversial issue, with disagreement over the nature of the modules that exist, and why, when, and how they emerge. It is a natural assumption that modularity offers some form of computational advantage, and hence evolution by natural selection has translated those advantages into the kind of modular neural structures familiar to cognitive scientists. However, simulations of the evolution of simplified neural systems have shown that, in many cases, it is actually non-modular architectures that are most efficient. In this paper, the relevant issues are discussed and a series of simulations are presented that reveal crucial dependencies on the details of the learning algorithms and tasks that are being modelled, and the importance of taking into account known physical brain constraints, such as the degree of neural connectivity. A pattern is established which provides one explanation of why modularity should emerge reliably across a range of neural processing tasks.     

Diversity in unity: practical unity and personal boundaries

In the spirit of the discussion in Daniel Kolak’s I Am You: The Metaphysical Foundation for Global Ethics, I consider the way in which divisions that we usually think of as borders between distinct people occur within a single life. Starting with the dispute between constructionist and non-constructionist views of persons, I argue for a view that places the unity of persons in the dynamic generated by simultaneously taking a constructionist and non-constructionist view of oneself. In order to unify ourselves as agents we need to treat past and future selves as others, but to motivate this endeavor we need to think of ourselves as temporally extended agents, and so identify with past and future selves. Understanding this dynamic illuminates the structure of our agency and the unity of the self.     

Single-probe serial position recall: Evidence of modularity for olfactory,visual, and auditory short-term memory

The present study examined and compared order memory for a list of sequentially presented odours, unfamiliar faces, and pure tones. Employing single-probe serial position recall and following a correction for a response bias, qualitatively different serial position functions were observed across stimuli. Participants demonstrated an ability to perform absolute order memory judgments for odours. Furthermore, odours produced an absence of serial position effects, unfamiliar faces produced both primacy and recency, and pure tones produced recency but not primacy. Such a finding is contrary to the proposal by Ward, Avons, and Melling (2005) that the serial position function is task, rather than modality, dependent. In contrast, the observed functions support a modular conceptualization of short-term memory (e.g., Andrade & Donaldson, 2007; Baddeley & Hitch, 1974), whereby separate modality-specific memorial systems operate. An alternative amodal interpretation is also discussed wherein serial position function disparities are accommodated via differences in the psychological distinctiveness of stimuli (Hay, Smyth, Hitch, & Horton, 2007).     

Modularist explanations of experience and other illusions

Debates about modularity invariably involve a crucial premise about how visual illusions are experienced. This paper argues that these debates are wrongheaded, and that experience of illusions is orthogonal to the core issue of the modularity hypothesis: informational encapsulation.     

"I won't do what you tell me!": elevated mood and the assessment of advice-taking in euthymic bipolar I disorder

We hypothesized that when individuals with bipolar disorder are engaged in goal-directed behaviour and experience elevated mood, their decision-making becomes less constrained by advice from other people. This process may allow their goal-directed behaviour to persist, contributing to manic symptoms. Three groups of 32 participants: euthymic-bipolar-I, remitted-unipolar and never-depressed healthy controls were allocated to either a high or low mood induction. Advice-taking was assessed before and after the induction by a computerized task incorporating facial images. The bipolar group significantly opposed the advice given in the task after the high mood induction. The effect was specific to bipolar disorder and remained when controlling for possible confounds. Future work could investigate the effects of this process on manic symptoms, its origins, and the wider theoretical and clinical implications.     

Cognitive inhibition in trichotillomania and obsessive-compulsive disorder

Cognitive inhibition was investigated in 21 trichotillomania (TTM), 21 obsessive-compulsive disorder (OCD) and 26 healthy control (HC) participants using a block cued directed forgetting task. After encoding a word list, participants were instructed to intentionally FORGET these words and to REMEMBER another word list. Both lists included TTM-related and neutral (kitchen-related) words in equal proportions, with the TTM-related words generally of negative valence and the kitchen-related words generally of neutral valence for all participants. A superior free recall of REMEMBER versus FORGET words suggests intact cognitive inhibition. The performance of OCD participants indicated a specific deficit in inhibiting the retrieval of information with negative valence, which was not found in TTM. HC participants, in contrast to TTM and OCD participants, were rather inattentive to negative information. In conclusion, although attention was disproportionately directed towards negative information in both disorders, cognitive inhibition deficits appeared specific to OCD.     

Domain generality and domain specificity in aesthetic appreciation

Aesthetic appreciation is looked at with respect to domain generality and domain specificity. Within the classic cognitive paradigm, modality- and domain-specific receptive processes are explored. These are then complemented with central processing structures. These reveal domain-specific as well as domain-general processing. Extending the classic cognitive science approach, the role of emotion in aesthetic appreciation is also explored. While domain-specific models of aesthetic appreciation are clearly called for, there are also numerous domain-general subprocesses and structures.     

Differences in preschoolers’ and adults’ use of generics about novel animals and artifacts: A window onto a conceptual divide

Children and adults commonly produce more generic noun phrases (e.g., birds fly) about animals than artifacts. This may reflect differences in participants’ generic knowledge about specific animals/artifacts (e.g., dogs/chairs), or it may reflect a more general distinction. To test this, the current experiments asked adults and preschoolers to generate properties about novel animals and artifacts (Experiment 1: real animals/artifacts; Experiments 2 and 3: matched pairs of maximally similar, novel animals/artifacts). Data demonstrate that even without prior knowledge about these items, the likelihood of producing a generic is significantly greater for animals than artifacts. These results leave open the question of whether this pattern is the product of experience and learned associations or instead a set of early-developing theories about animals and artifacts.     

The influence of contextual contrast on syntactic processing: evidence for strong-interaction in sentence comprehension

The present study compares the processing of unambiguous restrictive and non-restrictive relative clauses (RCs) within both a null context and a supportive discourse using a self-paced reading methodology. Individuals read restrictive RCs more slowly than non-restrictive RCs in a null context, but processed restrictive RCs faster than non-restrictive RCs in supportive context, resulting in an interaction between context and RC type. These results provide evidence for two theoretical points. First, principles analogous to those in referential theory [Altmann G. T. M., & Steedman, M. (1988). Interaction with context during human sentence processing. Cognition, 30, 191-238; Crain, S., & Steedman, M. (1985). On not being led up the garden path: The use of context by the psychological parser. In D. Dowty, L. Karttunnen, A. Zwicky (Eds.), Natural language parsing. Cambridge, UK: Cambridge University Press] apply not only in resolving ambiguity but also in processing unambiguous sentences. Second, the discourse context can guide and facilitate interpretive processing. This result suggests that intrasentential factors such as syntax are not autonomous from contextual processing, contrary to the modularity hypothesis [Fodor, J. A. (1983). Modularity of mind. Cambridge, MA: MIT Press].     

Parallels in Preschoolers' and Adults' Judgments About Ownership Rights and Bodily Rights

Understanding ownership rights is necessary for socially appropriate behavior. We provide evidence that preschoolers' and adults' judgments of ownership rights are related to their judgments of bodily rights. Four‐year‐olds (n = 70) and adults (n = 89) evaluated the acceptability of harmless actions targeting owned property and body parts. At both ages, evaluations did not vary for owned property or body parts. Instead, evaluations were influenced by two other manipulations—whether the target belonged to the agent or another person, and whether that other person approved of the action. Moreover, these manipulations influenced judgments for owned objects and body parts in the same way: When the other person approved of the action, participants' judgments were positive regardless of who the target belonged to. In contrast, when that person disapproved, judgments depended on who the target belonged to. These findings show that young children grasp the importance of approval or consent for ownership rights and bodily rights, and likewise suggest that people's notions of ownership rights are related to their appreciation of bodily rights.     

Domain-specificity in perfectionism: Variations across domains of life

Perfectionism has been assessed in relation to salient or narrow domains within specific populations, yet little is understood across broader domains of life. The aim was to assess positive perfectionism (PP) and negative perfectionism (NP) in five broad domains; university/work, relationships, physical activity, domestic environment and appearance and to determine any gender differences within domains. One hundred and forty four university students (females n = 101; males n = 43) completed a modified perfectionism measure for each domain. Correlations within and between domains for PP and NP ranged from low to moderate with differential patterns by gender, supporting more domain specificity and less of a universal trait. Repeated measures ANOVAs revealed that, overall, PP and NP in the university/work domain was significantly higher than all other domains. Females reported greater PP in the university domain compared to other domains, and more PP in the relationship, domestic environment and appearance domains as compared to the physical activity domain. In contrast, males reported significantly higher PP in the physical activity domain. Females reported significantly higher NP in the university and appearance domains, while males had similar NP across all domains. These findings present a more complex picture of perfectionism with implications for domain-specificity in perfectionistic behavior.     

Erroneous choice and foregone gains in hoarding gray jays (Perisoreus canadensis)

Under the conventional assumption that natural selection favors choice behavior that maximizes some fitness-related currency, a forager making repeated binary choices should consistently choose the more valuable option. Under the alternative assumption that natural selection favors choice behavior that minimizes costly errors, erroneous choice is not only expected but is expected to be common when the cost of errors is low. This cost depends on the potential rate of return: the higher this rate, the smaller the cost of choosing the less valuable option. When this rate is very high, a forager may err frequently and yet forego no appreciable fitness gain. Errors should thus be more common when interruptions to foraging are shorter. Our experimental results supported this prediction: gray jays chose the less valuable option more frequently when subjected to shorter interruptions (experimentally imposed delays to access to food rewards). This tendency is consistent with the idea that an adaptive decision-making process may routinely produce errors, not because errors are in some way adaptive but because their fitness cost is minimal, particularly when delays are short. From a proximate perspective, this tendency to commit errors more frequently following shorter delays may be due to constraints on the jays’ information-processing capacity. In general, choice behavior should be viewed as the joint byproduct of adaptive decision making and cognitive constraints. Received: 8 June 2000 / Accepted after revision: 21 October 2000     

Framing social information and generalized social phobia

Patients with generalized social phobia (GSP, N=33) and matched community controls (N=31) engaged in a social interaction that was constructed to go well, and then received feedback that framed social cues reflecting either the absence of negative outcomes or the presence of positive outcomes. Following feedback that framed positive social cues, the GSP group predicted they would experience more anxiety in a subsequent interaction than did non-phobic controls. In contrast, following feedback framing the absence of negative outcomes, the GSP group did not differ from controls in their anxiety predictions. The results demonstrated that framing paradigms and methods can be usefully applied to the study of cognitive processes in social phobia and indicated that research to examine how GSP patients process specific types of social information is needed.     

Basic Information Processing Abilities at 11 years Account for Deficits in IQ Associated with Preterm Birth

Although it is well established that preterms as a group do poorly relative to their full-term peers on tests of global cognitive functioning, the basis for this relative deficiency is less understood. The present paper examines preterm deficits in core cognitive abilities and determines their role in mediating preterm/full-term differences in IQ. The performance of 11-year-old children born preterm (birth weight < 1750 g) and their full-term controls were compared on a large battery of 15 tasks, covering four basic cognitive domains — memory, attention, speed of processing and representational competence. The validity of these four domains was established using latent variables and confirmatory factor analysis (CFA). Preterms showed pervasive deficits within and across domains. Additionally, preterm deficits in IQ were completely mediated by these four cognitive domains in a structural equation model involving a cascade from elementary abilities (attention and speed), to more complex abilities (memory and representational competence), to IQ. The similarity of findings to those obtained with this cohort in infancy and toddlerhood suggests that preterm deficits persist — across time, across task, and from the non-verbal to the verbal period.     

Domain specificity versus expertise: factors influencing distinct processing of faces

To explore face specificity in visual processing, we compared the role of task-associated strategies and expertise on the N170 event-related potential (ERP) component elicited by human faces with the ERPs elicited by cars, birds, items of furniture, and ape faces. In Experiment 1, participants performed a car monitoring task and an animacy decision task. In Experiment 2, participants monitored human faces while faces of apes were the distracters. Faces elicited an equally conspicuous N170, significantly larger than the ERPs elicited by non-face categories regardless of whether they were ignored or had an equal status with other categories (Experiment 1), or were the targets (in Experiment 2). In contrast, the negative component elicited by cars during the same time range was larger if they were targets than if they were not. Furthermore, unlike the posterior-temporal distribution of the N170, the negative component elicited by cars and its modulation by task were more conspicuous at occipital sites. Faces of apes elicited an N170 that was similar in amplitude to that elicited by the human face targets, albeit peaking 10 ms later. As our participants were not ape experts, this pattern indicates that the N170 is face-specific, but not specie-specific, i.e. it is elicited by particular face features regardless of expertise. Overall, these results demonstrate the domain specificity of the visual mechanism implicated in processing faces, a mechanism which is not influenced by either task or expertise. The processing of other objects is probably accomplished by a more general visual processor, which is sensitive to strategic manipulations and attention.     

Physical risk taking in elementary-school children: Measurement and emotion regulation issues

Children who engage in physical risk taking experience more injuries. In the present study children 7-12 years completed laboratory tasks and standardized questionnaires to explore inter-relations between measures of risk taking and to determine if the Balloon Analog Risk Task (BART) is a valid index of physical risk taking. Emotion regulation skills also were assessed to determine if poorer skills are associated with greater risk taking, and what measures of risk taking show these relations. Results revealed that general measures of risk taking propensity predicted both BART performance and physical risk taking. Similarly, poorer emotion regulation skills were associated with greater risk taking scores for both the BART and physical risk taking task. Measures of physical risk taking related to one another, however, none of these scores related to performance on the BART. Implications for measuring physical risk taking and exploring emotional links to risk taking in future research are discussed.     

Eye movements and spoken language comprehension: effects of visual context on syntactic ambiguity resolution

When participants follow spoken instructions to pick up and move objects in a visual workspace, their eye movements to the objects are closely time-locked to referential expressions in the instructions. Two experiments used this methodology to investigate the processing of the temporary ambiguities that arise because spoken language unfolds over time. Experiment 1 examined the processing of sentences with a temporarily ambiguous prepositional phrase (e.g., "Put the apple on the towel in the box") using visual contexts that supported either the normally preferred initial interpretation (the apple should be put on the towel) or the less-preferred interpretation (the apple is already on the towel and should be put in the box). Eye movement patterns clearly established that the initial interpretation of the ambiguous phrase was the one consistent with the context. Experiment 2 replicated these results using prerecorded digitized speech to eliminate any possibility of prosodic differences across conditions or experimenter demand. Overall, the findings are consistent with a broad theoretical framework in which real-time language comprehension immediately takes into account a rich array of relevant nonlinguistic context.     

Identification and conceptualization of procedural chunks in chess

When it comes to cognitive architecture and human information processing, chunks are one of the best known and most recognized constructs. Nevertheless, the nature of chunks is still very elusive, especially when it comes to chunks in procedural knowledge. This study deals with basic features of procedural information processing and examines the manifestation of chunks in procedural knowledge. The participants' task was to reconstruct sequences of chess moves. Chess was chosen as an experimental domain, because of its complexity, well-defined rules and standardized measure of chess player strength. From the results we conclude that short-term memory capacity is determined by the combination of the size and amount of procedural chunks recalled to the short-term memory. We have shown that on average, participants with more specialized knowledge operated faster and with larger chunks of procedural information than participants with less specialized knowledge. We have shown that in procedural information processing, the level of expertise and the sorting order of the retrieved information are important factors that influence the amount of procedural chunks retained in the short-term memory. Therefore, the capacity of short-term memory in complex situations cannot be expressed as a simple concept.     

Time course of selective attention in clinically depressed young adults: an eye tracking study

Depressed individuals display biased attention for emotional information when stimuli are presented for relatively “long” (e.g., 1 s) durations. The current study examined whether attentional biases are sustained over a much longer period. Specifically, clinically depressed and never depressed young adults simultaneously viewed images from four emotion categories (sad, threat, positive, neutral) for 30 s while line of visual gaze was assessed. Depressed individuals spent significantly more time viewing dysphoric images and less time viewing positive images than their never depressed counterparts. Time course analyses indicated that these biases were maintained over the course of the trial. Results suggest that depressed participants' attentional biases for dysphoric information are sustained for relatively long periods even when other emotional stimuli are present. Mood congruent information-processing biases appear to be a robust feature of depression and may have an important role in the maintenance of the disorder.