Second-order schedules of token reinforcement with pigeons: effects of fixed- and variable-ratio exchange schedules

Pigeons' key pecks produced food under second-order schedules of token reinforcement, with light-emitting diodes serving as token reinforcers. In Experiment 1, tokens were earned according to a fixed-ratio 50 schedule and were exchanged for food according to either fixed-ratio or variable-ratio exchange schedules, with schedule type varied across conditions. In Experiment 2, schedule type was varied within sessions using a multiple schedule. In one component, tokens were earned according to a fixed-ratio 50 schedule and exchanged according to a variable-ratio schedule. In the other component, tokens were earned according to a variable-ratio 50 schedule and exchanged according to a fixed-ratio schedule. In both experiments, the number of responses per exchange was varied parametrically across conditions, ranging from 50 to 400 responses. Response rates decreased systematically with increases in the fixed-ratio exchange schedules, but were much less affected by changes in the variable-ratio exchange schedules. Response rates were consistently higher under variable-ratio exchange schedules than tinder comparable fixed-ratio exchange schedules, especially at higher exchange ratios. These response-rate differences were due both to greater pre-ratio pausing and to lower local rates tinder the fixed-ratio exchange schedules. Local response rates increased with proximity to food under the higher fixed-ratio exchange schedules, indicative of discriminative control by the tokens.     

Complementarity of Linguistic and Prosodic Processes in the Intact Brain

Despite considerable speculation in the research literature regarding the complementarity of functional lateralization of prosodic and linguistic processes in the normal intact brain, few studies have directly addressed this issue. In the present study, behavioral laterality indices of emotional prosodic and traditional linguistic speech functions were obtained for a sample of healthy young adults, using the dichotic listening method. After screening for adequate emotional prosody and linguistic recognition abilities, participants completed the Fused Rhymed Words Test (FRWT; Wexler & Halwes, 1983) and the Dichotic Emotion Recognition Test (DERT; McNeely & Netley, 1998). Examination of the difference in ear asymmetries for these measures within individuals revealed a complementary pattern in 78% of the sample. However, the correlation between laterality quotients for the FRWT and DERT was near zero, supporting Bryden's model of "statistical" complementarity (e.g., Bryden, 1990).     

The acquisition of complex predicates in japanese specifically language-impaired and normally developing children

Japanese exhibits two different types of morphological processes. Some morphologically complex predicates are generated within the domain of the lexicon, whereas others are generated outside the domain of the lexicon. An elicited production task involving both types of complex predicates was administered to six Japanese children with specific language impairment (JSLI) and six children with normal language development (JNLD). The JSLI children experienced significant difficulty forming the lexicon-external complex predicates but much less difficulty with the lexicon-internal complex predicates while the performance of the JNLD children exhibited no such asymmetry. These preliminary results suggest that the deficit of SLI affects the ability to construct implicit procedural rules for morphology that are generated outside the lexicon while their lexical operations for morphology that are generated within the domain of the lexicon remain relatively unimpaired.     

The early acquisition of verb meaning in German by normally developing and language impaired children

The research reported here focuses on the early acquisition of event structure in German. Based on longitudinal studies from 5 normally developing (ND) and 6 language-impaired (LI) children, a model of "event structural bootstrapping" is presented that spells out how ND children log into the verb lexicon. They project a target-consistent event tree, depicting the head-of-event of transitions. Young LI children, failing to employ this bootstrapping strategy, resort to radically underspecified event representations. The results from a truth-value judgment experiment with 16 ND and 16 LI children showed that ND children perform correctly on transitional verbs, while LI children perform at chance level on the same tasks. These findings are accounted for by the model of event structural bootstrapping to the extent that LI children lack an explicit representation of the head-of-event.     

LF-interpretability and language development: a study of verbal and nominal features in Greek normally developing and SLI children

This paper includes (i) a comparison of the developmental pattern of certain morphosyntactic features in normally developing (ND) Greek children with similar data from a group of children with specific language impairment and (ii) a new analysis of the differences found. The analysis is based on a minimalist notion of LF interpretability. Depending on the feature-specification of lexical items (i.e., [+/- interpretable] at LF), a different route of development follows. In addition, phonological salience of both interpretable and noninterpretable features is argued to play an important role in an account of crosslinguistic differences in both normal and exceptional development.     

The recognition potential: An ERP index of lexical access

Recognition potential (RP) is a brain electrical response that appears when a subject views recognizable images of words. However, it has yet to be determined whether the processes reflected by RP are related to orthographic or to semantic analysis. This study aimed to resolve this question by studying the RP evoked by orthographically correct stimuli that were devoid of meaning. Results showed RP not only to this type of stimuli, but also to others achieving lower levels in the reading process. Strikingly, however, the RP amplitude significantly differed in parallel with the levels of the reading processes attained by the stimuli, the amplitude of the RP progressively increasing as the level approached the semantic one, which showed the highest amplitude. These results not only confirm the replicability of RP, but also its promise of potential usefulness in the study and assessment of language perception.     

Hemispheric asymmetry in lexical decisions: the effects of grammatical class and imageability

It has been suggested that neural systems for lexical processing of nouns and verbs are anatomically distinct. The aim of the present study was to investigate if brain asymmetry for the processing of these two grammatical classes is also different. Neurologically intact adults performed a lateralized lexical decision task with grammatically unambiguous words of high, medium, and low degrees of imagery. For error scores a right visual field (RVF) advantage and an overall effect of imageability were obtained. For latency scores grammatical class and imageability modified visual field differences: in the noun class a RVF advantage was obtained only for low imagery nouns, while for the verbs the RVF advantage was present for both medium and low imagery verbs. These results suggest that the participation of right hemisphere neural systems in the processing of verbs is more limited than in the processing of nouns.     

In Defense of Individualism

This paper offers a programmatic philosophical articulation of moral and political individualism. This individualism consists of two main components: value individualism and rights individualism. The former is the view that, for each individual, the end which is of ultimate value is his own well-being. Each individual's well-being has ultimate agent-relative value and the only ultimate values are these agent-relative values. The latter view is that individuals possess moral jurisdiction over themselves, i.e., rights of self-ownership. These rights (along with other rights individuals may come to possess) constrain the manner in which agents may pursue value. For this reason, the articulated individualism is an constrained individualism. Sketches of arguments are offered for both value and rights individualism. And it is argued that the sole legitimate function of legal/political institutions is to further delineate and protect the rights of individuals. However, the paper is also concerned to indicate why this radical moral and political individualism does not have many of the features or implications that are commonly ascribed to it. In this connection, I seek to show how this social doctrine accords with individuals' having concern for the well-being of others, with the emergence of relationships among individuals that have both instrumental and non-instrumental value, with a degree of responsibility for self and others that is often thought to be antithetical to individualism and, in general, with a flourishing of civil order.     

王夫之“阴阳向背”说的本体意义

王夫之阴阳十二位向背是根据乾坤并建之体的性质及体用一源的原理引申、推论出来的,他用这一原理来批评象数学的机械排比和框定,并用事物的自然自足、自立自全的性质,证明《序卦传》的三种卦序说不能成立,为自己独特的卦序说奠立基础。他要证明的哲学原理是,显现有向背,阳阳无或缺;本体所具有的性质与功能,同时就具于个体之中,个体因此而有了主体性、能动性,和自由地独立活动的品格。     

Finding MAPs using strongly equivalent high order recurrent symmetric connectionist networks

Belief revision is the problem of finding the most plausible explanation for an observed set of evidences. It has many applications in various scientific domains like natural language understanding, medical diagnosis and computational biology. Bayesian Networks (BN) is an important probabilistic graphical formalism widely used for belief revision tasks. In BN, belief revision can be achieved by finding the maximum a posteriori (MAP) assignment. Finding MAP is an NP-Hard problem. In previous work, we showed how to find the MAP assignment in BN using High Order Recurrent Neural Networks (HORN) through an intermediate representation of Cost-Based Abduction. This method eliminates the need to explicitly construct the energy function in two steps, objective and constraints. This paper builds on that previous work by providing the theoretical foundation and proving that the resultant HORN used to find MAP is strongly equivalent to the original BN it tries to solve.